U.S. patent application number 17/269684 was filed with the patent office on 2021-11-04 for mold with quick connection and disconnection.
The applicant listed for this patent is HUSKY INJECTION MOLDING SYSTEMS, LTD.. Invention is credited to Cedric BOULAY, Ralf Walter FISCH, Sven KMOCH.
Application Number | 20210339442 17/269684 |
Document ID | / |
Family ID | 1000005781424 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210339442 |
Kind Code |
A1 |
KMOCH; Sven ; et
al. |
November 4, 2021 |
MOLD WITH QUICK CONNECTION AND DISCONNECTION
Abstract
A mold assembly includes a services block and a cavity plate
defining at least a portion of a molding cavity. A quick connection
mechanism can connect and disconnect the plate and the services
block. The cavity plate may include a base block and a mold cavity
block. A mold assembly may include two opposed combinations of such
a service block and a cavity plate each mounted to an opposed
platen. The base block may include a quick connection device
operable connect with and disconnect from a quick connection device
on the services block. A services channel in the cavity plate may
connect with and disconnect from a service channel in the services
block with a quick connection mechanism. A molding system may
include a plurality of such cavity plates, each operable to connect
with and disconnect from the same services block.
Inventors: |
KMOCH; Sven; (Platten,
DE) ; FISCH; Ralf Walter; (Saarburg, DE) ;
BOULAY; Cedric; (Bulgneville, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HUSKY INJECTION MOLDING SYSTEMS, LTD. |
BOLTON |
|
CA |
|
|
Family ID: |
1000005781424 |
Appl. No.: |
17/269684 |
Filed: |
August 29, 2019 |
PCT Filed: |
August 29, 2019 |
PCT NO: |
PCT/CA2019/051203 |
371 Date: |
February 19, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62724790 |
Aug 30, 2018 |
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62770785 |
Nov 22, 2018 |
|
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62856833 |
Jun 4, 2019 |
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62866059 |
Jun 25, 2019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 45/661 20130101;
B29C 45/332 20130101; B29C 45/36 20130101; B29C 45/261 20130101;
B29C 45/0433 20130101; B29C 2045/662 20130101 |
International
Class: |
B29C 45/26 20060101
B29C045/26; B29C 45/33 20060101 B29C045/33; B29C 45/04 20060101
B29C045/04; B29C 45/36 20060101 B29C045/36; B29C 45/66 20060101
B29C045/66 |
Claims
1. A mold assembly comprising: a services block; a plate defining
at least a portion of a molding cavity; a quick connection
mechanism operable to connect and disconnect said plate and said
services block; wherein in operation of said mold assembly, said
services block is connected to said plate with said quick
connection mechanism.
2. A mold assembly as claimed in claim 1 wherein said plate
comprises a base block and a mold cavity block; and wherein in
operation of said mold assembly, said services block is connected
to a platen and said services block is connected to said base block
with said quick connection mechanism.
3. A mold assembly as claimed in claim 2 wherein said quick
connection mechanism is operable to connect and disconnect said
base block of said plate and said services block.
4. A mold assembly as claimed in claim 2 or 3 wherein said quick
connection mechanism is a first connection mechanism and wherein
said base block and said mold cavity block are two separate parts
that are connected together with a second connection mechanism.
5. A mold assembly as claimed in claim 4, wherein said second
connection mechanism is not a quick connection mechanism.
6. A mold assembly as claimed in claim 2 wherein said base block
and said mold cavity block are formed as a unitary body and wherein
said quick connection mechanism is operable to connect and
disconnect said base block of said plate and said services
block.
7. A mold assembly as claimed in any one of claims 1 to 6, wherein
the quick connection mechanism is operable to be selectively
engaged to hold said plate and the services block together.
8. A mold assembly as claimed in any one of claims 1 to 7, wherein
the quick connection mechanism is operable to selectively interlock
the plate and the services block.
9. A mold assembly as claimed in any one of claims 1 to 8, wherein
the quick connection mechanism is operable to selectively provide a
clamping action between the plate and the services block.
10. A mold assembly as claimed in any one of claims 1 to 9, wherein
the quick connection mechanism is operable to switch between
connected and disconnected states to connect and disconnect
respectively the plate and the services block.
11. A mold assembly as claimed in any one of claims 1 to 10,
further comprising an actuator operable to actuate said quick
connection mechanism.
12. A mold assembly as claimed in any one of claims 1 to 11,
wherein the quick connection mechanism comprises a spring device
operable to selectively bias a part of the plate against the
services block.
13. A mold assembly as claimed in any one of claims 1 to 12,
wherein the quick connection mechanism is operable to selectively
hold the services block and the plate together without the
installation of a fastener.
14. A mold assembly as claimed in claim 1 wherein said quick
connection mechanism comprises a releasable stud and a socket
connector apparatus.
15. A mold assembly as claimed in claim 2, wherein said mold cavity
block has a cavity side with a mold cavity surface topography that
comprises a contact surface area and a mold cavity wall
surface.
16. A mold assembly as claimed in claim 15 wherein the magnitude of
the contact surface area is to selected based on a clamping force
of said mold assembly to be applied to said contact surface
area.
17. A mold assembly as claimed in claim 15 or 16, wherein the
cavity wall surface provides a longitudinal sectional surface
profile of the item to be molded.
18. A mold assembly as claimed in claim 15, 16 or 17 wherein said
mold cavity wall surface is configured to provide a surface for
forming part of a mold cavity.
19. A mold assembly as claimed in any one of claims 15 to 18,
wherein said mold cavity wall surface is configured to provide a
surface for forming half of a mold cavity.
20. A mold assembly as claimed in claim 18 or 19, wherein said
contact surface area of said mold cavity block is configured and
operable to engage an opposed contact surface area of a
corresponding mold cavity block of a corresponding engaged and
mated plate.
21. A mold assembly as claimed in any one of claims 15 to 20,
wherein said mold cavity surface topography is configured to
provide at least part of a vent channel when said contact surface
area of said mold cavity block is engaged with an opposed contact
surface area of a corresponding mold cavity block of a
corresponding engaged and mated plate.
22. A mold assembly as claimed in any one of claims 15 to 21
wherein said mold cavity surface topography is configured to
provide at least part of a gate area when said contact surface area
of said mold cavity block is engaged with an opposed contact
surface area of a corresponding mold cavity block of a
corresponding engaged and mated plate.
23. A mold assembly as claimed in any one of claims 15 to 22
wherein said mold cavity surface topography is configured to
provide at least part of a core alignment surface located proximate
to said mold cavity wall surface of said mold cavity block when
said contact surface area of said mold cavity block is engaged with
an opposed contact surface area of a corresponding mold cavity
block of a corresponding engaged and mated plate.
24. A mold assembly as claimed in any one of claims 15 to 23,
wherein said mold cavity surface topography further comprises a
non-contact surface area and wherein said contact surface area and
said non-contact surface area are generally parallel to each
other.
25. A mold assembly as claimed in any one of claims 15 to 23,
wherein said mold cavity surface topography further comprises a
non-contact surface area that slopes inwardly toward said contact
surface.
26. A mold assembly as claimed in claim 1, wherein said mold
assembly further comprises a first services channel located within
said plate; a second services channel located within said services
block; wherein said first services channel is in communication with
said second services channel such that a service may be delivered
from said services block to said plate.
27. A mold assembly as claimed in claim 2, wherein said mold
assembly further comprises a first services channel located within
said base block; a second services channel located within said mold
cavity block; a third services channel located within said services
block; wherein said first services channel is in communication with
said second services channel and said first services channel is in
communication with said third services channel such that in
operation a service is delivered from said services block to said
base block to said mold cavity block.
28. A mold assembly as claimed in claim 27 wherein said service is
cooling fluid operable to cool said mold cavity block.
29. A mold assembly as claimed in claim 27 or 28, wherein said mold
cavity block has a cavity side with a mold cavity surface
topography that comprises a contact surface area and a mold cavity
wall surface and wherein said second services channel has a
plurality of portions configured to conform at least in part to the
mold cavity wall surface when extending through a body portion of
said mold cavity block.
30. A mold assembly as claimed in claim 27, 28 or 29, further
comprising a services connecting mechanism operable to connect said
first services channel and said third services channel.
31. A mold assembly as claimed in claim 30 wherein said services
connecting mechanism comprises a services quick connection
mechanism.
32. A mold assembly as claimed in any one of claims 27 to 31,
wherein said mold assembly further comprises a fourth services
channel located within said base block; a fifth services channel
located within said services block; wherein said fourth service
channel is in communication with said second services channel and
said fifth services channel is in communication with said second
services channel such that in operation a service is delivered from
said services block to said base block to said mold cavity block
and then to said base block and then to said services block.
33. A mold assembly as claimed in any one of claims 1 to 32,
wherein said quick connection mechanism comprises a pneumatically
biased mechanism.
34. A mold assembly as claimed in claim 33, wherein said base block
comprises pneumatic ports for operating said pneumatically biased
mechanism by a mold handling device.
35. A mold assembly as claimed in any one of claims 1 to 34,
wherein said base block and said cavity block have substantially
cylindrical mating surfaces.
36. A mold assembly as claimed in any one of claims 1 to 35,
wherein said mold assembly defines a mold for blow molding.
37. A mold assembly as claimed in any one of claims 1 to 36 wherein
said mold assembly further comprises a third connection mechanism
that is operable to connect said services block and said
platen.
38. A mold assembly as claimed in any one of claims 1 to 37 wherein
said services block comprises a first services block, said plate
comprises a first plate, and said quick connection mechanism
comprises a first quick connection mechanism; and wherein said mold
assembly further comprises a second services block; a second plate
defining another portion of said molding cavity; a second quick
connection mechanism operable to connect and disconnect said second
plate and said second services block; wherein in operation of said
mold assembly, said second services block is connected to said
second plate with said second quick connection mechanism.
39. A mold assembly as claimed in claim 38, wherein said first mold
cavity block has a cavity side with a first mold cavity surface
topography that comprises a first contact surface area and a first
mold cavity wall surface and wherein said second mold cavity block
has a cavity side with a second mold cavity surface topography that
comprises a second contact surface area and a second mold cavity
wall surface, such that in operation said first contact surface of
said first mold cavity block matingly engages with said second
contact surface of said second mold cavity block, said first mold
cavity wall surface of said first mold cavity block co-operates
with the second mold cavity wall surface of said second mold cavity
block to form a mold cavity for an item to be molded.
40. A mold assembly as claimed in claim 38 or 39 wherein said first
mold cavity surface topography further comprises a first
non-contact surface area and wherein said first contact surface
area and said first non-contact surface area are generally parallel
to each other.
41. A mold assembly as claimed in claim 38, 39 or 40, wherein said
second mold cavity surface topography further comprises a second
non-contact surface area and wherein said second contact surface
area and said second non-contact surface area are generally
parallel to each other.
42. A mold assembly as claimed in claim 38 or 39, wherein said
first mold cavity surface topography further comprises a first
non-contact surface area and wherein said first non-contact surface
area slopes inwardly toward said first contact surface, and wherein
said second mold cavity surface topography further comprises a
second non-contact surface area and wherein said second non-contact
surface area slopes inwardly toward said second contact
surface.
43. A mold assembly as claimed in any one of claims 1 to 42,
comprising a handling coupler projecting from an exterior surface
of said plate for engagement by a handling device to remove said
plate from said mold assembly.
44. The mold assembly of claim 43, wherein said handling coupler
comprises a handling quick connection mechanism.
45. A plate defining at least a portion of a molding cavity for use
in a mold assembly, said plate comprising: a base block; a mold
cavity block connected to said base block; a first quick connection
device on said base block operable to selectively connect to and
disconnect from a second quick connection device on a services
block; wherein in operation of said mold assembly, said base block
is connected to said services block by operation of said first and
second quick connection devices.
46. A plate as claimed in claim 45 wherein said base block and said
mold cavity block are two separate parts that are connected
together with a connection mechanism.
47. A plate as claimed in claim 45 wherein said base block and said
mold cavity block are formed as a unitary body.
48. A plate as claimed in claim 45 wherein said base block further
comprises: a first services channel located within said base block;
a second services channel located within said mold cavity block; a
third quick connection device operable to connect with a fourth
quick connection device on said services block; wherein in
operation, said first services channel is in communication with a
third services channel in said services block, and said first
services channel is in communication with said second services
channel located within said mold cavity block, when said third
quick connection device is operably connected with said fourth
quick connection device such that a service may be delivered from
said services block to said base block and on to said mold cavity
block through said first services channel, said second services
channel and said third services channel.
49. A plate as claimed in claim 48, wherein said plate further
comprises a fourth services channel located within said base block;
wherein said fourth services channel is in communication with said
second services channel, and said fourth services channel is in
communication with a fifth services channel in said services block,
such that in operation a service is delivered from said services
block to said base block to said mold cavity block and then back to
said base block and then back to said services block.
50. A plate as claimed in claim 48 wherein said first, second,
third, fourth and fifth services channels comprise at least part of
a fluid cooling circuit for supplying cooling fluid to cool said
mold cavity block.
51. A plate as claimed in claim 50, wherein said first quick
connection device comprises a pneumatically biased mechanism.
52. A plate as claimed in any one of claims 45 to 51, wherein said
base block and said cavity block have substantially cylindrical
mating surfaces.
53. A plate as claimed in any one of claims 45 to 52, comprising a
handling coupler projecting from an exterior surface of said plate
for engagement by a handling device to remove said plate from a
platen.
54. The plate of claim 53, wherein said handling coupler comprises
a handling quick connection mechanism.
55. A molding system comprising: a services block; a first plate
defining at least a portion of a first molding cavity; a first
quick connection mechanism operable to connect and disconnect said
first plate and said services block; a second plate defining at
least a portion of a second molding cavity; a second quick
connection mechanism operable to connect and disconnect said second
plate and said services block; wherein said first cplate is
operable to be connected to and disconnected from said services
block with said first quick connection mechanism and said second
plate is operable to be connected to and disconnected from said
services block with said second quick connection mechanism whereby
said first plate can be interchanged with said second plate to be
operable to modify said molding system between having said first
molding cavity and said second molding cavity.
56. A molding system as claimed in claim 55 wherein: said first
plate comprises a base block and a first mold cavity block; said
first quick connection mechanism is operable to connect and
disconnect said base block of said first plate and said services
block; said second plate comprises a base block and a second mold
cavity block; said second quick connection mechanism is operable to
connect and disconnect said base block of said second plate and
said services block.
57. A system as claimed in claim 56 wherein said base block of said
first plate and said first mold cavity block are two separate parts
that are connected by a third connection mechanism.
58. A system as claimed in claim 57 wherein said base block of said
second plate and said second mold cavity block are two separate
parts that are connected by a fourth connection mechanism.
59. A system as claimed in claim 58, wherein said third and fourth
connection mechanisms are not quick connection mechanisms.
60. A system as claimed in claim 56 wherein said base block of said
first plate and said first mold cavity block are formed as a
unitary body and said base block of said second plate and said
second mold cavity block are formed as a unitary body.
61. A molding system as claimed in any one of claims 55 to 60
wherein said first mold cavity block has a base block facing
surface connected to said base block of said first plate and an
opposed first cavity side with a first cavity surface topography
that comprises a first contact surface area and a first cavity wall
surface; and wherein said second mold cavity block has a base block
facing surface connected to said base block of said second c plate
and a second cavity side with a second cavity surface topography
that comprises a second contact surface area and a second cavity
wall surface, and wherein said first cavity surface topography is
configured differently to said second cavity surface
topography.
62. A molding system as claimed in claim 61 wherein said first
cavity wall surface is configured differently to said second cavity
wall surface.
63. A molding system as claimed in claim 61 or 62, wherein said
first contact surface is shaped differently to said second contact
surface.
64. A molding system as claimed in any one of claims 61 to 63,
wherein said first contact surface and said second contact surface
have substantially the same sized surface areas.
65. A mold assembly as claimed in any one of claim 61, 62 or 63,
wherein said first cavity surface topography further comprises a
first non-contact surface area and wherein said first contact
surface area and said first non-contact surface area are generally
parallel to each other; and wherein said second cavity surface
topography further comprises a second non-contact surface area and
wherein said second contact surface area and said second
non-contact surface area are generally parallel to each other.
66. A molding system as claimed in any one of claims 55 to 63,
comprising a handling coupler projecting from an exterior surface
of each of said first and second plates for engagement by a
handling device to remove said plates from said mold assembly.
67. The mold assembly of claim 66, wherein said handling coupler
comprises a handling quick connection mechanism.
68. A molding system comprising: a services block; a base block; a
first mold cavity block; a second mold cavity block a first
connection mechanism operable to connect and disconnect said base
block and said services block a second connection mechanism
operable to connect and disconnect each of said first and second
mold cavity blocks with said base block; wherein in operation said
first and second mold cavity blocks can be interchangeably
connected to said base block with said second connection mechanism,
and wherein said base block can be connected to said services block
with said first connection mechanism.
69. A molding system as claimed in claim 68 wherein said first
connection mechanism is a quick connection mechanism.
70. A molding system comprising: a first plate defining at least a
portion of a first molding cavity that is a separate part to a
services block, said first plate having a first cavity wall
surface; a first quick connection mechanism operable to connect and
disconnect said first plate to a services block; a second plate
defining at least a portion of a second molding cavity that is a
separate part to the services block, said second plate having a
second cavity wall surface; a second quick connection mechanism
operable to connect and disconnect said second cavity block and
said services block; wherein said first cavity wall surface is
configured differently to said second cavity wall surface.
71. A molding system as claimed in claim 70, wherein said first
plate has a cavity side with a first cavity surface topography that
comprises a first contact surface and the first cavity wall
surface; said second plate has a cavity side with a second cavity
surface topography that comprises a second contact surface and the
second cavity wall surface, and wherein said first cavity surface
topography is configured differently to said second cavity surface
topography.
72. A molding system as claimed in claim 71, wherein said first
contact surface is shaped differently to said second contact
surface.
73. A molding system as claimed in claim 71 or 72, wherein said
first contact surface and said second contact surface have
substantially the same sized surface areas.
74. A mold assembly as claimed in any one of claims 71 to 73,
wherein said first cavity surface topography further comprises a
first non-contact surface and wherein said first contact surface
and said first non-contact surface are generally parallel to each
other; and wherein said second cavity surface topography further
comprises a second non-contact surface and wherein said second
contact surface and said second non-contact surface are generally
parallel to each other.
75. A mold assembly as claimed in any one of claims 71 to 74
wherein said first cavity surface topography further comprises a
first non-contact surface; and wherein said second cavity surface
topography further comprises a second non-contact surface and
wherein the sum of the first contact surface area and the first
non-contact area is substantially of the same magnitude as the sum
of the second contact area and the second non-contact area.
76. A mold assembly comprising: a support frame; a first platen
supported by said support frame; a first services plate connected
to said first platen; a first plate defining a first portion of a
molding cavity; a first quick connection mechanism operable to
connect and disconnect said first plate and said first services
block; a second platen supported by said support frame; a second
services plate connected to said second platen; a second plate
defining a second portion of said molding cavity; a second quick
connection mechanism operable to connect and disconnect said second
plate and said second services block: wherein in operation: said
first plate is connected to said first services block with said
first quick connection mechanism, and said first services block is
connected to said first platen; and said second plate is connected
to said second services block with said second quick connection
mechanism, and said second services block is connected to said
second platen.
77. A mold assembly as claimed in claim 76 wherein said first
platen is a stationary platen such that in operation, said
stationary platen does not move relative to said support frame; and
wherein said second platen is a moving platen such that in
operation said moving platen moves relative to said support frame
and said stationary platen.
78. A mold assembly as claimed in claim 76 or 77, wherein: said
first plate comprises a first base block and a first mold cavity
block; and wherein in operation of said mold assembly, said first
services block is connected to a first platen and said first
services block is connected to said first base block with a third
quick connection mechanism; and said second plate comprises as
second base block and a second mold cavity block; and wherein in
operation of said mold assembly, said second services block is
connected to a second platen and said second services block is
connected to said second base block with a fourth quick connection
mechanism.
79. A mold assembly as claimed in claim 78 wherein said first mold
cavity block has a base block facing surface operable to be secured
to said first base block and a cavity side with a first cavity
surface topography that comprises a first contact surface area and
a first cavity wall surface and wherein said second mold cavity
block has a base block facing surface operable to be secured to
said second base block and a cavity side with a cavity surface
topography that comprises a contact surface area and a second
cavity wall surface.
80. A mold assembly as claimed in claim 79 wherein said mold
assembly further comprises a core assembly having a core device, in
operation said core device being received with a cavity formed by
said cavity wall surfaces of said first and second mold cavity
blocks to thereby form a mold cavity for an item to be molded.
81. An apparatus comprising: a plate defining at least a portion of
a molding cavity, said plate comprising a base block and a mold
cavity block, said base block having a services channel therein; a
connection mechanism operable to connect said mold cavity block to
said base block; wherein in operation, said mold cavity block is
connected to said base block with said connection mechanism;
wherein said mold cavity block has a cavity surface side and a base
block facing surface opposite to said cavity surface side, and said
mold cavity block has a trough area formed in said base block
facing surface; said apparatus further comprising a services
channel module received into said trough area, said services
channel module comprising at least one services channel operable to
be interconnected to said services channel in said base block.
82. An apparatus as claimed in claim 81 wherein said plate is made
at least in part from a metal material and said services channel
module is made at least in part from a plastic material.
83. An apparatus as claimed in claim 81 or 82 wherein said cavity
surface side has a mold cavity wall surface, and wherein said
services channel module is a channel for supplying cooling fluid
which is operable to cool said mold cavity block, and wherein said
services channel module comprises a cooling fluid channel having a
plurality of portions configured to conform at least in part of
said mold cavity wall surface when extending from an input port to
an output port.
84. A method of operating a mold assembly, said mold assembly
comprising: a platen; a services block connected to said platen; a
first plate defining at least a portion of a first molding cavity;
a second plate defining at least a portion of a second molding
cavity; a first quick connection mechanism operable to connect and
disconnect said first plate and a services block; a second quick
connection mechanism operable to connect and disconnect said second
plate and said services block; said method comprising interchanging
said first plate with said second plate on said services block by
operating said first and second quick connection mechanisms.
85. A method as claimed in claim 84, wherein said mold assembly
further comprises: a first services channel, said first services
channel being located within said first plate; a second services
channel, said second services channel being located within said
second plate; a third services channel located within said services
plate; a first services connecting mechanism operable to connect
and disconnect said first services channel and said third services
channel; a second services connecting mechanism operable to connect
and disconnect said second services channel and said third services
channel; wherein when said first plate is connected to said
services block and said first service channel is in communication
with said third services channel a service is delivered from said
services block to said first plate; wherein when said second plate
is connected to said services block and said second service channel
is in communication with said third services channel a service is
delivered from said services block to said second plate; said
method further comprises when said first plate and said second
cplate are interchanged by operating said first and second quick
connection mechanisms, said first services connecting mechanism
disconnects said first services channel and said third services
channel; and thereafter said second services connecting mechanism
connects said second services channel and said third services
channel.
86. A method as claimed in claim 85 wherein said first and second
services connecting mechanisms both comprise a quick connection
mechanism.
87. A method as claimed in any one of claims 84 to 86, wherein each
of said first and second quick connection mechanisms comprises a
pneumatically biased mechanism.
88. A method as claimed in claim 87, comprising releasing said
pneumatically biased mechanism of said first quick connection
mechanism or said second quick connection mechanism by providing a
pressurized air supply by way of said services block.
89. A method as claimed in any one of claims 84 to 87, wherein said
method comprises defining a mold for blow molding.
90. A method of forming a mold system comprising: forming a first
base block; forming a second base block that is configured
substantially the same as the first base block; forming a first and
a second mold cavity blocks, each having a base block facing
surface operable to be secured to said first and second respective
base blocks and a cavity side with a mold cavity surface topography
that comprises a contact surface area and a mold cavity wall
surface, wherein the configuration of the mold cavity wall surface
of the first mold cavity block is different from the configuration
of the mold cavity wall surface of the second mold cavity block,
but where the size of the contact surface area of the first mold
cavity block is substantially similar to the size of the contact
surface area of the second mold cavity block; connecting said first
base block to said first mold cavity block; connecting said second
base block to said second mold cavity block.
91. A method as claimed in claim 90 wherein said contact surface
area of said first mold cavity block is shaped differently than the
contact surface area of the second mold cavity block.
92. A method as claimed in claim 90 wherein the size of the contact
surface area of said first and second mold cavity blocks is
selected based on the known size of the clamping force of said mold
assembly to be applied to said contact surface area.
93. A method as claimed in any one of claim 90, 91 or 92 further
comprising: providing a quick connection device on each of said
first and second base blocks, each quick connection device being
operable to connect to and disconnect from a common quick
connection device on a common services block.
94. A method of manufacturing a cavity plate comprising: forming a
base block with a quick connection device operable to connect with
and disconnect from a quick connection device on a services block;
forming a mold cavity block by depositing material on a surface of
said base block with an additive manufacturing process to thereby
form a mold cavity surface topography that comprises a contact
surface area and a mold cavity wall surface.
95. A method of forming a cavity plate comprising: forming a base
block having a services channel; forming a mold cavity block said
mold cavity block having a cavity surface side and a base block
facing surface opposite to said cavity surface side, and wherein
said mold cavity block has a trough area formed in said base block
facing surface; inserting a services channel module into said
trough area, said services channel module comprising at least one
services channel operable to be interconnected to said services
channel in said base block.
96. A mold assembly, comprising: a pair of mating mold sections
cooperatively defining a mold cavity; a pair of services blocks,
each for mounting a respective one of said mold blocks to a platen
of a molding machine; a handling coupler projecting from an
exterior surface of each mold section, for engagement by a handling
device to hold said mold blocks together in a mating configuration
and to remove said mold assembly from said mold machine.
97. The mold assembly of claim 96, wherein said handling coupler
comprises a quick connection mechanism.
98. The mold assembly of claim 96 or claim 97, comprising a mold
quick connection mechanism operable to connect and disconnect each
of said mold sections and sa respective one of said services
blocks.
99. The mold assembly of claim 98, wherein said mold sections have
curved outer surfaces, and said services blocks have corresponding
curved inner surfaces to receive said mold blocks.
100. The mold assembly of claim 99, wherein said mold quick
connection mechanism comprises a connector projecting from one of
said curved surfaces.
101. The mold assembly of any one of claims 96 to 100, wherein said
mold assembly is a blow molding assembly.
102. The mold assembly of any one of claims 96 to 101, comprising a
third mold section operable to cooperatively define said mold
cavity with said mold blocks.
103. The mold assembly of claim 102, wherein said third mold
section comprises a quick connection mechanism for coupling to an
actuator.
104. The mold assembly of any one of claims 96 to 103, wherein said
services blocks comprise respective load limiting blocks, said load
limiting blocks opposing one another with clearance therebetween in
a molding configuration of said molding assembly, and operable to
abut one another and bear a clamping force in response to
compression of said mold blocks.
105. The mold assembly of any one of claims 96 to 104, wherein said
mold blocks are formed of an aluminum alloy.
Description
RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
patent application 62/724,790, filed Aug. 30, 2018, U.S.
Provisional Patent Application 62/770,785, filed Nov. 22, 2018,
U.S. Provisional patent application No. 62/856,833, filed Jun. 4,
2019, and U.S. Provisional patent application No. 62/856,059, filed
Jun. 25, 2019, the disclosures of which are incorporated herein by
reference.
FIELD
[0002] This relates to production of plastic articles, and more
particularly, to methods and apparatus for producing molten molding
material.
BACKGROUND
[0003] In conventional mold assemblies, mold components are bolted
together in a stack secured to a platen. Services, such as cooling,
pneumatic and electrical services are provided to the mold by way
of fixed channels which extend through the mold stack. For a
particular mold, most or all of the mold stack and routing of the
services channels must be custom-designed and fabricated according
to the configuration of the mold and the articles to be produced
with the mold. Components for such mold stacks tend to be very
expensive because of the amount of custom machining required.
Moreover, removing of components for maintenance or repair, or to
change the articles being produced, is cumbersome and time
consuming.
SUMMARY
[0004] An example mold assembly comprises: a service block; a plate
defining at least a portion of a molding cavity; a quick connection
mechanism operable to connect and disconnect the plate and the
services block; wherein in operation of the mold assembly, the
services block is connected to the plate with the quick connection
mechanism.
[0005] In some embodiments, the plate comprises a base block and a
mold cavity block; and wherein in operation of the mold assembly,
the services block is connected to a platen and the services block
is connected to the base block with the quick connection
mechanism.
[0006] In some embodiments, the quick connection mechanism is
operable to connect and disconnect the base block of the plate and
the services block.
[0007] In some embodiments, the quick connection mechanism is a
first connection mechanism and wherein the base block and the mold
cavity block are two separate parts that are connected together
with a second connection mechanism.
[0008] In some embodiments, the second connection mechanism is not
a quick connection mechanism.
[0009] In some embodiments, the base block and the mold cavity
block are formed as a unitary body and wherein the quick connection
mechanism is operable to connect and disconnect the base block of
the plate and the services block.
[0010] In some embodiments, the quick connection mechanism is
operable to be selectively engaged to hold the plate and the
services block together.
[0011] In some embodiments, the quick connection mechanism is
operable to selectively interlock the plate and the services
block.
[0012] In some embodiments, the quick connection mechanism is
operable to selectively provide a clamping action between the plate
and the services block.
[0013] In some embodiments, the quick connection mechanism is
operable to switch between connected and disconnected states to
connect and disconnect respectively the plate and the services
block.
[0014] In some embodiments, the mold assemble further comprises an
actuator operable to actuate the quick connection mechanism.
[0015] In some embodiments, the quick connection mechanism
comprises a spring device operable to selectively bias a part of
the plate against the services block.
[0016] In some embodiments, the quick connection mechanism is
operable to selectively hold the services block and the plate
together without the installation of a fastener.
[0017] In some embodiments, the quick connection mechanism
comprises a releasable stud and a socket connector apparatus.
[0018] In some embodiments, the mold cavity block has a cavity side
with a mold cavity surface topography that comprises a contact
surface area and a mold cavity wall surface.
[0019] In some embodiments, the magnitude of the contact surface
area is selected based on a clamping force of the mold assembly to
be applied to the contact surface area.
[0020] In some embodiments, the cavity wall surface provides a
longitudinal sectional surface profile of the item to be
molded.
[0021] In some embodiments, the mold cavity wall surface is
configured to provide a surface for forming part of a mold
cavity.
[0022] In some embodiments, the mold cavity wall surface is
configured to provide a surface for forming half of a mold
cavity.
[0023] In some embodiments, the contact surface area of the mold
cavity block is configured and operable to engage an opposed
contact surface area of a corresponding mold cavity block of a
corresponding engaged and mated plate.
[0024] In some embodiments, mold cavity surface topography is
configured to provide at least part of a vent channel when the
contact surface area of the mold cavity block is engaged with an
opposed contact surface area of a corresponding mold cavity block
of a corresponding engaged and mated plate.
[0025] In some embodiments, the mold cavity surface topography is
configured to provide at least part of a gate area when the contact
surface area of the mold cavity block is engaged with an opposed
contact surface area of a corresponding mold cavity block of a
corresponding engaged and mated plate.
[0026] In some embodiments, the mold cavity surface topography is
configured to provide at least part of a core alignment surface
located proximate to the mold cavity wall surface of the mold
cavity block when the contact surface area of the mold cavity block
is engaged with an opposed contact surface area of a corresponding
mold cavity block of a corresponding engaged and mated plate.
[0027] In some embodiments, the mold cavity surface topography
further comprises a non-contact surface area and wherein the
contact surface area and the non-contact surface area are generally
parallel to each other.
[0028] In some embodiments, the mold cavity surface topography
further comprises a non-contact surface area that slopes inwardly
toward the contact surface.
[0029] In some embodiments, the mold assembly further comprises: a
first services channel located within the plate; a second services
channel located within the services block; wherein the first
services channel is in communication with the second services
channel such that a service may be delivered from the services
block to the plate.
[0030] In some embodiments, the mold assembly further comprises: a
first services channel located within the base block; a second
services channel located within the mold cavity block; a third
services channel located within the services block; wherein the
first services channel is in communication with the second services
channel and the first services channel is in communication with the
third services channel such that in operation a service is
delivered from the services block to the base block to the mold
cavity block.
[0031] In some embodiments, the service is cooling fluid operable
to cool the mold cavity block.
[0032] In some embodiments, the mold cavity block has a cavity side
with a mold cavity surface topography that comprises a contact
surface area and a mold cavity wall surface and wherein the second
services channel has a plurality of portions configured to conform
at least in part to the mold cavity wall surface when extending
through a body portion of the mold cavity block.
[0033] In some embodiments, the mold assembly further comprises a
services connecting mechanism operable to connect the first
services channel and the third services channel.
[0034] In some embodiments, the services connecting mechanism
comprises a services quick connection mechanism.
[0035] In some embodiments, the mold assembly further comprises: a
fourth services channel located within the base block; a fifth
services channel located within the services block; wherein the
fourth service channel is in communication with the second services
channel and the fifth services channel is in communication with the
second services channel such that in operation a service is
delivered from the services block to the base block to the mold
cavity block and then to the base block and then to the services
block.
[0036] In some embodiments, the quick connection mechanism
comprises a pneumatically biased mechanism.
[0037] In some embodiments, base block comprises pneumatic ports
for operating the pneumatically biased mechanism by a mold handling
device.
[0038] In some embodiments, the base block and the cavity block
have substantially cylindrical mating surfaces.
[0039] In some embodiments, the mold assembly defines a mold for
blow molding.
[0040] In some embodiments, mold assembly further comprises a third
connection mechanism that is operable to connect the services block
and the platen.
[0041] In some embodiments, the services block comprises a first
services block, the plate comprises a first plate, and the quick
connection mechanism comprises a first quick connection mechanism;
and wherein the mold assembly further comprises: a second services
block; a second plate defining another portion of the molding
cavity; a second quick connection mechanism operable to connect and
disconnect the second plate and the second services block; wherein
in operation of the mold assembly, the second services block is
connected to the second plate with the second quick connection
mechanism.
[0042] In some embodiments, the first mold cavity block has a
cavity side with a first mold cavity surface topography that
comprises a first contact surface area and a first mold cavity wall
surface and wherein the second mold cavity block has a cavity side
with a second mold cavity surface topography that comprises a
second contact surface area and a second mold cavity wall surface,
such that in operation the first contact surface of the first mold
cavity block matingly engages with the second contact surface of
the second mold cavity block, the first mold cavity wall surface of
the first mold cavity block co-operates with the second mold cavity
wall surface of the second mold cavity block to form a mold cavity
for an item to be molded.
[0043] In some embodiments, the first mold cavity surface
topography further comprises a first non-contact surface area and
wherein the first contact surface area and the first non-contact
surface area are generally parallel to each other.
[0044] In some embodiments, the second mold cavity surface
topography further comprises a second non-contact surface area and
wherein the second contact surface area and the second non-contact
surface area are generally parallel to each other.
[0045] In some embodiments, wherein the first mold cavity surface
topography further comprises a first non-contact surface area and
wherein the first non-contact surface area slopes inwardly toward
the first contact surface, and wherein the second mold cavity
surface topography further comprises a second non-contact surface
area and wherein the second non-contact surface area slopes
inwardly toward the second contact surface.
[0046] In some embodiments, comprising a handling coupler
projecting from an exterior surface of the plate for engagement by
a handling device to remove the plate from the mold assembly.
[0047] In some embodiments, the handling coupler comprises a
handling quick connection mechanism.
[0048] An example plate defining at least a portion of a molding
cavity for use in a mold assembly, the plate comprises: a base
block; a mold cavity block connected to the base block; a first
quick connection device on the base block operable to selectively
connect to and disconnect from a second quick connection device on
a services block; wherein in operation of the mold assembly, the
base block is connected to the services block by operation of the
first and second quick connection devices.
[0049] In some embodiments, the base block and the mold cavity
block are two separate parts that are connected together with a
connection mechanism.
[0050] In some embodiments, the base block and the mold cavity
block are formed as a unitary body.
[0051] In some embodiments, the base block further comprises: a
first services channel located within the base block; a second
services channel located within the mold cavity block; a third
quick connection device operable to connect with a fourth quick
connection device on the services block; wherein in operation, the
first services channel is in communication with a third services
channel in the services block, and the first services channel is in
communication with the second services channel located within the
mold cavity block, when the third quick connection device is
operably connected with the fourth quick connection device such
that a service may be delivered from the services block to the base
block and on to the mold cavity block through the first services
channel, the second services channel and the third services
channel.
[0052] In some embodiments, the plate further comprises: a fourth
services channel located within the base block; wherein the fourth
services channel is in communication with the second services
channel, and the fourth services channel is in communication with a
fifth services channel in the services block, such that in
operation a service is delivered from the services block to the
base block to the mold cavity block and then back to the base block
and then back to the services block.
[0053] In some embodiments, the first, second, third, fourth and
fifth services channels comprise at least part of a fluid cooling
circuit for supplying cooling fluid to cool the mold cavity
block.
[0054] In some embodiments, the first quick connection device
comprises a pneumatically biased mechanism.
[0055] In some embodiments, the base block and the cavity block
have substantially cylindrical mating to surfaces.
[0056] In some embodiments, a handling coupler projecting from an
exterior surface of the plate for engagement by a handling device
to remove the plate from a platen.
[0057] In some embodiments, the handling coupler comprises a
handling quick connection mechanism.
[0058] An example molding system comprises: a services block; a
first plate defining at least a portion of a first molding cavity;
a first quick connection mechanism operable to connect and
disconnect the first plate and the services block; a second plate
defining at least a portion of a second molding cavity; a second
quick connection mechanism operable to connect and disconnect the
second plate and the services block; wherein the first plate is
operable to be connected to and disconnected from the services
block with the first quick connection mechanism and the second
plate is operable to be connected to and disconnected from the
services block with the second quick connection mechanism whereby
the first plate can be interchanged with the second plate to be
operable to modify the molding system between having the first
molding cavity and the second molding cavity.
[0059] In some embodiments, the first plate comprises a base block
and a first mold cavity block; the first quick connection mechanism
is operable to connect and disconnect the base block of the first
plate and the services block; the second plate comprises a base
block and a second mold cavity block; the second quick connection
mechanism is operable to connect and disconnect the base block of
the second plate and the services block.
[0060] In some embodiments, the base block of the first plate and
the first mold cavity block are two separate parts that are
connected by a third connection mechanism.
[0061] In some embodiments, the base block of the second plate and
the second mold cavity block are two separate parts that are
connected by a fourth connection mechanism.
[0062] In some embodiments, the third and fourth connection
mechanisms are not quick connection mechanisms.
[0063] In some embodiments, the base block of the first plate and
the first mold cavity block are formed as a unitary body and the
base block of the second plate and the second mold cavity block are
formed as a unitary body.
[0064] In some embodiments, the first mold cavity block has a base
block facing surface connected to the base block of the first plate
and an opposed first cavity side with a first cavity surface
topography that comprises a first contact surface area and a first
cavity wall surface; and wherein the second mold cavity block has a
base block facing surface connected to the base block of the second
c plate and a second cavity side with a second cavity surface
topography that comprises a second contact surface area and a
second cavity wall surface, and wherein the first cavity surface
topography is configured differently to the second cavity surface
topography.
[0065] In some embodiments, the first cavity wall surface is
configured differently to the second cavity wall surface.
[0066] In some embodiments, the first contact surface is shaped
differently to the second contact surface.
[0067] In some embodiments, the first contact surface and the
second contact surface have substantially the same sized surface
areas.
[0068] In some embodiments, the first cavity surface topography
further comprises a first non-contact surface area and wherein the
first contact surface area and the first non-contact surface area
are generally parallel to each other; and wherein the second cavity
surface topography further comprises a second non-contact surface
area and wherein the second contact surface area and the second
non-contact surface area are generally parallel to each other.
[0069] In some embodiments, a handling coupler projecting from an
exterior surface of each of the first and second plates for
engagement by a handling device to remove the plates from the mold
assembly.
[0070] In some embodiments, the handling coupler comprises a
handling quick connection mechanism.
[0071] An example molding system comprises: a services block; a
base block; a first mold cavity block; a second mold cavity block;
a first connection mechanism operable to connect and disconnect the
base block and the services block; a second connection mechanism
operable to connect and disconnect each of the first and second
mold cavity blocks with the base block; wherein in operation the
first and second mold cavity blocks can be interchangeably
connected to the base block with the second connection mechanism,
and wherein the base block can be connected to the services block
with the first connection mechanism.
[0072] In some embodiments, the first connection mechanism is a
quick connection mechanism.
[0073] An example molding system comprises: a first plate defining
at least a portion of a first molding cavity that is a separate
part to a services block, the first plate having a first cavity
wall surface; a first quick connection mechanism operable to
connect and disconnect the first plate to a services block; a
second plate defining at least a portion of a second molding cavity
that is a separate part to the services block, the second plate
having a second cavity wall surface; a second quick connection
mechanism operable to connect and disconnect the second cavity
block and the services block; wherein the first cavity wall surface
is configured differently to the second cavity wall surface.
[0074] In some embodiments, the first plate has a cavity side with
a first cavity surface topography that comprises a first contact
surface and the first cavity wall surface; the second plate has a
cavity side with a second cavity surface topography that comprises
a second contact surface and the second cavity wall surface, and
wherein the first cavity surface topography is configured
differently to the second cavity surface topography.
[0075] In some embodiments, the first contact surface is shaped
differently to the second contact surface.
[0076] In some embodiments, the first contact surface and the
second contact surface have substantially the same sized surface
areas.
[0077] In some embodiments, the first cavity surface topography
further comprises a first non-contact surface and wherein the first
contact surface and the first non-contact surface are generally
parallel to each other; and wherein the second cavity surface
topography further comprises a second non-contact surface and
wherein the second contact surface and the second non-contact
surface are generally parallel to each other.
[0078] In some embodiments, the first cavity surface topography
further comprises a first non-contact surface; and wherein the
second cavity surface topography further comprises a second
non-contact surface and wherein the sum of the first contact
surface area and the first non-contact area is substantially of the
same magnitude as the sum of the second contact area and the second
non-contact area.
[0079] An example mold assembly comprises: a support frame; a first
platen supported by the support frame; a first services plate
connected to the first platen; a first plate defining a first
portion of a molding cavity; a first quick connection mechanism
operable to connect and disconnect the first plate and the first
services block; a second platen supported by the support frame; a
second services plate connected to the second platen; a second
plate defining a second portion of the molding cavity; a second
quick connection mechanism operable to connect and disconnect the
second plate and the second services block: wherein in operation:
the first plate is connected to the first services block with the
first quick connection mechanism, and the first services block is
connected to the first platen; and the second plate is connected to
the second services block with the second quick connection
mechanism, and the second services block is connected to the second
platen.
[0080] In some embodiments, the first platen is a stationary platen
such that in operation, the stationary platen does not move
relative to the support frame; and wherein the second platen is a
moving platen such that in operation the moving platen moves
relative to the support frame and the stationary platen.
[0081] In some embodiments, the first plate comprises a first base
block and a first mold cavity block; and wherein in operation of
the mold assembly, the first services block is connected to a first
platen and the first services block is connected to the first base
block with a third quick connection mechanism; and the second plate
comprises as second base block and a second mold cavity block; and
wherein in operation of the mold assembly, the second services
block is connected to a second platen and the second services block
is connected to the second base block with a fourth quick
connection mechanism.
[0082] In some embodiments, the first mold cavity block has a base
block facing surface operable to be secured to the first base block
and a cavity side with a first cavity surface topography that
comprises a first contact surface area and a first cavity wall
surface and wherein the second mold cavity block has a base block
facing surface operable to be secured to the second base block and
a cavity side with a cavity surface topography that comprises a
contact surface area and a second cavity wall surface.
[0083] In some embodiments, the mold assembly further comprises a
core assembly having a core device, in operation the core device
being received with a cavity formed by the cavity wall surfaces of
the first and second mold cavity blocks to thereby form a mold
cavity for an item to be molded.
[0084] An example apparatus comprises: a plate defining at least a
portion of a molding cavity, the plate comprising a base block and
a mold cavity block, the base block having a services channel
therein; a connection mechanism operable to connect the mold cavity
block to the base block; wherein in operation, the mold cavity
block is connected to the base block with the connection mechanism;
wherein the mold cavity block has a cavity surface side and a base
block facing surface opposite to the cavity surface side, and the
mold cavity block has a trough area formed in the base block facing
surface; the apparatus further comprising a services channel module
received into the trough area, the services channel module
comprising at least one services channel operable to be
interconnected to the services channel in the base block.
[0085] In some embodiments, the plate is made at least in part from
a metal material and the services channel module is made at least
in part from a plastic material.
[0086] In some embodiments, the cavity surface side has a mold
cavity wall surface, and wherein the services channel module is a
channel for supplying cooling fluid which is operable to cool the
mold cavity block, and wherein the services channel module
comprises a cooling fluid channel having a plurality of portions
configured to conform at least in part of the mold cavity wall
surface when extending from an input port to an output port.
[0087] An example method of operating a mold assembly, the mold
assembly comprising: a platen; a services block connected to the
platen; a first plate defining at least a portion of a first
molding cavity; a second plate defining at least a portion of a
second molding cavity; a first quick connection mechanism operable
to connect and disconnect the first plate and a services block; a
second quick connection mechanism operable to connect and
disconnect the second plate and the services block; the method
comprising interchanging the first plate with the second plate on
the services block by operating the first and second quick
connection mechanisms.
[0088] In some embodiments, the mold assembly further comprises: a
first services channel, the first services channel being located
within the first plate; a second services channel, the second
services channel being located within the second plate; a third
services channel located within the services plate; a first
services connecting mechanism operable to connect and disconnect
the first services channel and the third services channel; a second
services connecting mechanism operable to connect and disconnect
the second services channel and the third services channel; wherein
when the first plate is connected to the services block and the
first service channel is in communication with the third services
channel a service is delivered from the services block to the first
plate; wherein when the second plate is connected to the services
block and the second service channel is in communication with the
third services channel a service is delivered from the services
block to the second plate; the method further comprises when the
first plate and the second cplate are interchanged by operating the
first and second quick connection mechanisms, the first services
connecting mechanism disconnects the first services channel and the
third services channel; and thereafter the second services
connecting mechanism connects the second services channel and the
third services channel.
[0089] In some embodiments, the first and second services
connecting mechanisms both comprise a quick connection
mechanism.
[0090] In some embodiments, each of the first and second quick
connection mechanisms comprise a pneumatically biased
mechanism.
[0091] In some embodiments, the method comprises releasing the
pneumatically biased mechanism of the first quick connection
mechanism or the second quick connection mechanism by providing a
pressurized air supply by way of the services block.
[0092] In some embodiments, the method comprises defining a mold
for blow molding.
[0093] An example method of forming a mold system comprises:
forming a first base block; forming a second base block that is
configured substantially the same as the first base block; forming
a first and a second mold cavity blocks, each having a base block
facing surface operable to be secured to the first and second
respective base blocks and a cavity side with a mold cavity surface
topography that comprises a contact surface area and a mold cavity
wall surface, wherein the configuration of the mold cavity wall
surface of the first mold cavity block is different from the
configuration of the mold cavity wall surface of the second mold
cavity block, but where the size of the contact surface area of the
first mold cavity block is substantially similar to the size of the
contact surface area of the second mold cavity block connecting the
first base block to the first mold cavity block; connecting the
second base block to the second mold cavity block.
[0094] In some embodiments, the contact surface area of the first
mold cavity block is shaped differently than the contact surface
area of the second mold cavity block.
[0095] In some embodiments, the size of the contact surface area of
the first and second mold cavity blocks is selected based on the
known size of the clamping force of the mold assembly to be applied
to the contact surface area.
[0096] In some embodiments, the method further comprises: providing
a quick connection device on each of the first and second base
blocks, each quick connection device being operable to connect to
and disconnect from a common quick connection device on a common
services block.
[0097] An example method of manufacturing a cavity plate comprises:
forming a base block with a quick connection device operable to
connect with and disconnect from a quick connection device on a
services block; forming a mold cavity block by depositing material
on a surface of the base block with an additive manufacturing
process to thereby form a mold cavity surface topography that
comprises a contact surface area and a mold cavity wall
surface.
[0098] An example method of forming a cavity plate comprises:
forming a base block having a services channel; forming a mold
cavity block the mold cavity block having a cavity surface side and
a base block facing surface opposite to the cavity surface side,
and wherein the mold cavity block has a trough area formed in the
base block facing surface; inserting a services channel module into
the trough area, the services channel module comprising at least
one services channel operable to be interconnected to the services
channel in the base block.
[0099] An example mold assembly comprises: a pair of mating mold
sections cooperatively defining a mold cavity; a pair of services
blocks, each for mounting a respective one of the mold blocks to a
platen of a molding machine; a handling coupler projecting from an
exterior surface of each mold section, for engagement by a handling
device to hold the mold blocks together in a mating configuration
and to remove the mold assembly from the mold machine.
[0100] In some embodiments, the handling coupler comprises a quick
connection mechanism.
[0101] In some embodiments, the assembly comprises a mold quick
connection mechanism operable to connect and disconnect each of the
mold sections and sa respective one of the services blocks.
[0102] In some embodiments, the mold sections have curved outer
surfaces, and the services blocks have corresponding curved inner
surfaces to receive the mold blocks.
[0103] In some embodiments, the mold quick connection mechanism
comprises a connector projecting from one of the curved
surfaces.
[0104] In some embodiments, the mold assembly is a blow molding
assembly.
[0105] In some embodiments, the mold assembly comprises a third
mold section operable to cooperatively define the mold cavity with
the mold blocks.
[0106] In some embodiments, the third mold section comprises a
quick connection mechanism for coupling to an actuator.
[0107] In some embodiments, the services blocks comprise respective
load limiting blocks, the load limiting blocks opposing one another
with clearance therebetween in a molding configuration of the
molding assembly, and operable to abut one another and bear a
clamping force in response to compression of the mold blocks.
[0108] In some embodiments, the mold blocks are formed of an
aluminum alloy.
BRIEF DESCRIPTION OF DRAWINGS
[0109] In the drawings, which depict example embodiments:
[0110] FIG. 1 is a schematic diagram of a molding system;
[0111] FIG. 2 is a schematic diagram of a molding system with
process cells defining multiple paths through the system;
[0112] FIG. 3 is an isometric view of a molding system;
[0113] FIG. 4A-4B are isometric views of a dispensing station of
the system of FIG. 3;
[0114] FIGS. 4C-4E are isometric views of sub-assemblies of the
dispensing station of FIG. 4A;
[0115] FIGS. 4F-4G are enlarged partial isometric views of a barrel
unit;
[0116] FIG. 4H is a schematic view of a coupling for holding the
barrel unit of FIGS. 4F-4G to a drive unit;
[0117] FIGS. 4I-4J are enlarged partial isometric views of the
barrel unit of FIG. 4F with a drive unit;
[0118] FIG. 4K is a schematic diagram of a removal tool for
removing a barrel unit from a drive unit;
[0119] FIGS. 4L-4O are enlarged partial cutaway views showing a
process of coupling a barrel unit to a drive unit;
[0120] FIGS. 4P-4R are enlarged partial cutaway views showing a
process of removing a barrel unit from a drive unit;
[0121] FIG. 4S is a schematic view of the removal tool of FIG. 4K
installing a barrel unit to a drive unit;
[0122] FIG. 5 is a longitudinal cross-sectional diagram of the
dispensing station of FIG. 4;
[0123] FIGS. 6A-6B are isometric and isometric cutaway views,
respectively, of a vessel for transporting molding material;
[0124] FIGS. 7A-7B are isometric views of the material vessel of
FIGS. 6A-6B and a carrier;
[0125] FIGS. 8A, 8B, 8C, and 8D are side and cross sectional views
showing stages of a dispensing operation at the dispensing station
of FIG. 4;
[0126] FIG. 9 is an exploded view of a gate assembly;
[0127] FIGS. 10A-10B are enlarged cross-sectional views showing
operation of the gate assembly of FIG. 9;
[0128] FIG. 11 is an isometric view of a shaping station of the
system of FIG. 3;
[0129] FIGS. 12A-12D are cross-sectional and isometric views of the
shaping station of FIG. 11;
[0130] FIGS. 13A-13B are isometric and side views, respectively, of
a linkage for a clamping assembly;
[0131] FIG. 13C is a diagram of forces on the linkage of FIGS.
13A-13B;
[0132] FIGS. 14A-14B are isometric and side views, respectively, of
another linkage for a clamping assembly;
[0133] FIGS. 15A-15B are isometric and side views, respectively, of
another linkage for a clamping assembly;
[0134] FIG. 16 is a side view of another linkage for a clamping
assembly;
[0135] FIG. 17 is an isometric view of a core actuation assembly of
the shaping station of FIG. 11;
[0136] FIGS. 18A-18B are isometric and cross-sectional views,
respectively, of a core positioning actuator of the core actuation
assembly of FIG. 17;
[0137] FIG. 19 is an isometric view of a loading actuator of the
core actuation assembly of FIG. 17;
[0138] FIG. 20 is a partial cutaway view of the loading actuator of
FIG. 19;
[0139] FIG. 21A is a schematic view showing interlocking between
the core positioning actuator of FIGS. 18A-18B and the loading
actuator of FIG. 17;
[0140] FIG. 21B is a partial cross-sectional view of the core
positioning actuator of FIGS. 18A-18B and the loading actuator of
FIG. 17, showing interlocking;
[0141] FIG. 22 is an isometric view of a secondary mold opening
actuator of the core actuation assembly of FIG. 17;
[0142] FIGS. 23A-23D are side, isometric, enlarged top and enlarged
perspective views, respectively, of a shaper module of the shaping
station of FIG. 11;
[0143] FIG. 24A-24B are front isometric and top elevation views of
another shaping station;
[0144] FIG. 24C is a rear isometric view of the shaping station of
FIG. 24A;
[0145] FIG. 24D is front isometric view of support structures of
the shaping station of FIG. 24A;
[0146] FIGS. 24E-24F are isometric views of the support structures
of FIG. 24D, cutaway at lines E-E and F-F in FIG. 24B;
[0147] FIG. 24G is an isometric view of the shaping station of FIG.
24A, cutaway to show internal components;
[0148] FIG. 24H is an enlarged partial cross-sectional of the
shaping station of FIG. 24A;
[0149] FIGS. 24I-24J are isometric and cross-sectional views of the
shaping station of FIG. 24A in a mold-open state;
[0150] FIGS. 24K-24L are isometric and cross-sectional views of the
shaping station of FIG. 24A in a mold-open state, with the mold
core in a molding position;
[0151] FIGS. 24M-24N are isometric and cross-sectional views of the
shaping station of FIG. 24A in a mold-closed state;
[0152] FIGS. 24O-24P are isometric and cross-sectional views of the
shaping station of FIG. 24A in a mold-closed state, with a preload
force applied to the mold core;
[0153] FIGS. 24Q-24R are isometric and cross-sectional views of the
shaping station of FIG. 24A in a mold-open state;
[0154] FIGS. 24S-24T are isometric and cross-sectional views of the
shaping station of FIG. 24A during mold removal;
[0155] FIG. 25A is a side perspective view of a one embodiment of
part of a mold assembly;
[0156] FIG. 25B is a front elevation view of a portion of the part
of the mold assembly of FIG. 25A;
[0157] FIG. 25C are side perspective views of the embodiment of
portions of the part of the mold assembly of FIG. 25A;
[0158] FIGS. 25D, E and F are similar side perspective views as
FIG. 25C, of portions of the part of the mold assembly of FIG.
25A;
[0159] FIG. 25G is top perspective view of an embodiment of a mold
cavity block;
[0160] FIG. 25H is a is top perspective view of an embodiment of a
cavity plate that includes the mold cavity block of FIG. 25G;
[0161] FIG. 25I is top perspective view of an alternate embodiment
of a mold cavity block;
[0162] FIG. 25J is top plan view of the mold cavity block of FIG.
25I
[0163] FIG. 25K is another top perspective view of the mold cavity
block of FIG. 25I;
[0164] FIGS. 26A and 26B are side perspective views of an alternate
embodiment of portions of a mold assembly;
[0165] FIG. 26C is a top plan section view at part marked 26C in
FIG. 26A;
[0166] FIG. 26D is a side perspective view of part of the
embodiment of the portions of the mold assembly of FIGS. 26A and
26B;
[0167] FIG. 26E is a perspective view of a disconnected components
of the part shown in FIG. 26D;
[0168] FIG. 26F is a perspective view of another disconnected
components of the part shown in FIG. 26D;
[0169] FIG. 26G are rear elevation views of the disconnected
component of the part shown in FIG. 26D;
[0170] FIG. 26H is top plan view of the mold cavity block used in
the part of FIG. 26D;
[0171] FIG. 26I is a top perspective view of the mold cavity block
of the part of FIG. 26D;
[0172] FIG. 26J is a top perspective view of an alternate mold
cavity block that can be employed in the part of FIG. 26D;
[0173] FIG. 27A is a top perspective view of a base block;
[0174] FIG. 27B is a rear perspective view of the base block of
FIG. 27A;
[0175] FIG. 28A is an assembly diagram for part of a mold assembly;
and
[0176] FIG. 28B is a schematic view of a cooling fluid circuit.
[0177] FIG. 29 is a cross-sectional view of a mold of the shaping
station of FIG. 11 and a vessel;
[0178] FIG. 30 is a sequence of overhead and isometric views
showing sealing of a vessel;
[0179] FIG. 31 is an isometric view showing sealing of another
vessel;
[0180] FIG. 32 is an isometric view of the actuator assembly of the
shaping station of FIG. 11;
[0181] FIGS. 33A, 33B and 33C are isometric, cutaway and
cross-sectional views, respectively, of a vessel and an actuation
assembly at the shaping station of FIG. 11;
[0182] FIGS. 34A-34K are cross-sectional and partial
cross-sectional views showing stages of a shaping operation at the
shaping station of FIG. 11;
[0183] FIGS. 35A-35F are cutaway views of the vessel and actuation
assembly of FIGS. 17A-17C, showing operations of the vessel and
actuation assembly;
[0184] FIG. 36 is an exploded view of a gate assembly;
[0185] FIGS. 37A-37B are enlarged cross-sectional views showing
operation of the gate assembly of FIG. 36;
[0186] FIG. 38 is an isometric view of a conditioning station and a
shaping station of the system of FIG. 3.
[0187] FIG. 39 is a side cross-sectional view of the conditioning
station of FIG. 38;
[0188] FIGS. 40A, 40B and 40C are side and cross-sectional views
showing stages of a conditioning operation at the conditioning
station of FIG. 38;
[0189] FIG. 41A is an isometric view of a shaping station;
[0190] FIG. 41B is a side view of a press of the shaping station of
FIG. 41;
[0191] FIG. 42 is a side view of another shaping station;
[0192] FIG. 43 is a top view of the shaping station of FIG. 42;
[0193] FIG. 44 is an exploded view of a mold and services plates of
the shaping station of FIG. 42;
[0194] FIG. 45 is an exploded view of the mold of FIG. 44;
[0195] FIG. 46 is a cross-sectional view of the mold of FIG.
44;
[0196] FIGS. 47A-47B are top and side schematic views of the
shaping station of FIG. 42 during mold removal;
[0197] FIGS. 48A-48B are top and side schematic views of the
shaping station of FIG. 42 during mold removal;
[0198] FIGS. 49A-49B are top and side schematic views of the
shaping station of FIG. 42 during mold removal;
[0199] FIG. 50 is a schematic view showing mold components at a
shaping station;
[0200] FIGS. 51A, 51B, 51C and 51D are schematic views showing
stages of a shaping operation with the mold components of FIG.
50;
[0201] FIG. 52 is a top plan view of the molding system of FIG. 3,
showing a transport subsystem;
[0202] FIG. 53 is a plan view of an injection molding system in
accordance with another embodiment;
[0203] FIG. 54 is a cross-sectional view along the lines I-I of
FIG. 53;
[0204] FIG. 55A is a side view of a track section;
[0205] FIG. 55B is a cross-sectional view along the lines II-II of
FIG. 55A;
[0206] FIG. 55C is a perspective fragmentary view of a portion of
the track of the system of FIG. 55A;
[0207] FIG. 56 is a side view of a portion of the system of FIG.
53;
[0208] FIG. 57 is a perspective fragmentary view of another portion
of the system of FIG. 53;
[0209] FIG. 58 is a perspective fragmentary view of a further
portion of the system of FIG. 53;
[0210] FIG. 59 is a perspective fragmentary view of a yet a further
portion of the system of FIG. 53;
[0211] FIG. 60 is a perspective detail view of a portion of FIG.
58;
[0212] FIG. 61 is a top view of a conditioner and shaper station
and associated transfer system;
[0213] FIG. 62 is a side view of the stations and transfer system
of FIG. 61
[0214] FIGS. 63A-63B are isometric and side views, respectively, of
a carriage of the transfer system of FIG. 61;
[0215] FIG. 64 is a block diagram;
[0216] FIG. 65 is a perspective fragmentary view of a portion of a
modified system;
[0217] FIG. 66 is a perspective detail view of a portion of FIG.
63.
[0218] FIG. 67 is a flow chart showing a method of transporting
molding material; and
[0219] FIG. 68 is a flow chart showing a method of producing
plastic molded products.
DETAILED DESCRIPTION
[0220] FIG. 1 schematically depicts an example plastic molding
system 100 for producing plastic molded articles. As described in
further detail below, plastic molding system 100 is capable of
carrying out molding processes comprising dispensing, conditioning
and shaping operations.
[0221] Plastic molding system 100 includes a plurality of process
cells, each including one or more process stations at which an
operation of a molding process can be performed. Specifically, the
depicted embodiment comprises a dispensing cell 102, shaping cells
104, 106 and a conditioning cell 108. Other embodiments may include
more or fewer cells and carry out molding processes with more or
fewer process steps. Alternatively or additionally, plastic molding
system 100 may include cells for other operations. For example,
plastic molding system 100 may include cells for post-molding
operations such as container filling, labelling or capping.
[0222] The process cells of plastic molding system 100 are
connected by a transport subsystem 110.
[0223] Any of process cells 102, 104, 106, 108 may have more than
one station of a given type. Transport subsystem 110 selectively
connects stations of the process cells to one another. Transport
subsystem 110 is configurable to define multiple possible process
paths through process cells of molding system 100. For example,
transport subsystem 110 may be capable of transporting an article
from a given station in one process cell 102, 104, 106, 108, to a
selected one of a plurality of possible stations in a another
process cell 102, 104, 106, 108.
[0224] FIG. 2 schematically depicts an example embodiment with a
dispensing cell 102 having 4 dispensing stations 102-1, 102-2,
102-3, 102-4; a shaping cell 104 having 8 shaping stations 104-1,
104-2, 104-3, 104-4, 104-5, 104-6, 104-7, 104-8; a shaping cell 106
having 2 shaping stations 106-1, 106-2; and a conditioning cell 108
having 2 conditioning stations 108-1, 108-2.
[0225] In the embodiment of FIG. 2, transport subsystem 110 is
capable of connecting any of dispensing stations 102-1, 102-2,
102-3, 102-4 to any of shaping stations 104-1, 104-2, . . . 104-8;
and of connecting any of shaping stations 104-1, 104-2, . . . 104-8
to any of conditioning stations 108-1, 108-2; and of connecting any
of conditioning stations 108-1, 108-2 to any of shaping stations
106-1, 106-2. Thus, numerous possible paths are defined through
molding system 100. As depicted, there exist 128 unique
combinations of one dispensing station 102, one shaping station
104, one conditioning station 108 and one shaping station 106 and
each unique combination corresponds to a possible path. In some
embodiments, one or more of the process cells may be omitted from
some paths, such that additional paths are possible. For example,
conditioning at conditioning cell 108 or shaping at shaping cell
106 may not be required in all instances.
[0226] In other embodiments, more or fewer stations may be present
in each process cell, and more or fewer paths through the molding
system may be possible.
[0227] In some embodiments, process cells or stations of process
cells may be physically separated from one another. Transport
subsystem 110 may include apparatus for moving molding material
through space between process cells or stations thereof. The
apparatus may include one or both of vessels 124 (FIGS. 6A-6B) for
holding molding material and carriers 125 (FIG. 7) for moving the
vessels through space, e.g. along a guide or track, between the
process cells or stations. In the embodiment described in detail
herein, the vessel is selectively coupled to the carrier such that
the vessel may be coupled and decoupled to the carrier at one or
more process stations. In another embodiment, not shown, the vessel
could otherwise be fixed to the carrier and the process stations
configured to accommodate the vessel that remains connected with
the carrier. In either case, the vessel may be thermally insulated
from the carrier.
[0228] In the depicted embodiment, shaping cell 104 contains
injection molding stations and shaping cell 106 contains blow
molding stations. Conditioning cell 108 contains stations for
thermally conditioning articles to prepare for blow molding. For
example, injection molded articles formed at shaping cell 104 may
cool after molding and be subsequently warmed to a temperature
suitable for blow molding. Alternatively or additionally, stations
of conditioning cell 108 may be configured to create a specific
desired thermal profile in an article. For example, some shaping
operations may call for an input article having a non-uniform
temperature distribution. Stations of conditioning cell 108 may
generate such temperature distribution by selectively heating
specific regions, with or without a net transfer of heat into or
out of the article. In some embodiments, articles may experience a
net loss of heat in conditioning cell 108, despite warming of
specific regions. Thus, stations of conditioning cell 108 may
achieve thermal profiles not easily achieved by heat input at the
dispensing cell 102.
[0229] As explained in further detail below, each station may have
identical or unique characteristics. For example, the dispensing
stations of dispensing cell 102 may each be configured to dispense
the same or a different feedstock (e.g. a different material and/or
colour). The shaping stations of shaping cells 104, 106 may be
configured to mold articles having identical or different shapes,
features or the like. The conditioning stations of conditioning
cell 108 may each be configured to condition parts in common or to
a different state. Accordingly, molding system 100 may be
configured so that it is simultaneously capable of producing up to
128 identical or unique parts at any time. Alternatively or
additionally, molding system 100 may be configured so that
identical parts may be produced on multiple paths. For example, a
single dispensing station can produce shots of feedstock to feed
multiple stations of shaping cells 104, 106. In some embodiments,
cells can be rapidly reconfigured. Accordingly, the number of
system resources being used to produce parts of a given type may
vary.
[0230] Each unique path through molding system 100 includes a
unique combination of selected stations of dispensing cell 102,
shaping cells 104, 106 and possibly other process cells such as,
for example, the conditioning cell 108. Likewise, each unique
combination of stations may produce finished articles with
identical or unique characteristics. For example, different
stations of dispensing cell 102 may produce articles having
different colour material type or weight. Different stations of
shaping cells 104, 106 may produce articles having different
shapes. Different stations of conditioning cell 108 may produce
articles having different shapes or other characteristics.
[0231] FIG. 3 is a perspective view of molding system 100. In the
depicted embodiment, molding system 100 is for forming hollow
plastic articles such as bottles or other containers. Molding
system 100 has two shaping cells. Specifically, shaping cell 104 is
an injection molding cell for molding a dose of feedstock material
into a molded preform shape. Shaping cell 106 is a blow-molding
cell (specifically, a stretch blow-molding cell) for transforming a
preform of a particular shape into a finished hollow container of
another, (e.g. a further-expanded) shape. Conditioning cell 108
prepare in-progress articles for operations performed at a shaping
cell. Transport subsystem 110 links stations of the respective
cells 102, 104, 106, 108. Links between cells are flexible. For
example, in some embodiments, transport subsystem 110 links every
station of each cell to every station of the neighboring cells. In
other examples, some or all stations in a given cell are each
linked to a plurality of stations in a neighboring cell. In some
examples, some stations may be linked to stations of neighboring
cells in a 1:1 manner. For instance, in the embodiment of FIG. 3,
each station of dispensing cell 102 is linked to a plurality of
stations of shaping cell 104, and each station of shaping cell 104
is linked to a plurality of stations of conditioning cell 108.
However, each station of conditioning cell 108 is linked to one
corresponding station of shaping cell 106.
Feedstock Dispensing
[0232] With primary reference to FIGS. 4A-4S, details of an example
dispensing cell 102 will now be described.
[0233] Each station 102-1, 102-2, 102-3, 102-4 of dispensing cell
102 comprises one or more devices for melting a feedstock such as a
plastic feedstock and for transferring the feedstock. In the
depicted embodiment, the dispensing devices output molding material
in doses of a specific size. However, in other embodiments, the
dispensing devices may simply perform bulk transfer of molding
material, without precise metering of dose size.
[0234] In the depicted embodiment, each station of dispensing cell
102 comprises an extruder 112. However, other types of dispensing
devices are possible. For example, melting and dispensing doses of
feedstock may be accomplished by use of a conduction melter. In the
depicted example, extruders 112 receive feedstock material in the
form of polyethylene terephthalate (PET) pellets. However, other
feedstock materials and other forms are possible. For example,
feedstock may be provided as a filament (e.g. on a spool), or as
bars or blocks.
[0235] Extruders 112 may dispense different feedstock materials. In
some examples, extruders 112 may dispense feedstock materials in
differing volume, colors, different material types or grades, or at
different temperatures. In some embodiments, extruders may be
capable of dosing or blending additives, such as dyes or oxygen
scavenging agents, into the feedstock material. In some
embodiments, extruders 112 may be of different sizes, or may be
configured to dispense feedstock at different rates or in different
dose sizes. For example, system 100 may be set up to form
containers of different size, with each extruder 112 being
configured to dispense feedstock in doses corresponding to a
specific size.
[0236] FIGS. 4A-4B are isometric and exploded views, respectively
of an extruder 112 showing components thereof in greater detail. As
depicted, extruder 112 has a barrel 114, in which a screw 116 (FIG.
5) is housed, and a drive unit 115 for driving rotation of the
screw 116. Rotation of the screw 116 is driven by a drivetrain 130
within drive unit 115, which may include an electric motor. Barrel
114 has an inlet opening for supply of feedstock and an outlet
orifice 122 (FIG. 5) for dispensing of molten feedstock into a
vessel 124.
[0237] Referring to FIG. 4B, in the depicted embodiment, extruders
112 are mounted to supports 162 within dispensing cell 102. A set
of supports 162 may be provided for each dispensing station 102-1,
102-2, 102-3, 102-4. As depicted, barrel 114 and the screw 116
within barrel 114 (collectively referred to as barrel unit 117) are
releasably coupled to drive unit 115. Specifically, a coupling 161
rotationally couples the screw 116 to drivetrain 130 and one or
more locating features 163 are received in corresponding recesses
of supports 162 to position and secure barrel 114 relative to the
support 162. Alternatively, alignment features 163 may be part of
supports 162 and may be received in corresponding recesses on
barrel 114. Supports 162 may include actuators for selectively
engaging or releasing locating features 163. Thus, barrel 114 and
screw 116 may be released and removed as a unit and replaced by
another barrel 114 and screw 116. Coupling 161 and locating
features 163 are located on one or both of a coupling block 4010 of
barrel unit 117 and a frame 4012 of drive unit 115. References
herein to removal, replacement or installation of extruders 112 are
intended to include removal, replacement or installation of a
barrel 114 and screw 116 as an assembly. In this way, extruder
characteristics or characteristics of a feedstock may be rapidly
and easily changed.
[0238] In some embodiments, removal, replacement or installation of
extruders 112 may be affected automatically. For example, extruders
112 may be gripped and removed from supports 162 and may be moved
by one or more robots under computer control. The computer control
may be part of an overall control system of system 100, and
releasing or engaging of locating features such as locating
features 163 on barrel 114 may be coordinated with operation of the
robot, such that extruders 112 are securely retained upon
installation by a robot, and until subsequent removal by a
robot.
[0239] FIGS. 4C and 4D depict barrel unit 117 and drive unit 115 of
an extruder 112 in greater detail. In the configuration of FIG. 4C,
barrel unit 117 is coupled to drive unit 115. In the configuration
of FIG. 4D, barrel unit 117 is released from drive unit 115.
[0240] As depicted, barrel unit 117 includes a barrel 4002 and a
screw 116 within barrel 4002. A nozzle assembly 4006 is positioned
at the distal end of barrel 4002, in which outlet orifice 122 is
defined. Rotation of screw 116 within barrel 4002 causes heating
and melting of molding material, and conveys the molding material
towards outlet orifice 122 in nozzle assembly 4006. A shroud 4008
is positioned around barrel 4002. During operation, barrel 4002 may
become very hot. Shroud 4008 serves as a barrier to guard against
damage to surrounding components and to protect against injury to
operators.
[0241] Barrel 4002 is mounted to coupling block 4010. For example,
barrel 4002 may have a flange (not shown) which interfaces with
block 4010 and is secured thereto by fasteners. As will be
described in greater detail, screw 116 is received in and supported
by barrel 4002.
[0242] Nozzle assembly 4006 includes a thermal conditioning element
4007 proximate outlet 122. Thermal conditioning element 4007
maintains nozzle assembly 4006 at a desired temperature, to in turn
control the temperature of molding material in nozzle assembly 4006
and molding material exiting nozzle assembly 4006 through outlet
122. One or more temperature measurement devices such as
thermocouples may be positioned at nozzle assembly 4006, and
thermal conditioning element 4007 may be controlled based on
measurements from such devices.
[0243] Drive unit 115 and barrel unit 117 are connected by way of a
coupling system operated by one or more actuators. The one or more
actuators are operable to couple and decouple the drive unit 115
and barrel unit 117 using the coupling system. That is, the
coupling system is operable to physically fix barrel unit 117 in
position relative to drive unit 115. The coupling system is further
operable to connect screw 116 with the drive unit 115 for driving
rotation of the screw 116. In the depicted embodiment, the coupling
system includes a retaining mechanism 4014 and a drive mechanism
4016. Retaining mechanism 4014 is operable to physically hold
barrel unit 117 in place against drive unit 115. Drive mechanism
4016 rotationally connects drive unit 115 to screw 116 for rotating
the screw.
[0244] In the depicted embodiment, retaining mechanism 4014 and
drive mechanism 4016 are operated by separate actuators. In other
embodiments, a single actuator may operate both of retaining
mechanism 4014 and drive mechanism 4016. In other embodiments, a
single mechanism may provide both the retention and drive
functions.
[0245] In the depicted embodiment, the actuators for retaining
mechanism and drive mechanism 4016 are pneumatic. However, other
types of actuators may be used, including electro-mechanical
actuators such as solenoids, magnetic actuators, or hydraulic
actuators.
[0246] Barrel unit 117 further includes one or more service ports
4018, each for connecting to a corresponding port of drive unit 115
or proximate drive unit 115. Service ports may include, for
example, conduits for circulation of coolant such as water to and
from barrel unit 117, conduits for supply of air, e.g. pressurized
air for pneumatic actuation systems, and electrical connections.
Electrical connections may, include, for example, any of power
supplies, controls, and signal wiring. Drive unit 115 also includes
a resin feed port 4076 (FIG. 41). Resin feed port 4076 receives a
feed of molding material, e.g. pelletized molding material, and
communicates with barrel unit 117 to supply molding material to the
barrel. Service ports 4018 may be configured for quick connection
to and disconnection from the corresponding ports of drive unit
115. In an example, service ports 4018 may couple using
push-to-connect pneumatic or hydraulic connectors, magnetic
connectors, barb fittings or the like. Thus, service ports 4018 may
automatically connect or disconnect from the corresponding ports by
application of force, e.g. due to movement of barrel unit 117, or
in response to a control signal.
[0247] FIG. 4E depicts barrel unit 117, with coupling block 4010
and shroud 4008 removed to show internal features. Barrel unit 117
has a resin input port 4074 which communicates with the interior of
barrel 4002 to deliver molding material to the interior of barrel
4002. Molding material is typically input to barrel 4002 in solid
granular form and may be delivered, e.g. from a hopper (not shown).
The hopper may be mounted to drive unit 115 or proximate drive unit
115 and deliver molding material to resin input port 4074 by way of
a corresponding resin feed port 4076 on drive unit 115. In some
embodiments, resin input port 4074 and resin feed port 4076 abut
one another. In other embodiments, one of input port 4074 and feed
port 4076 may be received within the other. In some embodiments,
input port 4074 and feed port 4076 may be positively coupled to one
another, for example, using quick connect fittings such as
push-to-connect pneumatic or hydraulic connectors, magnetic
connectors, barb fittings or the like. Connection and disconnection
of such fittings may be automatically affected by application of
force, e.g. due to movement of barrel unit 117, or in response to a
control signal.
[0248] As best shown in FIG. 4F-4G, one or more locating devices
may be provided to position drive unit 115 and barrel unit 117. The
locating devices position barrel unit relative to drive unit 115 as
the barrel unit is moved toward a coupling position. Specifically,
the locating devices guide barrel unit 117 so that it seats against
drive unit 115 in a coupling position, in which retention mechanism
4014 and drive mechanism 4016 can be engaged. That is, in the
coupling position, components of the retaining mechanism 4014 and
drive mechanism 4016 on barrel unit 117 align with the
corresponding components on drive unit 115. The locating devices
may progressively bias barrel unit 117 into its correct alignment
as the barrel unit 117 is moved towards drive unit 115. In the
depicted embodiment, the locating devices comprise leader pins 4020
and mating recesses 4022 (FIG. 4D). As shown, leader pins 4020
project from coupling block 4010 of barrel unit 117 and are
received in recesses 4022 in frame member 4012 of drive unit
115.
[0249] Leader pins 4020 and recesses 4022 engage one another as
barrel unit 117 is moved toward drive unit 115. Such engagement
aligns barrel unit 117 relative to drive unit 115 such that the
barrel unit 117 and drive unit 115 can be coupled by actuation of
retaining mechanism 4014. In the depicted example, the alignment
devices engage one another prior to engagement of the coupling
system.
[0250] FIG. 4H depicts retaining mechanism 4014 in greater detail.
In the depicted embodiment, retaining mechanism 4014 includes a
stud 4024 and a socket 4026 which can selectively interlock with
stud 4024. As shown, stud 4024 is part of barrel unit 117 and
socket 4026 is part of drive unit 115. Stud 4024 may, for example,
be threaded to coupling block 4010. Socket 4026 may be a recess cut
into frame 4012 or an insert attached (e.g. threaded) to frame
4012. However, socket 4026 may instead be part of barrel unit 117
and stud 4024 may instead be part of drive unit 115.
[0251] Stud 4024 has inner and outer flanges 4028, defining a
channel 4032 therebetween. Socket 4026 has an opening 4034, sized
to receive stud 4024, and a gripping device 4036. Gripping device
4036 is configured for reception in channel 4032, in interlocking
engagement with flanges 4028.
[0252] Gripping device 4036 is movable between engaged and
disengaged states. In the disengaged state, gripping device 4036
clears flanges 4028 of stud 4024 such that stud 4024 may be freely
inserted in or withdrawn from socket 4026. In the engaged state,
gripping device interlocks with stud 4024, preventing stud 4024
from being withdrawn from socket 4026.
[0253] In the depicted embodiment, gripping device 4036 comprises a
series of balls 4038 and a movable locking collar 4040. In the
engaged state, locking collar 4040 holds balls 4038 against channel
4032. Balls 4038 bear against the distal flange 4028 of stud 4024,
urging stud 4024 (and barrel unit 117) against drive unit 115. In
the disengaged state, locking collar 4040 is withdrawn, allowing
balls 4038 to shift away from stud 4024.
[0254] As shown, locking collar 4040 is spring-biased to the
engaged state. An actuator is provided to selectively overcome the
spring bias and thereby release locking collar 4040 and balls 4038.
In the depicted embodiment, the spring bias is overcome by
pneumatic pressure provided by a retention control line 4044, which
is controlled by a valve (not shown).
[0255] Drive mechanism 4016 is shown in detail in FIGS. 4I-4J.
Drive mechanism 4016 includes a driveshaft 4050 driven by an
electric motor (not shown). Driveshaft 4050 has an end with a
toothed connector, e.g. spline 4052. The connector interfaces with
a mating connector of screw 116, namely, spline 4054. As shown,
spline 4052 of drive unit 115 and spline 4054 of screw 116
interface by way of a spline insert 4056.
[0256] Spline insert 4056 mates to both of splines 4052, 4054.
Spline insert 4056 is movable along the axis of rotation of
driveshaft 4050, between an engaged position and a retracted
position.
[0257] In the engaged position, spline insert 4056 meshes with
splines 4052, 4054 and rotationally couples driveshaft 4050 and
screw 116. In the retracted position, spline insert 4056 is
retracted along the axis of driveshaft 4050, to disengage from
spline 4054 of screw 116. Thus, in the retracted position of spline
insert 4056, driveshaft 4050 and screw 116 are de-coupled from one
another. Retraction of spline insert 4056 may occur without any
movement of driveshaft 4050. That is, spline insert may move along
a longitudinal axis relative to both of driveshaft 4050 and spline
4054 of screw 116 to disengage.
[0258] The position of spline insert 4056 is controlled by an
actuator, namely, drive actuation assembly 4060. As shown, drive
actuation assembly 4060 includes a pneumatic cylinder 4062. The
piston of pneumatic cylinder 4062 is connected to spline insert
4056 by way of a link 4064. Movement of the piston through its
stroke in a first direction moves spline insert 4056 to its engaged
position. Movement of the piston through its stroke in the opposite
direction moves spline insert 4056 to its disengaged position.
[0259] A shroud is also coupled to link 4064 and moves along with
link 4064 and spline insert 4056. In the engaged position, the
shroud is positioned around the mating interface between spline
insert 4056 and spline 4054 of screw 116. The shroud guards against
ingress of objects or contaminants such as dust or other
particulates, which may cause premature wear or reduced performance
of the splines 4052, 4054.
[0260] Splines 4052, 4054 and spline insert 4056 define mating
interfaces, namely interfaces between mating teeth at which torque
can be transferred. The mating faces have relatively large axial
length, such that the mating interfaces can accommodate some
movement of driveshaft 4050 and screw 116 along their longitudinal
axes. In other words, screw 116 and driveshaft 4050 can shift
axially relative to one another without interfering with meshing of
splines 4052, 4054 and spline insert 4056.
[0261] Screw 116 is rotationally supported by a bearing 4070 which
is in turn supported on coupling block 4010 by a flange 4071. A
support ring 4072 is secured to screw 116 above bearing 4070, by
press-fit or other suitable technique.
[0262] In operation, screw 116 may be vertically supported at least
in part by friction between spline insert 4056 and spline 4054 and
by pressure of molding material within barrel 114. In this
condition, there may be clearance between support ring 4072 and
bearing 4070. When operation is terminated, screw 116 may fall
until support ring 4072 abuts bearing 4070. Support ring 4072 is
positioned such that, when screw 116 falls in this manner, a
clearance gap opens between the ends of screw 116 and drive shaft
4050. In this state, drive unit 117 may be moved without rubbing
and consequent wearing of drive shaft 4050 and screw 116 against
one another.
[0263] Conveniently, in the depicted embodiment, engagement and
disengagement of drive mechanism 4016 and retaining mechanism 4014
may occur independently of one another. That is, drive mechanism
4016 may be engaged or disengaged without changing the state of
retaining mechanism 4014. Engagement of drive mechanism 4016 occurs
by movement along the longitudinal axis of screw 116, and barrel
unit 117 is physically located relative to drive unit 115 by
movement in a perpendicular direction. Likewise, physical fixation
of barrel unit 117 to drive unit 115 occurs by clamping in a
direction perpendicular to the axis of screw 116, i.e. in a
direction perpendicular to that in which engagement of drive
mechanism 4016 occurs. Alignment of barrel unit 117 relative to
drive unit 115 also occurs by movement along an axis perpendicular
to that of screw 116. That is, leader pins 4020 extend in a
direction perpendicular to the axis of screw 116. Independent
operation of drive mechanism 4016 and retaining mechanism 4014
could also be achieved in other configurations. For example, the
mechanisms could be configured to engage by movement along parallel
axes, but the movements could be independent of one another.
[0264] Coupling block 4010 comprises at least one mating surface
4076. When barrel unit 117 is coupled to drive unit 115, mating
surface 4076 abuts a corresponding face of drive unit 115 (i.e. a
corresponding face of frame 4012). Mating surface 4076 may bear
against frame 4012 to hold barrel unit 117 square to drive unit
115.
[0265] In some embodiments, mating surface 4076 may be located so
as to limit stress on drive mechanism 4016. For example, as shown
in FIG. 4F, mating surface 4076 is located at a central plane C of
coupling block 4010. Longitudinal axis L of screw 116 lies within
central plane C.
[0266] In operation, forces may be exerted on the tip of barrel
114. Such forces may include axial forces, i.e. forces parallel to
longitudinal axis L, and transverse forces perpendicular to
longitudinal axis L. Transverse forces may for example be caused by
misalignment. The length of barrel 114 may act as a moment arm,
such that transverse forces exert torque on barrel 114.
[0267] Contact between mating surface 4076 and frame 4012 may
resist torque on barrel 114. That is, frame 4012 may exert reaction
forces on mating surface 4076 which resist movement or twisting of
barrel unit 117.
[0268] Alignment of plane C and longitudinal axis L may limit
stress on barrel 114 and on spline 4054. Conversely, if place C and
longitudinal axis L were spaced apart, transverse forces could also
act around a secondary moment arm, perpendicular to longitudinal
axis L. Alignment of mating face 4076 and longitudinal axis L
avoids such secondary moment arms and therefore limits the torque
to which spline 4054 and barrel 114 may be subjected.
[0269] Coupling block 4010 has a rear surface 4078 opposite mating
surface 4076. When barrel unit 117 is coupled to drive unit 115,
rear surface 4078 faces outwardly, away from drive unit 115. At
least one pull stud 4080 is fixedly attached (e.g. threaded) to
coupling block 4010. Each pull stud 4080 protrudes from coupling
block 4010 for engagement by a removal tool to remove barrel unit
117 from drive unit 115.
[0270] FIG. 4K shows an example removal tool 4082. Removal tool
4082 is an automated (e.g. robotic) transportation device. Removal
tool 4082 has a base 4084 and a rack 4086 supported on the base.
Rack 4086 has a plurality of nests 4088, each capable of engaging
and retaining a barrel unit 117. Two nests 4088-1 and 4088-2 are
shown in FIG. 4K. However, any number of nests may be present.
[0271] Each nest 4088 has one or more couplings 4090 operable to
selectively engage pull studs 4080. In some embodiments, couplings
4090 may be identical to gripping devices 4036 of drive unit 115
and pull studs 4080 may be identical to studs 4024 of barrel unit
117. Couplings 4090 are controlled by actuators (not shown). The
actuators may be, for example, electronic, pneumatic or hydraulic
actuators.
[0272] Rack 4086 may be mounted to base 4084 with a movable arm
4092. Arm 4092 is operable to extend to engage a barrel unit 117
for removal from drive unit 115, and to retract for transportation
once the barrel unit is secured in a nest 4088. Arm 4092 may, for
example, be drive by an electric servomotor or by a hydraulic or
pneumatic cylinder.
[0273] As noted, plastic molding system 100 may include a plurality
of barrel units 117, which may be interchangeably mountable to one
or more drive units 115. For example, each barrel unit 117 may
contain a different type of molding material, such as a different
resin type different colour of material or the like.
[0274] Interchangeability of barrel units 117 may allow for rapid
setup of molding system 100 to produce a specific variety of molded
part. Removal tool 4082 may allow for automated changing of barrel
units 117 at a drive unit 115. That is, removal tool 4082 may be
capable of automatically approaching a drive unit 115, engaging a
barrel unit 117 installed at that drive unit 115, removing the
barrel unit 117 and retaining it, and installing a new barrel unit
117. Removal tool 4082 may then be capable of automatically
transporting the removed barrel unit to a storage or cleaning
area.
[0275] FIGS. 4L-4O depict a process of installing a barrel unit 117
to a drive unit 115.
[0276] As shown in FIG. 4L, a barrel unit 117 is carried by removal
tool 4082 to a position facing drive unit 115. In some embodiments,
removal tool 4082 may be guided into position relative to drive
unit 115. For example, a beacon, such as an infra-red or other
light-based beacon, or a radio-frequency (RF) beacon may be
installed at drive unit 115 or barrel unit 117 and corresponding
sensors may be installed at removal tool 4082. Removal tool 4082
may be programmed to detect signals from the beacon and move toward
the detected signals. In other embodiments, removal tool 4082 may
be programmed to monitor and record its position. For example,
removal tool 4082 may initially be manually moved into position at
a particular drive unit 115 and may record coordinates
corresponding to that position. Thereafter, on receipt of a
specific instruction, removal tool 4082 may automatically return to
the recorded position. In some embodiments, removal tool 4082 may
be programmed in this manner to retain a number of transfer
positions, each for engaging with a respective drive unit 115.
[0277] With removal tool 4082 aligned with drive unit 115, arm 4092
is extended to move the barrel unit 117 towards drive unit 115.
[0278] As barrel unit 117 approaches drive unit 115, gripping
devices 4036 of barrel unit 117 are opened. In the depicted
embodiment, opening of gripping devices 4036 entails energizing the
gripping device to overcome a spring bias towards the closed state.
Energizing may be by providing a stream of pressurized air or
water, or by an electrical signal.
[0279] Alignment devices on the barrel unit 117 and drive unit 115
engage one another to position barrel unit 117 relative to drive
unit 115. Specifically, leader pins 4020 are received in recess
4022 and guide barrel unit 117 onto drive unit 115.
[0280] As shown in FIG. 4M, stud 4024 is received in socket 4026.
The tapered leading end of stud 4024 may bear against walls of
socket 4026 or against gripping device 4036 to provide fine
alignment of stud 4024.
[0281] What barrel unit 117 is being installed, screw 116 is
supported by support ring 4072 resting atop bearing 4070. In this
condition, with barrel unit 117 positioned so that stud 4024 aligns
with socket 4026 of drive unit 115, a clearance gap exists between
the ends of screw 116 and drive shaft 4050. Thus, as barrel unit
117 is moved into position, screw 116 passes below drive shaft 4050
and spline insert 4056 without contacting either the drive shaft or
the spline insert.
[0282] As shown in FIG. 4N, Barrel unit 117 is moved towards drive
unit 115 until stud 4024 is fully received within socket 4026. The
retaining actuator is activated to close gripping device 4036,
thereby locking stud 4024 and barrel unit 117 in place relative to
the drive unit 115. Engagement of stud 4024 by gripping device 4036
pulls stud 4024 and barrel unit 117 towards drive unit 115. With
stud 4024 so engaged, mating surface 4076 of coupling block 4010 is
clamped tightly against drive unit 115. In some embodiments,
gripping device 4036 remains closed, engaging stud 4024 unless
energy is applied to release it, for example, in the form of
hydraulic or pneumatic pressure.
[0283] As shown in FIG. 4O, with barrel unit 117 physically fixed
to drive unit 115, drive mechanism 4016 may be activated to
rotationally couple screw 116 to a motor by way of drive shaft
4050. A signal is provided to drive actuation assembly 4060,
causing pneumatic cylinder 4062 to extend and move spline insert
4056 to its engaged position. Extension of spline insert 4056
causes spline insert 4056 to mesh with spline 4054, thereby
rotationally coupling screw 116 to drive shaft 4050 and the motor
driving drive shaft 4050.
[0284] FIGS. 4P-4R and 4S depict a process of removing a barrel
unit 117 from a drive unit 115.
[0285] As shown in FIG. 4P, drive actuation assembly 4060
disengages drive mechanism 4016 prior to movement of barrel unit
117. Drive actuation assembly 4060 receives a signal causing
retraction of cylinder 4062 and thus, of spline insert 4056.
Retraction of spline insert 4056 releases the mesh between spline
insert 4056 and spline 4054 so that screw 116 and drive shaft 4050
can rotate independently of one another.
[0286] Screw 116 may fall so that support ring 4072 supports drive
screw 116 on bearing 4070. Screw 116 may fall immediately after
retraction of spline insert 4056, or after pressure of molding
material within barrel 114 is reduced. When supported by support
ring 4072 on bearing 4070, and with spline insert 4056 retracted,
screw 116 does not contact drive shaft 4050 or spline insert 4056
and barrel unit 117 is clear of drive shaft 4050 and spline insert
4056 for removal.
[0287] As shown in FIG. 4S, removal tool 4082 approaches barrel
unit 117 and arm 4092 extends into contact or nearly into contact
with barrel unit 117.
[0288] Gripping devices 4036 of drive unit 115 are energized so
that they release stud 4024. Couplings 4090 of removal tool 4082
are positioned on pull stud 4080 of barrel unit 117 and are locked
in a closed position engaging the pull studs. Locking of couplings
4090 holds the barrel unit 117 to nest 4088 and to rack 4086 of
removal tool 4082.
[0289] With barrel unit 117 locked to arm 4092, removal tool 4082
retracts the arm to pull barrel unit 117 away from drive unit 115.
Stud 4024 is withdrawn from socket 4026 and service ports 4018 and
resin input port 4076 decouple from the corresponding ports of
drive unit 115. The alignment mechanism also decouples, as leader
pins 4020 are withdrawn from recesses 4022 (not shown).
[0290] After barrel unit 117 is removed from drive unit 115, a new
barrel unit may be installed. In some examples, removal tool 4082
moves the new barrel unit into alignment with drive unit 115.
Specifically, removal tool 4082 may shift a nest 4088 carrying the
new barrel unit into alignment with drive unit 115.
[0291] With the new barrel unit aligned, removal tool 4082 extends
arm 4092 to couple the new barrel unit to drive unit 115, as
described above with reference to FIGS. 4L-4O.
[0292] In some examples, the removed barrel unit 117 may remain in
its nest 4088 on arm 4092 while a new drive unit at another nest
4088 is installed to drive unit 115. Removal tool may arrive at
drive unit 115 carrying a first barrel unit, and may automatically
remove a second barrel unit from the drive unit 115 and replace the
second barrel unit with the first barrel unit.
[0293] Upon removal from drive unit 115, a barrel unit may be
stored. The barrel unit may, for example, be transferred from the
removal tool 4082 to a rack or other storage area. Alternatively,
the barrel unit may simply remain on the removal tool 4082 for
storage. In some examples, a plurality of removal tools 4082 may be
present, and each stored barrel unit may be stored on a removal
tool having at least one vacant nest 4088. Accordingly, any stored
barrel unit could be installed by sending its respective removal
tool to a drive unit, and the removal tool would also be capable of
removing the previous barrel unit from the drive unit.
[0294] Interchangeability of barrel units 117, and particularly,
automated interchangeability, may allow for rapid configuration and
reconfiguration of molding system 100. In particular, different
barrel units may be used with different molding materials, e.g.
different material types or colours. Molding system 100 can
therefore be reconfigured for molding parts of different materials
by simply swapping barrel units 117.
Transport Vessels
[0295] Details of transport vessels in which molten feedstock may
be moved between process stations, as associated features at
process stations will now be described, with primary reference to
FIGS. 5-12.
[0296] FIG. 5 is an enlarged cross-sectional view of an extruder
112 and vessel 124 depicting components in greater detail.
[0297] Feedstock such as PET pellets is introduced into the cavity
of barrel 114 and is urged toward outlet orifice 122 by rotation of
screw 116. Rotation of screw 116 compresses the feedstock and
thereby causes heating and ultimately melting of the feedstock for
dispensing into a vessel 124.
[0298] Extruder 112 includes a nozzle assembly 113 positioned at
the dispensing end of barrel 114. As will be explained in further
detail, a vessel 124 may be positioned opposite nozzle assembly 113
to receive molten feedstock. A gate assembly 1130 may be interposed
between the extruder and nozzle assembly.
[0299] In some embodiments, only a subset of available extruders
may be installed at any given time. For example, molding system 100
may have four or more extruders 112 available for use, only a
subset of which may be installed or in active use at any given
time.
[0300] In such embodiments, each extruder 112 may be used with a
specific feedstock (e.g. a specific combination of colour and
material). Conveniently, this may reduce or eliminate the need to
change feedstock in any given extruder 112. That is, a switch from
a first to a second feedstock may be accomplished by removing an
extruder containing the first feedstock and replacing it with
another extruder containing the second feedstock. Optionally, the
first feedstock may be left in its extruder 112 for the next time
that feedstock is needed. Alternatively, the extruder may be
subjected to a cleansing process, which may be automated, to remove
the first feedstock and ready the extruder for its next use.
[0301] In contrast, changing a feedstock within a specific extruder
112 is relatively difficult, time consuming, expensive (wasted
molding material) and labour intensive. Typically, the existing
feedstock must be thoroughly purged from the extruder before a new
feedstock can be introduced.
[0302] Vessel 124 is carried by transport subsystem 110 and is
positioned adjacent extruder 112 to receive molten feedstock. In
the depicted embodiment, vessel 124 is a cartridge with an outer
wall 132 defining an internal cavity 134. Outer wall 132 may be
insulated, or may be formed of a material with relatively high
thermal resistance. In some embodiments, temperature control
elements, such as heating and/or cooling devices, may be mounted to
or integrated with wall 132 for maintaining thermal control of
feedstock within internal cavity 134.
[0303] Vessel 124 may be thermally conditioned such that, prior to
receiving molten feedstock, the vessel has a thermal profile
consistent with a desired feedstock temperature. For example,
vessel 124 may be heated prior to receiving feedstock, to limit
head loss from the feedstock to vessel 124.
[0304] A buffering area may be defined, e.g. within or proximate
dispensing cell 102, in which one or more vessels 124 may be
collected and prepared for receiving feedstock, e.g. by thermal
conditioning such as heating. Vessels may be carried to and from
the buffering area by transport subsystem 110.
[0305] FIGS. 6A and 6B depict isometric and cutaway isometric
views, respectively, of a vessel 124. The vessel has a gate orifice
136 designed to matingly engage outlet orifice 122 of extruder 112
to receive flow therefrom. As further described below, in the
depicted embodiment, gate orifice 136 also mates to a mold of a
shaping station 104-1, 104-2, . . . 104-8 to deliver molten
feedstock into the mold. In other embodiments, a separate orifice
may be provided for permitting feedstock to exit vessel 124. In
such embodiments, vessel 124 may be configured so that feedstock is
handled in a first-in first-out manner. That is, the first
feedstock that enters vessel 124 through gate orifice 136 may also
be the first feedstock that is pushed out of vessel 124 through an
exit orifice. This may limit degradation of material within vessel
124.
[0306] Vessel 124 comprises a barrel 1320 and a tip 1322. Tip 1322
fits over and seals with an end portion of barrel 1320 and the
barrel and tip cooperate to define inner cavity 134. Barrel 1320
and tip 1322 may be formed of different materials. For example,
barrel 1320 may be formed of an alloy with high surface hardness
for durability. Tip 1322 may be formed of an alloy with high
thermal conductivity.
[0307] A sealing member 140 (FIG. 6B) is positioned within cavity
134. Sealing member 140 is operable to control flow through the
gate orifice 136. Sealing member 140 is sized to occlude and
substantially seal one or both of extruder outlet orifice 122 and
vessel gate orifice 136. As depicted, sealing member 140 has a
shoulder 1402 that contacts and forms a seal with a corresponding
shoulder 1404 of the internal wall of tip 1322. Thus, sealing
member 140 and tip 1322 may seal against one another with axial
facing surfaces, rather than, or in addition to, sealing between
complementary circumferential surfaces of the vessel gate orifice
136 and an end portion of the sealing member 140. Such axial
sealing may be less prone to leakage and wear.
[0308] Sealing member 140 includes an elongate stem, also referred
to as a valve stem, which is axially moveable relative to the gate
orifice 136. Sealing member 140 may be moved by manipulation of the
stem. Specifically, sealing member 140 may be retracted away from
gate orifice 136 to permit flow therethrough, or may be extended to
occlude and seal gate orifice 136. In some embodiments, when fully
extended, sealing member 140 may protrude from vessel 124 and into
outlet orifice 122 of extruder 112. In such embodiments, sealing
member 140 may form seals with both of orifices 136 and 122.
[0309] Vessel 124 also includes an ejection mechanism for forcing
material out of cavity 134. As depicted, the ejection mechanism
includes a piston 182 received within cavity 134 and movable within
the cavity between an extended position in which piston 182 is
proximate orifice 136, and a retracted position (shown in FIG. 6B)
in which piston 182 is displaced away from orifice 136 and cavity
134 is occupied by molding material. Piston 182 is configured to
seal against the inner wall of vessel 124 as the piston moves
between its extended and retracted positions. Thus, piston 182 may
scrape molding material from the inner wall as it moves toward
orifice 136.
[0310] A thermal regulating assembly 1324 may be positioned over at
least a portion of barrel 1320 and tip 1322. As depicted, thermal
regulating assembly 1324 includes a metallic sleeve 1326 and a
heating device, namely, heating coil 1328.
[0311] In the depicted embodiment, sleeve 1326 is a thermal
insulator and inhibits heat loss through underlying surfaces of
barrel 1320 and tip 1322. Sleeve 1326 may, for example, be formed
of an alloy with relatively low thermal conductivity. In other
embodiments, sleeve 1326 may serve as a heat sink, such that it
tends to promote heat transfer out of molding material within
cavity 134.
[0312] Heating coil 1328 is configured to selectively introduce
heat into barrel 1320 and tip 1322, and thereby, into molding
material within cavity 134. Heating coil 1328 may be provided with
contacts 1330, which may be external to sleeve 1326. Contacts 1330
are configured to interface with an external power source to
activate heating coil 1328. The external power source may be
provided at discrete locations. For example, contacts 1330 may
connect with corresponding contacts at a station of dispensing cell
102, shaping cells 104, 106 or conditioning cell 108, or at a
heating station between stations of cells 102, 104, 106, 108.
Alternatively, contacts 1330 may interface with corresponding power
lines along the length of track 144 such that vessel 124 is heated
continuously or throughout a portion of its travel between
stations.
[0313] Sleeve 1326 and heating coil 1328 may be configured to
produce a desired thermal profile in molding material within cavity
134. Sleeve 1326 is positioned proximate tip 1322 and the inlet end
of barrel 1320, and extends toward the base of vessel 124, i.e.
toward the retracted position of piston 182. In some embodiments,
sleeve 1326 does not reach to the retracted position of piston 182.
That is, in some embodiments, in the retracted position of piston
182, sleeve 1326 does not overlie piston 182 or the portion of
barrel 1320 that surrounds the piston 182.
[0314] In an alternative embodiment, not shown, heating of the
vessel 124 may be indirect. For example, the vessels 124 may be
induction heated, wherein the vessel includes a heating jacket
formed of a suitable material, e.g. brass, aluminum, copper or
steel, for coupling with an applied electromagnetic field emanating
from a coil located at a heating station or otherwise arranged
along a path of travel.
[0315] In the depicted embodiment, vessel 124 has an insulator 1332
positioned at the end of tip 1322. A cap 1334 fits tightly over
insulator 1332. Orifice 136 is cooperatively defined by holes in
tip 1322, insulator 1332 and cap 1334, which align with one another
are which are sized to receive sealing member 140.
[0316] Insulator 1332 is formed of a material selected for
sufficient mechanical strength and low thermal conductivity and may
be, for example, plastic, ceramic or metallic. Cap 1334 is formed
of a material selected for relatively high thermal conductivity. As
will be explained in further detail, cap 1334 interfaces with a
mold plate of a station of shaping cell 104, such that cap 1334 is
interposed between the mold and tip 1322 of vessel 124. High
thermal conductivity of cap 1334 promotes heat transfer from the
cap to the mold. Thus, cap 1334 tends to be cooler than tip 1322.
Cap 1334 cools the distal tip of sealing member 140, which in turn
promotes solidification of molding material. Thus, at the end of an
injection operation, the relatively cool cap 1334 and sealing
member 140 tend to promote solidification of residual material in
orifice 136. Such solidification may allow for clean parting of
molded articles. Insulator 1332 tends to inhibit heat transfer
between tip 1322 of vessel 124 and mold. Thus, the portion of tip
1322 and insulator 1332 that surround orifice 136 may remain at a
temperature close to that of the molten molding material, such that
the molding material experiences a large temperature gradient upon
passing through cap 1334. In some embodiments, cap 1334 may have an
internal profile configured to limit surface area of contact
between cap 1334 and tip 1322. For example, cap 1334 may have
ridges or castellation (not shown) to locate cap 1334 relative to
tip 1322 without continuous contact between components.
[0317] Tip 1322, insulator 1332, cap 1334, orifice 136 and sealing
member 140 cooperatively define a coupling assembly for mating of
vessel 124 to stations of the dispensing and shaping cells.
External features such as the outer diameter of cap 1334 and the
shoulder of tip 1322 engage with corresponding locating features of
the shaping or injecting station to position orifice 136 in
alignment with a mold or extruder. The coupling assembly may also
serve to seal vessel 124, e.g. by sealing member 140 sealing
orifice 136.
[0318] In the depicted embodiment, transport subsystem 110
comprises a track 144. Vessel 124 is received in a carriage 125,
which is slidably received on the track 144. Vessel 124 and
carriage 125 may be moved along the tracks, e.g. by pneumatic or
electromagnetic manipulation, or by a mechanical device such as a
belt or chain. Transport subsystem 110 is capable of precisely
indexing the position of each carriage 125 mounted to track 144.
Thus, transport subsystem 110 may align a specific carriage 125 and
vessel 124 with a specific extruder 112, such that gate orifice 136
of vessel 124 aligns with outlet orifice 122 of extruder 112.
[0319] Vessel 124 is movable with carriage 125, towards or away
from extruder 112. In the depicted embodiment, movement of vessel
124 within carriage 125 is in a direction perpendicular to track
144. Carriage 125 may have a channel that defines a seat for the
vessel and for otherwise defining a path of motion of vessel
124.
[0320] Movement of vessel 124 within carriage 125 and operation of
sealing member 140 are affected by an actuator assembly 172.
[0321] Actuator assembly 172 includes a vessel positioning
actuator, a piston actuator 176 and a sealing member actuator
178.
[0322] With vessel 124 in a dispensing (i.e. filling) position
aligned with extruder 112, the vessel positioning actuator is
likewise aligned with vessel 124 and is operable to extend into
contact with vessel 124 and urge the vessel 124 into engagement
with nozzle assembly 113 of extruder 112. So engaged, the outlet
orifice 122 of extruder 112 and the gate orifice 136 of vessel 124
align in fluid communication with one another.
[0323] A piston 182 is movable by piston actuator 176 between an
empty position in which piston 182 is located proximate orifice 136
and a filled position, in which piston 182 is displaced by
feedstock within cavity 134. Piston 182 is biased towards its empty
position, for example, by a spring or by mechanical force from
actuator assembly 172.
[0324] Sealing member actuator 178 is operable to engage and
retract sealing member 140 from gate orifice 136, thereby
permitting flow of molten feedstock through gate orifice 136 and
into cavity 134 of vessel 124. In the depicted embodiment, sealing
member 140 includes a detent 180 for gripping by sealing member
actuator 178, such that sealing member actuator 178 can push
sealing member 140 into sealing engagement with gate orifice 136 or
withdraw the sealing member 140 to permit flow.
[0325] FIGS. 7A-7B show isometric views of vessel 124 and carriage
125. Carriage 125 has a base 1250 configured for mounting to track
144 and a retaining mechanism 1252 for releasably engaging vessel
124 to hold the vessel 124 to the base 1250.
[0326] Retaining mechanism 1252 has grips, e.g. tongs 1254
configured to securely hold vessel 124. In the depicted embodiment,
retaining mechanism 1252 includes two sets of tongs 1254. However,
more or fewer sets may be present. Tongs 1254 are mounted to a
carrier plate 1262, which is in turn mounted to base 1250.
[0327] Tongs 1254 are movable between an open position (FIG. 7A)
and a closed position (FIG. 7B). In the closed position, tongs 1254
retain vessel 124. Such retention may be achieved, for example, by
friction or by interlocking or a combination thereof. In the
depicted embodiment, one set of tongs 1254 interlocks with a
corresponding detent 1255 in the surface of vessel 124. A second
set of tongs 1254 frictionally grips an outer surface of the barrel
1320 of vessel 124. The second set of tongs 1254 is positioned
above a second detent 1256 in vessel 124. As explained in detail
below, detent 1256 is for engaging a locating feature at a
processing station. Tongs 1254 are therefore positioned to avoid
interfering with the locating feature. In the open position,
clearance is provided between tongs 1254 and vessel 124, such that
vessel 124 can freely pass between or be removed from tongs
1254.
[0328] Tongs 1254 may be biased toward a closed position. For
example, tongs 1254 may be biased by a spring assembly 1260. In
some embodiments, spring assembly 1260 may be double-acting such
that, when tongs 1254 are partially opened, e.g. by a threshold
amount, spring assembly 1260 instead biases tongs 1254 to the open
position. Tongs 1254 may be configured so that insertion of vessel
124 between tongs 1254 toggles tongs 1254 to their closed position.
For example, tongs 1254 may have a profile such that insertion of
vessel 124 moves the tongs to an intermediate position between the
open and closed positions, in which spring assembly 1260 biases
tongs 1254 to snap to the closed position. The profile of tongs
1254 may be such that they tend to center vessel 124 as it is
inserted between the tongs. Thus, some horizontal misalignment of
vessel 124 may be tolerated and corrected during seating of the
vessel inside tongs 1254 and closing of the tongs.
[0329] Tongs 1254 and carrier plate 1262 are suspended on base 1250
such that they have some vertical freedom of movement relative to
base 1250. For example, tongs 1254 may be free to move vertically
to align with detent 1255. Such freedom of movement may compensate
for vertical mis-alignment of vessel 124.
[0330] Carrier 125 further includes a closure assembly 1270. In the
embodiment of FIGS. 7A-7B, closure assembly 1270 is mounted
proximate the bottom of base 1250.
[0331] Closure assembly 1270 has a movable arm 1272, which is
movable between a sealing position, shown in FIGS. 7A-7B and an
open position. In the embodiment of FIGS. 7A-7B, in the sealing
position, arm 1272 contacts an end of sealing member 140 and urges
it upwardly toward tip 1322 of vessel 124 to seal orifice 136.
[0332] Referring to FIGS. 8A-8D, a sequence of operations for
dispensing feedstock from extruder 112 to vessel 124 is shown in
detail. FIG. 8A shows a side elevation view of part of extruder 112
and vessel 124 prior to engagement thereof. FIG. 8B shows a side
elevation view of extruder 112 and vessel 124 after engagement and
just prior to dispensing of feedstock. FIGS. 8C-8D show
longitudinal cross-sectional views of extruder 112 and vessel 124
prior to and during dispensing.
[0333] As shown in FIG. 8A, vessel 124 is held in a carriage 125,
movably mounted on track 144. Carriage 125 and vessel 124 are moved
on track 144, into a dispensing position, between a dispensing
nozzle of extruder 112 and actuator assembly 172. The vessel
positioning actuator (not shown) extends to move vessel 124 into
abutment with nozzle assembly 113 of extruder 112, as shown in FIG.
8B.
[0334] As shown in FIG. 8C, sealing member actuator 178 retracts
sealing member 140 to permit flow of feedstock from extruder 112
into vessel 124. Piston 182 is displaced away from extruder 112,
increasing the volume of cavity 134, as molten feedstock flows into
vessel 124. In the depicted embodiment, vessel 124 has a stop (not
shown) which limits displacement of piston 182 and thereby controls
the amount of feedstock that is permitted to flow into vessel 124.
The stop may be adjustable. Alternatively, extruder 112 may include
a metering mechanism. For example, the extruder 112 may include a
pumping device for dispensing a specific preset volume of
feedstock. Screw 116 may itself function as such a pumping device.
For example, rotation of screw 116 may be controlled to dispense a
specific volume. Alternatively, screw 116 may be axially translated
to dispense a specific volume.
[0335] A dose of feedstock is deposited in vessel 124. The
dispensed dose may be referred to as a workpiece 101. As used
herein, workpiece 101 refers to a dose of feedstock throughout its
processing in system 100. Primes of the workpiece, i.e. 101', 101''
denote changes in form of the feedstock dose as it is
processed.
[0336] When filling of vessel 124 is complete, sealing member
actuator 178 extends sealing member 140 to seal gate orifice 136,
as shown in FIG. 8C. The vessel positioning actuator then retracts
and vessel 124 moves away from extruder 112 and into carriage
125.
[0337] A vessel 124 filled with feedstock material may be
transported to a shaping station of shaping cell 104 for a molding
operation.
[0338] In some embodiments, a gate assembly 1130 may be interposed
between nozzle assembly 113 and vessel 124. FIG. 9 shows an
exploded view of nozzle assembly 113 and vessel 124 with gate
assembly 1130. The gate assembly has particular utility when used
in combination with a vessel without a sealing member 140 (FIG.
8B). Gate assembly 1130 may serve to locate orifice 136 of vessel
124 with nozzle assembly 113. Gate assembly 1130 may further serve
to cut a stream of feedstock between nozzle assembly 113 and vessel
124 when filling of vessel 124 is complete.
[0339] Gate assembly 1130 includes a guide block 1132 and a blade
1134. Guide block 1132 has respective recesses 1136 for receiving
and aligning each of nozzle assembly 113 and the tip of vessel 124.
Blade 1134 can be extended through a pocket in guide block to cut
off a stream of feedstock. As depicted, blade 1134 has an arched
cross-sectional shape and is compressed within the pocket of guide
block 1132 such that blade 1134 is biased against nozzle 113. A
scraper 1133 is positioned opposing blade 1134, such that scraper
1133 contacts blade 1134 to dislodge molding material from the
blade.
[0340] Blade 1134 may be extended to cut off a stream of feedstock
when filling of vessel 124 is complete. FIGS. 10A-10B are enlarged
cross-sectional views of nozzle assembly 113, vessel 124 and gate
assembly 1130 during cutting of a feedstock stream.
[0341] As shown in FIG. 10A, a stream of feedstock is dispensed
from nozzle assembly 113 into vessel 124 through orifice 136. When
filling of vessel 124 is complete, blade 1134 is advanced toward
the stream.
[0342] As shown in FIG. 10B, blade 1134 is biased against nozzle
assembly 113. As blade 1134 is advanced into the feedstock stream,
blade 1134 parts the stream. Blade 1134 fits tightly against nozzle
assembly 113 such that feedstock is substantially prevented from
leaking between blade 1134 and nozzle assembly 113. Blade 1134 has
a tab 1138 which extends downwardly into contact with vessel 124.
As blade 1134 advances across vessel 124, tab 1138 scrapes
feedstock away to limit or eliminate residue on the exterior of the
vessel.
Primary Shaping
[0343] With primary reference to FIGS. 11-24, features and
operation of example stations of shaping cell 104 will now be
described in detail. In the depicted embodiments, the example
stations are for injection molding of plastic articles. However,
many features of the described embodiments are not limited to
injection molding, as will be apparent.
[0344] FIGS. 11-12 show an enlarged isometric view and a side
cross-sectional view, respectively, of a shaping station 104-1 of
shaping cell 104. Shaping station 104-1 cycles between an open
state for discharging a molded workpiece and a closed state for
receiving a dose of feedstock to form a molded workpiece 101'. As
shown in FIGS. 11-12, shaping station 104-1 is in an open
state.
[0345] Shaping station 104-1 has a mold defined by a core assembly
190 and a cavity assembly 192. Cavity assembly 192 has two cavity
plates 194-1, 194-2 (individually and collectively, cavity plates
194), mounted to platens 196-1, 196-2 (individually and
collectively, platens 196). Platen 196-1 is mounted to a clamping
mechanism, such as a hydraulic or electro-mechanical piston. Platen
196-1 is movable relative to platen 196-2, the latter of which is
fixedly mounted to a base structure.
[0346] As shown in FIG. 12A, in the open state of shaping station
104-1, platen 196-1 is withdrawn from platen 196-2. Cavity plate
194-2 is aligned with a mold axis M-M and core assembly 190 is
aligned with an ejection axis E-E.
[0347] FIGS. 12B-12D depict components of shaping station 104-1 in
greater detail. In the depicted example, shaping station 104-1
includes a mold subassembly 3040, a clamp subassembly 3042 and a
core actuation subassembly 3044, the latter of which includes a
core positioning actuator 3046 and a load actuator 3050. For
simplicity, core actuation assembly is omitted from FIG. 12D.
[0348] Each of mold subassembly 3040, clamp subassembly 3042 and
core actuation subassembly 3044 are mounted to a shaper frame 3052.
Mold subassembly 3040, clamp subassembly 3042, core actuation
subassembly 3044 and shaper frame 3052 collectively define a shaper
module 3054. The shaper frame 3052 may be removably mounted to a
support base 3056 of shaping station 104-1, such that shaper module
3054 may be installed or removed as a unitary assembly.
[0349] As best shown in FIG. 12C, mold subassembly 3040 may be
opened and closed along multiple axes. That is, platens 196, with
cavity plates 194, may be opened and closed along a clamping axis
C1-C1. Core assembly 190 may be moved towards or away from cavity
plates 194 along core axis C2-C2. Opening and closing along
clamping axis C1-C1 may be affected by clamp subassembly 3042.
Movement of core assembly 190 along core axis C2-C2 may be affected
by core actuation subassembly 3042.
[0350] FIG. 12D shows details of coupling between clamp subassembly
3042 and shaper frame 3052. For simplicity, core actuation
subassembly 3044 is omitted from FIG. 12D.
[0351] Platens 196 may be supported by shaper frame 3052. Platens
196 and shaper frame 3052 may have mating guide features which
maintain position and alignment of platens 196 during opening and
closing. In the depicted embodiment, the guide features include
guide rails 3062 on shaper frame 3052 which matingly receive pins
(not shown) on platens 196. In other embodiments, the guide
features may be interlocking tracks. Other guide structures are
possible, as will be apparent.
[0352] As depicted, platen 196-1 is slidably mounted to support
frame 3052 using the guide features. Platen 196-2 is rigidly
mounted to support frame 3052 in a fixed position. In this
embodiment, clamp subassembly 3042 causes opening and closing by
movement of platen 196-1 relative to platen 196-2 along clamping
axis C1-C1. In other embodiments, opening and closing is achieved
by movement of both platens toward and away from one another.
[0353] Clamp subassembly 3042 includes a multi-bar linkage 3070.
Linkage 3070 includes an anchor block 3072 rigidly mounted to
support frame 3052, and a plurality of pivotably-connected links
coupling a platen 196 to the anchor block 3072. In the depicted
embodiment, the links include a drive link 3074 and first and
second rockers 3076, 3078. Drive link 3074 is coupled to a
crosshead 3080.
[0354] Crosshead 3080 may be reciprocated by a suitable linear
actuator, such as a ballscrew. Drive link 3074 may pivot relative
to crosshead 3080 and relative to rockers 3076, 3078 as the
crosshead moves through its stroke, likewise causing rockers 3076,
3078 to pivot relative to one another to drive platen 196 in either
direction along clamping axis C1-C2.
[0355] Clamp subassembly 3042 has a plurality of pivotable
connections 3082, each of which may be formed by press-fitting a
pin and a bushing (not shown) through holes in the links or in
support frame 3052. Other connection types may be used, provided
they have sufficient strength and provide adequate range of
motion.
[0356] Anchor block 3072 is mounted to support frame 3052 such that
the center axis of anchor block 3072 aligns with the center axis of
support frame 3052. Guide rails 3062 maintain the position of
platen 196 such that the center axis of platen 196 aligns with the
center axis of support frame 3052. Thus, anchor block 3072 and
platen 196 are coupled to linkage 3070 at the center axes of anchor
block 3072, platen 196 and support frame 3052. In other words,
pivotable connection 3082 between the anchor block 3072 and rocker
3076 is located along the center axis of anchor block 3072 and
along the center axis of support frame 3052. Likewise, pivotable
connection 3082 between platen 196 and rocker 3078 is located along
the center axis of anchor block 3072 and along the center axis of
support frame 3052.
[0357] Movement of crosshead 3080 causes platens 196 to move
between open and closed positions. In the closed (molding)
position, a clamping force may be applied through crosshead 3080
and linkage 3070 to urge the platens together. The clamping force
may be substantial--in some embodiments, the clamping force may be
on the order of 300 kN. As will be apparent, a reaction force is
applied to support frame 3052. In the depicted embodiment, platen
196 and anchor block 3072 are loaded substantially in pure
compression, and that support frame 3052 is loaded substantially in
pure tension because linkage 3979 is coupled to platen 196 and
anchor block 3072 at the center axis of platen 196, anchor block
3072 and frame 3052. In contrast, location of any of the pivotable
connections away from the center of a given component could produce
significant shear force or bending moment. For example, platens in
conventional injection molding machines tend to be closed by rams
(e.g. hydraulic rams or ball screws) positioned proximate the
corners of a platen. Exerting of clamping force in such
configurations may produce a bending moment in the platens and may
in some cases lead platens to deflect.
[0358] In some embodiments, the stroke length between the open and
closed positions of platen 196 is relatively short. The length of
the stroke is influenced by the amount of clearance required to
remove (de-mold) a finished part. De-molding may be possible with a
relatively small opening along an axis perpendicular to the
longitudinal axis of the part. Thus, some example embodiments have
a mold-opening stroke on the order of 60-120 mm. Conversely, if
parts were to be de-molded by opening along the longitudinal axis
of the part, a longer opening stroke may be required, to create a
larger amount of clearance.
[0359] Other linkage configurations are possible. For example, in
some embodiments, the linkage may include one or more rockers which
are pivotably connected to support frame 3052. FIGS. 13A-13C show a
linkage 3070' exemplary of such a configuration.
[0360] Linkage 3070' has a drive link 3074' anchored to a linear
actuator 3088 (as shown, a ball screw driven by an electric motor)
with one or more intermediate links 3086. Drive link 3074 is
mounted on a linear guide 3090. As depicted, the linear guide
constrains drive link 3074' to move in a single direction, namely,
vertically. Specifically, linear actuator 3088 reciprocates
horizontally, and intermediate links 3086 pivot to move the drive
link through reciprocating vertical path I-I defined by linear
guide 3090 (FIG. 13B).
[0361] Drive link 3074' is pivotably connected to two rockers
3076', 3078' by way of further intermediate links 3086. Each rocker
3076', 3078' is mounted to a respective platen 196 for driving the
platen through a reciprocating open-close motion. Each rocker
3076', 3078' is pivotably mounted to support frame 3052.
Reciprocation of drive link in direction I-I (FIG. 13B) causes
rockers 1-76', 3078' to pivot about their connection to support
frame 3052, i.e. in direction II-II. Such pivoting in turn drives
reciprocation of platens 196 along direction III-III. The position
and orientation of platens 196 during such reciprocation is
maintained by guide rails 3062 on support frame 3052. FIG. 13C
shows an example loading state of linkage 3070' and support frame
3052 when platens 196 are in a mold-closed position. As depicted,
drive link 3074' applies a force to rockers 3076', 3078'. The
rockers 3076', 3078' pivot to around their connections to drive
platens 196 together and apply a clamping force against the
platens. Because rockers 3076', 3078' pivot about their midpoints,
the clamping force and the force applied by drive link 3074 are
substantially equal in magnitude. Equal reaction forces are applied
against rockers 3076', 3078', which are resisted by support frame
3052. Transfer of forces between rockers 3076', 3078' and support
frame 3052 occurs at pivotable connections 3082, which are located
at the center axis of support frame 3052. Accordingly, application
of clamping force loads support plate 3052 substantially in pure
tension.
[0362] The length of the opening/closing stroke of platens may be
determined by geometric specifications of linkage 3070'.
Specifically, the stroke may be determined by a combination of the
lengths of drive link 3074', rockers 3076', 3078', intermediate
link 3086, and the length of stroke of linear actuator 3088.
[0363] In some embodiments, the linkage may be configured to
maintain position and alignment of platens 196 without the use of
guiding structures such as guide rails 3082. FIGS. 14A-14B show an
example of one such linkage 3070''.
[0364] Linkage 3070'' is generally identical to linkage 3070',
except that linkage 3070'' further includes secondary rockers 3096,
3098, and that support plate 3052' is somewhat larger than support
plate 3052 in order to accommodate the extra rockers.
[0365] Secondary rocker 3096 cooperates with rocker 3076' to
control a first platen 196 and secondary rocker 3098 cooperates
with rocker 3078' to control a second platen 196. Each pair of
rockers constrains the position and alignment of platens 196 during
opening and closing. Secondary rockers 3096 and 3098 are connected
at one end to drive link 3074' and at the other end to an
intermediate link 3086, which is also connected to the
corresponding rocker 3076'/3078' and to a platen 196. The multiple
connections between platens 196 and support frame 3052 hold platens
192 square to support frame 3052 and to one another. Likewise,
rockers 3076'/3078' and secondary rockers 3096/3098 cooperate to
align the positions of platens 196 at the end of the closing
stroke.
[0366] In some embodiments, the clamp assembly 3042 may be driven
by a rotary actuator rather than a linear actuator. For example,
clamp assembly 3042 may be driven by the crank of an electric
motor. FIGS. 15A-15B show a linkage 3070''' exemplary of such an
embodiment. Linkage 3070' is generally similar to linkage 3070',
but drive link 3074' is replaced by a rotor 3100. Rotor 3100 is
driven by a crank shaft, e.g. a crank shaft of an electric motor.
Rotor 3100 may be coupled to the crank shaft by way of a gearset,
such as a planetary gearset, to provide a suitable speed
reduction.
[0367] Rotor 3100 is driven to rotate around its midpoint, and the
ends of rotor 3100 are coupled to rockers 3076', 3078' by way of
intermediate links 3086, such that rotation of rotor 3100 causes
rockers 3076', 3078' to pivot about their connections 3082 to
support frame 3052. When the mold is closed and clamping pressure
is applied to platens 196, rockers 3076', 3078' and support frame
3052 are subjected to a loading condition similar to that of FIG.
13C. That is, the clamping force is equivalent to the force exerted
on rockers 3076', 3078' by rotor 3100 and intermediate links 3086,
and support frame 3052 is loaded substantially in pure tension.
[0368] Linkage 3070' may be relatively easily adjustable. For
example, the length of rotor 3100 and its associated intermediate
links 3086 may be changed to adjust the length of the
opening/closing stroke of platens 196. Increasing the length of
rotor 3100 may increase the stroke. Clamping force may be adjusted
by changing the length of rockers 3076', 3078' or by changing the
torque applied to rotor 3100 (e.g. by changing ratio of the set to
which it is coupled). Accordingly, linkage 3070''' may be
relatively easily adapted for use with a range of molds.
[0369] Embodiments may include combinations of features of the
above-described crank assemblies and linkages. For example, FIG. 16
shows a linkage which includes a crank-driven clamp assembly and
has multiple rockers connected to each platen to provide positional
stability.
[0370] In the embodiments depicted in FIGS. 12-15, rockers 3076',
3078' are mounted to support frame 3052 at their midpoint, so that
they rotate symmetrically. In some embodiments, the pivot point may
be off-center. For example, the pivot point may be moved closer to
the driven end of the rockers 3076', 3078' in order to increase the
clamping force or to increase the length of the opening-closing
stroke. Conversely, the pivot point may be moved closer to the
opposite end to decrease the clamping force or stroke length.
[0371] As depicted in FIGS. 13-16, linkages 3070', 3070'' and
3070''' of clamp subassembly 3042 act on both platens 196 to move
them towards and away from one another. In other embodiments, the
clamp subassembly may be configured to act on a single movable
platen 196, while the other platen 196 is fixed. For example, drive
link 3074' or rotor 3100 may be coupled to only a single rocker and
platen 196.
[0372] With reference to FIGS. 17, 18A-18B, 19, 20 and 21A-21B,
components of core actuation subassembly 3044 are shown in greater
detail. Core actuation subassembly 3044 is configured to move core
assembly 190 along a core axis. In the depicted embodiment, core
actuation subassembly 3044 comprises a core positioning actuator
3046 operable to move core assembly 190 through a first stroke
between molding (closed) and de-parting (open) positions. Core
positioning actuator 3046 may be mounted to a secondary mold
opening actuator 3180. Core actuation subassembly 3044 further
comprises a load actuator 3050 operable to exert force on core
assembly 190 and move core assembly 190 through a shorter stroke to
initiate de-parting after molding and to resist molding forces.
FIGS. 18A-18B show isometric and cross-sectional views,
respectively, of core positioning actuator 3046.
[0373] Core positioning actuator 3046 has a primary frame 3102 for
securing to support frame 3052. Core positioning actuator further
includes a loading frame 3104 positioned atop primary frame 3102.
In the depicted embodiment, loading frame 3104 is mounted to
primary frame 3102 using locating pins, such that loading frame
3104 may be moved vertically relative to primary frame 3102 while
maintaining alignment.
[0374] Core positioning actuator 3046 may include one or more
pneumatic pistons 3108 for moving loading frame 3104 relative to
primary frame 3102. As best shown in FIG. 18B, pneumatic pistons
3108 are mounted to loading frame 3104 and act against primary
frame 3102 to move loading frame 3104 towards or away from primary
frame 3102. As depicted, pistons 3108 are coupled to an
intermediate structure, namely pins 3110. In other embodiments,
pistons 3108 may be coupled directly to primary frame 3102. Two
hydraulic pistons 3108 are shown in FIG. 18B, however, any number
of pneumatic pistons may be present. In some embodiments, other
suitable linear actuators may be used instead of or in addition to
pneumatic pistons. Primary frame 3102 has a central opening sized
to receive core assembly 190. Core assembly 190 is mounted to
loading frame 3104 and extends through the central opening. Core
assembly 190 includes an inner core 3112 and an outer core 3114.
During molding, inner core 3112 defines the inside surface of the
part to be molded. Outer core 3114 seals the top of the mold
defined by core assembly 190 and cavity assembly 192.
[0375] Inner core 3112 is mounted to loading frame 3104 and is
received within outer core 3114 such that inner core 3112 is
movable relative to outer core 3114. Specifically, inner core 3112
is movable relative to outer core 3114 along the core axis by
motion of loading frame 3104. Outer core 3114 is fixedly mounted to
primary frame 3102 by a retaining assembly 3116 which engages a
flange 3118 of the outer core. Thus, relative movement of frames
3102, 3104 likewise causes relative movement of inner and outer
cores 3102, 3104. After molding of a part, loading frame 3104 may
be moved away from primary frame 3102, causing retraction of inner
core 3112 to release the molded part.
[0376] A locating pin assembly 3120 is positioned on primary frame
3102 to align loading frame 3104 and primary frame 3102 (and thus,
to align inner core 3112 with outer core 3114 and core assembly 190
with central opening 3106).
[0377] Locating pin assembly 3120 includes a pin 3122 and a
pneumatic piston 3124. When loading frame 3104 is spaced apart from
primary frame 3102, piston 3124 may extend pin 3122. Loading frame
3104 may have a recess (not shown) sized and positioned for
registration with pin 3122. Thus, when loading frame 3104 is
lowered against primary frame 3102 for molding, pin 3122 may
register with the recess, guiding frame 3104 into proper
alignment.
[0378] Referring again to FIG. 18A, loading frame 3104 defines an
interlocking aperture 3130. Locking aperture 3130 is sized and
positioned to engage a corresponding interlocking feature of
loading actuator 3050.
[0379] FIG. 19 depicts loading actuator 3050 in greater detail.
Loading actuator 3050 includes a base plate 3140 and a moving plate
3142. Moving plate 3142 is movable relative to base plate 3140 and
one or more guide rods 3144 are mounted to base plate 3140 and
received in corresponding openings in moving plate 3142 to guide
motion of the moving plate.
[0380] Loading actuator 3050 has a drive assembly 3146 comprising a
motor 3148, gearset 3150, and rocker 3152. Motor 3148 is coupled to
rocker 3152 through gearset 3150 and a camshaft 3154 to cause
rotation of and impart torque on rocker 3152. Moving plate 3142 is
mounted to one end of rocker 3152 and base plate 3140 is mounted to
the other end of rocker 3152.
[0381] Rocker 3152 may be rotated by motor 3148 through gearset
3150 and camshaft 3154 to move moving plate 3142 relative to base
plate 3140. Guide rods 3144 constrain the movement to a vertical
axis, i.e. core axis.
[0382] FIG. 20 is a cutaway view of load actuator 3150 showing
coupling of motor 3148, gearset 3150 and camshaft 3154, to move
rocker 3152 and plates 3140, 3142 in greater detail. As depicted, a
camshaft 3154 is supported on moving plate 3142. Camshaft 3154 is
received through one end of rocker 3152. Ends of camshaft 3154 are
received in fittings 3155 in movable plate 3142. Rocker 3152
supports moving plate 3142 by way of camshaft 3154 and fittings
3155.
[0383] The opposite end of rocker 3152 is mounted to base plate
3140 by a retainer shaft 3160. Retainer shaft 3160 is received by a
pair of blocks 3162 which are rigidly fixed to base plate 3140.
[0384] Camshaft 3154 is supported by bearings 3164 within rocker
3152 and within fittings 3155. Likewise, retainer shaft 3160 is
supported by bearings 3166 within blocks 3162. Camshaft 3154 and
retainer shaft 3160 may therefore rotate relative to plates 3140,
3142 with relatively little resistance.
[0385] Camshaft 3154 is rotationally coupled to gearset 3150 (not
shown) by way of a coupling 3156. Gearset 3150 may be configured to
drive camshaft to rotate with relatively low speed and relatively
high torque. Camshaft 3154 has an offset lobe such that the radius
to from the center of rotation of shaft 3154 to the outside of its
offset lobe is greater than the radius from the center of rotation
to any other part on the periphery of the crankshaft. As crankshaft
3154 turns with gearset 3150, its offset lobe engages with a
bearing 3166 within rocker 3152. As the offset lobe falls, camshaft
3154 bears against rocker 3152 and urges moving plate 3142
upwardly. As the offset lobe falls, rocker 3152 and moving plate
3142 are allowed to fall.
[0386] As shown in FIG. 19, a measurement device, namely, proxy
bracket 3170 may be installed to provide an indication of the
position of camshaft 3154. Proxy bracket 3170 is fixed to base
plate 3140 and extends upwardly past camshaft 3154. A sensor 3172
is mounted to proxy bracket 3170 and provides a signal
representative of the rotational position of camshaft 3154.
Alternatively or additionally, a sensor may provide a signal
representative of the vertical position of moving plate 3142.
Alternatively or additionally one or more position transducers
could be mounted between base plate 3140 and moving plate 3142 to
provide a signal representative of the relative positions of the
plates.
[0387] As best shown in FIGS. 19 and 21A-21B, moving plate 3142 has
projections 3174 for engaging loading frame 3104 of core
positioning actuator 3046. Projections 3142 are sized, shaped and
positioned for engagement with interlocking recess 3130 defined by
loading frame 3104. With the mold in a closed position, projections
3174 are received in recess 3130. Projections 3174 have
upward-facing surfaces 3176 which abut corresponding surfaces of
loading frame 3104 in the mold-closed position. In the depicted
embodiment, upward-facing surfaces 3176 are inclined, such that
they may bear on the corresponding surfaces of loading frame 3104
during closing and guide the projections 3174 into mating alignment
with the recess 3130. Projections 3174 further include
downward-facing surfaces 3178 which abut corresponding faces of
loading frame 3104.
[0388] Movement of moving plate 3142 while projections 3174 are
received in apertures 3130 causes projections 3174 to bear against
frame 3104. Specifically, upward movement of moving plate 3142
causes surfaces 3176 to bear against frame 3104, urging the frame
upwardly. Downward movement of moving plate 3142 causes surfaces
3178 to bear against frame 3104, urging the frame downwardly.
[0389] Rotation of camshaft 3154 may therefore selectively cause an
upward or downward force to be exerted against frame 3104, in turn
causing frame 3104 to move through a short stroke. Rotation of
camshaft 3154 to urge plate 3142 upwardly by way of rocker 3152
(FIG. 20) causes a short upward movement of frame 3104, and
therefore, a short upward movement of inner mold core 3112 (FIG.
18B). Such upward movement may serve to dislodge or break a seal
between a molded part and mold core 190.
[0390] The depicted configuration may eliminate the need for a
separate stripper plate to remove molded articles, and may thus
reduce mechanical complexity of the molding apparatus relative to a
typical configuration including a stripper plate.
[0391] Rotation of camshaft 3154 to urge plate 3142 downwardly by
way of rocker 3152 (FIG. 20) causes a downward force to be exerted
on frame 3104 and a short downward movement of frame 3104. The
force and short movement are transferred to inner mold core 3112
and may function as a pre-load to resist pressure exerted by
molding material against mold core 190 during molding.
[0392] Core positioning actuator 3046 may be mounted to one of
platens 196. Loading actuator 3050 may be mounted to the other of
platens 196. Loading actuator 3050 may be rigidly mounted, such
that base plate 3140 does not move relative to the platen 196 to
which it is mounted.
[0393] Core positioning actuator 3046 may be mounted by way of a
secondary mold opening actuator 3180, shown in FIGS. 17 and 22.
Secondary mold opening actuator 3180 includes one or more blocks
3182 rigidly mounted to a platen 196. Secondary mold opening
actuator 3180 further includes a pneumatic cylinder 3186 carried on
a plate 3184 mounted to the block 3182. Pneumatic cylinder 3186 has
a coupling 3190 for fixation to primary frame 3102 of core
positioning actuator 3046. Pneumatic cylinder 3186 is operable to
move core positioning actuator between a retracted position in
which the mold core 190 is located in its molding position relative
to the mold cavity portions, and an extended position in which it
is spaced apart from the mold cavity portions for removal of molded
parts.
[0394] As noted, shaper module 3054 may be capable of installation
or removal from support base 3056 of shaping station 104-1 as a
unitary assembly. Installation and removal features of shaper
module 3054 are shown in greater detail in FIGS. 23A-23C.
[0395] In the depicted embodiment, the shaper module 3054 includes
a drive unit, namely, electric motor 3190. When installed in an
operational position, there may be insufficient clearance between
components of shaper module 3054 and support base 3056 to remove
shaper module 3054. Likewise, there may be insufficient clearance
to remove mold components. Accordingly, shaper module 3054 includes
a position adjustment mechanism 3192 operable to move the shaper
module 3054 relative to support base 3056 along an adjustment axis
indicated as A-A in FIG. 23A. Shaper module 3054 may be moved
between an operational position, as depicted in FIGS. 12A-12D, and
a removal position, in which shaper module 3054 can pass without
interference through a removal opening 3194 defined by support base
3056. As depicted, adjustment axis A-A is parallel to the
longitudinal axis of shaper frame 3052. However, in some
embodiments, shaper module 3054 may be adjustable along a different
axis, or along multiple axes. Likewise, in the removal position, a
mold may be removed and replaced. That is, the mold may be removed
from shaper module without contacting support base 3056.
Accordingly, such removal and replacement may be affected
automatically, e.g. using a robot
[0396] Once in its removal position, shaper module 3054 may be
removed from base 3056. For example, a lifting tool such as a crane
or a lift truck may engage couplings on shaper module 3054. In an
example, the couplings may be hooks rigidly mounted to shaper frame
3052 for secure engagement by a crane. The lifting tool may remove
the shaper module by vertical or horizontal translation or a
combination thereof.
[0397] As shown in FIG. 23C, support base 3056 may include one or
more guide blocks 3196 for locating the shaper module 3054 in its
operational position. Shaper module 3054 may include corresponding
locking pins 3195, rigidly mounted to shaper frame 3052. Locking
pins 3195 may selectively engage guide blocks 3196 to prevent
movement of shaper module 3054 relative to support base 3056.
Locking pins may be operated, for example, by an electric motor or
using manual tools. Other modes of actuation are possible, such as
pneumatic.
[0398] FIG. 23C shows adjustment mechanism 3192 in greater detail.
As depicted, adjustment mechanism has a linear actuator, such as
ballscrew 3197, positioned between two anchor plates 3198. One
anchor plate 3198 abuts support base 3056 and the other is rigidly
coupled to shaper frame 3052. Actuation of the ballscrew 3197 in a
first direction pushes the anchor plates 3198 away from one
another, such that shaper module 3054 moves relative to support
base 3056 in a first direction along the adjustment axis. Actuation
of the ballscrew 3197 in the opposite direction moves shaper module
3054 relative to support base 3056 in the opposite direction along
the adjustment axis.
[0399] In some embodiments, adjustment mechanism 3192 may be
configured such that shaper module is in its operational position
at either the maximum extension or the minimum extension of
ballscrew 3197, and the shaper module 3054 is in its removal
position at the other of the maximum extension and the minimum
extension of ballscrew 3197. Alternatively or additionally,
adjustment mechanism may be equipped with a sensor to report the
position of shaper module 3054 to confirm when it is in its
operational and removal positions. For example, ballscrew 3197 may
be driven by an electrical motor with a position encoder, or the
position may be measured by a sensor such as an optical, mechanical
or magnetic sensor.
[0400] Installation and removal of shaper module 3054 as a unitary
assembly may permit relatively easy changes of tooling in shaping
station 104-1. For example, if it is desired to change a mold, the
associated clamping assembly, drive unit and core actuation
assembly may be removed as a unit with the mold, and a new unit may
be installed to base 3056. Mold-specific setup may be minimized or
eliminated entirely. For example, because a clamping assembly may
remain assembled to a mold after removal from base 3056, it could
be reinstalled without requiring adjustments for mold shut height
or the like.
[0401] In the closed state of shaping station 104-1 (FIG. 12B,
FIGS. 29B-29F), core assembly 190 is aligned to axis M-M and cavity
plates 194-1, 194-2 are clamped together by platens 196-1, 196-2.
Core assembly 190 and cavity plates 194-1, 194-2 collectively form
a mold 200 for producing a molded workpiece from molten feedstock
material. Core assembly 190 defines an inner surface of the molded
workpieces. Cavity plates 194-1, 194-2 collectively define the
outer surface of the molded workpiece. Mold 200 has an inlet gate
202, aligned with axis M-M.
[0402] Track 144 of transport subsystem 110 passes through an
injection position aligned with mold axis M-M.
[0403] FIGS. 24A-24T depict an alternate shaper module 3054'. As
shown in FIGS. 12-23, shaper module 3054 is configured so that mold
opening and closing is affected by linkage 3070, 3070', 3070'',
3070' pivoting about a horizontal axis. As depicted in FIGS.
24A-24L, shaper module 3054' is configured so that its linkage
generally lies in a horizontal plane and pivots about a vertical
axis.
[0404] Shaper module 3054' is supported by a tower structure 7000,
depicted in greater detail in FIGS. 24C-24F Shaper module 3054' has
a support plate 3052' that is structurally identical to the support
plate of shaper module 3054, except that it is mechanically
suspended on tower structure 7000 and is oriented in a vertical
plane.
[0405] Shaper module 3054' has a mold subassembly 3040', a clamp
subassembly 3042' including a linkage 3070'''', and a core
actuation subassembly 3044'.
[0406] Like mold subassembly 3040, mold subassembly 3040' may be
opened and closed along multiple axes, namely, vertical and
horizontal axes. Specifically, platens 196 and mold cavity plates
194 open and close along clamping axis C1-C1 and core assembly 190
is movable along core axis C2-C2. In the depicted embodiment, core
axis C2-C2 is vertical. Accordingly, with reference to this
embodiment, "up" refers to a direction along core axis C2-C2 away
from mold cavity plates 194, and "down" refers to a direction along
core axis C2-C2 toward cavity plates 194. However, other
orientations of shaper module 3054' are possible. For example, in
some embodiments, shaper module 3054' could be rotated 90 degrees
such that clamping axis C1-C1 and core axis C2-C2 lie in a common
horizontal plane.
[0407] Mold cavity plates 194 and mold core 190 lie within a
bounding envelope E between platens 196. The ends of the bounding
envelope are defined by platens 196. The top and bottom of the
bounding envelope are defined by the top and bottom edges of
platens 196, and the lateral sides of the bounding envelope are
defined by the sides of platens 196.
[0408] Throughout molding and throughout movement of platens 196
through their opening-closing stroke, mold cavity plates 194 lie
entirely within the bounding envelope.
[0409] The tower structure 7000, shaper frame 3052', and linkage
3070'''' are located on one side of bounding envelope E. That is,
all of the tower structure 7000, shaper frame 3052' and linkage
3070'''' are adjacent the same lateral side of bounding envelope E.
Conveniently, the opposite lateral side of bounding envelope E is
substantially unobstructed, as is the bottom of bounding envelope
E.
[0410] FIG. 24B is a top elevation view of shaper module 3054',
showing linkage 3070'''' in greater detail. Linkage 3070''''
includes a pair of drive links 3074 and rockers 3076, 3078.
[0411] Each drive link 3074 is pivotably supported at one end by
tie bars 7002 of tower structure 7000, and is pivotably connected
at the other end to a rocker 3076 or 3078. Drive links 3074 are
coupled to and reciprocated through a stroke by a drivetrain 7006.
Drivetrain 7006 is supported on tower structure 7000 and may
include an electric motor and one or more gear reductions.
[0412] Each of rockers 3076, 3078 is pivotably attached to one of
drive links 3074 at one end, and to a respective platen 196 at the
other end. In the depicted embodiments, rockers 3076, 3078 are
connected to platens 196 by way of intermediate links 3086. Rockers
3076, 3078 are supported on tie bars 7002 of tower structure 7000
at pivotable connections 3082, so that drive links 3074 cause
rockers 3076, 3078 to rotate around pivotable connections 3082. As
depicted, pivotable connections 3082 are approximately at the
mid-point of rockers 3076, 3078, but could be located at a
different positions along the length of the rockers. Moving the
pivotable connection 3082 toward the connection with drive link
3074 would result in a longer stroke of platen 196 while the rocker
is rotated. Conversely, movement of the pivotable connection 3082
away from the drive link 3074 would result in a shorter stroke of
platen 196.
[0413] FIGS. 24C-24F depict tower structure 7000 in greater detail.
FIG. 24C is an isometric view of shaper module 3054' from a rear
perspective, opposite the mold. FIG. 24D is an isometric view of
shaper module 3054' from a front perspective, with components other
than tower structure 7000 and shaper frame 3052' omitted. FIGS.
24E, 24F are cross-sectional views of tower structure 7000 along
planes E-E and F-F shown in FIG. 24B.
[0414] Tower structure 7000 includes a pair of vertical columns
7010. Columns 7010 are supported on a base (not shown) and bear the
weight of components of tower structure 7000 and of mold assembly
3040', clamping assembly 3042' and core actuation assembly
3044'.
[0415] Shaper frame 3052' is coupled to columns 7010 by way of
mounting blocks 7012. Shaper frame 3052' is oriented in a vertical
plane. Tracks 7024 are mounted to shaper frame 3052'. Tracks 7024
are configured to slidably support platens 196. Tracks 7024 are
oriented in a vertical plane, such that connections between platens
196 and shaper frame 3052' are likewise in a vertical plane.
[0416] As will be apparent, platens 196 hang on tracks 7024. Tracks
7024 are therefore configured to interlock with platens 196 in
order to retain the platens. For example, platens 196 may have
runners with cross-sectional shapes that interlock with the
cross-sectional shapes of tracks 7024.
[0417] Tower assembly 7000 further includes tie bars 7002.
Components of linkage 3070'''' of clamping assembly 3042' are
coupled to tie bars 7002. For example, drivetrain 7006 is partly
supported by tie bars 7002. A rotor 7007 of drivetrain 7006, which
is directly coupled to drive links 3074, is rotatably mounted
between tie bars 7002. Rockers 3076. 3078 are also rotatably
mounted between tie bars 7002. Pivotable connections 3082 at which
rockers 3076, 3078 are connected to tie bars 7002, permit rotation
of the rockers, but substantially prevent translation of the
rockers in any direction. Thus, stresses such as tensile or
compressive stresses may be transferred between the rockers and the
tie bars.
[0418] In the depicted embodiment, tie bars 7002 are not coupled
directly to columns 7010. Rather, tie bars 7002 are mounted to a
support block 7020. As shown in FIGS. 24E-24F, support block 7020
is positioned between tie bars 7002, abutting both of tie bars 7002
and shaper frame 3052. Support block 7020 braces tie bars 7002
relative to one another and relative to shaper frame 3052'.
Fasteners 7022 are inserted through tie bars 7002 and received in
support block 7020 to secure the tie bars against the support
block. A second set of fasteners 7024 is inserted through shaper
frame 3052' to secure the tie bars against shaper frame 3052'. As
noted, shaper frame 3052' is in turn coupled to towers 7010 by way
of mounting blocks 7012. Thus, tie bars 7002 are coupled to shaper
frame 3052' by way of support block 7020, and to columns 7010 by
way of support block 7020 and shaper frame 3052.
[0419] FIGS. 24G, 24H are cut-away and cross-sectional views,
respectively, showing details of mold assembly 3040', clamping
assembly 3042' and core actuation assembly 3044'.
[0420] Mold assembly 3040' has a pair of platens 196 movable by
linkage 3070' toward and away from one another in a closing stroke
and an opening stroke, respectively. Platens 196 are supported on
tracks 7024 on shaper frame 3052. Platens 196 and tracks 7024 may
be configured to interlock, such that platens 196 hang securely
from tracks 7024, and can move freely along the tracks. For
example, platens 196 may have runners which interlock with the
tracks.
[0421] A mold cavity plate 194 is mounted to each platen. With
platens 196 in a mold-closed position (FIG. 24A), mold cavity
plates 194 abut one another to cooperatively define a mold
cavity.
[0422] During molding, rockers 3076, 3078 exert a clamping pressure
on platens 196 and mold assembly 3040' by way of intermediate links
3086. Clamping pressure generally acts along clamping axis C1-C1. A
reaction force is applied to tie bars 7002 by way of rockers 3076,
3078 at pivotable connections 3082. This in turn causes a load to
be transferred to shaper frame 3052' at pivotable connections
3082.
[0423] Because linkage 3070'''' is symmetrical, equal forces are
applied to shaper frame 3052' by rockers 3076, 3078. Shaper frame
3052' experiences strain due to the tensile force applied by the
rockers. That is, shaper frame 3052' tends to elongate in the
direction of clamping axis C1-C1 due to tension.
[0424] In contrast, columns 7010 generally do not deflect during
molding. Shaper frame 3052' is therefore coupled to columns 7010 so
as to limit the deflection of shaper frame 3052' relative to
columns 7010 at the points of attachment.
[0425] For example, elongation of shaper frame 3052' due to tensile
stress during clamping is most pronounced at the ends of shaper
frame 3052'. In other words, a feature at an end of shaper frame
3052' may move more between stressed and un-stressed conditions of
shaper frame 3052' than would a feature located at the center of
shaper frame 3052'.
[0426] Thus, fasteners 7024 couple shaper frame 3052 to support
block 7020 near the center of shaper frame 3052 in order to limit
stress due at the connections.
[0427] A mold core assembly 190 is positioned between mold cavity
plates 194 and defines the mold core when cavity plates 194 are in
their closed position. Mold core assembly 190 substantially does
not move in the direction of the clamping axis C1-C1, but can be
moved along a perpendicular core axis C2-C2.
[0428] Mold core assembly 190 includes an outer core 7030 and an
inner core 7032. The outer core 7030 is generally annular in
cross-section, and the inner core 7030 is received through the
outer core and is movable relative to outer core 7030 along core
axis C2-C2.
[0429] A core cap 7034 is positioned atop inner core 7032 and is
coupled to inner core 7032 by way of a mounting block 7035.
Coupling of inner core 7032 to core cap 7034 is achieved using
quick-connect couplings 7037 (FIGS. 24R-24S). For example, the
quick-connect couplings 7037 may be controlled by a locking device
(not shown). With the locking device engaged, couplings 7037 retain
the core such that it cannot move relative to core cap 7034.
However, the locking device may be disengaged to release the
connection of the core to core cap 7034. Movement of core cap 7034
selectively applies or releases a preload force against outer core
7030 and inner core 7032.
[0430] As best shown in FIG. 24G, in the depicted embodiment, a
locking device 7031 includes an actuator, namely a piston 7038 that
can be selectively extended or retracted (e.g. by electronic or
pneumatic control). Extension or retraction of piston 7038 causes
extension or retraction of a locking block 7039. In an extended
(locked)_position, locking block 7039 interlocks with a flange of a
retaining device 7041 fixed to mounting block 7035. Interlocking of
block 7039 and retaining device 7041 prevents movement of core cap
7034, mounting block 7035 and retaining device 7041, relative to
locking device 7031.
[0431] Inner core 7032 and outer core 7030 mate to a core support
block 7042, which is in turn fixedly mounted to shaper frame
3052.
[0432] Core cap 7034 is movable by actuators 7046. In the depicted
example, two actuators 7046 are present. However, in other
embodiments, more or fewer actuators could be used.
[0433] In the depicted example, actuators 7046 are roller screws
driven by electric motors. However, other types of linear actuators
may be used, such as pneumatic or hydraulic cylinders.
[0434] Each actuator 7046 includes a housing 7048 and an output
shaft 7050. Housing 7048 is rigidly coupled to a floating support
plate 7052. Output shaft 7050 is coupled to housing 7048 and to a
fixed support plate 7054.
[0435] Each fixed support plate 7054 is rigidly coupled (e.g.,
bolted) to respective platen 196. Each floating support plate 7052
is free to move relative to the corresponding fixed support plate
7054 in both directions along core axis C2-C2.
[0436] Movement of floating plates 7052 relative to fixed plates
7054 is caused by operation of actuators 7046. Specifically,
extension of output shaft 7050 pushes housing 7048 and floating
plate 7052 away from fixed plate 7054 and the platen 196 to which
it is mounted. Conversely, retraction of output shaft 7050 pulls
floating plate 7052 toward the corresponding fixed plate 7054 and
the platen 196 to which it is mounted. One or more guide rods 7056
may be mounted to each fixed plate 7054 and extend through a
corresponding slot in floating plate 7052 in order to constrain
movement of floating plate 7052 relative to fixed plate 7054.
Specifically, guide rods 7056 are parallel to core axis C2-C2 and
constrain movement of floating plate 7052 to be parallel to that
axis.
[0437] Because actuators 7046 and fixed plates 7054 are mounted to
platens 196, they move along with the platens as clamping assembly
3042' is opened and closed. Thus, actuators 7046 move relative to
core assembly 190 and core cap 7034 along clamping axis C1-C1.
[0438] A lifter 7058 may extend between floating plate 7052 and
core cap 7034. Lifter 7058 couples floating plate 7052 and core cap
7034 in the direction of the core axis. In other words, lifter 7058
and floating plate 7052 engage one another so that movement of the
lifter in either direction along core axis C2-C2 causes movement of
core cap 7034 in the same direction, the connection between lifter
7058 and floating plate 7052 is slidable, such that floating plate
7052 can move along clamping axis C2-C2 while the lifer and the
floating plate remain engaged with one another.
[0439] As best shown in FIG. 24A, lifter 7058 has a pair of arms
7059 and an extension of floating plate 7052 is received between
the arms in a vertically interlocking relationship. In other
embodiments, lifter 7058 may be permanently fixed to floating plate
7052 and project towards core cap 7034. In the depicted embodiment,
lifter 7058 is a discrete structure that is coupled to core cap
7034. However, lifter 7058 may be integrally formed with one of
core cap 7034 or floating plate 7052
[0440] Movement of floating plate 7052 causes the floating plate to
contact lifter 7058, such that core cap 7034 can be forced upwardly
or downwardly. In the depicted example, lifter 7058 contacts
floating plate 7052 in an interlocking relationship.
[0441] Retraction of output shaft 7050 causes floating plate 7052
to move downwardly toward fixed plate 7054. Lifter 7058 contacts
and bears against core cap 7034, forcing core cap 7034 and core cap
7034 downwardly against inner core 7032 and outer core 7030.
[0442] Extension of output shaft 7050 causes floating plate 7052 to
move upwardly, away from fixed plate 7050. Lifter 7058 contacts and
bears against core cap 7034, forcing core cap 7034 and core cap
7034 upwardly and away from inner core 7032 and outer core
7030.
[0443] A guide structure is provided to maintain alignment between
floating plates 7052 and fixed plate 7054. Specifically, guide pins
7060 project upwardly from each fixed plate 7054 and extend through
the corresponding floating plate 7052. Guide pins 7060 constrain
the movement of floating plate 7052 such that the floating plate
can only move along the axis of the guide pin.
[0444] FIG. 24H depicts mounting of inner core 7032 and outer core
7030 to core support block 7042 in greater detail. Core support
block 7042 is rigidly mounted such that it does not move during
operation of shaper module 3054'. For example, core support block
7042 may be mounted to shaper frame 3052 or to fixed platens.
[0445] Inner core 7032 and outer core 7030 are received through
core support block 7042 and supported thereon with a core reset
assembly 7070. During molding, core reset assembly 7070 is
compressed under a preload force with which inner core 7032 and
outer core 7030 are urged into the mold cavity to resist molding
pressure. At mold opening, core reset assembly 7070 urges inner
core 7032 and outer core 7030 into neutral positions for release of
molded parts.
[0446] Core reset assembly 7070 includes a retainer ring 7072 and a
core load spring 7074. Retainer ring 7072 cooperates with outer
core 7030 and core support block 7042 to define a pocket in which
core load spring 7074 is received. When inner core 7032 and outer
core 7030 are urged downwardly by core cap 7034, retainer ring 7072
bears against load spring 7074 and compresses it. The downward
(closing) force exerted on inner core 7032 and outer core 7030 may
be referred to as a preload and exceeds the opening force due to
pressure within the mold cavity during molding, such that the
closing force on inner core 7032 and outer core 7030 is sufficient
to resist the injection pressure.
[0447] When the preload on inner core 7032 and outer core 7030 is
released, load spring 7074 rebounds and bears against retainer ring
7072, which in turn bears against a flange 7080 of outer core 7030,
moving outer core 7030 slightly upwardly. Such movement brings
outer core 7030 out of contact with mold cavity plates 194, such
that the plates 194 may be opened without outer core 7030 and
plates 194 rubbing against one another.
[0448] FIGS. 24I-24L depict an operational sequence of shaper
module 3054'.
[0449] FIGS. 24I and 24J are isometric and cross-sectional views,
respectively, of shaper module 3054' in a mold-open state. Drive
links 3074 and rockers 3076, 3078 are positioned so that platens
196 (and thus, cavity plates 194) are spaced apart from one
another.
[0450] As will be apparent, shaper module 3054' affords relatively
unobstructed access to the mold area when the mold is open.
Specifically, with the mold open, operators or machinery may access
mold core assembly 190, cavity plates 194 or other components
between platens 196 from a direction transverse to clamping axis
C1-C1 and transverse to core axis C2-C2. Such access may simplify
operations such as removal of molded parts, maintenance, or mold
changes.
[0451] As shown in FIGS. 24I-24J, core actuation assembly 3042' is
also in an open state, with the mold core assembly 190 withdrawn
from its molding position. Actuators 7046 are extended, so that
they urge floating plates 7052 away from fixed plates 7054.
Floating plates 7052 in turn move linkages 7058 upwardly, thereby
urging core cap 7034 upwardly away from inner core 7032 and outer
core 7030.
[0452] Core reset assembly 7070 is in an unloaded state, with load
spring 7074 extended. Extension of load spring 7074 causes retainer
ring 7072 to bear against outer core 7030, thereby pushing the core
along core axis C2-C2, away from its molding position.
[0453] After a completed part is removed, shaper module 3054'
returns to its molding configuration for a new molding cycle. FIGS.
24K-24L are isometric and cross-sectional views, respectively,
showing shaper module 3054' in an intermediate configuration, with
cavity plates 194 and platens 196 open and mold core 190
approximately in its molding position.
[0454] Transition of shaper module 3054' from an open to a closed
(molding) state begins with movement of core assembly 190 towards
its molding position. Specifically, actuators 7046 of core
actuation assembly 3042' retract output shafts 7050. Retraction of
output shafts 7050 draws floating plates 7052 downwardly towards
fixed plates 7054. Floating plates 7052 in turn bear against
lifters 7058, urging the lifters and core cap 7034 downwardly.
[0455] As lifter 7058 and core cap 7034 are pulled downwardly, core
cap 7034 bears against inner core 7032 and outer core 7030.
Downward movement of core cap 7034 therefore also causes downward
movement of inner core 7032 and outer core 7030.
[0456] The position of core cap 7034 may be measured by an optical
sensor, a physical probe or another suitable sensor. Additionally
or alternatively, the position of core cap 7034 may be determined
based on the status of actuators 7046. For example, actuators 7046
may be equipped with encoders to report the position of output
shafts 7050.
[0457] When core assembly 190 reaches the molding position, shown
in FIGS. 24K-24L, clamping assembly 3042' is activated to move
platens 196 and cavity plates 194 to their molding positions. Drive
links 3074 are extended by drivetrain 7006 and cause rockers 3076,
3078 to urge platens 196 towards one another.
[0458] Cavity plates 194 contact one another in their molding
positions, i.e., in the closed position of clamping assembly 3042'.
In the closed position, core assembly 190 is enclosed within the
cavity defined by the cavity plates.
[0459] When cavity plates 194 reach their closed positions, shown
in FIGS. 24M-24N, core cap 7034 is again urged downwardly by
actuators 7046 to apply a preload to core assembly 190. Core cap
7034 is urged against inner core 7032 and outer core 7030. Outer
core 7030 in turn bears against retainer ring 7072 and load spring
7074 of core reset assembly 7070. The load spring 7074 is
compressed by retainer ring 7072. A compressive force is exerted
against load spring 7074. As load spring 7074 compresses, shoulder
7033 of outer core 7030 are pressed into sealing contact with
corresponding surfaces of cavity plates 194. The preload force is
sufficient to resist movement of core assembly 190 due to pressure
from injected molding material, and to prevent leakage of molding
material at the sealing surfaces. The applied preload force is
typically determined using the product of the injection pressure at
which the mold will be operated and the projected area of the mold
cavity. The applied preload force may be measured, for example,
using a load cell, or inferred, for example, based on electrical
current drawn by actuators 7046.
[0460] Drivetrain 7006 exerts closing pressure against platens 196
and cavity plates 194 by way of drive links 3074 and rockers 3076,
3078. The drive pressure exceeds the pressure expected from
injection of molding material into the mold cavity, and maintains
the cavity plates 194 in tight abutment during molding. As
previously noted, application of closing pressure against platens
196 results in reaction forces being transferred through linkage
3070'. Such transfer of forces results in tension being placed on
tie bars 7002 by way of pivotable connections 3082.
[0461] Molten molding material is injected into the mold cavity
defined by cavity plates 194 and core assembly 190. After
injection, the molding material is allowed to cool and harden.
[0462] FIGS. 24O-24V depict operation of shaper module 3054' after
forming of a molded article.
[0463] As shown in FIGS. 24O-24P, mold assembly 190 is moved by the
mold actuation subassembly 3044' while clamp subassembly 3042' is
maintained in its closed position. Actuators 7046 extend output
shafts 7050, thereby urging floating plates 7052 away from fixed
plates 7054.
[0464] As floating plates 7052 are forced upwardly, they push
lifters 7058 and core cap 7034 upwardly. Once core cap 7034 moves
slightly upwardly, core reset assembly 7070 is no longer
restrained. Accordingly, load spring 7074 extends back to its
uncompressed condition and urges retainer plate 7072 upwardly.
[0465] Retainer plate 7072 bears against outer core 7030 and may
push the outer core upwardly. Such upward movement brings outer
core 7030 out of contact with cavity plates 194. Thus, platens 196
and core plates 194 may be withdrawn without causing damage due to
friction between outer core 130 and cavity plates 194.
[0466] Once outer core 7030 is lifted out of contact with cavity
plates 194, linkage 3070'''', platens 196 and mold cavity plates
194 are moved to their open positions, shown in FIGS. 24Q-24R.
[0467] With the platens 196 and cavity plates 194 in the mold-open
position, mold core assembly 190 is moved to its mold-open
position, shown in FIGS. 24I-24J, and the molded part is removed.
As shown, cavity plates 194 are opened with the molded part lightly
held on inner core 7032. The released part may be removed from the
mold using a handling device. In other embodiments, the part may be
fully dislodged from core assembly 190 prior to opening cavity
plates 194, such that the part falls out upon opening.
[0468] Core cap 7034 pulls inner core 7032 upwardly. Thus, inner
core 7032 retracts along core axis C2-C2 relative to outer core
7030. Such relative movement of inner core 7032 and outer core 7030
dislodges the molded part from core assembly 190.
[0469] The molded part tends to have some resistance to removal
from the core assembly. That is, the part tends to stay on the mold
inner core 7030. However, when inner core 7032 is pulled upwardly,
a top edge of the molded part abuts an annular edge of outer core
7030. The annular edge of the outer core prevents the molded part
from being withdrawn along with the inner core and dislodges the
part from inner core 7032.
[0470] Retraction of inner core 7032 may occur in two stages,
namely, an initial short movement, followed by a longer movement.
The initial movement may be fast, in order to break the molded part
loose from inner core 7032. For example, the initial movement may
overcome suction that can occur between the molded part and inner
core 7032. A second, longer, movement of inner core 7032 further
withdraws the inner core from the molded part, until the molded
part can freely fall or be easily removed from the core.
[0471] Conveniently, the configuration of shaper station 3054'
provides flexibility for part removal. Because linkage 3070', drive
train 7006, shaper frame 3052' and tower structure 7000 are
disposed on the same side of the mold, i.e. on one side of bounding
envelope E (FIG. 24A), the opposite lateral side of bounding
envelope E is substantially unobstructed, as is the bottom.
Accordingly, material handling devices may freely access the space
between platens 196 from the bottom or from the unobstructed
lateral side to remove parts.
[0472] The access afforded by the configuration of shaper module
3054' also eases the process of changing or performing maintenance
on mold components.
[0473] FIGS. 24S-24T depicts shaper module 3054' in a configuration
for removal of mold cavity plates 194. Clamping assembly 3042'
includes a wedge block (not shown), that is operable to selectively
lock cavity plates 194 in their closed positions. The wedge block
may, for example, be mounted to shaper frame 3052' and may be
extended into contact with cavity plates 194 to bias the cavity
plates to their closed positions. Some embodiments may include
multiple wedge blocks, e.g. one per cavity plate.
[0474] As shown in FIG. 24S, with the wedge block engaged, cavity
plates 194 remain in their closed positions when platens 196 are
opened. Couplings (not shown) between cavity plates 194 and platens
196 are configured to release upon application of force away from
the platens, such that opening of the platens with the wedge block
engaged disconnects the mold cavity plates 194 from the
platens.
[0475] As shown, cavity plates 194 are removed from platens 196
while core assembly 190 is positioned between the cavity plates.
Thus, the mold may be removed from shaper module 3054' as an intact
unit, i.e. cavity plates 194 may be removed with mold core assembly
190 captive between the cavity plates.
[0476] In order to permit removal of core assembly 190, it is
detached from core cap 7034. Specifically, couplings 7037 are
released so that mounting block 7035 and core cap 7034 can be
separated from one another. After the couplings are released,
actuators 7046 extend drive shafts 7050 to push floating plates
7052, lifters 7058 and core cap 7034 upwardly. The maximum
extension of drive shafts 7050 is sufficient to raise core cap 7034
clear of mounting block 7035.
[0477] Once core cap is clear of mounting block 7035, cavity plates
194 and core assembly 190 can be removed from shaper module 3054'
as a single assembly. Conveniently, shaper core 3054' provides
sufficient clearance for machinery to access and remove the mold
assembly from the side opposite shaper frame 3052' and linkage
3070''''.
Primary Shaping Mold
[0478] With primary reference to FIGS. 25-28, details of example
molds for use at a station of shaping cell 104 will now be
described. The depicted embodiments are molds for injection
molding, such as injection molding of preforms from which
containers may be formed. However, many features of the described
embodiments are not limited to injection molding, as will be
apparent.
[0479] In mold sub-assemblies 3040 and 3040' as illustrated in
FIGS. 12B-D and FIGS. 24A-T respectively, each platen 196 may have
secured thereto one or more services blocks 5196 (see FIGS. 25A and
28A). Attached to each services block 5196 may be a cavity plate
194. Cavity plates 194 may take a wide range of configurations.
Cavity plates 194 of different configurations may be
interchangeable with one another on a services block 5196 within
mold sub-assemblies 3040, 3040'. With particular reference to FIGS.
25A to 28B, examples of cavity plates 194 are illustrated and are
described hereinafter in detail.
[0480] With reference to FIGS. 25A and 28A, services block 5196 may
be connected to a platen 196 by threaded bolts 5197 received
through openings 5198 in services block 5196 and into threaded
openings 5195 in a platen 196.
[0481] Services block 5196 may have channels operable for
delivering services such as pressurized air, cooling fluid,
electrical/electronic services to a cavity plate 194. Services
block 5196 may during operation of plastic molding system 100
remain connected to a platen 196.
[0482] In some embodiments, cavity plate 194 may be a single
unitary body. In other embodiments, cavity plate 194 may have two
separately identifiable portions. The two portions may be
integrally formed to create a single continuous unitary body or the
two portions may be configured as two separate units or parts and
be connected to each other during operation of plastic molding
system 100.
[0483] In the embodiments of FIGS. 25A to 25K, each cavity plate
194 comprises two separately identifiable portions: a base portion
and a mold cavity portion. The base portion, which is identifiable
as a base block 5000, may be first formed as a separate body, and
then the mold cavity portion, which is identifiable as a mold
cavity block 5010 or 5010', may be formed by a manufacturing
process by which the two portions/blocks are melded or merged
together into a cavity plate 194 that comprises a single unitary
body.
[0484] In the embodiments of FIGS. 26A-J, each cavity plate 194
comprises two separate parts: a base part (also referred to herein
as a base block 5000) and a mold cavity part (referred to herein as
a mold cavity block 5010'' or 5010'''). In these embodiments of
FIGS. 26A-J, base block 5000 and mold cavity block (5010'' or
5010''') are formed as separate parts and then connected together
by a connection mechanism.
[0485] Each mold cavity block 5010, 5010', 5010'', 5010''' of a
cavity plate 194 may be formed in a specific configuration that is
adapted to provide one half of an outer mold cavity surface for an
item to be molded having a particularly desired profile/shape. In a
plastic molding system 100, a plurality of differently configured
cavity plates 194, with differently configured mold cavity blocks
5010, 5010', 5010'', 5010''' with differently configured mold
cavity surfaces, may be available for selection and use in a mold
sub-assembly 3040, 3040'.
[0486] In the embodiments of FIGS. 26A-J, each base block 5000 may
be configured and operable to connect to, and disconnect from, a
plurality of differently configured mold cavity blocks 5010'',
5010' which when used in a pair of mated mold cavity blocks 5010''
or 5010''' may provide a differently shaped molding cavity surface
to produce a differently shaped/configured molded item.
[0487] Each base block 5000 of a cavity plate 194 may have one or
more "quick connection" mechanisms (as described further
hereinafter) for coupling each cavity plate 194 to a services block
5196 and thus to a platen 196.
[0488] With reference again to the embodiment of cavity plate 194
depicted in FIGS. 25C-D, further details of base block 5000 and
mold cavity blocks 5010, 5010' of a cavity block 194 are
illustrated in FIGS. 25E-K and FIGS. 27A-B, as described
hereinafter.
[0489] With particular reference to FIG. 27B, base block 5000 may
be used with any of mold cavity blocks mold cavity blocks 5010,
5010', 5010'', 5010''' to form a cavity plate 194. Base block 5000
may have a length Y1 and width X1.
[0490] With reference to FIG. 25G, mold cavity block 5010' may have
a length Y2 and width X2. X1 may be the same magnitude as X2, and
Y1 may be the same magnitude as Y2. Mold cavity blocks 5000, (as
well as mold cavity blocks 5000'' and 5000''') may have the same
length and width Y2 and X2.
[0491] With reference to FIGS. 27A and 27B, each base block 5000
may have a mold cavity block facing surface 5000a (FIG. 27A) that
may be generally planar and extend vertically (direction Y) and
transversely (direction X). Mold cavity block 5010, 5010' of FIGS.
25A to 25K may be formed by an additive manufacturing process
whereby by deposition of a material on top of mold cavity block
facing surface 5000a the material bonds to the material of base
block 5000 at mold cavity block facing surface 500b of base block
5000.
[0492] In other embodiments, mold cavity block 5010'' (FIG. 26B),
may have a base block facing surface 5010'a that may be generally
planar and extend vertically (direction Y) and transversely
(direction X). Base block facing surface 5010a'' of mold cavity
block 5010 and mold cavity block facing surface 5000a of base block
5000 may be configured to be able to connected together and be held
in face to face, flush mating contact with each other. Base block
5000 may also have, on the opposite side to mold cavity block
facing surface 5000a, a services block facing surface 5000b (FIG.
27B) that may also be generally planar and extend transversely.
Services block facing surface 5000b of base block 5000 of cavity
plate 194 may be operable to be able to be connected and be held in
face to face flush mating contact with a generally planar and
transversely extending surface 5196a of a services block 5196
associated with a platen 196 (FIGS. 25A, 25C, 25D, 26A, 26B, and
28A).
[0493] The connection mechanism employed between the base block
5000 of a cavity plate 194 and the mold cavity block 5010'', to
hold surfaces 5000a and 5010a'' in face to face, flush mating
contact and in engagement may be, or may not be, a mechanism that
provides for a relatively easy and quick connection to, and
disconnection from, each other. Each base block 5000 may be
disconnected from, and connected to, a mold cavity block 5010''
when the cavity plate 194 is removed from mold sub-assemblies 3040
and 3040'. It is contemplated in the embodiments of FIGS. 26A-J
each base block 5000 may be connected to and disconnected from, a
mold cavity block 5010'', 5010''' using threaded bolts 5025
received through open holes 5026 that pass through base plates 5000
and extend longitudinally (direction Z) into threaded holes (not
shown) appropriately positioned in cavity block 5010'' (see FIGS.
26D and 26G).
[0494] With reference again to FIGS. 27A and 27B, counter-bore
openings 5003 may be provided which extend longitudinally through
the body of each base block 5000. Openings 5003 are adapted to
receive therein and secure threaded base portions of alignment
dowels (5004 (FIG. 25B) which may have portions that pass through
openings in the mold cavity block 5010' to which the base block
5000 is attached (in the embodiments of FIGS. 26A-J) and extend
longitudinally outwards. A protruding end of an alignment dowel/pin
may be received in a corresponding opening in the mold cavity block
(as for example as described further below).
[0495] Additionally, each base block 5000 may have upper clamp
connection openings 5002a, 5002b on upper horizontal surface 5000c
and lower clamp connections have lower clamp connection openings
5002c, 5002d on lower horizontal surface 5000d (FIGS. 27A, 27B).
These clamp connection openings may be utilized to connect to
fixtures during manufacturing of the base blocks 5000 themselves
(e.g. when clamping of base blocks 5000 is required) or when
combining the base block with a mold cavity block 5010, 5010',
5010'' or 5010'''. Such clamp connecting openings may also be used
to connect to fixtures associated with a handling robot when it is
required to conduct tooling maintenance activities. Additionally,
lower clamp connection openings 5002c, 5002d may also be used for
retaining gate cutter assembly 2200 as referenced above.
[0496] Another connection mechanism is employed between base block
5000 and services block 5196 to releasably but securely hold
surfaces 5000b and 5196a in face to face, flush contact and
engagement. This connection/retaining mechanism may be a quick
connection/disconnection mechanism (referred to herein as a "quick
connection" or "quick connect" mechanism) that facilitates
relatively easy and quick connection and disconnection of each base
block 5000 of a cavity plate 194. A "quick connection" or "quick
connect" mechanism may be considered herein to be a mechanism
whereby the connection and disconnection between the two components
can be affected relatively easily and it has one or more of the
following functional characteristics.
[0497] One characteristic indicative of a quick connection is that
the connection and disconnection mechanism is selectively
engageable to hold the base block 5000 against the services block
5196.
[0498] Another characteristic indicative of a quick connection is
that the mechanism has the capability of selectively interlocking
the base block 5000 and the services block 5196.
[0499] Another characteristic indicative of a quick connection is
that the mechanism is operable to provide a clamping action when
connecting base block 5000 and the services block 5196.
[0500] Another characteristic indicative of a quick connection is
that the mechanism is switchable between connected and disconnected
states to connect and disconnect the base block 5000 and the
services block 5196.
[0501] Another characteristic indicative of a quick connection is
that the connection and/or disconnection is made by way of a spring
activated force operating between a part on the base block 5000 and
the services block 5196.
[0502] Another characteristic indicative of a quick connection is
that the connection and/or disconnection does not require the
installation of fasteners e.g. does not involve twisting or turning
forces to be applied to screws, bolts, nuts, or the like.
[0503] By way of example, a quick connect mechanism like retaining
mechanism 4014 illustrated in FIG. 4H as described above may be
employed to releasably connect a base block 5000 to a services
block 5196. A connection/retaining mechanism such as the model
306019 zero point pull-stud and model 305979 zero point clamping
module socket available from AMF (Andreas Maier GmbH & Co KG
referred to herein as "AMF"--see www.amf.de/en). Thus, the
connection/retaining mechanism may include a plurality of
vertically spaced studs 4024 and a corresponding plurality of
mating sockets 4026 which can selectively interlock with the studs.
The studs 4024 (FIGS. 25B, 27B) may be mounted on and extend
longitudinally (direction Z) outward from services block facing
surface 5000b of base block 5000 of cavity plate 194 and engage
with a socket 4026 formed in base block facing surface 5196a of
services block 5196 (FIG. 25A) and which extends longitudinally
(direction Z) into the body of services block 5196 (see also FIG.
28A).
[0504] Other features of this retaining mechanism shown in FIG. 4H
are described above. By providing a quick connect mechanism whereby
different molding cavity plates 194 can be readily interchanged on
a services block 5196, the mold sub-assemblies 3040, 3040' can be
easily and quickly changed from one particular set-up to another
set-up without significant changeover downtime.
[0505] Each base block 5000 and services block 5196 may each be
made from any suitably strong and rigid material or combination of
materials, such as for example 1.2085 grade steel or AISI 422
stainless steel.
[0506] A suitably sized, generally cuboid shaped block may be
initially formed such as by casting using known techniques and
methods, and then the particular features of the base block 5000
and services block 5916 as described herein may be formed in the
cast block using known manufacturing techniques and methods such as
conventional machining apparatuses and methods.
[0507] Each mold cavity block 5010, 5010', 5010'', 5010''' may also
be made from suitably strong and rigid material(s) such as for
example 1.2085 or AISI 422 steel.
[0508] In the embodiments of FIGS. 26A-J, a suitably sized,
generally cuboid shaped block may be initially formed such as by
casting using known techniques and methods, and then the particular
features of the mold cavity block 5010'', 5010''' as described
herein may be formed in the cast block using known manufacturing
techniques and methods such as conventional machining apparatuses
and methods.
[0509] One technique that may be employed for forming a mold cavity
block 5010, 5010', including forming the shape of its mold cavity
wall surface 5011, 5011' and interior core alignment surface 5009,
5009' (FIG. 25D-K) is a 3D printing process, and in particular
direct metal laser sintering (DMLS). Such a process can be employed
in which the material is directly applied and deposited on top of
surface 5000a of a base block 5000 such that the 3D profile of the
mold cavity block 5010, 5010' is built on top of the base block.
Such a process has flexibility in terms of the shape of the mold
cavity wall surface 5011, 5011' that can be formed and allowing the
formation of internal hollow features, such as providing hollow
service channels therein (e.g. fluid cooling channels). Such an
additive manufacturing process provides a high level of flexibility
in being able to provide an optimized cooling fluid channel which
can surround/cover the entire molding cavity surface. Traditional
manufacturing techniques may not be able to achieve the same
configuration/placement of cooling channels or if they can, it may
be very difficult to achieve and incur extremely high cost.
[0510] With particular reference now to FIGS. 27A-B and FIG. 28B,
base block 5000 may be provided with one or more service channels
extending there through. Such services may include pressurized air
(which can be used to operate a quick connection mechanism
operating between a base block 5000 and a services block 5196),
electrical/electronic wiring (e.g. for
electronically/electronically connecting to sensors such as
temperature sensors), and fluid cooling (e.g. cooled gas; cooled
water) channels.
[0511] By way of example, in the embodiment of FIGS. 26A-J, where
each base block 5000 is configured and operable to connect to, and
disconnect from, a plurality of differently configured mold cavity
blocks 5010'', 5010''', base block 5000 may have a fluid cooling
channel 5020 (FIG. 28B) that is a part of a cooling fluid circuit
5200 that delivers cooling fluid from a cooling fluid reservoir
5199 to a services block 5196, then into the base block 5000 and
then into a mold cavity block 5010'' (or mold cavity block 5010''')
so as to promote rapid cooling and solidification of melted
material after injection into a mold cavity formed by a pair of
mated, clamped mold cavity blocks 5010 (or mold cavity blocks
5010', 5010'', 5010'). The cooling fluid circuit 5200 returns the
cooling fluid to a fluid channel 5181 in the services block 5196
for return to the cooling fluid reservoir 5199. Examples of cooling
fluid are chilled water, liquid CO.sub.2 and other fluids with
different heat exchange characteristics.
[0512] Services block 5196 may have a cooling channel 5080 with an
output port 5050a. Cooling channel 5020 in base block 5000 may have
an input port 5020d in surface 5000b of base block 5000 which is in
fluid communication with an aligned output port 5050a in surface
5196a of services block 5196, when the base block 5000 is engaged
with the services block 5196 as shown in FIGS. 26A and 26B. Fluid
channel 5020 passes through base block 5000 to an output port 5020a
in surface 5000a of base block 5000 which is in fluid communication
with an aligned input port 5030a in surface 5010a of mold cavity
block 5010 (FIG. 25B) (or the corresponding surface of mold cavity
block 5010', 5010'', 5010'''). Input port 5030a provides an intake
for a cooling channel 5030 (FIG. 28B) that that passes through the
body of the mold cavity block 5010 (or mold cavity block 5010',
5010'', 5010'''). Cooling channel 5030 may be formed to allow
cooling fluid to flow along a tortuous path through the body of
mold cavity block 5010 (or mold cavity block 5010', 5010'',
5010''') to an output port 5030b. The tortuous path have portions
that are configured to conform at least in part to the mold cavity
wall surface to enhance the cooling effect of the cooling fluid
within the mold cavity block 5010. In some example embodiments, the
cooling channel 5030 may, at least in part, be formed as an
indented groove that may be milled into base block facing surface
5010a'' of mold cavity block 5010''. The groove may be fully
enclosed at its top by the opposed mating surface 5000a of base
block 5000 when mold cavity block 5010'' is engaged with a base
block 5000 and surface 5000a in mating contact with surface
5010a''.
[0513] Output port 5030b in surface 5010a of mold cavity block 5010
(or corresponding surface of mold cavity block 5010', 5010'',
5010''') is in fluid communication with an aligned input port 5020b
in surface 5000b of base block 5000 (FIG. 27A). A second fluid
channel 5021 passes through base block 5000 from input port 5020b
to an output port 5020c. The output port 5020c is in fluid
communication with an input port 5050b in services block surface
5196a of services block 5196.
[0514] Services block 5196 has a services channel 5081 that
provides communication between input port 5050b and is in fluid
communication with cooling fluid reservoir 5199 so that cooling
fluid can be returned to the reservoir.
[0515] With reference to the cooling fluid circuit 5200 depicted in
FIG. 28B, cooling fluid may be communicated from the cooling fluid
reservoir 5199 by various cooling fluid channels passing through
other components of the mold sub-assembly 3040, 3040' into the
cooling channel 5080 in the services block 5196, then pass into the
cooling channel 5020 in base block 5000 and then into the cooling
channel 5030 in mold cavity block 5010'' (or mold cavity block
5010'''). Cooling fluid may then flow through the cooling channel
5030 and exit output port 5030b into input port 5020b into the
cooling channel 5021 in base block 5000 where it can flow through
channel 5021 exiting into input port 5050b in services block
surface 5196a of the services block 5196. Then the cooling fluid
can flow through cooling fluid channel 5181 to be returned to the
cooling fluid reservoir 5199 by various channels passing through
other components of the mold sub-assembly 3040, 3040'. As part of
the cooling fluid circuit 5200, in addition to the cooling fluid
reservoir 5199 and the flow channels, an apparatus for cooling the
fluid is required as well as a pump and possibly valves to provide
for a cooling fluid flow to and from the mold cavity blocks
5010.
[0516] Each of cooling fluid input port/output port couplings
5020a/5030a; 5030b/5020b; and 5020c/5050b may be any suitable
cooling fluid communication fittings. For example, suitable water
fittings for couplings 5020c/5050b may be the model AMF 6989N
[164988, built-in coupling nipple] and 6989M [164996, built-in
coupler] water fittings made by AMF. Couplings 5030a/5020a; and
5030b/5020b may be suitable sealing O-rings between the mated
surfaces of base block 5000 and mold cavity block 5010'' (or mold
cavity block 5010') of cavity plate 194 and in particular in the
vicinity of where channels 5020 and 5021 connect with channel
5030.
[0517] In such water fittings, there may be provided a valve
mechanism that opens and closes the channel of fluid flow. When the
male part of such a cooling fluid fitting is received into the
female part, the valve mechanism is opened. When the male part is
removed from the female part, the valve mechanism is closed. The
valve mechanism may be provided on the cooling fluid source side of
the fluid circuit supply arrangement, such as for example, at the
output port 5050a on a services block 5196. Accordingly, when a
base block 5000 is removed from connection to services block 5196,
cooling fluid will not flow out of output port 5050a on the
services block 5196.
[0518] It is also noted that with male/female type couplings (both
cooling fluid fittings and fittings associated with the
connection/retaining mechanism referenced above) between the base
blocks 5000 and the services blocks 5196, there will be a male part
and a female part. In some embodiments, the female part of the
couplings may be formed in the services block 5196 and the male
part of the coupling on the base block 5000. This is because the
male part of such a coupling is typically a less expensive
component and in any molding system 100, there may be a much
greater number of base blocks 5000 that are utilized compared to
the number of service blocks 5196, it may be cost effective to
provide the male parts of such cooling fluid fittings and
retention/connection mechanisms, on the base blocks 5000. In other
embodiments, the male part of the couplings may be formed in the
services block 5196 and the female part of the coupling on the base
block 5000.
[0519] Similarly, in the embodiments of FIGS. 25A-25K, where each
base block 5000 is integrally connected with a mold cavity block
5010 (or a mold cavity block 5010'). Again each base block 5000 may
have a fluid cooling channel 5020' (FIG. 28C) that is a part of a
cooling fluid circuit 5200' that delivers cooling fluid from a
cooling fluid reservoir 5199 to a services block 5196, into the
base block 5000 and then into a mold cavity block 5010 (or mold
cavity block 5010') so as to promote rapid cooling and
solidification of melted material after injection into a mold
cavity formed by a pair of mated, clamped mold cavity blocks 5010
(or mold cavity block 5010'). The cooling fluid 5200' returns the
cooling fluid to a fluid channel 5181' in the services block 5196
into a fluid channel in platen 196 for return to the cooling fluid
reservoir 5199.
[0520] Services block 5196 may have a cooling channel 5080' with an
input port 5051a and an output port 5050a. Cooling channel 5020' in
base block 5000 may have an input port 5020d in surface 5000b of
base block 5000 which is in fluid communication with an aligned
output port 5040a in surface 5196a of services block 5196, when the
base block 5000 is engaged with the services block 5196 as shown in
FIGS. 26A and 26B. Fluid channel 5020' passes through and is
integrally connected for fluid communication with a cooling channel
5030' (FIG. 28C) that that passes through the body of the mold
cavity block 5010 (or mold cavity block 5010'). Like cooling
channel 5030, cooling channel 5030' may be formed to allow cooling
fluid to flow along a tortuous path through the body of mold cavity
block 5010 (or mold cavity block 5010') and then fluidly connect
with a second fluid channel 5021' passes through base block 5000 to
an output port 5020c. Output port 5020c is in fluid communication
with an input port 5050b in services block surface 5196a of
services block 5196.
[0521] Services block 5196 has a services channel 5081' that
provides communication between input port 5050b and output port
5051b. Output port 5051b is in communication with an input port
5040b in platen 196.
[0522] With reference to the cooling fluid circuit 5200' depicted
in FIG. 28C, cooling fluid may be communicated from the cooling
fluid reservoir 5199 by various cooling fluid channels passing
through other components of the mold sub-assembly 3040, 3040' into
the platen 196 and then exit from an output port 5040a at platen
surface 196a of platen 196, and pass into and through the cooling
channel 5080 in the services block 5196, then pass into the cooling
channel 5020' in base block 5000 and then into the cooling channel
5030' in mold cavity block 5010 (or mold cavity block 5010').
Cooling fluid may then flow through the cooling channel 5030' and
then flow through channel 5021' exiting into input port 5050b in
services block surface 5196a of the services block 5196. Cooling
fluid can then flow through cooling fluid channel 5181' to an input
port 5040b in platen surface 196a of the platen 196 to which
service block 5196 is mounted. Cooling fluid may then flow through
the platen 196 and be returned to the cooling fluid reservoir 5199
by various channels passing through other components of the mold
sub-assembly 3040, 3040'. As part of the cooling fluid circuit
5200', in addition to the cooling fluid reservoir 5199 and the flow
channels, an apparatus for cooling the fluid is required as well as
a pump and possibly valves to provide for a cooling fluid flow to
and from the mold cavity blocks 5010.
[0523] Each of cooling fluid input port/output port couplings
5051a/5040a; 5050a/5020d; 5020c/5050b and 5051b/5040b may be any
suitable cooling fluid communication fittings. For example,
suitable water fittings for couplings 5051a/5040a; 5050a/5020d;
5020c/5050b and 5051b/5040b may also be the model AMF 6989N
[164988, built-in coupling nipple] and 6989M [164996, built-in
coupler] water fittings made by AMF.
[0524] In addition to base block facing surface 5010a, in the
embodiments of FIGS. 25G-H, mold cavity blocks 5010 have an upper
horizontal surface 5010c and a lower horizontal surface 5010d,
which are generally parallel to each other and orthogonal to
surface 5010a. On the opposite side of base block 5000 to base
block facing surface 5010a, may be a cavity side 5010b with a
surface topography generally designated 5012, which may vary in its
configuration depending upon one or more of several factors
including the configuration of the item which is desired to be
molded between a pair of mated mold cavity blocks 5010 and the type
of molding material that is going to be injected into the cavity.
Cavity side surface topography 5012 typically includes at least a
surface area for forming half of a mold cavity and a contact
surface area that is configured to engage an opposite contact
surface on a corresponding mating mold cavity block. In mold cavity
block 5010, a contact surface area 5010g may be provided that is
generally parallel to base block facing surface 5010a. Extending
interiorly of contact surface area 5010g is a cavity wall surface
5011 which defines the outer surface of a cavity half 5015. The
orientation of cavity wall surface 5011 is such that the lengthwise
axis of the cavity wall surface (in the Y direction) that leads to
the top open end of the mold cavity is vertical such that the split
line is a longitudinal line on either side of the item to be
molded. In other words, the cavity wall surface 5011 provides a
longitudinal sectional surface profile of the item to be molded
with the item to be molded having an opening at a vertical end of
the profile.
[0525] Mold cavity block 5010' is similar in configuration as shown
in FIGS. 25I-K. in which a contact surface area 5010g' may be
provided that is generally parallel to base block facing surface
5010a'. Extending interiorly of contact surface area 5010g' is a
cavity wall surface 5011' which defines the outer surface of a
cavity half.
[0526] In each mold cavity block 5010, 5010', located above cavity
wall surface 5011, 5011' is a core alignment surface area 5009,
5009' which in generally tapered inwardly towards the cavity wall
surface 5011, 5011'', and which defines half of the cavity adapted
to receive and align the outer core 7030 and an upper part of the
inner core 7032 of a mold core assembly 190 (see FIGS. 25D, 25E)
that is received within the cavity formed by cavity wall surfaces
5011, 5011'.
[0527] During operation of system 100, the inner core 7032 extends
vertically into the mold cavity formed by opposed cavity wall
surfaces 5011, 5011' of opposed mating mold cavity blocks 5010,
5010' and the wall surface of inner core 7032.
[0528] A gate area 5016, 5016' may be formed vertically through a
lower portion the body of each mold block cavity 5010, 5010' to
provide a channel from the exterior of the mold cavity block into
the cavity half 5015 and into the mold cavity formed when the inner
core 7032 and outer core 7030 of the mold core assembly 190 are
received into cavities formed by interior core receiving surfaces
5009, 5009' and cavity wall surfaces 5011, 5011' of mated mold
cavity blocks 5010 (or mated mold cavity blocks 5011'). It is to be
noted that the two opposed, face-to-face gate areas 5016, 5016' of
opposed pairs of mold cavity blocks 5010, 5010' cooperate to define
a gate structure 5017, 5017' (FIG. 25D) when, in operation of a
mold sub-assembly 3040, 3040', a pair of mold cavity blocks 5010
(or pair of mold cavity blocks 5010') are mated with each other. It
is through the formed gate structure 5017' (FIG. 25D) that molding
material may be injected into the formed mold cavity as generally
described herein.
[0529] A vent area 5037, 5037' may also be formed through sides of
the body of each mold block cavity 5010, 5010' to provide opposed
vent channels between the exterior of the mold cavity block and the
interior of the cavity half 5015, 5015'. It will be appreciated
that when during operation of system 100, two mold cavity blocks
5010 (or mold cavity blocks 5010') are oriented in face-to-face
mated relation with each other, with opposed contact surface areas
5010g, 5010g' being in contact with, and forced towards, each
other, a pair of complete opposed vent structures 5038' (FIG. 25C)
will be formed by the two opposed, face to face vent areas 5037' of
the opposed mold cavity blocks 5010'. It is through the formed vent
structures 5038' (FIG. 25C) that air may escape from the interior
of the mold cavity as molding material is injected into the formed
mold cavity.
[0530] It will be appreciated that when during operation of system
100, two mold cavity blocks 5010 are oriented in face to face mated
relation with each other, with opposed contact surface areas 5010g
being in contact with and forced towards each other, the outer
surface of a complete mold cavity will be formed by the opposed
cavity wall surfaces 5111. This will result in a longitudinal split
line being present between the two mating mold cavity blocks 5010
at the inward edges defined by the boundary between cavity wall
surfaces 5011 and contact surface areas 5010g. It is important that
the mating edges of the two cavity wall surfaces be in tight,
unbroken contact with each other and that the edges be flush with
each other to avoid a discontinuity at the join of the adjacent
cavity mold surfaces. To minimize problems associated with a
visible longitudinal split line, it is important that the interface
between a pair of mated and engaged mold cavity blocks 5010 be
controlled with a very high degree of tolerance during operation of
system 100.
[0531] Again with primary reference to FIGS. 25G and 25I, in some
embodiments, extending from opposed sloped side surfaces 5010e and
5010f of mold cavity blocks 5010 may be generally wedge shaped
abutments 5033. Abutments 5033 on a stationary mold cavity block
5010 may have longitudinally extending guide pin openings 5035 to
receive a guide pin (not shown in FIG. 25G, but refer to FIG. 26D
for similar guide pins 5007'') that may be mounted on an opposed
wedge shaped abutment 5033 on a moving mold cavity mold block 5010.
For further clarity, it may be appreciated that of a pair of mating
mold cavity blocks 5010, one mold cavity block 5010 may be
stationary during operation of a mold sub-assembly, as it may be
secured to a base block 5000 that is mounted to a stationary platen
196, whereas the opposite mold cavity block 5010 may move during
operation, as it is secured to a base block 5000 that is mounted to
a moving platen 196. In other embodiments, both mold cavity blocks
5010 may move during operation a mold sub-assembly, as each mold
cavity block 5010 is secured to a base block 5000 that is mounted
to a moving platen 196.
[0532] Guide pin openings 5035 and guide pins may be formed to very
high tolerances to ensure that when two mold cavity blocks 5010 are
brought together in face to face mated relation with each other,
with opposed contact surface areas 5010g being in contact with each
other, and forced towards each other, all the features of the
desired outer surfaces of the mold cavity are formed properly (e.g.
the two mold cavity halves are accurately aligned with each other
to assist in avoiding/minimizing visible longitudinal split lines
on the molded items).
[0533] The upper surfaces 5033a of abutments 5033 are recessed
below the level of contact surface areas 5010g. Accordingly, when
during operation of system 100, two mold cavity blocks 5010 are
oriented in face to face mated relation with each other, with
opposed contact surface areas 5010g being in contact with and being
forced towards each other at a specific known clamping force, the
only surfaces that in contact with each other will be contact
surface areas 5010g. Thus, the contact pressure at surfaces 5010g
can be calculated as the clamping force divided by the area of a
contact surface area 5010. Additionally, the contact pressure
desired to ensure proper sealed formation of a mold cavity by two
mold cavity blocks may be within a known range. It is possible that
for a particular standard clamp tonnage that is applied by the
clamping mechanism of a mold sub-assembly 3040', 3040', the
acceptable range of contact surface area can be calculated and
provided for a particular cavity mold block 5010. Thus instead of
changing the clamp pressure for differently sized/shaped items to
be molded, the surface contact area 5010g for a mold cavity block
can be selected and the contact pressure on the surface contact
areas 5010g may be appropriately maintained within a desired
range.
[0534] An alternately configured mold cavity block 5010' is shown
in FIG. 25I-K. Mold cavity block 5010' may generally configured the
same as mold cavity block 5010 including having the same
corresponding overall width X2 but different length Y3, a cooling
channel 5030', and wedge shaped abutments 5033' with recessed top
surfaces 5033a'. Abutments 5033' on a stationary mold cavity block
5010' may also have guide pin openings 5035' to receive a guide pin
(not shown) that may be mounted on a mated opposed cavity mold
block 5010'. However, the configuration of side surfaces 5010e' and
5010f' and cavity wall surface 5011' may be such that a larger
contact surface area 5010g' is present in mold cavity block 5010'
compared to the size of the contact surface area 5010g in mold
cavity block 5010.
[0535] A mold cavity block 5010' having the same length Y2 as, or a
shorter length Y3 than, the length Y2 of mold cavity block Y2 of
mold cavity block 5010, for a standard clamping pressure, may
require a different configuration of contact surface area 5010g'
compared to contact surface area 5010g to ensure that the contact
pressure is within an acceptable range.
[0536] Table 1 below, provides an example of how the configuration
and size of contact surface areas can be selected/varied for a
variety of different items to be molded, where a standard clamping
load is applied to clamp together two opposed cavity mold blocks,
and illustrates the resulting contact pressures from a variety of
somewhat differently sized and shaped contact surface areas 5010g,
with a clamping force of 30 tonnes (294 300 N).
TABLE-US-00001 TABLE 1 Contact Surface 6000 mm{circumflex over (
)}2 Contact Pressure 49.1 N/mm{circumflex over ( )}2 Contact
Surface 5750 mm{circumflex over ( )}2 Contact Pressure 51.2
N/mm{circumflex over ( )}2 Contact Surface 5500 mm{circumflex over
( )}2 Contact Pressure 53.5 N/mm{circumflex over ( )}2 Contact
Surface 5250 mm{circumflex over ( )}2 Contact Pressure 56.1
N/mm{circumflex over ( )}2 Contact Surface 5000 mm{circumflex over
( )}2 Contact Pressure 58.9 N/mm{circumflex over ( )}2
[0537] Therefore, if the size and shape of the mold cavity surface
is different between mold cavity blocks, the shape of the contact
surface area can be altered to some extent between the two mold
cavity blocks, to ensure that with a given set clamping pressure,
the contact pressure is held within a desired pressure range.
[0538] The ability to vary the shape of the surface contact areas
5010g, 5010g', 5010g'' also permits the pressure distributions
applied across the contact surfaces on the mold cavity blocks to be
adjusted having regard to the locations of the forces applied via
the clamping mechanisms. In some situations the forces applied by
the clamping mechanisms will not be evenly distributed. The size of
the contact surfaces in a particular area can be adjusted to
accommodate uneven application of force by the clamping mechanism,
such that the pressure across the entire contact surface area is
fairly even. A further alternate embodiment of a mold cavity plate
194'' is shown in FIGS. 26D-F which may be formed as two separate
parts: (a) a base block 5000''; and (b) a mold cavity block 5010''
that may be connected together in use. Base block 5000'' may be
generally formed like base block 5000 including to base block
5000'' having side surfaces 5000e'' and 5000f'' which are generally
longitudinally extending and planar. Mold cavity block 5010'' may
be generally formed like mold cavity block 5010 except that its
side surfaces 5010e'' and 5010f'' are also generally extending
vertically and longitudinally and are planar. As is evident in FIG.
26B, and FIGS. 26D-F, when a mold cavity block 5010'' is mounted to
a base block 5000, surface 5010e'' is generally flush with, and
extends in same plane as, surface 5000e. Similarly, surface 5010f''
is generally flush with and extends in the same plane as surface
5000f. Additionally, surface 5010c'' is generally flush with and
extends in the same plane as surface 5000c, and surface 5010d'' is
generally flush with and extends in the same plane as surface
5000d. Also, the cavity side surface topography 5012'' of mold
cavity block 5010'' can be generally be divided into areas: (i) a
contact surface area 5010g''; (ii) a slightly lower recessed
non-contact surface area 5010h''; and (iii) a cavity wall surface
area 5011''. It may be appreciated, that if the size and shape of
the mold cavity surface is different between two mold cavity blocks
5010'', the shape of the contact surface area 5010g'' and
non-contact surface area 5010h'' can be altered to some extent
between the two mold cavity blocks, to ensure that with a given set
clamping pressure, the contact pressure is held within a desired
pressure range, even though the two mold cavity blocks 5010'' are
used for producing differently sized/shaped items.
[0539] With particular reference to FIG. 26A-C, the mold cavity for
an item to be molded is formed between the outer surface of inner
core 7032 and the cavity wall surfaces 5011'' of mated and engaged
cavity mold blocks 5010''. The upper portion of the mold cavity is
sealed by the bottom horizontal circular ring shaped edge 7030a of
the outer core 7030. By the alignment of the outer core 7030 and
the upper part of inner core 7032 with cavity wall surface 5011',
the lower part of the inner core 7032 will be properly positioned
within the cavity wall surfaces 5011' to form the precise mold
cavity configuration that is desired. Each mold cavity block 5010'
may also have opposed outer side surfaces 5010e'' and 5010f''.
[0540] Again with primary reference to FIGS. 26E-F, longitudinally
extending guide pin openings 5035'' may be provided in non-contact
surface areas 5010h'' of stationary mold cavity blocks 5010'' (FIG.
26E) interconnected to a stationary platen 196, to receive a guide
pin 5007'' that may be mounted in openings 5008'' on a moving mold
cavity mold block 5010'' (FIG. 26F) interconnected to a moving
platen 196. Guide pin openings 5035'', 5008'' and guide pins 5007''
may be formed to very high tolerances to ensure that when two mold
cavity blocks 5010'' are brought together in face to face mating
relation with each other, with opposed contact surface areas
5010g'' being in contact with and forced towards each other, all
the features of the desired outer surfaces of the mold cavity are
formed properly (e.g. the two mold cavity halves are accurately
aligned with each other to assist in avoiding/minimizing visible
longitudinal split lines on the molded items).
[0541] Additionally, as shown in FIGS. 26D-F, mounting blocks 5060
may be secured by bolts 5063 received in openings 5064 through
mounting blocks 5060 into aligned threaded openings in surface
5000b''. Mounting blocks 5060 may also be secured to service plates
5196, 5196' with bolts 5062 received through openings 5061 into
aligned threaded openings in 5196, 5196'. Mounting blocks 5060 help
to stabilize the base blocks 5000 (and the mold cavity blocks
mounted thereto), before and when they are subjected to loading by
the clamping mechanism.
[0542] Advantages of the cavity plate combination of a base block
5000 and a mold cavity block 5010'' is that the outer surface area
is generally consistent or of a standard shape, yet the cavity side
surface topography 5012'' can be varied to accommodate any shape
and size (within certain limits) of item to be molded. Thus, the
relative size of contact surface area 5010g''; lower recessed
non-contact surface area 5010h''; can be adjusted and can take into
account the configuration and size of the cavity wall surface area
5011''.
[0543] With reference to FIGS. 26A-F, a gate area 5016'' may be
formed vertically through a lower portion of the body of each mold
block cavity 5010'', to provide a channel from the exterior of the
mold cavity block into the cavity half 5015'' and into the mold
cavity formed when the inner core 7032 and outer core 7030 of the
mold core assembly 190 are received into cavities formed by
interior core receiving surfaces 5009'' and cavity wall surfaces
5011'' of mated mold cavity blocks 5010'' (FIG. 26A). The two
opposed, face to face gate areas 5016'' of opposed pairs of mold
cavity blocks 5010'' cooperate to define a gate structure 5017''
(FIG. 26D) when, in operation of a mold sub-assembly 3040, 3040', a
pair of mold cavity blocks 5010'' are mated with each other. It is
through the formed gate structure 5017'' that molding material may
be injected into the formed mold cavity as generally described
herein.
[0544] Pairs of opposed vent areas 5037'' may also be formed
through each opposed sides of the body of each mold block cavity
5010'' (FIG. 26E) to provide opposed pairs of vent channels between
the exterior of the mold cavity block and the interior of the
cavity half 5015''. It will be appreciated that when during
operation of system 100, two mold cavity blocks 5010'' are oriented
in face to face mated relation with each other, with opposed
contact surface areas 5010g'' being in contact with each other and
forced towards each other, a pair of complete opposed vent
structures will be formed by the two opposed, face to face vent
areas 5037' of the opposed mold cavity blocks 5010'. It is through
the formed vent structures that air may escape from the interior of
the mold cavity as molding material is injected into the formed
mold cavity.
[0545] It will be appreciated that when during operation of system
100, two mold cavity blocks 5010'' are oriented in face to face
mated relation with each other, with opposed contact surface areas
5010g'' being in contact with and forced towards each other, the
outer surface of a complete mold cavity will be formed by the
opposed cavity wall surfaces 5111''. This will result in a
longitudinal split line being present between the two mating mold
cavity blocks 5010'' at the inward edges defined by the boundary
between cavity wall surfaces 5011'' and contact surface areas
5010g. Again, it is important that the mating edges of the two
cavity wall surfaces be in tight, unbroken contact with each other
and that the edges be flush with each other to avoid a
discontinuity at the join of the adjacent cavity mold surfaces. To
minimize problems associated with a visible longitudinal split
line, it is important that the interface between a pair of mated
and engaged mold cavity blocks 5010'' be controlled with a very
high degree of tolerance during operation of system 100.
[0546] With reference now to FIG. 26J, a further mold cavity block
5010''' is illustrated and in which the cavity side surface
topography 5012' may be formed generally in the same manner as the
cavity side surface topography of mold cavity block 5010'' as
referenced above. Base block facing surface 5010a''' of mold cavity
block 5010' and its surface topography and features may be
generally be the same manner as that of mold cavity block 5010''
except for the following. A generally cuboid bottom open trough
area 5013' may be formed in surface 5010a'. Trough area 5010a'''
may be formed by milling out the material from surface 5010a' using
conventional milling apparatuses and methods. Trough area 5010'''
may be configured to receive therein a cooling channel module
5019'''.
[0547] Cooling channel module 5019' may have one or more cooling
channels 5030''' (FIG. 26J) with respective input and output ports
for connecting to corresponding ports to channels 5020/5021 in base
block 5000 such that cooling fluid can flow through cooling
channels 5030''', in a manner as described above. The configuration
for the cooling channel in a cooling channel module 5019' may vary
and may be designed to provide desired cooling in the particular
configuration of cavity wall surface 5011. The cooling channel
module 5019' may have an outer generally rectangular framework with
side frame members and a base that support the cooling channels
therein. The outer framework may provide a friction fit of the
cooling channel module 5019'' with the vertical walls of trough
area 5010'''.
[0548] In each embodiment where a mold cavity block is manufactured
as a separate piece to the base block (such as mold cavity block
5010'' and base block 5000'' or cavity block 5010''' and base block
5000''') a sealing ring may be provided on the opposed mating
surfaces of the cavity block and base block around the water
fittings to provide a water seal. For example, as shown in FIG. 26J
a sealing o-ring 5022 made from a suitable material such as a
suitable rubber may be provided between the mold cavity block 5010'
and base block 5000''' to provide a fluid seal between mold cavity
blocks 5010''' and base blocks 5000'''. Internal sealing within
mold cavity block 5010''' and cooling channel module 5019''' is
typically not required.
[0549] The result is that a standard configuration for a surface
topography 5012''' defining the trough area 5013''' can be milled
on the cavity side surface of a cavity mold block 5010''' and then
a particularly configured cooling channel module 5019'' can be
inserted therein to provide the desired specific cooling channel
configuration for the particular cavity wall surface configuration
for the particular item to be molded. This enhances the efficiency
of the manufacturing process.
[0550] The components of cooling channel module 5019''' may be
formed from any one or more suitable material(s) such as copper or
stainless steel or a suitable plastic such as PP (polypropylene) or
PE (polyethylene).
[0551] With reference to FIG. 28A, a sequence of steps (a) to (f)
is shown by which a services block 5196 and a cavity plate 194 may
be connected to a platen 196. In the first steps (a) to (c), a
services block 5196 is mounted to a platen 196. Services block 5196
may be connected to a platen 196 by threaded bolts 5197 being
received through openings 5198 in services block 5196 and into
threaded openings 5195 in platen 196.
[0552] In step (d) a pre-prepared cavity plate 194 which may
comprise a base block 5000 and a mold cavity block 5010, 5010',
5010'' or 5010''', is made available to be connected to the
services block 5196. A quick connection of the type described above
may be utilized to connect the base block 5000, and thus cavity
plate 194, to the services block 5196 to provide a platen and
cavity plate assembly shown in (f) of FIG. 28A.
[0553] During operation of a mold sub-assembly 3040, 3040' as
described elsewhere herein, the platen pairs 196 will have at least
one services block 5196 attached thereon. One or more mold cavity
plates 194 will be attached to a services block 5196. The cavity
plates 194 may comprise a base block 5000 and a mold cavity block
5010, 5010', 5010'' or 5010''', and may produce molded items within
the mold cavities formed between opposed pairs of mold cavity
blocks 5010, 5010', 5010'' or 5010'''. Cooling fluid and/or other
services may be provided from the platens 196 to a services block
5196 and onto the base blocks 5000 and their corresponding mold
cavity blocks 5010.
[0554] When it is desired to change the type of molded item being
produced by particular mold cavity plate 194 of a mold sub-assembly
3040, 3040', the quick connection mechanism associated with the
appropriate pair of cavity plates 194 can be operated to disconnect
the base block 5000 from the services block 5196 with the quick
connection mechanism, along with the currently being used mold
cavity blocks 5010 attached to the base block 5000. A replacement
cavity plate 194 can then be installed by connecting the base block
5000 to that services block 5196 with a quick connection mechanism,
to thereby connect a replacement mold cavity blocks 5010 attached
to the replacement base block 5000. The replacement pairs of base
blocks 5000 and their respective mold cavity blocks 5010, 5010',
5010'' or 5010''' may be configured to produce a different
type/shape molded item than the removed pairs of base blocks and
mold cavity blocks 5010, 5010', 5010'' or 5010'''.
Transfer of Material to Shaper
[0555] With primary reference to FIGS. 29-37, details of example
features for transferring molding material into a shaper will now
be described.
[0556] FIG. 29 depicts a partial cross-sectional view of vessel 124
and a portion of cavity plate 194 of mold 200. As shown, orifice
136 of vessel 124 is aligned with a gate passage 2002, through
which feedstock is injected into mold 200. In order for such
injection to occur, sealing member 140 is withdrawn to un-seal
orifice 136. Injection is then caused by driving piston 182 towards
orifice 136 to reduce the volume of cavity 134 and force molding
material out through orifice 136.
[0557] During injection of feedstock into mold 200, the tip of
vessel 124 mates to a corresponding recess defined in cavity plate
194 proximate gate passage 2002. Vessel 124 is heated to a
temperature corresponding to that of molten feedstock. Mold 200 is
maintained at a cooler temperature, e.g. ambient temperature, to
promote rapid cooling and solidification of feedstock after
injection into the mold 200.
[0558] Typically, it is desirable for molten feedstock to be
maintained at a target elevated temperature until immediately prior
to injection, and then to subject the feedstock to a significant
thermal gradient in order to rapidly cool and solidify the material
within the mold. Such thermal control may maintain flowability of
the feedstock during injection, to achieve uniform filling of the
mold. Moreover, such treatment may ensure desired product
characteristics. For example, rapid cooling tends to limit or
prevent crystallization of feedstock, providing desired strength
and appearance characteristics in finished parts. Such rapid
cooling may be achieved by maintaining mold 200 at a low
temperature relative to the molten feedstock.
[0559] Insulator 1332 and cap 1334 help maintain the desired
thermal gradient at the interface of vessel 124 and mold 200.
Specifically, as noted, insulator 1332 has low thermal conductivity
and thus presents a barrier to heat transfer between with tip 1322
of vessel 124 and mold 200.
[0560] In contrast, cap 1334 has relatively high thermal
conductivity and tends to promote cooling of sealing member 140 by
heat transfer with mold 200.
[0561] Referring again to FIGS. 12A-12D, shaping station 104-1 also
comprises an actuator assembly 204, aligned with the injection
assembly and aligned with axis M-M. Actuator assembly 204 includes
a vessel positioning actuator (not shown) and an injector 210. The
vessel positioning actuator can be extended to urge vessel 124 into
abutment with mold 200. In this position, gate orifice 136 of
vessel 124 aligns with mold inlet gate 202 of mold 200.
[0562] Shaping station 104-1 may also comprise a valve locking
assembly. The valve locking assembly may serve as a trigger for
releasing sealing member 140 from its sealing position. FIG. 30 is
a series of corresponding isometric and overhead views showing the
operation of an example valve locking assembly 2080.
[0563] Valve locking assembly 2080 includes a cam guide 2082 with a
slot 2084 for receiving a bearing 1276 rigidly mounted to movable
arm 1272 of carrier 125. Bearing 1276 is received in slot 2084 as
carrier 125 moves vessel 124 toward molding axis M-M of the shaping
station. The direction of motion of the carrier 125 and vessel 124
is indicated by the arrow D in FIG. 36.
[0564] Slot 2084 has a profile such that it acts as a cam for
bearing 1276 and arm 1272. That is, as the carrier 125 and vessel
124 progress toward molding axis M-M, slot 2084 causes bearing 1276
and arm 1272 to pivot from an initial position in which arm 1272
engages sealing member 140, holding the sealing member in its
sealing position, toward a final position in which arm 1272 clears
sealing member 140 such that the sealing member can be displaced
from its sealing position.
[0565] With arm 1272 clear of sealing member 140, sealing member
140 can be pushed downwardly into vessel 124, clearing the
occlusion of orifice 136 and allowing molten molding material to be
transferred into the vessel 124. Sealing member 140 may, for
example, be retracted by way of an actuator positioned above or
below vessel 124, or by the pressure of the molten molding material
acting on sealing member 140 through orifice 136.
[0566] As shown in FIGS. 7 and 30, closure assembly 1270, including
movable arm 1272 and bearing 1276 are located at the bottom of
carrier 125. However, in other embodiments, the closure assembly
may be located at the top of the vessel.
[0567] For example, FIG. 31 depicts a carrier 125' with a
top-mounted closure assembly 1270', movable arm 1272' and bearing
1276'. In the depicted embodiment, cam guide 2082 with slot 2084 is
likewise positioned atop carrier 125, above vessel 124. Movable arm
1272' externally occludes orifice 136. Thus, arm 1272' functions as
a sliding gate to seal orifice 136. That is, as arm 1272' moves
towards a closed position, the arm slides over the top of vessel
124. In this embodiment, sealing member 140 may be omitted from
vessel 124 or alternatively, may provide redundant sealing along
with movable arm 1272'.
[0568] Referring to FIGS. 12A-12D, injector 210 of actuator
assembly 204 can be extended to act against piston 182 of vessel
124, urging piston 182 towards gate orifice 136 and expelling
molten feedstock out of cavity 134 through gate orifice 136.
Injection of feedstock into mold 200 and subsequent cooling of the
feedstock forms a molded workpiece 101'.
[0569] A second track 144 of transport subsystem 110 passes through
an ejection position below shaping station 104-1 and aligned with
ejection axis E-E.
[0570] A carriage 129 is received on track 144 and is slidable
along the track, e.g. by electromagnetic, pneumatic or mechanical
manipulation. Transport subsystem 110 is capable of indexing
individual carriages to specific locations on track 144. For
example, transport subsystem may comprise sensors or encoders (not
shown) for repeating the precise position of carriage 129.
[0571] Carriage 129 includes a workpiece grip 131 for physically
holding a workpiece to the carriage. As depicted, grip 131
comprises a nest which may be shaped to receive the molded
workpiece 101'. In some embodiments, the nest may have a shape that
is complementary to workpiece 101'. In other embodiments, the nest
may not be precisely complementary to any specific workpiece 101;
but may instead have a shape, e.g. a concave curve, designed to
securely receive workpieces in a range of shapes and sizes. Suction
may be applied to the nest to draw workpiece 101' against carriage
129. An actuator assembly 201 is located at the ejection position,
and is operable to extend and push carriage 129 toward mold 200 so
that the nest 133 is positioned immediately adjacent mold 200.
[0572] Tracks 144 of transport subsystem 110 are offset from one
another to provide clearance for carriages 125, 129 and workpiece
101' and vessel 124. The offset between the tracks may be one or
both of horizontal and vertical.
[0573] FIG. 32 depicts actuation assembly 204 of shaping station
104-1 in greater detail. In some embodiments, injection stations of
dispensing cell 102 may have actuation assemblies substantially
similar to actuation assembly 204. Actuation assembly 204 includes
a carriage 2040 for supporting a vessel 124 proximate mold 200.
Carriage 2040 is movable relative to mold 200 by linear drives
(e.g. servos or hydraulic pistons) 2042.
[0574] Carriage 2040 has a nest 2044 mounted thereto, for receiving
a vessel 124. Nest 2044 is positioned adjacent track 144 such that
a vessel 124 can be transferred onto nest 2044 by a carriage 125
travelling along track 144 as indicated by arrow Tin FIG. 38.
[0575] FIGS. 33A, 33B and 33C are isometric, cutaway isometric and
cross-sectional views, respectively, showing details of nest 2044
and a vessel 124.
[0576] As shown, nest 2044 has an opening 2045 to receive the base
of a vessel 124. The nest 2044 has side walls that project upwardly
but are sized to provide clearance for tongs 1254 (FIG. 7A, 7B),
such that vessel 124 may be inserted in nest 2044 while gripped by
tongs 1254.
[0577] Nest 2044 has a locking projection 2046 sized and positioned
to interlock with detent 1256 of vessel 124. Projection 2046 may be
semi-annular in shape. As vessel 124 is inserted in nest 2044,
projection 2046 is received in detent 1256 and retains the vessel
in nest 2044.
[0578] Although closure assembly 1270 and valve locking assembly
2080 are not shown in FIGS. 32, 33A and 33B, it should be
understood that valve locking assembly 2080 is positioned proximate
nest 2044, such that it causes arm 1272 to pivot clear of nest 2044
prior to or concurrently with insertion of vessel 124 into nest
2044 (see FIG. 30).
[0579] Nest 2044 comprises a channel 2048 for receiving the base of
sealing member 140, including detent 180.
[0580] The bottom of nest 2044 is open to permit interaction of
actuation assembly 204 with the body of vessel 124 and with sealing
member 140 and piston 182. Specifically, in the depicted
embodiment, actuation assembly 204 includes actuators, e.g.
pneumatic or servo-driven pistons, cylinders or the like, that can
extend through the bottom of nest 2044 to act against the body of
vessel 124, sealing member 140 or piston 182.
[0581] With reference to FIG. 33C, actuators for acting against
vessel 124, sealing member 140 and piston 182 may be in a nested
(e.g. concentric) arrangement. Specifically, a hollow vessel
locking actuator 2062 is positioned to abut the base of vessel 124.
A flow actuator, namely, injection actuator 2102 is nested within
vessel positioning actuator 2062. A gate operating actuator 2104 is
in turn nested within injection actuator 2102.
[0582] Vessel locking actuator 2062 and injection actuator 2102 may
be tubular, i.e. with annular top and bottom surfaces. The top
surfaces of actuator 2062 and 2102 (i.e. the surfaces closest to
orifice 136 along the longitudinal axis) abut vessel 124 and piston
180, respectively. Gate operating actuator 2104 may include a
gripping feature 2106 with a notch shaped to receive and interlock
with detent 180 of sealing member 140.
[0583] In the depicted embodiment, vessel locking actuator 2062 and
gate operating actuator 2104 are pneumatically driven and injection
actuator 2102 is servo-driven. However, each actuator may be driven
by any suitable drive type.
[0584] As will be explained in further detail, vessel locking
actuator 2062 is operable to bias vessel 124 toward mold 200, such
that the tip of vessel 124 tightly abuts the mold. In such
condition, vessel 124 is loaded against projection 2046 of nest
2044.
[0585] In the depicted embodiment, gate operating actuator 2104
includes a first section 2105 and a second section 2107, which are
coupled by a coupling pin 2109 that extends through a slot defined
in the injection actuator 2102. Specifically, pin 2109 may be
extended through holes in first and second sections 2105, 2107, to
couple the sections such that they extend together. In the depicted
embodiment, first section 2105 is a generally hollow tubular
element whereas the second element is a generally cylindrical
member. First section 2105 has an internal diameter to accommodate
independent sliding motion of the injection actuator 2102 nested
therein. Similarly, the injection actuator 2102 is a tubular member
with an internal diameter to accommodate the second section 2107 of
the gate operating actuator 2104 nested therein.
[0586] Gate operating actuator 2104 is operable to extend sealing
member 140 into its sealing condition, in which the sealing member
140 substantially prevents flow of material through orifice 136,
and to retract the sealing member 140 to open orifice 136.
[0587] As noted, in the depicted embodiment, injection actuator
2102 is driven by a servo. Servo drive of injection actuator 2102
may allow for large forces to be applied, to subject molding
material to suitable injection pressure, with relatively high
positional accuracy of injection actuator 2102, and thus, of piston
182. Other suitable drives may be used in other embodiments. For
example, in some embodiments, injection actuator 2102 may be
hydraulically driven.
[0588] Injection actuator 2102 is operable to act against piston
182 to force molding material out of vessel 124.
[0589] FIGS. 34A-34K depict shaping station 104-1 at various stages
of a shaping operation. For simplicity, core positioning actuator
1046 and loading actuator 1050 are omitted from FIGS. 34A, 34B-34C,
34E, 34I and 34J.
[0590] As shown in FIG. 34A, a carriage 125 carrying a vessel 124
is transported on track 144 to the injection position facing
injection station 104-1 and aligned with mold axis M-M. Orifice 136
of vessel 124 is opened as carriage 125 and vessel 124 are moved
into position at molding axis M-M, for example, as described above
with reference to FIG. 30. Once in position the vessel locking
actuator 2062 extends to lock the vessel 124 in the injection
station 104-1.
[0591] As shown in FIGS. 34B-34C, core assembly 190 is moved to
align with mold axis M-M and cavity plate 194-2. Platen 196-1 is
moved toward platen 196-2 and clamps mold 200 in a closed
position.
[0592] As shown in FIG. 34D, camshaft 3154 of load actuator 3050
rotates to urge moving plate 3142, loading frame 3104, and core 190
downwardly. The moving plate 3142, loading frame 3104 and core 190
move through a short stroke. In the depicted example, the length of
the stroke is about 2 mm. A downward force is exerted on loading
frame 3104 and core 190 to resist pressure from injection of
molding material into mold 200. The downward force may be referred
to as a pre-load. In the depicted example, the pre-load is about 60
kN.
[0593] Linear drives 2042 retract to move carriage 2040 toward mold
200 such that the coupling assembly of the vessel sealingly abuts
with the mold plates of the mold 200 and the orifice 136 of vessel
124 aligns with gate 202 of mold 200. The linear drives also
controls the contact force (effectively the sealing force) between
the mold and vessel. Gate operating actuator 2104 next retracts the
sealing member 140 away from the mold 200 thereby fluidly
connecting the vessel 124 with the molding cavity.
[0594] Injector 210 extends and forces piston 182 towards orifice
136, reducing the volume of cavity 134 and urging molten feedstock
through gate 202 and into mold 200. The feedstock cools and
solidifies, forming a solid molded article (FIG. 34E). Gate
operating actuator 2104 then extends the sealing member 140 towards
the mold 200 closing thereby isolating the vessel 124 from the
molding cavity.
[0595] As shown in FIG. 34F, once molding is complete, loading
actuator 3050 causes moving plate 3142, loading frame 3104 and core
190 to move upwardly through a short stroke. In the depicted
embodiment, the stroke may typically be 3 mm or less in length.
Camshaft 3154 rotates to bear against rocker 3152 and forces moving
plate 3142 upwardly. Projections 3174 of moving plate 3142 bear
against load frame 3104, moving the load frame upwardly. Inner core
3112 moves upwardly with load frame 3104. The force applied to
inner core 3112 during the upward stroke may be relatively large.
In some embodiments, the force may be similar in magnitude to the
preload created by load actuator 3050 prior to molding. The upward
movement dislodges the molded article from inner core 3112. That
is, it forms a small initial crack between the molded article and
inner core 3112.
[0596] As shown in FIG. 34G, mold 200 is moved to its open state by
clamping subassembly 3042 retracting platen 196-1 and cavity plate
194-1 from platen 196-2 and cavity plate 194-2.
[0597] As shown in FIG. 34H, secondary mold opening actuator 3180
extends to move the core assembly 190 away from platen 194 so that
core assembly 190 is aligned with ejection axis E-E (FIG. 39G).
[0598] Carriage 129 is extended upwardly so that its nest is
positioned immediately below molded workpiece 101' and suction is
applied through nest to assist in drawing molded workpiece 101' off
of core assembly 190. Carriage 129, carrying molded workpiece 101',
is then moved along track 144 for further processing.
[0599] Workpiece 101' may be removed from core assembly 190 by
retracting the inner core 3112 away from carriage 129 along
ejection axis E-E. Specifically, cylinders 3108 of core positioning
actuator 3046 extend to move load frame 3104 and inner core 3112
away from outer core 3114 and carriage 129. As inner core 3112
retracts, outer core 3114 bears against the workpiece and pushes
the workpiece off core assembly 190 as the core retracts.
[0600] FIGS. 35A-35F show operation of actuation assembly 204 in
greater detail. FIGS. 35A-35F are isometric cutaway views, which
are cut away at a 90 degree angle to the views of FIGS. 33B-33C. As
shown in FIG. 35A, once vessel 124 is moved into position on nest
2044, vessel locking actuator 2062 is extended, which biases vessel
toward mold 200 and against projection 2046 of nest 2044. As
mentioned previously, linear drives then retract to move carriage
toward mold such that the vessel sealingly abuts the mold plates of
the mold and the orifice of vessel aligns with gate of the
mold.
[0601] As shown in FIG. 35B, injection actuator 2102 is extended
into contact with piston 182. As shown in FIG. 35C, gate operating
actuator 2104 retracts and sealing member 140 retracts from its
sealed position to its open position, in which molding material is
free to flow through orifice 136.
[0602] Once sealing member 140 has been retracted to unseal orifice
136, injection actuator 2102 is extended through a stroke as shown
in FIG. 35C to force molding material out of vessel 124 and into
mold 200. The stroke may be a specific length, as defined by the
drive mechanism of injection actuator 2102, or the stroke may
continue until piston 182 abuts vessel tip 1322. Thus, the amount
of material forced out of vessel 124 may be determined by injection
actuator 2102 or its drive mechanism, or by the internal volume of
vessel 124.
[0603] Orifice 136 is resealed by extension of sealing member 140
as shown in FIG. 35E. That is, the gate operating actuator 2104
extends, moving sealing member 140 into a sealing position.
[0604] Following completion of injection, injection actuator 2102
may be withdrawn as shown in FIG. 35F. As depicted, piston 182 may
remain in its extended position following retraction of injection
actuator 2102. For example, piston 182 may be maintained in its
position by friction. In other embodiments, piston 182 may be
retracted along with injection actuator 2102.
[0605] In an alternative embodiment, as depicted in FIG. 36, the
shaping station 106-1 may further include a gate assembly 2200
provided between vessel 124 and mold 200 for selectively cutting a
vestige of injected feedstock between vessel 124 and mold 200 after
injection of the molding material is complete. The gate assembly
2200 is particularly useful when used in conjunction with a vessel
without a sealing member 140 as mentioned previously. When used
with the vessel 124 having a sealing member 140 the gate assembly
2200 nonetheless may assist with trimming of the vestige formed on
the base of the preform prior to demolding. Gate assembly 2200 may
comprise a plate 2202, which may be mounted below mold 200, and a
blade 2204. Blade 2204 may be received in a pocket 2206 defined in
plate 2202. As depicted, blade 2204 has an arched cross-sectional
shape. The arched portion of blade 2204 is compressed within pocket
2206 between plate 2202 and mold 200. Compression of blade 2204
biases the blade against the lower surface of mold 200 such that
the blade fits tightly against mold 200. However, in other
embodiments, blade 2204 may have different cross-sectional shapes.
For example, blade 2204 may be substantially flat. Gate assembly
2200 may also include a scraper 2208 positioned to rub against the
underside of blade 2204 as it extends and thereby dislodge residual
molding material from the underside of the blade. In the depicted
embodiment, scraper 2208 is serrated. In other embodiments, scraper
2208 may have a straight edge.
[0606] FIGS. 37A-37B are cross-sectional views showing a process of
cutting a stream of molding material between vessel 124 and mold
200. The process may occur immediately after injection of molding
material into mold 200 is completed. As shown in FIG. 37A, blade
2104 is advanced toward the stream of molding material, which may
be partially or fully solidified.
[0607] As shown in FIG. 37B, blade 2104 cuts the stream of molding
material, thereby parting the article within mold 200 from any
residual molding material outside mold 200 or within vessel 124.
After such parting, vessel 124 may be withdrawn from mold 200.
Blade 2104 then extends past scraper 2108 to dislodge molding
material, if any, from the underside of the blade.
[0608] FIG. 38 depicts a conditioning cell 108 and shaping cell 106
in greater detail. As shown, stations of conditioning cell 108 and
stations of shaping cell 106 are located in close proximity to one
another. That is, conditioning station 108-1 and shaping station
106-1 are located close together.
Thermal Conditioning
[0609] With primary reference to FIGS. 39-40, details of an example
conditioning cell 108 will now be described.
[0610] In the depicted embodiment, conditioning cell 108 is for
creating a desired thermal profile by heating a molded workpiece in
order to prepare the workpiece for a subsequent shaping operation
at shaping cell 106. For example, stations of conditioning cell 108
may be configured to heat or cool a workpiece, changing its overall
temperature; or to change the temperature distribution in a
workpiece by preferentially heating or cooling some regions of the
workpiece; or a combination thereof.
[0611] FIG. 39 shows a cross-sectional view of conditioning station
108-1. Conditioning station 108-1 includes a frame 400 and a
heat-generation assembly 402, a heating chamber 404, a thermal
monitoring system 406, and a mandrel 408, all of which are
supported on the frame 400.
[0612] Heat-generation assembly 402 includes a device for applying
heat to a received workpiece. In some embodiments, heating may be
achieved by exposing the workpiece to microwave radiation. In other
embodiments, heating may be achieved by directing infrared light
onto the workpiece. Other suitable techniques may be used in other
embodiments. For example, a workpiece may be immersed in a heated
fluid such as air.
[0613] Heat generation assembly 402 may include one or more thermal
metering devices 410. Thermal metering devices 410 are operable to
control the rate at which heat is applied to a workpiece. For
example, thermal metering devices 410 may comprise wave tuners for
influencing characteristics of microwave radiation, e.g. by
altering a standing wave pattern of radiation within chamber 404 to
control the position of high-radiation regions relative to a
workpiece within the chamber. Alternatively or additionally,
thermal metering devices 410 may comprise shields to partially or
fully block incident radiation, or valves to regulate the flow of
heated fluid.
[0614] Heating chamber 404 is configured to receive the workpiece,
and heat from heat-generation assembly 402 is directed towards
heating chamber 404, such that the temperature of the workpiece
increases while it resides in heating chamber 404. In some
embodiments, heat may be applied focally to specific areas of the
workpiece, in order to produce a specific desired temperature
profile. The overall (e.g. average) temperature of the workpiece
may increase, remain static, or decrease. For example, in some
embodiments, portions of the workpiece may be permitted to cool
while heat is retained in or added to other portions. Thermal
metering devices 410 may provide for control of the heat
distribution and resulting temperature profile.
[0615] Mandrel 408 is mounted to frame 400 and is rotatable about
its axis and movable in three dimensions.
[0616] Mandrel 408 has a grip assembly 412 configured to releasably
engage a workpiece. As depicted, grip assembly 412 has a fixed
block 414 and a movable block 416. Fixed block 414 is rigidly
supported on mandrel 408. Movable block 416 is mounted to a linear
actuator 418, which is in turn mounted to mandrel 408.
[0617] A compressible member 415 is positioned between fixed block
414 and movable block 416. Linear actuator 418, thereby axially
compressing the compressible member 415, can retract movable block
416. Axial compression of the compressible member 415 causes a
radial expansion of the member into contact with an interior wall
of workpiece 101. The compressible member 415 frictionally engages
the workpiece, and thereby retains the workpiece on the mandrel
408.
[0618] Movable block 416 has a tapered leading surface, which at
its widest extent is sized for slight interference with a cavity of
workpiece 101'. Movable block 416 may be extended into workpiece
101'. Such extension relieves strain in compressible member 415,
allowing it to rebound to its original shape and release workpiece
101'. Extendable block 416 can then push workpiece 101' off mandrel
408.
[0619] Heating chamber 404 has a top opening 422 through which
mandrel 408 can lower a workpiece into the chamber. Thermal
monitoring system 406 comprises temperature probes 407 proximate
top opening 422, to measure and record a temperature profile of a
workpiece entering heating chamber 404. In the depicted embodiment,
four temperature probes 407 are present, and are spaced evenly
around top opening 422. The depicted temperature probes 407 are
infrared cameras. In other embodiments, other types of temperature
measuring devices may be used. For example, temperature probes may
include thermocouples. Other suitable temperature-measuring devices
may be used, as will be apparent to skilled persons.
[0620] FIGS. 40A-40C depict conditioning station 108-1 at various
stages of a conditioning operation. FIG. 40C shows the conditioning
station 108-1 in cross-section to show internal components.
[0621] As shown in FIG. 40A, a workpiece 101' is delivered to
conditioning station 108-1 by a carriage 129 travelling along track
144. Carriage 129 is moved to a carriage loading position.
[0622] As shown in FIG. 40B, mandrel 408 is positioned over
workpiece 101', with grip assembly 412 received inside the
workpiece. Movable block 416 of grip assembly 412 is retracted
toward fixed block 414 to squeeze compressible member 415 against
the workpiece. Friction between compressible member 415 and
workpiece 101' holds the workpiece to mandrel 408.
[0623] Mandrel 408 moves workpiece 101' into position proximate top
opening 422 of heating chamber 404 and then, as shown in FIG. 40C,
passes workpiece 101' into the heating chamber 404. A treatment is
applied to the workpiece 101'. Specifically, heat is generated by
heat generation assembly 402 and applied to the workpiece within
heating chamber 404.
[0624] Once treatment of workpiece 101' has been completed, mandrel
408 withdraws the workpiece 101' from heating chamber 404.
Secondary Shaping
[0625] With primary reference to FIGS. 41-51, features and
operation of example stations of an example shaping cell 106 and a
mold for the shaping cell will now be described in detail. In the
depicted embodiments, the example stations are for blow molding of
plastic articles. However, many features of the described
embodiments are not limited to blow molding, as will be
apparent.
[0626] FIGS. 41A-41B show a shaping station 106-1 of shaping cell
106 in greater detail.
[0627] As depicted, shaping station 106-1 is a stretch blow-molding
station, for forming a hollow container from a molded workpiece. In
an alternative embodiment, not shown, the shaping station is a
liquid-molding station, wherein the operation of forming and
filling of a container are combined. Station 106-1 includes a mold
500, defined by a plurality of mold sections 502-1, 502-2, . . .
502-n (individually and collectively, mold sections 502). In the
depicted embodiment, mold 500 includes two sections 502-1, 502-2
and a bottom plug 503. However, more or fewer sections may be
present.
[0628] Mold sections 502 are mounted to respective platens 504 of a
press 506. Some or all of mold sections 502 are mounted to movable
platens, so that the mold 500 can be opened to allow insertion of a
workpiece or removal of a completed part, and so that the mold 500
can be clamped shut during molding.
[0629] Press 506 is mounted to a support frame 510 which is in turn
removably mounted to a base 512. A clamping assembly 514 is mounted
to support frame 510 and platens 504 are fixed to clamping assembly
514 for opening and closing of the platens.
[0630] Clamping assembly 514 is shown in greater detail in FIG. 47.
In the depicted embodiment clamping assembly 514 has two linkages
516, each coupled to a respective platen 504.
[0631] Each linkage 516 is substantially identical to linkage 3070
depicted in FIG. 12D and has a drive link 518 and rockers 520, 522.
Drive link 518 is coupled to a crosshead 524 which is driven in
reciprocating motion by a linear actuator, such as a ball screw
driven by an electric motor 526.
[0632] In other embodiments both platens may be driven by a single
linkage. For example, the linkage may be substantially identical to
any of linkages 3070', 3070'', 3070', 3070'.
[0633] Press 506, mold sections 502 and bottom plug 503 may be
installed to and removed from a support base as a unitary assembly,
substantially as described above with reference to shaper module
3054 of shaping station 104-1.
[0634] Shaping cell 106 is located close to conditioning cell 108
and lies within an area reachable by mandrel 408, such that mandrel
408 is able to reach stations of conditioning cell 108 as well as
stations of shaping cell 106. In other words, mandrel 408 is
capable of removing a workpiece from heating chamber 404 of
conditioning station 108-1 and placing the workpiece in mold 500 of
shaping station 106-1 for molding into a container.
[0635] A molding head 504 is mounted on a second mandrel 506 and is
operable to inject pressurized fluid into a workpiece within mold
500 to expand the workpiece to conform to the mold. Molding head
504 has a grip assembly similar to grip assembly 412 of mandrel
408. The grip assembly comprises fixed and moving blocks 510, 512
and a compressible member 514 to frictionally grip workpiece 101'
when squeezed between blocks 510, 512. Molding head 504 further
comprises a fluid injection passage extending along an axis of
mandrel 506 through which pressurized fluid (e.g. air or liquid)
can be injected into workpiece 101'.
[0636] FIGS. 42-43 depict components of shaper station 106-1 in
greater detail. As noted, mold 500 includes mold sections 502-1,
502-2 and a bottom puck 503. Mold sections 502-1 and 502-2 are
mounted to platens 196 which are supported on a shaper frame
8052.
[0637] Platens 196 are movable by a clamp 8070 between open and
closed positions. In the closed position, mold sections 502-1,
502-2 and bottom puck 503 mate to cooperatively define a mold
cavity 8000. In the open position, platens 196 are spaced apart. In
a first mode, mold sections 502-1, 502-2 are coupled to the platens
so that a molded part may be removed. In a second mode, mold
sections 502-1, 502-2 are de-coupled from platens 196, so that they
can be removed as an assembly.
[0638] Shaper frame 8052 and clamp 8070 are substantially identical
to shaper frame 3052 and clamp 8070. Multiple interchangeable molds
500 may be present, each comprising a set of mold sections 502-1,
502-1 and bottom puck 503. Each mold defines a specific mold cavity
8000 in operation, for forming parts of a specific configuration.
For example at any given time, a single mold 500 may be installed
to platens 196 of a shaper station 106-1. The mold 500 may be
interchanged with another mold, for example, to produce parts of a
different configuration or for maintenance or repair.
[0639] Each mold section 502 is removably mounted to services block
8004. Each services block 8004 is in turn mounted directly to
platen 196. Mold sections 502 may be formed of a relatively
lightweight material such as an aluminum alloy. Services blocks
8004 may be formed of a suitable tool steel or a high-strength
aluminum alloy.
[0640] During molding (as shown in FIGS. 42-43), clamp 8070 exerts
a closing force on the mold 500. The closing force urges mold
sections 502 against one another and provides mold conditions
consistent with high-quality molded articles. However, mold
sections 502 tend to be formed of relatively low-strength material.
Accordingly, services blocks 8004 have load limiting features,
namely, load limiting blocks 8005 formed in the opposing faces of
services blocks 8004.
[0641] Under nominal molding conditions, load limiting blocks 8005
are spaced apart by a small margin. However, in the event that the
load applied by clamp 8070 is excessive, mold sections 502 may
deform or compress incrementally, such that load limiting blocks
8005 abut one another. In this condition, load limiting blocks 8005
bear at least part of the clamping load, and thus protect against
further deformation of mold sections 502.
[0642] FIG. 44 shows an isometric view of mold 500 and services
blocks 8004, with services blocks 8004 exploded from mold sections
502. FIG. 45 shows an isometric view of mold 500 with mold sections
502 and puck 503 exploded from one another. As depicted, each mold
section 502 has a half-cylindrical outer surface and an inner
surface 8012 shaped according to the desired configuration of mold
cavity 8000 (and thus, of the produced parts).
[0643] Each mold section 502 has a support ledge 8014 at its top
surface. Each support ledge 8014 is generally annular. In the
closed position, with mold sections 502 abutting one another, the
support ledges 8014 cooperate to define a mold opening. A preform
from shaper cell 104 may be supported on support ledges 8014, such
that a neck ring of the preform abuts support ledges 8014 and the
preform extends into mold cavity 8000.
[0644] Mold sections 502 have handling studs 8020 which extend
outwardly from their outer surfaces. Handling studs 8020 have
connectors 8022 for engagement by a material handling device such
as a robot. Mold sections 502 additionally have connectors 8024 on
outer surfaces 8010 which, in operation, face towards services
blocks 8004. As which be explained in further detail, connectors
8024 can be selectively engaged with corresponding connectors on
services block 8004 to couple mold sections 502 to services blocks
8004.
[0645] As shown in FIG. 45, mold sections 502 have recesses 8019 at
their lower ends. Recesses 8019 are half-cylindrical and are sized
to cooperatively receive bottom puck 503 when mold 500 is closed
(see FIG. 46). Semi-annular retaining flanges 8021 project inwardly
from the walls of recesses 8019. When mold 500 is closed, flanges
8021 are received by and interlock with puck 503. Thus, puck 503 is
captive as part of mold 500 when the mold is closed.
[0646] Each services block 8004 has a mold-facing surface 8030 and
a rear surface 8032. Rear surface 8032 is shaped to mate to platen
196 and mold-facing surface 8030 is shaped to mate to the outer
surface 8010 of a mold section 502. In the depicted embodiment,
rear surface 8030 is generally planar and cavity block-facing
surface 8030 is generally half-cylindrical.
[0647] Rear surface 8032 has a plurality of connectors 8034 which,
in operation, align to corresponding connectors of platen 196. In
the depicted embodiment, the connectors between services block 8004
and platen 196 are fasteners such as bolts. Dowels (not shown) may
be installed to locate services block 8004 relative to platen
196.
[0648] Cavity block-facing surface 8032 has connectors 8036 which,
in operation, face towards the corresponding mold portion 502 and
align with connectors 8024. As noted, connectors 8036 and
connectors 8024 may selectively engage one another to lock mold
section 502 and services block 8004 together.
[0649] In the depicted embodiment, services blocks 8004 also has
services connections. For example, electrical circuits connect
sensors such as thermocouples, and power heating elements.
Pneumatic circuits are be used to drive actuators, e.g. to control
quick connection mechanisms. Water circuits provide cooling. As
depicted, cooling and pneumatic services need not be routed to mold
sections 502. Rather, pneumatic operation of connectors 8024/8036
is provided within services blocks 8004. Cooling fluid flows in a
circuit through services blocks 8004, which cool mold sections 502
are cooled by conduction. In some embodiments, services connections
are routed to lateral sides of services blocks 8004. Alternatively
or additionally, services connections may be routed through platens
196 or through a discrete distribution plate mounted between each
platen 196 and services block 8004. In other embodiments, in
addition to physical coupling by way of connectors, 8024, 8036,
mold sections 502 and base plates 8004 may be connected with one or
more services such as electrical, pneumatic and water circuits. For
example, liquid cooling circuits may be defined in mold sections
502 and pneumatic lines may be defined in mold sections 502 for
operation of connectors. Services blocks 8004 have auxiliary
pneumatic ports 8037, 8039. Auxiliary pneumatic ports 8037, 8039
are for providing a supply of pressurized air to operate connectors
8036. Port 8037 is for receiving a pressurized stream to center
connectors 8036, 8024 relative to one another. That is, with a
connector 8024 and a connector 8036 coupled together, a stream of
pressurized air may be provided to port 8037 to briefly unload the
connectors. Upon release of the pressurized air, the connectors
return to nominal locked positions. Port 8039 is for receiving a
pressurized stream of air to disengage connectors 8036, that is, to
bias them to a released state in which connectors 8024 can be
freely removed.
[0650] Referring to FIG. 46, bottom puck 503 comprises a puck
cavity block 8050, a puck base block 8053 and a connecting block
8054. Connecting block 8054 is in turn connected to an actuator
block 8056. Puck 503 is movable as an assembly along an axis
perpendicular to the closing axis of clamp 8070. Such movement may
be affected, for example, by one or more linear actuators mounted
beneath actuator block 8056 and supported on shaper frame 8052. The
linear actuators may be, for example, servos, or hydraulic or
pneumatic pistons.
[0651] Puck cavity block 8050 defines the bottom surface of mold
cavity 8000 when mold 500 is closed. As will be appreciated,
molding occurs at relatively high temperatures. Once the part has
assumed its final shape, it is desirable to quickly cool the part
to avoid deformation or other defects, and to enable the part to be
removed. A thermal regulation circuit 8058 is defined between puck
cavity block 8050 and puck base block 8053. Fluid such as water may
be circulated through the circuit to promote removal or heat from
the molded part or introduction of heat to the molded part.
[0652] Puck base block 8053 is mounted (e.g. bolted) to the
underside of puck cavity block 8050. Base block 8053 has an annular
lock ring 8060 fitted around its outer periphery. Lock ring 8060
defines a pocket in which locking flange 8021 of cavity blocks is
received when mold 500 is closed, thereby locking base block 8053
connecting block 8054 and puck cavity block 8050 to mold sections
502.
[0653] Connecting block 8054 is mounted (e.g. bolted) to base block
8053. Connecting block 8054 has a connector 8062 on its underside
which faces actuator block 8056 in operation. Connecting block 8054
further has one or more ports for services, such as pneumatic,
cooling and electrical circuits. A flow path for cooling fluid
extends from the port through base block 8053 and connecting block
8054 to cooling circuit 8058. Connecting block 8054 and actuator
block 8056 may connect in fluid communication by way of
quick-connection ports that couple to one another upon being
brought together. Coupling may be automatic, e.g. electronically
triggered and operated or spring-loaded and triggered by
insertion.
[0654] Connector 8062 is received in a corresponding socket 8064 of
actuator block 8056 (FIG. 43). Actuator block 8056 is configured to
mate with linear actuators for movement of puck 503.
[0655] Any of connectors 8024, 8036, 8062, 8064 may be quick
connectors. That is, any of connectors 8022, 8024, 8034, 8036 and
may form quick connection mechanisms with their counterpart
connectors. Such quick connection mechanisms may have
characteristics as previously described above.
[0656] In the depicted embodiment, the quick connection mechanisms
comprise studs projecting from mold sections 502 towards mating
sockets defined in services block 8004, and connectors 8062 which
are studs projecting from connection block 8054 towards mating
connectors 8064 which are sockets defined in actuator block
8056.
[0657] As described above, the sockets are operable in engaged and
disengaged states. In the disengaged state, a stud may freely pass
into or out of the socket. In the engaged state, grippers in the
socket are biased into interlocking engagement with the studs. The
studs may be shaped such that interlocking by a socket biases a
stud into a precise position relative to the socket. In other
words, the quick connection mechanisms may locate mold sections 502
and services blocks 8004 relative to one another, as well as
retaining them together.
[0658] The sockets of the quick connection mechanisms may, for
example, be spring-biased to one operating state (e.g. the engaged
state), and may be shifted to the other state (e.g., the disengaged
state) by application of pneumatic pressure. Accordingly, pneumatic
supply may be routed to services blocks 8004 for operation of the
quick-connection mechanisms.
[0659] In the depicted embodiment, the quick connection mechanisms
may be substantially similar to those depicted in FIG. 4H above.
For example, the quick connection mechanisms may be model 305979
and 306050 connectors, manufactured and sold by Andreas Maier GMBH
& CO. KG (AMF) of Germany.
[0660] Quick connection mechanisms for services ports such as fluid
ports may be model 6989N and 6989M connectors, manufactured and
sold by AMF.
[0661] Conveniently, coupling and de-coupling of mold sections 502
and services blocks 8004 by way of quick-connect couplings allows a
mold 500 to be quickly and easily removed and substituted with
another mold 500.
[0662] FIGS. 47-49 depict stages of changing a mold 500.
[0663] As shown in FIGS. 47A-47B, platens 196 are held in their
closed positions, with mold sections 502-1, 502-1 abutting one
another. With the mold in a closed position, material handling
devices, namely, gripping plates 8080 mounted on robotic arms (not
shown), move towards the lateral faces of mold 500. Gripping plates
8080 have connectors corresponding to handling connectors 8022 of
mold sections 502. Specifically, the connectors of gripping plates
8080 are positioned and sized to mate to connectors 8022 of mold
sections 502. In the depicted embodiment, connectors are sockets
configured to matingly receive connectors 8022 to define a quick
connection mechanism.
[0664] In some embodiments, gripping plates 8080 may approach
vertically. In other embodiments, the gripping plates may approach
horizontally.
[0665] Once engaged with connectors 8022, as shown in FIGS.
48A-48B, gripping plates 8080 and their associated robot arms are
capable of supporting and lifting mold 500 as a unitary assembly.
Specifically, mold sections 502-1, 502-2 and puck 503 may be
removed as an assembly.
[0666] After gripping plates 8080 engage connectors 8022,
pressurized air is provided to auxiliary port 8039 of services
block 8004. Application of pressurized air by way of auxiliary port
8039 causes connectors 8036 to release connectors 8024, thereby
de-coupling mold sections 502 from services blocks 8004. In the
depicted embodiment, the pressurized air is provided from a line
associated with the shaper station 106-1. Alternatively, supply
lines may be associated with gripping plates 8080.
[0667] Platens 196 and services blocks 8004 pull away from mold
sections 502. Meanwhile, gripper plates 8080 hold mold sections 502
together.
[0668] Holding of mold sections 502 in assembly with services
blocks 8004 likewise holds bottom puck 503 to the assembly.
Specifically, semi-annular annular retaining flanges 8021 of mold
sections 502 are held in registration with lock ring 8060 of bottom
puck 503.
[0669] Connector 8062 of puck connecting block 8054 is released
from actuator block 8058. The release may be affected, for example,
by pneumatic actuation. Once connector 8062 is released, bottom
puck 503 may be freely pulled away from actuator block 8058.
[0670] Gripping plates 8080 and the associated robot arms may then
remove mold 500 as a single assembly, shown in FIGS. 49A-49B.
Specifically, in the depicted embodiment, the robot arms lift
gripping plates 8080 and mold 500 away from services blocks 8004,
actuator block 8056 and platens 196. Installation of a new mold 500
may follow.
[0671] Gripping plates 8080 and the associated robot arms interface
with and lock to connectors 8022 of another mold 500.
[0672] Once the new mold 500 is engaged by gripping plate 8080, the
robot arms position the new mold in shaper cell 106-1 for mounting
of the new mold 500 to platens 196. Clamp 8070 then moves platens
196 and services blocks 8004 inwardly. Connectors 8024 of mold
sections 502 align in registration with connectors 8036 of services
blocks 8004. Connectors 8024, 8036 engage and lock together. A
pneumatic supply may be provided to auxiliary port 8037 of services
block 8004 to seat connectors 8024, 8036 together.
[0673] Actuator block 8056 is extended upwardly towards connecting
block 8054 of bottom puck 503. Connector 8064 of actuator block
8056 and connector 8062 of connecting block 8054 are aligned with
one another. Connector 8064 receives and locks with connector 8062
of connecting block 8054. Once connector 8062 is received by
connector 8064, connector 8064 is actuated to a closed shape, e.g.
by application of pneumatic pressure. Bottom puck 503 is therefore
locked to actuator plate 503. Once base plates 8004 are coupled to
services plates 8006, and bottom puck 503 is coupled to actuator
plate 8056, mold 500 can be operated by clamping unit 8070 produce
parts according to the configuration of cavity 8000.
[0674] In the depicted embodiment, swapping of molds 500 can
therefore be accomplished relatively quickly and easily, with
little or no manual setup. Indeed, connections between base plates
8004 and mold sections 502, and between actuator plate 8056,
connecting block 8054, puck base block 8053 and puck cavity block
8050, may be entirely automated. For example, all of the connectors
may be operated by actuators, such that they can be simply switched
between locked and unlocked states.
[0675] Accordingly, shaper station 106-1 can be readily configured
for molding a variety of parts in a variety of different shapes and
sizes.
[0676] In the depicted embodiment, shaping station 106-1 is a
stretch blow molding apparatus. A rod 520 extends within mandrel
506 and is extendible into workpiece 101' within mold 500 to
mechanically stretch the workpiece. In other embodiments, stations
of shaping cell 106 may be for other types of shaping operations.
For example, stations of shaping cell 106 may be any suitable type
of blow-molding apparatus.
[0677] FIGS. 51A-51D depict mold components of a shaping cell 106-1
at various stages of a shaping operation.
[0678] Mandrel 408 (FIGS. 39-40) carries workpiece 101' from
conditioning cell 108-1 to a mold position within mold 500 of
shaping cell 106-1. Grip assembly 412 releases the workpiece and
mandrel 408 is withdrawn. Mandrel 506 moves to a position proximate
mold 500.
[0679] As shown in FIG. 51B, mandrel 506 moves toward workpiece
101' and grip assembly 508 extends into workpiece 101'.
Compressible member 514 is squeezed into the workpiece to grip it.
Rod 520 is extended into workpiece 101' and the workpiece is
stretched by rod 520 and injection of pressurized air to conform to
the shape of mold 500 (FIG. 37C). The stretched workpiece cools and
hardens to form a final-shaped workpiece 101'', e.g. a hollow
container such as a bottle. Mold 500 is opened and workpiece 101''
is removed by mandrel 508.
Transport Subsystem
[0680] With primary reference to FIGS. 52-66, details of example
transportation systems will now be described.
[0681] As described above and shown in FIGS. 39-40 and 50-51,
shaping cell 106 and conditioning cell 108 have associated mandrels
408, 506 that form part of transport subsystem 110. Each mandrel
can reach a conditioning station 108-1, 108-2, . . . 108-n and a
shaping cell 106-1, 106-2, . . . 106-n. In other embodiments,
mandrels 408, 506 may be longer, such that a single mandrel is
capable of reaching multiple conditioning stations and multiple
shaping stations.
[0682] In other embodiments, one or both of mandrels 408, 506 may
be replaced with one or more tracks 144. The tracks may include one
or more loops and one or more branches connecting individual
conditioning or shaping stations to the one or more loops.
[0683] Thus, as depicted, molding material is processed in four
stages to produce a workpiece 101'' such as a bottle. Specifically,
molding material is dispensed at dispensing station 102-1 and
shaped into a preform in a primary shaping operation, i.e.
injection molding at shaping station 104-1. The preform is heated
at conditioning station 108-1 to produce a temperature profile
suitable for blow molding, and the heated preform is shaped into a
final shape in a secondary shaping operation, i.e. stretch blow
molding at shaping station 106-1.
[0684] The workpiece 101'' so produced has specific characteristics
according to the processing stages. For example, properties such as
material type, colour and mass depend on the configuration of
dispensing station 102-1. The shape of the bottle depends on the
configuration of shaping station 104-1, conditioning station 108-1
and shaping station 106-1.
[0685] Dispensing stations 102-2, 102-3, 102-4 may be configured
differently than dispensing station 102-1. For example, dispensing
stations 102-2, 102-3, 102-4 may contain different feedstock
materials and/or different colours.
[0686] Likewise, shaping station 104-1 may be configured
differently from the other stations of shaping cell 104 and shaping
station 106-1 may be configured differently from other stations of
shaping cell 106. For example, each station of shaping cell 104 may
have installed a mold defining a unique preform size and shape.
Each station of shaping cell 106 may have installed a mold defining
a unique bottle size and shape. A pre-shaped workpiece 101' having
a given size, shape and weight may be transformed into any of
multiple possible types of finished workpiece 101'' (e.g. bottles
of different sizes and shapes), depending on the shaping station
106 at which the pre-shaped workpiece is processed. Similarly, a
station of shaping cell 106 may be used to form any of multiple
possible types of finished workpiece 101'', depending on the
pre-shaped workpiece 101' that is used. For example, a larger
pre-shaped workpiece 101'
[0687] Stations of conditioning cell 108 may also be configured
differently to produce articles with different characteristics. For
example, the final shape created at a station of shaping cell 106
may be influenced by the temperature profile of workpiece 101' at
the beginning of shaping. That is, higher-temperature portions of
workpiece 101' may be more readily re-shaped. Accordingly, a
station of conditioning cell 108 may be configured to a produce a
non-uniform temperature distribution in a workpiece 101' in order
to result in non-uniform stretching, e.g. into an oblong shape.
[0688] Transport subsystem 110 flexibly interconnects stations of
process cells 102, 104, 106, 108, such that molding system 100 can
be rapidly configured to produce parts having varied
characteristics. In some embodiments, multiple types of parts
having different colours, shapes, sizes, or the like can be
produced simultaneously.
[0689] FIG. 52 is an overhead plan view of system 100, showing an
example configuration of transport subsystem 110.
[0690] As noted, in the depicted example, transport subsystem 110
includes a series of tracks 144. Tracks 144 are arranged in
individual segments 144-1, 144-2, 144-3, . . . 144-n. Segments
144-1, 144-2 are shared loops for accessing any station of
dispensing cell 102, shaping cell 104 and conditioning cell 108,
respectively. Other segments are branches connecting the shared
loops with individual stations or connecting shared loops together.
In the depicted embodiment, 16 track segments are present,
including two shared loops. However, more or fewer tracks may be
present, including more or fewer shared loops, depending on the
configuration of system 100. For example, the number of stations
within each of process cells 102, 104, 106, 108 and the physical
layout of the stations may influence the total number of tracks 144
and the number of shared loops of tracks 144. In some embodiments,
transport subsystem 110 may not include any shared loops of tracks
144.
[0691] Each of tracks 144 is configured to releasably engage and
retain carriages 125, 129. The carriages may, for example, be
coupled to the tracks 144 by rollers which interlock with the
tracks 144. Alternative, carriages 125, 129 may be magnetically
coupled to tracks 144. In some embodiments, carriages 125, 129 may
be mounted to shuttles which themselves are coupled to and movable
along tracks 144. In some embodiments, such coupling may be
electromagnetic or may be achieved using suitable mechanical
fasteners.
[0692] Carriages 125, 129 may be moved along tracks 144 by any
suitable drive mechanism. In some embodiments, carriages 125, 129
may be coupled to a belt or chain drive carried on tracks 144. In
other embodiments, carriages 125, 129 may be moved by
electromagnetic drives. For example, the magnetic drive may
comprise an array of driving electromagnetic induction coils which
can be sequentially activated to lift and move a magnetized vessel
125, 129 along track 144. An array of electromagnetic detection
coils may be positioned proximate the array of driving induction
coils and may be used to detect and track the position of the
vessels 125, 129.
[0693] As will be apparent from FIG. 52, paths through system 100
may include one or more of shared track loops 144-1, 144-2 as well
as one or more individual track segments. For example, a path
through dispensing station 102-1, shaping station 104-1,
conditioning station 108-1 and shaping station 106-1 may require
carriages 125, 129 to bear a workpiece along each of track loops
144-1, 144-2 and track segments 144-3, 144-7 and 144-15.
[0694] Transport subsystem 110 is equipped with a control system
1000 for directing and tracking the positions of carriages 125,
129. In some embodiments, the position of individual carriages 125,
129 may be tracked using a drive mechanism with a position encoder.
In other embodiments, position of carriages 125, 129 may be tracked
using a machine vision system, radio frequency tracking or other
suitable techniques.
[0695] In some embodiments, a large number of carriages 125, 129
may simultaneously be carried on tracks 144. Accordingly, control
system 1000 may maintain a data structure containing position data
for each carriage 125, 129.
[0696] At some locations in transport subsystem 110, carriages 125,
129 may be transferred from one segment of track 144 to another
segment of track 144. Such transfers may be affected by diverter
units (not shown). For example, a diverter unit may be provided at
each junction between a shared track loop 144-1, 144-2 with another
track segment. Diverter units, under control of control system 1000
are operable to selectively engage a carriage 125, 129 remove the
carriage from a first segment of track 144, move the carriage 125,
129 to a second segment of track 144, and disengage from the
carriage once the carriage is coupled to the second segment of
track 144. Diverter units may be activated based on measured
position of carriages 125, 129 on track 144.
[0697] Thus, by operation of diverter units under control of
control system 1000, each part produced by molding system 100 may
follow a specific selectable path through the system 100.
[0698] Molding system 100 can therefore be configured to
contemporaneously produce one or more parts of common or multiple
types, in substantially any proportion. For example, parts may be
produced in a lot size as small as one unit, i.e. a single part
having a particular set of characteristics.
[0699] For example, in a specific configuration, dispensing cell
102 may include multiple stations with the same materials, while
each station of shaping cells 104, 106 includes a mold of a unique
shape. By coordinated operation of diverter units, any given dose
of feedstock material may be directed through a sequence of process
stations to produce a specific type of article, while a different
arrangement of operation of diverter units would direct a dose of
feedstock material through a different sequence of process
stations, to produce a different type of part.
[0700] Transport subsystem 110 and the stations of process cells
102, 104, 106, 108 collectively define a large number of paths
through molding system 100. For instance, a unique path corresponds
to and is defined by each unique combination of a dispensing
station; a shaping station of cell 104; a conditioning station of
cell 108 and a shaping station of cell 106. In addition, in some
embodiments, one or more of cells 104, 106, 108 may be bypassed.
For example, in some cases it may be possible to immediately
transport a workpiece from shaping cell 104 to shaper cell 106,
without an intermediate conditioning step. This may be possible,
for example, when the workpiece temperature following the first
shaping operation is relatively high, and when the workpiece can be
transported relatively quickly to a station of shaping cell 106,
such that it does not lose significant heat, or when the shaping
processes and molds are designed such that the temperature profile
of a workpiece exiting a station of shaping cell 104 is ideal for a
process to be performed at shaping cell 106.
[0701] Alternatively or additionally, in some embodiments,
additional process cells may be present and may be included in some
paths through molding system 100. For example, one or more of a
bottle or preform coating cell, labelling cell, filling cell,
capping cell or inspection cell may be present.
[0702] An inspection cell (not shown) may include a detection
device positioned proximate part of transport subsystem 110, for
observation of a workpiece such as a molded preform or a finished
molded article as it is conveyed past the detection device. The
detection device generally comprises a camera and an evaluation
unit. Images of the workpiece are produced by the camera, the
images being compared with setpoint values of a fault-free
workpiece using image processing methods, in order to determine
whether defects are present. The inspection cell may include
further means for diverting molded articles that are considered
defective.
[0703] FIGS. 53 and 54 are plan and side views of an injection
molding system 6000 made in accordance with another embodiment of
the subject system. Parts of system 6000 which are the same as
parts of system 100 are given like reference numerals.
[0704] In overview, molten molding material is transferred to
individual vessels 124, which are then conveyed to subsequent
process cells along a track 6110. The vessels are carried by
independently controllable carriages and progress serially along an
outgoing line of the track. A vessel may be stopped at a molten
molding material dispensing cell 102 where a dose of molten molding
material is dispensed from a molten molding material dispenser
(which may also be referred to as a molten molding material
station) 102-1, 102-2--which, in the illustrated embodiment is an
extruder 112--into the vessel. The vessel is then advanced further
along the track to a preform molding cell 6104 where the molten
molding material is dispensed from the vessel to a preform molder
(preform molding station) 6104-1, 6104-2, 6104-3, 6104-4, 6104-5,
6104-6. The vessel is then shunted to a return line. Preforms 101'
molded at a preform molding cell are transferred to carriages on
the return line. The return line runs past conditioning cell 108
and blow molding cell 106 where preforms on the return line are
transferred to conditioners 108-1, 108-2 and blow molders 106-1,
106-2 and blow molded into articles. At the end of the return line,
vessels are shunted back to the outgoing line, optionally after
having been first parked at a buffering and cleaning cell 6530.
[0705] A controller monitors the location of each carriage, vessel,
and preform and controls movement, so that the right vessel is
filled with the right molten molding material, this molten molding
material is dispensed to the right preform molder, and the preform
formed at this molder is transferred to the right blow molder.
[0706] With this system, a variety of different blow molded
articles can be made by providing differing preform molders and
blow molders at cells along the track, and filling vessels with
different doses and different compositions of molten molding
material suited for ones of the preform and blow molders.
[0707] The track 6110 of injection molding system 6000 is made up
of repeating segments. With reference to FIGS. 55A and 55C, each
track segment 6540 has an array of electromagnets 6542 extending
along its length. Each track segment also has a scale 6543 and an
encoder output sensor 6544 extending along its length. The
controller provides control voltages to the electromagnets of the
track segments and is connected to the encoder output sensor.
[0708] Carriages ride on the track. With reference to FIGS. 55B and
55C, each carriage 6125, 6129 is supported on the track by rollers
6546 that ride on upper and lower track surfaces which prevent a
carriage from lifting off the track. Each carriage has a series of
permanent magnets 6548 and a position encoder flag 6550 that is
responsive to the scale carried by the track to output position
pulses sensed by the encoder output sensor of the track. With this
arrangement, the controller remains aware of the current location,
identity, and velocity of each carriage on the track and can
independently move each carriage in either direction on the track
by application of suitable control voltages to the electromagnets
of the track.
[0709] Track 6110 and carriages 6125, 6129 may be those
manufactured by Beckhoff Automation GmbH & Co. KG under the
trademark XTS.
[0710] Returning to FIG. 54, the track of injection molding system
6000 has an outgoing line 6110o, a parallel return line 6110r
disposed directly above the outgoing line, a spur line 6110sp stood
off from the left end of the return line, a left side shunt line
61101s that may be shifted from a lower position where it extends
the outgoing line to a raised position where it extends the return
line and joins the return line to the spur line, and a right side
shunt line 6110rs that may be shifted from a lower position where
it extends the outgoing line to a raised position where it extends
the return line.
[0711] Referring to FIG. 56 along with FIGS. 55A and 55B, an
upwardly extending arm 6564 is attached to each carriage 6125 and
an upwardly extending arm 6569 is attached to each carriage 6129.
The arm 6564 of carriages 6125 has a pair of horizontally
projecting flanges 6566, each of which terminates in a concave
arcuate tip 6568. The upwardly extending arm 6569 of carriages 6129
has a horizontally projecting flange 6576 which terminates in a
concave arcuate tip (not shown). The arms 6564, 6569 alternate in
orientation from one carriage to the next such that a carriage
6125a on the outgoing line 6110o with rightwardly projecting
flanges 6564a trails a carriage 6125b on the outgoing line 6110o
with an arm having leftwardly projecting flanges 6564b. (On the
return line 6110r this is reversed: a carriage 6125a on the return
line 6110r with rightwardly projecting flanges 6564a leads a
carriage 6125b with an arm having leftwardly projecting flanges
6564b.) With this arrangement, carriages can be grouped into pairs
of adjacent carriages which have complementary features, namely
flanges that are opposed to one another. The carriages 6125, 6129
with different lengths of arms are arranged such that, on the
outgoing line 6110o, a pair of carriages 6129a, 6129b with longer
length arms 6569a, 6569b leads a pair of carriages 6125a, 6125b
with shorter length arms 6564a, 6564b. (On the return line 6110r
this is reversed: a pair of carriages 6125a, 6125b with shorter
length arms leads a pair of carriages 6129a, 6129b with longer
length arms.)
[0712] The flanges 6566 of the shorter arms are configured so that
an opposed pair of such flanges, when moved toward each other, will
fit within the annular notches 1255, 1256 (FIG. 7A) of a vessel 124
and trap (pinch) the vessel between the pair of flanges. Moreover,
the length of the shorter arms is such that, with a vessel trapped
between a pair of flanges, the vessel clears the base of the
carriages 6125 below the vessel. The flanges of the longer arms are
configured so that an opposed pair of such flanges, when moved
toward each other, will extend around a preform workpiece 101'
(FIGS. 29J and 68) below the lip 6570 (FIG. 60) of the preform such
that the lip 6570 of the preform will be supported on the opposed
flanges.
[0713] Returning to FIGS. 53 and 54, the injection molding system
6000 is divided into a number of cells. Cells that are used along
the outgoing line 6110o are, from left to right, a left side
shunting cell 6620, a re-ordering cell 6630, a molten molding
material dispensing cell 102, a preform molding cell 6104 and a
right side shunting cell 6640. Cells that are used along the return
line are, from right to left, the right side shunting cell 6640,
the preform molding cell 6104, conditioning and blow molding cell
106/108, the left side shunting cell 6620, and a buffering and
cleaning cell 6530.
[0714] Each shunting cell 6620, 6640 comprises a shunt line and an
elevator to which the shunt line is mounted. Returning to FIG. 56,
the right side shunt line 6110rs is attached for sliding movement
on vertical pillar 6660. The vertical pillar is essentially a track
segment with a series of electromagnets, like track segment 6540.
Magnets (not shown) are mounted to the shunt line 6110rs such that
the shunt line is a carriage riding on the pillar. The controller
is connected to a control input of the pillar. With this
arrangement, the pillar acts as an elevator 6662 for the shunt line
6110rs to move the shunt line between the lower outgoing line 6110o
and the upper return line 6110r. It will be apparent that when the
right side shunt line is vertically aligned with the outgoing line,
the shunt line abuts the right side end of the outgoing line 6110o
and effectively lengthens the outgoing line. Similarly, when the
shunt line is vertically aligned with the return line 6110r, the
shunt line abuts the right side end of the return line and extends
the return line. The left side shunt line is configured in like
manner, however, additionally, when the left side shunt line is
aligned with the return line, it also abuts the end of the spur
line 6110sp (FIG. 54) so as to join the return line 6110r to the
spur line.
[0715] Re-ordering cell 6630 has one or more re-ordering devices
6632. Turning to FIG. 57 which illustrates one re-ordering device
6632, the device has a rail 6670 extending transversely of the
outgoing line 6110o, which is configured as the primary part of a
linear actuator, and a carriage 6672 slidably mounted on the rail,
which carriage is the secondary part of the linear actuator. A
rotary servo motor is mounted to the carriage and a turntable 6676
(which is a gearbox) is mounted to the rotor (not shown) of the
servo motor. Four outwardly directed grippers 6680-1, 6680-2,
6680-3, 6680-4 are mounted to, and equally spaced about, the
turntable. The grippers may be servo driven or spring biased closed
with an air circuit to open. The controller provides a control
input to the linear actuator and to the rotary servo motor, as well
as to the grippers.
[0716] As seen in FIG. 53, the two molten molding material
dispensers 102-1, 102-2 are positioned one on each side of the
outgoing line and staggered along the line. A hand-off device 6730
is associated with each molten molding material dispenser. Turning
to FIG. 58, the hand-off device 6730 has a rail 6770 extending
transversely of the outgoing line 6110o, which is the primary part
of a linear actuator, and a carriage 6772 slidably mounted on the
rail, which carriage is the secondary part of the linear actuator.
The stator (not shown) of a rotary servo motor is mounted to the
carriage and a turntable 6776 is mounted to the rotor (not shown)
of the servo motor. Two pairs of outwardly directed grippers
6780-1, 6780-2--closed by a spring bias and opened with an air
circuit, or servo controlled--are mounted to the turntable opposite
one another. The controller provides a control input to the linear
actuator and to the servo motor, as well as to the grippers.
[0717] The preform molding cell 6104 has preform molders 6104-1,
6104-2, 6104-3, 6104-4, 6104-5, and 6104-6 staggered along either
side of the outgoing line. The preform molders are similar to
preform molders 104-1, 104-2, 104-3, 104-4, 104-5, 104-6, 104-7,
104-8, except as to differences described hereinafter. Referencing
FIG. 59, similar to the preform molders of cell 104, an actuator
assembly has a vertically moveable nest 2044 with a semi-annular
slot (seen in FIG. 32) that the base of a vessel 124 can slide into
so as to be retained by the nest. A hand-off device 6830 having two
pairs of outwardly directed grippers 6840-1, 6840-2, like the
hand-off device 6730, is associated with each molten molding
material dispenser and is mounted between each preform molder and
the outgoing line 6110o for transferring a vessel to and from the
nest 2044 of a preform molder.
[0718] With the preform molders 104, a carriage 129 (FIG. 34I)
riding on a second track 144 that extends below the preform molder
104 is positioned below the preform mold 200 prior to the inner
mold core 3112 (FIG. 18B) being moved upwardly to a short extent to
break a seal between the preform and the mold core 190. The
carriage 129 has a nest shaped to receive the preform and suction
may be applied to draw the preform into the nest. In contrast, in
injection molding system 6000, as shown in FIG. 59, the transfer
device is a robot arm 6850 which is mounted beside the mold 200 of
each preform molder 6104. With injection molding system 6000, prior
to breaking the seal between the preform and mold core, the robot
arm is manipulated so that its end effector grips the preform.
[0719] With reference to FIG. 60 along with FIG. 59, robot arm 6850
has a fixed trunk 6852 supporting the stator of a first servo motor
6854. An upper robot arm 6856 is mounted at a first end to the
rotor 6858 of the first servo motor. The second end of the upper
robot arm supports the stator of a second servo motor 6860 and one
end of a lower robot arm 6862 is mounted to the rotor 6864 of the
second servo motor 6860. The second end of the lower robot arm 6862
has a distal rotatable pulley 6870, and the end effector 6872 is
mounted to the shaft of the distal pulley so as to project
transversely from the shaft. The end effector has a pair of servo
controlled grippers 6874a, 6874b. A base pulley 6876 is fixed to
the trunk 6852 such that it does not rotate. A double width medial
pulley 6878 is rotatably mounted to the robot arm coincident with
the rotational axis of the rotor 6864 of the second servo motor
6860. All three pulleys 6870, 6876, 6878 have the same radius A
coupling belt 6880 extends around the base pulley 6876 and medial
pulley 6878. A second coupling belt 6882 extends around the medial
pulley and the distal pulley 6870. The controller controls the
servo motors of the robot arm to position the end effector. In this
regard, as will be appreciated by those skilled in the art, with
the end effector initially projecting horizontally, the end
effector will maintain its horizontal orientation as the lower and
upper arms are rotated by the servo motors 6850, 6860 due to the
operation of the coupling belts 6880 and 6882. The controller also
controls the grippers of the end effector.
[0720] Referring to FIG. 59 along with FIG. 60, with this
arrangement, after the robot arm is moved into position with its
grippers 6874a, 6874b gripping a preform 101' and the seal is
broken between the preform and mold core 3112 (FIG. 18B), the robot
arm is controlled to first lower the preform 101' so that it
descends to clear the mold core. (It will be appreciated that the
spent vessel is first removed from below the mold 200 so that it
will not interfere with this operation.) After the preform clears
the mold core, it is translated to the return line 6110r and,
specifically, to a position between a spaced pair of carriages
6129a, 6129b with opposed longer length arms 6569, with the lip
6570 of the preform above the horizontally projecting flanges 6576
(FIG. 56) of arms 6569. These carriages are then moved together to
trap the preform between the opposed arms 6569. The end effector of
the robot arm then releases the preform and withdraws. The preform
is then retained by the opposed arms 6569 with its lip 6570 resting
on the flanges 6576 of the opposed arms 6569 of the pair of
carriages 6129a, 6129b.
[0721] Returning to FIGS. 53 and 54, a blow molder 106-1, 106-2,
with its associated conditioner 108-1, 108-2, lies on either side
of the return line 6110r. A track 6996 perpendicular to main track
6110 is associated with each blow molder/conditioner to transfer a
preform from the return line to a particular blow
molder/conditioner. Alternatively, the transfer device may be the
aforedescribed mandrel 408 (FIG. 34), or a robot arm similar to the
robot arm illustrated in FIGS. 59 and 60.
[0722] Details of track 6996 are depicted in FIGS. 61-63. FIGS. 61
and 62 depict top and side views, respectively, of blow molder
106-1 and associated conditioner 108-1, and the transfer device.
FIGS. 64A and 71B depict isometric and side views, respectively, of
carriages mounted on track 6996.
[0723] As shown in FIG. 61, track 6996 extends away from main track
6110 and spans across block molder 106-1 and conditioner 108-1.
Track 6996 is substantially identical to main track 6110, except
that track 6996 is inclined at an angle to the vertical. Likewise,
pairs of carriages 6129' are mounted to track 6996. Carriages 6129'
are substantially identical to carriages 6129 except that carriages
6129' have arms 6569' which extend horizontally, at an angle to
track 6996.
[0724] Pairs of carriages 6129' are movable towards one another to
grip a preform between arms 6569'. Specifically, a pair of
carriages 6129' on track 6996 is positioned above a pair of
carriages 6129 on main track 6110. Carriages 6129' grip a preform
held by carriages 6129, and the carriages 6129 are then moved to
release the preform. Accordingly, the preform is transferred from
carriages 6129 to carriages 6129'. Arms 6569' of carriages 6129'
may grip the preform above flanges 6576 of carriages 6129,
proximate the top edge of the preform.
[0725] After picking up the preform, carriages 6129' are moved
along track 6996 to position the preform above conditioner 108-1. A
mandrel then engages the preform, and carriages 6129' move apart to
release the preform. The mandrel inserts the preform into
conditioner 108-1 for treatment and subsequently withdraws the
preform to a position proximate carriages 6129' after treatment is
completed. The carriages 6129' then move together to again grip the
preform and are conveyed along track 6996 to a position aligned
with blow molder 106-1.
[0726] Specifically, with platens 196 of blow molder 106-1
withdrawn from one another, such that mold 500 is opened, carriages
6129' move the preform to a position between the molds. The height
of arms 6569' is selected such that the preform is slightly above a
molding position when gripped by the arms.
[0727] With carriages 6129' holding the preform in a position
aligned with mold 500, platens 196 are moved to their closed
(molding) position by clamp 8070. Thus, mold 500 is closed around
the preform. Carriages 6129' are then moved apart, so that the
preform drops into position in mold 500. In the depicted
embodiment, the preform drops only a small distance, e.g. a few
millimetres. In some embodiments, closing of mold 500 may occur in
two steps. Specifically, the mold may initially be partially
closed, leaving a small clearance around the preform so that it can
be supported on mold 500 by an annular support ledge near the top
of the preform, but the preform can freely fall into the correct
molding position, without binding against the mold.
[0728] A mandrel is then moved to engage the preform substantially
as described with reference to FIGS. 51A-51D. A rod is extended
into the preform and stretches the preform as pressurized air is
injected through the mandrel to stretch the preform into the shape
defined by mold 500.
[0729] After molding, the preform is permitted to cool. Carriages
6219' are then moved together to again grip the finished molded
article (e.g. a bottle). When gripping the finished article in mold
500, arms 6596' grip at a location slightly higher than when they
grip the preform at conditioner 108-1. The height difference
corresponds to the distance the preform is dropped subsequent to
closing of mold 500.
[0730] Carriages 6129' then move the completed article away from
blow molder 106-1, where it may be removed for further processing
such as labelling.
[0731] After removal of the completed article, carriages 6129' are
returned along track 6996 to a position for gripping a new preform
from main track 6110.
[0732] The buffering and cleaning cell 6530 comprises spur line
6110sp with an enclosure 6890 containing vessel cleaners (not
shown).
[0733] The right side shunting cell 6640 comprises the right side
shunt line 6110rs and the elevator 6662 to which the right side
shunt line is mounted.
[0734] A reader 6894 is positioned along the track downstream of
the re-ordering cell 6630 to read an identifier of passing vessels
124.
[0735] Turning to FIG. 64, the controller 6900 has a control input
to the electromagnets 6542 of each track segment, the elevator 6662
of each shunt line, each re-ordering device 6632, each hand-off
device 6730, 6830 and each robot arm 6850, and each transfer track
6996. The controller receives an input from the encoder flag 6550
of each carriage and from the vessel identification reader 6894. As
illustrated, the controller also has a control input to each molten
molding material dispenser of molding material dispensing cell 102,
each preform molder of preform molding cell 6104, each conditioner
of cell 108 and each blow molder of cell 106, and the buffering and
cleaning cell 6890. Alternatively, some of these devices may have
independent controls. For example, a preform molder could have a
microswitch that is triggered when a hand-off device 6830, under
control of the controller, loads a vessel into its nest which
causes the preform molder to cycle through its molding operation,
and a second microswitch which is triggered when the controller
positions a robot arm 6850 to receive a molded preform in order to
release the molded preform.
[0736] To prepare injection molding system 6000 for operation,
feedstock is provided to the molten molding material dispensers of
cell 102. The composition of the feedstock provided to each molten
molding material dispenser may differ in material or colour or
both. Thus, by way of an example embodiment, one molten molding
material dispenser holds blue (pellets) feedstock and the second
molten molding material dispenser holds green (pellets) feedstock.
The type of feedstock provided to each dispenser is uploaded to the
controller.
[0737] Given green and blue feedstock, the vessels 124 are divided
into first vessels which are dedicated to holding blue molten
molding material--referred to hereinafter as "blue vessels" for
simplicity--and second vessels which are dedicated to holding green
molten molding material--referred to hereinafter as "green
vessels". The vessels are organized in this fashion as, even after
cleaning, a vessel will retain some molten molding material
residue. Thus, using only one type of molten molding material in a
vessel avoids cross-contamination. Each vessel is marked with an
identifier and the identifier on a vessel is read by reader 6894 so
that the controller 6900 becomes aware of which vessels are blue
vessels and which vessels are green vessels and can thereafter
track the location of each vessel to maintain this awareness. A
suitable identifier that may be used is an annular strip code,
i.e., a pattern of strips that encircle the vessel which may be
visually read. An annular strip code has the advantage that it may
be read no matter what the rotational orientation of the vessel
about its longitudinal axis. In an alternate embodiment, the
information as to which carriage pairs and which grippers hold blue
vessels and which hold green prior to start-up is input to the
controller and the controller thereafter tracks the location of
each vessel so as to maintain awareness of which vessel is which.
However, it is generally preferred to mark each vessel with an
identifier to avoid problems that could otherwise result should any
vessels be manually swapped out or switched during a shut down
without informing the controller.
[0738] Continuing with the example, the carriages on the track are
organized as gangs 6880 (FIG. 56) of four carriages each. On the
outgoing line 6110o, the leading pair of carriages 6129a, 6129b of
each gang 6880 has opposed longer arms 6596a, 6596b and the
trailing pair of carriages 6125a, 6125b has opposed shorter arms
6564a, 6564b. (On the return line 6110r, it is the pair of
carriages with shorter arms that is the leading pair of carriages
in a gang.) At start-up, each trailing pair of carriages on the
outgoing line may hold an empty blue vessel or an empty green
vessel.
[0739] The controller 6900 may receive a product order, say fifty
blue bottles and twenty-five green bottles. Given this, two of the
four grippers of each re-ordering device may be loaded with blue
vessels and one gripper may be loaded with a green vessel, leaving
the fourth gripper of each device free: if the system is not
configured so that the controller can identify these vessels, this
information is fed to the controller.
[0740] The controller may (rapidly) advance the gangs of carriages
along the track until a gang 6880 of carriages holding a blue
vessel is presented at a molten molding material dispenser holding
blue molten molding material feedstock. In this regard, if there
happened to be an uninterrupted series of green vessels upstream of
the molten molding material dispensing cell, the controller may use
the re-ordering cell 6630 upstream of the molten molding material
dispensing cell to swap out green vessels from the outgoing line
6110o and insert blue vessels in their place. More specifically,
the next carriage gang with a green vessel can be advanced by the
controller to a re-ordering device 6632 of the re-ordering cell
6630 where it is halted, the turntable 6676 of a re-ordering device
6632 operated to direct the empty grippers 6680-1 of the
re-ordering device toward the outgoing line, and then the turntable
advanced. If the grippers are spring biased, the turntable is
advanced until the biased empty grippers are first deflected by,
and then snap around, the green vessel. The opposed arms of the
leading carriage pair 6125a, 6125b of the gang which trap the green
vessel absorb the reaction force as the empty grippers of the
re-ordering device are deflected by the vessel. With the grippers
holding the green vessel, the controller then separates the leading
pair of carriages so that the green vessel is released from the
outgoing line. The turntable is then retracted, turned to present
grippers holding a blue vessel toward the outgoing line, and
advanced again to position the blue vessel between the opposed open
arms of the leading pair of carriages of the carriage gang. The
controller then brings the leading carriage pair back together to
close the open arms of this pair in order to trap the blue vessel.
The grippers are then opened (with an air circuit or under servo
control) to release the blue vessel, and the turntable is
retracted. The carriage gang, now holding a blue vessel, may then
be advanced to the molten molding material dispensing cell.
[0741] It will be apparent that, after this swap, the re-ordering
cell 6630 continues to have one set of empty grippers but now holds
two green vessels and one blue vessel.
[0742] Referencing FIG. 58 and assuming dispenser 102-2 holds blue
feedstock, if an empty blue vessel 124-1 is advanced to molten
molding material dispenser 102-2, the controller can operate the
carriages 6125a, 6125b and hand-off device 6730 to transfer the
vessel 124-1 to grippers 6780-1. More specifically, with the blue
vessel halted under at the molten molding material dispenser 102-2,
empty grippers 6780-1 of the hand-off device associated with the
dispenser are advanced toward the empty blue vessel 124-1 and
brought into engagement with the vessel. The pair of carriages
6125a, 6125b trapping the vessel is then separated to release the
vessel. Since the grippers 6780-2 of the hand-off device hold a
blue vessel 124-2 that would have been previously filled at
dispenser 102-2, the hand-off device rotates to deliver this
previously filled blue vessel 124-2 between the pair of carriages
6125a, 6125b and these carriages are advanced toward each other to
trap this vessel 124-2 between them. The grippers 6780-2 are then
opened and the hand-off device retracted to present the vessel
124-1 held by grippers 6780-1 at the outlet of the molten molding
material dispenser. The retraction of the hand-off device also
frees the pair of carriages 6125a, 6125b with vessel 124-2 to
progress along the track. With vessel 124-1 at the outlet of the
molten molding material dispenser 102-2, blue molten molding
material is dispensed to this vessel 124-1, as aforedescribed in
conjunction with the embodiment of FIGS. 8A-8D. In this regard, the
dose of material received by a vessel at the molten molding
material dispenser is a dose sufficient to make a single preform,
which dose may or may not fill the vessel. Filled blue vessel 124-1
is then ready to be picked up by a subsequent pair of carriages
arriving on the track. Note that if grippers 6780-2 did not hold a
vessel on the arrival of vessel 124-1, the pair of separated
carriages 6125a, 6125b may be paused in place at dispenser 102-2
until blue vessel 124-1 is filled and returned to the pair of
grippers.
[0743] The filled blue vessel returned to the pair of carriages
6125a, 6125b at the dispenser is advanced along the track to the
preform molding cell 6104. In this regard, specific preform molders
may be dedicated for molding blue preforms if there is a risk of a
residue of blue molten molding material remaining in the preform
molder mold 200. The controller preferentially chooses a "blue"
preform molder further toward the right end of the outgoing line
6110o in order to leave open other preform molders between the
chosen preform molder and the molten molding material dispensing
cell 102 so that while carriages are paused at the chosen preform
molder, they do not block vessels from being advanced to these
other preform molders.
[0744] Referencing FIG. 59, assuming the chosen preform molder for
a green vessel 124-3 is preform molder 6104-6, the vessel is
advanced by the carriage gang holding it to this preform molder,
engaged by grippers 6840-1 of hand-off device 6830, and released by
carriages 6125-a, 6125b of the carriage gang. A previously emptied
green vessel held by grippers 6840-2 may then be returned to the
carriage gang so that the gang is freed to advance further along
the track 6110o. The hand-off device then transfers vessel 124-3 to
the nest 2044 of the preform molder. The vessel positioning
actuator is then extended vertically to urge the vessel into
abutment with the mold 200 (FIG. 12A), with gate orifice 136 of
vessel 124 aligned with mold inlet gate 202 of mold 200. The molten
molding material in the green vessel may then be injected into the
mold 200--by operation of piston 182 (FIG. 6B) of the vessel as
aforedescribed--and the spent green vessel is then ready to be
returned to the outgoing line 6110o when a next carriage gang
arrives at the preform molder 6104-6.
[0745] A carriage gang leaving the preform molding cell is advanced
to the right side shunting cell where the elevator 6662 moves the
shunt line 6110rs up into engagement with the return line 6110r.
The elevated carriage gang then moves back toward the preform
molding cell 6104. Once this carriage gang leaves the shunt line
6110r, the shunt line is again returned to the outgoing line
6110o.
[0746] A carriage gang 6880 arriving on the return line 6110r with
a spent blue vessel may be moved to the preform molder, e.g.,
preform molder 6104-6, that will next have a completed preform
101', regardless of whether the preform is green or blue. At this
preform molder, the pair of carriages 6129a, 6129b with the longer
arms 6569a, 6569b (which is now the trailing pair of carriages of
the gang) is separated while the robot arm 6850 moves a preform
101' released from the preform mold 200 to a position in between
the arms of the separated carriages. The carriages 6129a, 6129b of
the pair are then brought together to trap the preform between them
and the robot end effector 6872 is withdrawn to release the preform
from the robot arm.
[0747] The carriage gang may then advance with the preform 101' to
the conditioning and blow molding cell 106/108 where the preform is
removed from the carriage gang by a transfer device. More
specifically, the transfer device engages the preform, subsequent
to which the pair of carriages trapping the preform is separated to
release the preform. The transfer device then inserts the preform
into the heating chamber 404 of a conditioner, say conditioner
108-1. After heating, the transfer device withdraws the preform
from the heating chamber past a thermal monitor 406. If the preform
is properly conditioned, the transfer device then moves the
conditioned preform to blow molder 106-1 and inserts the preform
into the mold 500 of the blow molder. The transfer device then
releases the conditioned preform and the preform is engaged by the
molding head 504 of a mandrel 506, whereupon the preform is blown
into a bottle as aforedescribed. Where each blow molder blows a
bottle of identical shape, the preform can be transferred to any of
the blow molders. However, if the bottles blown by different blow
molders are of different shapes, then the preform must be
transferred to a blow molder which is suited to blowing a bottle
from that preform.
[0748] After the preform is transferred from the carriage gang
6880, the carriage gang is further advanced to the buffering and
cleaning cell 6890 where the empty vessel carried by the gang is
optionally cleaned. The controller could then immediately return
the carriage gang to the left side shunt line 61101s or,
alternatively, hold the carriage gang in the buffering and cleaning
cell for future use. When the carriage gang is returned to the
shunt line 61101s, the shunt line descends to return the carriage
gang to the outgoing line 6110o, and when the carriage gang is
advanced beyond the left side shunt line, the left side shunt line
61101s again returns to the return line 6110r.
[0749] It will be apparent from the foregoing that carriage gangs
6880 circulate on the track, moving to the right along the outgoing
line 6110o, then being elevated to the return line 6110r where they
move to the left and, when they reach the left hand end of the
upper track, may be offloaded to the buffering and cleaning cell
6530 or returned to the outgoing line. With this operation, it will
be apparent that the vessels 124 are maintained upright throughout
their travels. This helps ensure molten molding material does not
leak from the vessels while moving through the system. It will also
be apparent from the foregoing that carriage gangs riding on the
outgoing line may hold a vessel but do not hold a preform 101', and
carriage gangs riding on the return line may hold a vessel, and, in
addition, may also hold a preform.
[0750] From the foregoing, it will be apparent that the controller
has logic to control the carriages 6125, 6129, logic to control the
vessels 124, and logic to control the preforms 101'. The carriage
control is enabled by the encoder flag 6550 on each carriage that
is monitored by the controller 6900. This allows the controller to
track the location of each carriage and control its movement as
desired. The vessel control is enabled either by the controller
being provided with the initial location and designation of each
vessel (e.g., a blue vessel) or by each vessel being marked with an
identifier that is input to the controller from a reader at one or
more locations in the system and the controller storing the
designation of each marked vessel. The preform control is enabled
by the controller storing which preform molders are associated with
which blow molders, and by the controller tracking carriage gangs
that are loaded with a particular preform so as to offload the
particular preform held by the carriage gang at the appropriate
blow molder.
[0751] The example operation described assumed the system was run
with feedstock of two different colours. The system could also be
run with feedstock more than two colours, for example, five
different colours. In this instance, the system may be modified to
provide five molten molding material dispensers, one for each
colour of feedstock, and at least two separate re-ordering devices
in the re-ordering cell, such that at least one vessel for each of
the five colours may be held at the re-ordering cell while ensuring
at least one of the two re-ordering devices has an empty set of
grippers. The system could also be run with multiple different
types of feedstock. In general, the system could be run with any
feedstock that forms a flowable molten material. For example, the
feedstock could be a thermoplastic, a thermoset plastic resin, or a
glass. Giving a specific example, in a system with three molten
molding material dispensers, one could hold high density
polyethylene (HDPE), one polypropylene (PP), and one polyethylene
terephthalate (PET).
[0752] The system could be modified to have preform molders and
blow molders with different sized molds which form blow molded
articles of different sizes. In this instance, preforms molded at a
particular preform molder are fed to a particular blow molder
adapted to blow mold the particular preform. Thus, the controller
must track the carriage gang 6880 which receives a preform 101' to
ensure the preform reaches the correct blow molder. Further, it may
be that less molten molding material is needed to form a smaller
molded article. In this situation, vessels 124 supplying the
preform molder for the articles requiring less molten molding
material are not filled to capacity at a molten molding material
dispenser but are instead filled a metered amount reflective of the
needed volume of molten molding material for the smaller blow
molded articles.
[0753] While the example embodiment shows a re-ordering cell 6630
with two re-ordering devices, each having one set of empty
grippers, optionally a re-ordering device may have several sets of
empty grippers and there may be multiple re-ordering devices so
that several pairs of grippers may be empty and several may hold
vessels, so that a selected pair of grippers (with or without a
vessel) may be advanced toward the track.
[0754] Optionally, heaters may be added to system 6000 to warm
vessels 124 at periodic intervals in order to make up for heat loss
in the vessels during vessel transit along the track. For example,
heaters may be located upstream of the dispensing cell 102 so that
vessels are warmed prior to melt being dispensed to them. FIGS. 65
and 66 illustrate such an arrangement where a heating system is
associated with a re-ordering cell 6330' upstream of the dispensing
cell. Turning to these figures, each re-ordering device 6632' is
identical to the re-ordering device 6632 of FIG. 57 except that
each device 6632' has two pairs of grippers 6680-1 and 6680-2
rather than four pairs of grippers. Two heaters 6690 are positioned
beside each device 6632'. Each heater has a pair of reciprocal
prongs 6692 that may be extended by an air cylinder (not shown)
inside the housing. A power supply (not shown) inside the housing
selectively supplies AC power to the prongs. To adapt the vessels
for use with the heaters 6690, the vessels 124' are provided with a
pair of conductive bands 6694. The heating system also has a
temperature sensor 6696 associated with each heater 6690. The
temperature sensor is an infrared sensor that emits an infrared
beam. The heating system is positioned such that a re-ordering
device 6632', when retracted away from the outgoing line 6110o of
the track, may be rotated about its carriage 6672 to a parked
position whereat a vessel 124' in each of the two pair of grippers
6680-1, 6680-2 of the device 6632' is adjacent a heater 6690 and in
the path of a beam emitted from the associated temperature sensor
6696. The controller is operatively connected to the heaters and
temperature sensors. Based on the temperature of a vessel 124'
detected by a temperature sensor, the associated heater may be
selectively energized by the controller to heat the vessel to a
desired temperature as measured by the temperature sensor. More
specifically, the prongs of the heater are extended into contact
with the conductive bands of the vessel and AC power is applied to
the prongs until the temperature sensor measures the target
temperature. The heater may then be de-energised and the prongs
retracted. The vessel, warmed to the target temperature, may then
be transferred to the outgoing line of the track.
[0755] Given the provision of a heater and temperature sensor for
each of the two pairs of grippers 6680-1, 6680-2 of a re-ordering
device 6632', if two vessels are held by the re-ordering device
(and another upstream re-ordering device has at least one pair of
free grippers to take a vessel off the line or some upstream
carriage gangs on the outgoing line are not carrying vessels), both
vessels may be simultaneously heated. This is useful if both
vessels are currently needed on the outgoing line 6110o. On the
other hand, if only one of the vessels were needed on the outgoing
line, only that vessel would be heated.
[0756] In a modification, only one heater and associated
temperature sensor is associated with each re-ordering device.
[0757] While in the example embodiment the buffering and cleaning
cell 6530 is located at the left hand end of the track, optionally
this cell could instead be located elsewhere. In this instance, the
buffering and cleaning cell may not include a spur line, but
instead could include another arrangement to transfer vessels from
the track to the enclosure 6890 containing vessel cleaners. For
example, a vessel cleaning enclosure could be located at the
re-ordering cell 6630 and the grippers of the re-ordering cell
could selectively transfer vessels from the track to the vessel
cleaning enclosure 6890. Alternatively, the buffering cell could be
located elsewhere along the track and a robot arm, similar to robot
arm 6850, could be provided in place of the spur line to transfer
vessels from the track to the vessel cleaning enclosure.
[0758] Each carriage gang may hold a vessel as the carriage gang
travels along the track. Alternatively, some of the carriage gangs
may travel all or portions of the track without holding a
vessel.
[0759] While the carriages have been described as travelling in
gangs of four, alternatively, the carriages could travel in gangs
of two, with one type of gang designed for holding vessels and a
second type of gang designed for holding preforms. As a further
option, carriages could travel in gangs of three where the middle
carriage has two arms--a right facing arm for co-operating with a
left facing arm of the leading carriage and a left facing arm for
co-operating with a right facing arm of the trailing carriage.
While the carriages 6125 are shown as having a pair of horizontally
projecting flanges 6566, in another embodiment, they may have a
single horizontally projecting flange, or multiple horizontally
projecting flanges.
[0760] As another option, each carriage could support a set of
grippers opening along the length of the track, such as the biased
tongs 1252 of carriage 125 of FIG. 7A, to hold vessels. With this
option, it will be apparent a vessel is held by a single carriage.
With this option, each carriage can also be provided with a further
set of spring biased tongs projecting in the opposite direction to
that of the first set of tongs with the further set of spring
biased tongs being adapted to hold preforms.
[0761] Other track configurations are possible. For example, the
function of the upper and lower lines could be reversed such that
molten molding material is dispensed to vessels on the upper track
and preforms are moved to the conditioning and blow molding cell
along a lower track. Also, track and carriage systems other than
the XTS system of Beckhoff may be used to provide controlled
movement of carriages on a track.
[0762] It will be apparent from the foregoing that injection
molding system 6000 may be adapted to form a variety of different
sized or shaped bottles by switching in suitable molten molding
material dispensers, preform molders and conditioners and blow
molders.
[0763] While the injection molding system 6000 has been described
as first molding a preform and subsequently blow molding a bottle
from the preform, the system may also be used without the
conditioning and blow molding cell to produce preforms for blow
molding in a different location. Also, the system can be used
without the conditioning and blow molding cell and the molds of the
preform molders adapted to mold articles other than preforms such
as, for example, plastic toys. Other modifications will be apparent
to those of skill in the art.
[0764] FIG. 67 is a flow chart showing an example method 600 of
transporting molding material.
[0765] At block 602, a vessel 124 is positioned at a station of
dispensing cell 102. The coupling assembly of vessel 124 is aligned
to and coupled with the nozzle assembly 113 of an extruder 112.
Orifice 136 is opened and molding material is dispensed into cavity
134 of vessel 124 through orifice 136.
[0766] After filling of vessel 124 is complete, at block 604,
vessel 124 is sealed, e.g. by operation of sealing member 140. At
block 606, the sealed vessel is moved, e.g., along track 144 of
transport subsystem 110, to a subsequent processing station. The
subsequent station may be, for example, a shaping station.
[0767] At block 608, the vessel 124 is aligned with the subsequent
processing station. The vessel is unsealed during such alignment.
In some embodiments, alignment causes unsealing of the vessel, e.g.
by interaction of closure assembly 1270 with slot 2084.
[0768] At block 610, the vessel 124 is mated to the processing
station. For example, the coupling assembly of vessel 124 is moved
into sealing engagement with mold 200 of a shaping station and
orifice 136 is aligned with the mold gate.
[0769] At block 612, piston 182 is actuated to reduce the volume of
the internal cavity 134 of vessel 124, thereby forcing molding
material out of vessel 124 and into mold 200.
[0770] FIG. 68 is a flow chart showing an example method 700 of
producing plastic molded articles.
[0771] At block 702, a process path, defined by a sequence of
process stations, is selected according to the desired
characteristics of an article to be produced. That is, a dispensing
station 102-1, 102-2, . . . 102-n is selected according to the
desired material, colour and the like. Shaping and conditioning
stations may also be selected, as applicable. In some embodiments,
multiple possible process paths may exist for forming a specific
type of article. In such cases, a process path may be chosen based
on one or more criteria such as production time, idle process
stations and the like.
[0772] At block 704, the selected dispensing station is activated
and molten feedstock is dispensed from the corresponding extruder
112 into a vessel 124 as described above. The dispensed feedstock
in its molten form is referred to as a workpiece 101. The workpiece
is transformed at other stages in the process path. For example,
the workpiece may experience state changes (e.g. from molten to
solid states); shape changes; and condition changes such as
temperature or thermal profile changes.
[0773] At block 706, the vessel 124 is conveyed in its carriage 125
along track 144 to the next processing station. Diverters of the
transport subsystem 110 are operated to direct the carriage along
track 144 to the selected shaping station 104-1, 104-2, . . .
104-n. For example, selected ones of the diverters may be activated
at specific times to move vessel 124 to each station along the
process path. The molten feedstock, i.e., workpiece 101 is injected
into mold 200. The workpiece is shaped according to the shape of
the mold into a pre-shaped workpiece 101' (e.g. a preform for
molding a bottle) as described above.
[0774] The pre-shaped workpiece 101' is removed from the shaping
station by a carriage 129. If a conditioning operation is selected,
at block 708, the carriage 129 is conveyed to a conditioning
station 108-1, 108-2, . . . 108-n. Diverters of the transport
subsystem are operated to direct the carriage 129 to the selected
conditioning station. If no conditioning operation is selected,
conditioning cell 108 is bypassed.
[0775] If a further shaping operation is selected, at block 710,
the pre-shaped workpiece 101' is conveyed to the selected shaping
station 106-1, 106-2, . . . 106-n. Shaping, e.g. blow molding, is
performed as described above to transform the pre-shaped workpiece
101' into a finished workpiece 101''.
[0776] In some embodiments, additional finishing operations may be
performed. For example, labels may be applied to containers, or
containers may be filled and closed.
[0777] The process repeats as long as there are parts to be
produced, or until operation of molding system 100 is interrupted,
e.g. for changing or maintenance of components.
[0778] In some embodiments, components may be subjected to a
cleaning process. For example, vessels 124 may be cleaned after
transferring feedstock to a shaping station. Cleaning may, for
example, be affected by heating of vessels to melt and drain
feedstock residue, by scraping or other mechanical agitation of
feedstock within vessels 124, or by a fluidized bed bath,
pyrolysis, or dry ice blast cleaning. Cleaning may be performed in
a buffering area or in a discrete cleaning area.
[0779] During a period in which molding system 100 is operated,
process sequences may be varied, such that molding system 100
produces heterogeneous output including molded articles of multiple
types. Output including multiple types of molded articles may
correspond to one or more production orders. That is, a first order
may call for containers of a first type to be produced in a first
quantity, while a second order may call for containers of a second
type to be produced in a second quantity. The two orders may be
fulfilled concurrently according to systems and methods described
herein. Orders (also referred to as "lots") may be as small as a
single molded article.
[0780] In some configurations, molding system 100 is configured so
that a single process path is available to produce a given part
type. That is, containers having a given size, shape and material
type may be produced by a unique combination of stations in each of
dispensing cell 102, shaping cells 104, 106, and conditioning cell
108. In other examples, molding system 100 may be configured such
that multiple process paths are available to produce parts of the
same type. For example, a single dispensing station 102 may
dispense feedstock of a particular material type and colour. That
feedstock may be provided to two stations of shaping cell 104, two
stations of conditioner cell 108, and two stations of shaping cell
106. That is, a single dispensing station may correspond to and
feed two parallel sets of pre-shaping, conditioning and final
shaping stations. The ratios of stations of shaping cell 104,
conditioning cell 108 and shaping cell 106 need not be 1:1. Rather,
the ratios may differ based, for example, on the length of time
required for each operation. For example, if an injection molding
process at cell 104 takes twice as long as a conditioning process
at cell 108 or a blow molding process at cell 106, twice as many
stations in cell 106 may be provided for producing a particular
type of part.
[0781] As described above, transport subsystem 110 includes a
guide, namely tracks 144, along which vessels 124 and workpieces
are moved. Alternatively or additionally, other types of guides may
be used. For example, transport subsystem 110 may include one or
more conveyors such as belt conveyors. Alternatively or
additionally, transport subsystem 110 may include one or more
robotic devices. Such robotic devices may for example be multi-axis
robots with suitable end effectors, and may be operable to transfer
vessels 124 or workpieces between stations of cells 102, 104, 106,
108. In such embodiments, process paths may be defined by stations
through which workpieces can be processed.
[0782] As described above, stations of dispensing cell 102 dispense
doses of feedstock material into vessels 124 to define workpieces.
The amount of material in each dose corresponds to the amount of
material in a single preform workpiece 101' and a single
final-shape workpiece 101''. In other embodiments, doses of
feedstock dispensed by stations of dispensing cell 102 may differ.
For example, doses may comprise any multiple of the amount of
material in a single preform workpiece 101' or in a single
final-shape workpiece 101''. In such embodiments, feedstock
material in a single vessel 124 may feed multiple injection cycles
at a shaping station 106. For a vessel 124 containing sufficient
feedstock for two preform workpieces 101', half of the feedstock
may be injected into the mold of a shaping station 106-1, 106-2, .
. . 106-n in each of two cycles. Alternatively or additionally, one
or more shaping stations may have a mold 200 with multiple molding
cavities, for simultaneously producing multiple preforms. In other
embodiments, feedstock doses may be slightly larger than the amount
of material required to mold one or more parts. In other words, a
small surplus of material may be dispensed into vessels 124, such
that residual material remains in the vessel after transferring to
a station of shaping cell 104. The residual material may remain in
the vessel for a subsequent filling of the vessel, or may be
cleaned from the vessel.
[0783] In other embodiments, stations of dispensing cell 102 may
dispense doses of a smaller quantity of material than is required
to form a single preform workpiece 101' or final-shape workpiece
101''. For example, a vessel 124 may receive doses of different
materials from multiple stations of dispensing cell 102, such that
the vessel 124 simultaneously holds multiple types of materials.
The vessel 124 may then be transported to a station of a shaping
cell to form a molded workpiece of composite material construction,
such as multi-layered construction.
[0784] In some embodiments, vessels 124 may be sequentially
delivered to a station of a shaping cell 104, 106, such that
feedstock doses from multiple vessels 124 contribute to a single
molded article. For example, an article of composite material
construction may be formed by injection of a first material from a
first vessel 124 and a second material from a second vessel 124,
prior to molding.
[0785] Apparatus and methods disclosed herein may allow for
relatively flexible reconfiguration. Each station of dispensing
cell 102, shaping cell 104 and shaping cell 106 can be reconfigured
by removal and replacement of components such as an extruder barrel
114 and screw 116, or a mold 200 or a mold 500 may be easily
removed from a station and replaced with a different barrel and
screw or mold. Stations of conditioning cell 108 may be
reconfigured by removal and replacement of components, or by
adjusting controls based on a desired thermal profile.
[0786] In some embodiments, reconfiguration of stations may be done
without interrupting operation of system 100. For example, an
extruder 112 may be removed while other stations of dispensing cell
102 continue to dispense feedstock. Likewise, a mold 200 or a mold
500 can be removed and replaced during operation of the other
cells, and reconfiguration (e.g. physical adjustment of
re-programming) of a conditioning statement may be done while other
conditioning stations continue to operate.
[0787] Thus, apparatus and methods disclosed herein may provide for
flexibility of production in that the plurality of process paths
through dispensing cell 102, shaping cell 104, conditioning cell
108 and shaping cell 106 allow for concurrent production of many
different types of articles. Moreover, some or all stations of the
cells may be changed or reconfigured without interruption of
production, which further increases the variety of articles that
may be produced during a production run.
[0788] When introducing elements of the present invention or the
embodiments thereof, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0789] The term "comprise", including any variation thereof, is
intended to be open-ended and means "include, but not limited to,"
unless otherwise specifically indicated to the contrary.
[0790] When a set of possibilities or list of items is given herein
with an "or" before the last item, any one of the listed items or
any suitable combination of two or more of the listed items may be
selected and used.
[0791] The above described embodiments are intended to be
illustrative only. Modifications are possible, such as
modifications of form, arrangement of parts, details and order of
operation. The examples detailed herein are not intended to be
limiting of the invention. Rather, the invention is defined by the
claims.
* * * * *
References