U.S. patent application number 13/921291 was filed with the patent office on 2013-10-24 for blow molding apparatus.
The applicant listed for this patent is GRAHAM ENGINEERING CORPORATION. Invention is credited to David N. FIORANI, John M. MATHY, JR..
Application Number | 20130280360 13/921291 |
Document ID | / |
Family ID | 44801185 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130280360 |
Kind Code |
A1 |
MATHY, JR.; John M. ; et
al. |
October 24, 2013 |
BLOW MOLDING APPARATUS
Abstract
A rotary molding machine having a movable member mounted for
rotation on a base about a rotational axis. The movable member has
a first component and a second component which is parallel to the
first component. The first and second components extend
transversely to the rotational axis. A plurality of mold clamp
assemblies are positioned on the movable member, with each mold
clamp assembly being moveable between an open and a closed
position. Each mold clamp assembly has mounting areas which are
mounted with respective mounting locations of the first and second
components. An array of mounting openings are provided in the
mounting locations of the first and second components of the
movable members. The mounting openings are configured to
accommodate multiple mold clamp assembly configurations.
Inventors: |
MATHY, JR.; John M.;
(Stewartstown, PA) ; FIORANI; David N.; (Jacobus,
PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GRAHAM ENGINEERING CORPORATION |
York |
PA |
US |
|
|
Family ID: |
44801185 |
Appl. No.: |
13/921291 |
Filed: |
June 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12898832 |
Oct 6, 2010 |
8485810 |
|
|
13921291 |
|
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Current U.S.
Class: |
425/182 |
Current CPC
Class: |
B29C 49/56 20130101;
B29C 49/36 20130101; B29C 49/04 20130101; B29C 49/42 20130101 |
Class at
Publication: |
425/182 |
International
Class: |
B29C 49/42 20060101
B29C049/42; B29C 49/36 20060101 B29C049/36 |
Claims
1. A rotary molding machine comprising: a base; a movable member
mounted for rotation on the base about a rotational axis, the
movable member having a first component and a second component, the
first and second components extend essentially transversely to the
rotational axis; a plurality of mold clamp assemblies positioned on
the movable member, each mold clamp assembly being moveable between
an open and a closed position, each mold clamp assembly having
mounting areas which are mounted with respective mounting locations
of the first and second components; an array of mounting openings
is provided in the mounting locations of the first and second
components of the movable members, the mounting openings are
configured to accommodate multiple mold clamp assembly
configurations.
2. The rotary molding machine as recited in claim 1, wherein a pair
of shafts is positioned along the rotational axis of the movable
member, a first shaft cooperates with the first component and a
second shaft cooperates with the second component.
3. The rotary molding machine as recited in claim 2, wherein
mounting hardware prevents the first and second components from
inward axial movement and disengagement from respective shafts.
4. The rotary molding machine as recited in claim 1, wherein a
drive gear is removably mounted to the movable member, the drive
gear cooperating with a drive mechanism to rotate the movable
member about the rotational axis.
5. The rotary molding machine as recited in claim 1, wherein a pair
of shafts are positioned along the rotational axis of the movable
member, the pair of shafts are tubular, outer ends of the pair of
shafts being attached to rotary joints through which air and fluid
respectively pass.
6. The rotary molding machine as recited in claim 1, wherein each
mold clamp assembly has a frame having a base member, a first end
member and an oppositely-facing second end member, the
oppositely-facing first and second end members having the mounting
areas provided thereon, first and second platens being movably
mounted on the base member, the platens being movable between open
and a closed position.
7. The rotary molding machine as recited in claim 1, wherein a
respective component has a manifold for gaseous fluid removably
attached thereto, the manifold transmits the gaseous fluid from a
respective shaft to the mold clamp assembly.
8. The rotary molding machine as recited in claim 1, wherein a
respective component has a manifold for liquid removably attached
thereto, the manifold transmits the liquid from a respective shaft
to the mold clamp assembly.
9. The rotary molding machine as recited in claim 1, wherein the
mold clamp assemblies have cam followers which cooperate with a cam
member provided in the base, the cam followers are movable between
different openings of the mold clamp assembly to allow the cam
followers to be positioned at the same diameter, whether the mold
clamp assemblies are used with first and second components having a
large diameter or a small diameter.
10. A rotary molding machine comprising: a base; a wheel mounted
for rotation on the base about a rotational axis, the wheel having
a first turntable and a second turntable, the first and second
turntables extend essentially transversely to the rotational axis;
a pair of shafts positioned along the rotational axis of the wheel,
a first shaft cooperates with the first turntable and a second
shaft cooperates with the second turntable; a plurality of mold
clamp assemblies positioned on the wheel, each mold clamp assembly
being moveable between an open and a closed position, each mold
clamp assembly extending between the first and second turntables;
the mold clamp assemblies provide the structure and rigidity
between the turntables to help maintain the turntables in position
relative to each other.
11. The rotary molding machine as recited in claim 11, wherein
mounting hardware prevents the turntables from inward axial
movement and disengagement from respective shafts.
12. The rotary molding machine as recited in claim 12, wherein a
drive gear is removably mounted to the wheel, the drive gear
cooperating with a drive mechanism to rotate the wheel about the
rotational axis.
13. The rotary molding machine as recited in claim 12, wherein the
first and second shafts are tubular and outer ends of the first and
second shafts being attached to rotary joints through which air and
fluid respectively pass.
14. The rotary molding machine as recited in claim 11, wherein each
mold clamp assembly has a frame having a base member, a first end
member and an oppositely-facing second end member, the
oppositely-facing first and second end members having the mounting
areas provided thereon, first and second platens being movably
mounted on the base member, the platens being movable between open
and a closed position.
15. The rotary molding machine as recited in claim 11, wherein an
array of mounting openings are provided in the mounting locations
of the first and second turntables of the wheels, the mounting
openings are configured to accommodate multiple mold clamp assembly
configurations.
16. The rotary molding machine as recited in claim 11, wherein the
mold clamp assemblies have cam followers which cooperate with a cam
member provided in the base, the cam followers are movable between
different openings of the mold clamp assembly to allow the cam
followers to be positioned at the same diameter, whether the mold
clamp assemblies are used with turntables having a large diameter
or a small diameter.
17. A rotary molding machine comprising: a base; a movable member
mounted for rotation on the base about a rotational axis, the
movable member having a first component and a second component; a
drive gear removably mounted to the movable member, the drive gear
cooperating with a drive mechanism to rotate the movable member
about the rotational axis; a plurality of mold clamp assemblies
positioned on the movable member, each mold clamp assembly being
moveable between an open and a closed position, each mold clamp
assembly extending between the first and second components; the
mold clamp assemblies provide the structure and rigidity between
the first and second components to help maintain the first and
second components in position relative to each other.
18. The rotary molding machine as recited in claim 17, wherein a
pair of shafts are positioned along the rotational axis of the
movable member, a first shaft cooperates with the first component
and a second shaft cooperates with the second component.
19. The rotary molding machine as recited in claim 18, wherein the
pair of shafts have outer ends which are attached to rotary joints
through which air and fluid pass.
20. The rotary molding machine as recited in claim 17, wherein each
mold clamp assembly having mounting areas which are mounted with
respective mounting locations of the first and second components,
the mounting locations of the first and second components of the
movable members having an array of mounting openings, the mounting
openings configured to accommodate multiple mold clamp assembly
configurations.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is claiming the benefit of prior-filed
nonprovisional U.S. Application Ser. No. 12/898,832, filed Oct. 6,
2010, and entitled "BLOW MOLDING APPARATUS," the disclosure of
which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is related to a multi-station blow
molding machine or apparatus. In particular, the invention relates
to a blow molding machine or apparatus in which the components are
modular.
BACKGROUND OF THE INVENTION
[0003] Rotary plastic blow molding machines conventionally include
a structural frame or wheel mounted on a base for rotation about a
horizontal rotational axis. The wheel includes a frame that
supports a plurality of mold stations, each of which are mounted
around the circumference of the machine, and each of which has a
pair of mold supports for mounting a pair of mold portions of a
mold. A continuously extruded parison is guided between open mold
halves. With rotation, the molds close on the parison, the parison
is blown, the molds open to eject containers, and the cycle is
repeated. The molds are continuously rotated at high speed to
produce containers in high volumes. These machines are expensive to
construct and operate. As many as twenty-four or more new molds may
be required. Change-over to a different style container is
expensive and time-consuming due to the need to build and install a
set of new molds on the supports.
[0004] One such machine is disclosed in U.S. Pat. No. 3,764,250
issued to Waterloo. Waterloo discloses a blow molding machine which
includes a shaft, through which air and fluid pass, which extends
through the wheel. A pair of side means are provided, which are
parallel to each other and extend transversely to the axis of the
shaft. Extending between the side means, in even,
circumferentially-spaced relationship to each other, are pairs of
similar guide rods, which are firmly secured at the ends thereof,
respectively, to the side means. Mounted upon each pair of guide
rods is a pair of similar complementary jaws, which are provided
with opposing vertical faces against which the mold dies are firmly
mounted by appropriate attaching means, such as bolts or the like,
not shown, in accordance with conventional practice in blow molding
machines. Thus, the basic elements of the wheel are the side means
and the guide rods which extend therebetween and are connected
firmly thereto. The support of the side means, and other components
on the continuous shaft, is an essential feature of the
machine.
[0005] Because of the supports and shafts required to properly
operate the machines, the machines are complicated to manufacture
and require significant expertise and time to repair or replace the
mold clamp assemblies. It would, therefore, be beneficial to
provide a blow molding machine in which the components are more
modular, thereby allowing the components to be easily repaired or
replaced when a change-over to a different style container is
required.
SUMMARY OF THE INVENTION
[0006] An object of the invention is to provide a rotary blow
molding machine in which the inventory of parts required to
accommodate various configurations is minimized, thereby reducing
the need to manufacture specific mold clamp assemblies for specific
machines.
[0007] Another object of the invention is to provide a rotary blow
molding machine which is less expensive to manufacture and operate
by allowing the same components to be used in various machines,
thereby reducing the need to manufacture specific components for
specific machines.
[0008] Another object of the invention is to provide a modular
rotary blow molding machine in which components can be easily
removed and replaced with minimal downtime, thereby minimizing the
impact to the productivity of the operation.
[0009] Another object of the invention is to provide a modular
rotary blow molding machine in which components can be easily
removed and replaced by maintenance level personnel rather than
factory technicians, thereby minimizing the cost.
[0010] Another object of the invention is to provide a simplified
structure of a rotary molding wheel by using a modular mold clamp
assembly which provides the structural support necessary between
components of the rotary molding wheel.
[0011] Another object of the invention is to provide a modular mold
clamp assembly in which the bending moments are not transferred to
the components of a rotary molding wheel.
[0012] An embodiment of the invention is directed to a rotary
molding machine having a movable member mounted for rotation on a
base about a rotational axis. The movable member has a first
component and a second component which is parallel to the first
component. The first and second components extend transversely to
the rotational axis. A plurality of mold clamp assemblies are
positioned on the movable member, with each mold clamp assembly
being moveable between an open and a closed position. Each mold
clamp assembly has mounting areas which are mounted with respective
mounting locations of the first and second components. An array of
mounting openings are provided in the mounting locations of the
first and second components of the movable members. The mounting
openings are configured to accommodate multiple mold clamp assembly
configurations.
[0013] Another embodiment is directed to the rotary molding which
has a pair of shafts positioned along the rotational axis of the
movable member. The first shaft cooperates with the first component
and the second shaft cooperates with the second component.
[0014] Another embodiment of the invention is directed to a wheel
for use in rotary molding machine. The wheel is mounted for
rotation on a base about a rotational axis, The wheel has a first
turntable and a second turntable mounted for rotation about a
rotational axis. The first and second turntables extend
transversely to the rotational axis. A plurality of mold clamp
assemblies are provided on the wheel and extend between the first
turntable and the second turntable. Each modular mold clamp
assembly is moveable between an open and a closed position. The
modular mold clamp assemblies provide the structure and rigidity
between the turntables to help maintain the turntables in position
relative to each other.
[0015] Another embodiment of the invention is directed to a rotary
molding machine which has a movable member mounted for rotation on
a base about a rotational axis. The movable member has a first
component and a second component. A drive gear is removably mounted
to the movable member. The drive gear cooperates with a drive
mechanism to rotate the movable member about the rotational axis. A
plurality of mold clamp assemblies are positioned on the movable
member, with each mold clamp assembly being moveable between an
open and a closed position. Each mold clamp assembly extends
between the first and second components. The mold clamp assemblies
provide the structure and rigidity between the first and second
components to help maintain the first and second components in
position relative to each other.
[0016] Other features and advantages of the present invention will
be apparent from the following more detailed description of the
preferred embodiment, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a side elevation of an exemplary blow molding
machine embodying the principles of the present invention.
[0018] FIG. 2 is a front elevation of the blow molding machine
shown in FIG. 1.
[0019] FIG. 3 is a side view of an exemplary embodiment of a
modular mold clamp assembly for use in the blow molding machine,
the modular mold clamp assembly having molds inserted therein and
being shown in the closed position.
[0020] FIG. 4 is a side view of the modular mold clamp assembly,
the modular mold clamp assembly having molds inserted therein and
being shown in the open position.
[0021] FIG. 5 is a cross-sectional view of the modular mold clamp
assembly of FIG. 3, taken along the longitudinal axis of the
modular mold clamp assembly.
[0022] FIG. 6 is a cross-sectional view of the modular mold clamp
assembly of FIG. 4 taken along the horizontal axis of the modular
mold clamp assembly.
[0023] FIG. 7 is a top view of the modular mold clamp assembly of
FIG. 3.
[0024] FIG. 8 is a cross-sectional view thru the tie bars of the
modular mold clamp assembly of FIG. 3 with the molds removed.
[0025] FIG. 9 is a vertical cross-sectional view of the modular
mold clamp assembly of FIG. 3, looking toward a first end of the
assembly.
[0026] FIG. 10 is an end view of the modular mold clamp assembly of
FIG. 3, as viewed from outside of the assembly.
[0027] FIG. 11 is a perspective view of a wheel of the blow molding
machine with several modular mold clamp assemblies attached
thereto, the mold clamp assemblies being shown with no molds
positioned therein.
[0028] FIG. 12 is a cross-sectional view of the wheel shown in FIG.
11.
[0029] FIG. 13 is a cross-sectional view of the wheel, taken along
the line 13-13 of FIG. 12.
[0030] FIG. 14 is an enlarged top plan view of the power means of
the blow molding machine, certain parts of the blow molding machine
being shown fragmentarily in phantom to illustrate operative
relationship between the blow molding machine and the power
means.
[0031] FIG. 15 is a large scale vertical elevation of a cam unit
carried by the base of the blow molding machine.
[0032] FIG. 16 is a vertical sectional view of the fluid manifold
as seen on the line 16-16 of FIG. 17.
[0033] FIG. 17 is a vertical sectional elevation of the fluid
manifold shown in FIG. 16 as seen on the line 17-17 of said
figure.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The rotary blow molding machine described herein is adapted
to engage a tubular parison and transform the same into hollow,
molded objects, such as containers of various types. As is known in
the industry, the parison comprises resin which is homogeniously
melted within an extruder of suitable type.
[0035] Referring now to FIG. 1 and FIG. 2, there is illustrated a
plastic blow molding machine shown generally by reference numeral
20. The blow molding machine 20 includes a base 22 and a movable
member or wheel 24 mounted on the base for rotation thereon about a
rotational axis A. The movable member 24 may be in the form of a
wheel or other such configurations which are rotatable about the
rotational axis. As illustrated, the blow molding machine includes
a ring gear or drive gear 26 driven by a drive mechanism 28. The
ring gear 26 is mounted to turntable 42 and rotates the wheel
24.
[0036] As best shown in FIG. 1, the plastic blow molding machine 20
includes a plurality of blow molding stations 38 mounted on the
wheel 24 for rotation therewith about the rotational axis A. As
shown, the wheel 24 has eighteen mold stations 38, provided between
components or turntables 42, 44 of the wheel 24, although other
configurations are included within the scope of the claims. The
components 42, 44 may be in the form of turntables or other such
configurations which are rotatable about the rotational axis.
[0037] The turntables 42, 44 of wheel 24 are mounted for rotation
within a substantially vertical plane transverse to the axis of the
base 22. For this purpose, base 22 supports, in transversely-spaced
relationship, a pair of vertical standards 50, 52, which are heavy
castings or the like, firmly secured, at the lower ends thereof,
directly to base 22 by appropriate means. The upper ends of the
standards 50, 52 respectively support bearings 54, 56 (FIG. 14),
from which the main supporting stub shafts 58, 60 extend. The outer
ends of the stub shafts 58, 60 project beyond the outer ends of the
bearing, respectively, for the attachment of rotary joints thereto
through which air and fluid respectively pass. The shafts 58, 60
are tubular to accommodate certain conduits which are described in
detail hereinafter. As shown in FIG. 2, the stub shafts 58, 60 do
not extend into the open space provided between the turntables 42,
44.
[0038] The turntables 42, 44 of wheel 24 are fixed to and carried
by respective shafts 58, 60. The turntables 42, 44 are parallel to
each other and extend transversely to the axis of the shafts 58,
60. In an embodiment, the turntable 42 comprises a manifold for
gaseous fluid, preferably air, removably attached to the turntable
42, The manifold transmits the gaseous fluid from conduits within
the shaft 58 to one of the mold halves by which a parison needle is
supported, and relative to which it is movable to and from the mold
cavity by means described hereinafter. In another embodiment, the
turntable 42 may be a plate having the strength characteristics
required, and the gaseous fluid may be transmitted through conduits
within the shaft 58 to the mold halves by means of tubing or the
like.
[0039] In an embodiment, the turntable 44 comprises a manifold for
liquid, preferably water, removably attached to the turntable 44.
The manifold transmits the liquid from conduits within the shaft 60
to one of the mold halves. In another embodiment, the turntable 44
may be a plate having the strength characteristics required, and
the liquid may be transmitted through conduits within the shaft 60
to the mold halves by means of tubing or the like.
[0040] Each of the turntables 42, 44 is prevented from inward axial
movement and disengagement from respective stub shafts 58, 60 by
any known suitable means, such as a lock ring. Extending between
turntables 42, 44, at each mold station 38 and in even,
circumferentially-spaced relationship to each other, are the mold
clamp assemblies 100, which are firmly secured at the ends thereof,
respectively, to the turntables 42, 44.
[0041] The circumferentially-spaced arrangement of the various mold
clamp assemblies 100 is best illustrated in FIG. 1. In order that
the illustration in FIG. 2 might be simplified for clarity of
concept, only several of the mold clamp assemblies 100 are
illustrated therein, whereas the intervening mold clamp assemblies
100 have been omitted. It is to be understood, however, that the
machine shown in FIG. 2 embodies a full complement of the mold
clamp assemblies 100 at each molding station 38, such as shown in
FIG. 1.
[0042] Firmly and removably secured to the outer face of the
turntable 42 is the ring gear 26 of extensive diameter, as can
readily be seen from FIGS. 1 and 2. The ring gear 26 and drive
mechanism 28 generally operate at a predetermined speed which is
capable of adjustment by conventional means.
[0043] Referring to FIGS. 3-10, an exemplary embodiment of mold
clamp assembly 100 is shown, the modular mold clamp assembly 100
having a frame 110. The frame 110 has a base member 112 and two
oppositely-facing end members 111, 113. The end members 111, 113
extend from either end of the base member 112 in a direction that
is essentially transverse to the longitudinal axis of the base
member 112. The end members 111, 113 are integrally attached to the
base member in any known manner which has the strength
characteristics required. Mounting openings 115 are provided on the
frame 110 proximate the ends of the base member 112. The openings
115 cooperate with mounting hardware (FIG. 10) to mount the modular
mold clamp assembly 100 to mounting openings 25 of the turntables
42, 44 of the wheel 24. The base member 112 and end members 111,
113 are made from any material that has the strength
characteristics required to support the components of the modular
mold clamp assembly 100 and to provide the structural integrity
required to support the radially extending turntables 42, 44 of the
wheel 24. The mold clamp assemblies 100 provide the main structural
support between the turntables. Small diameter support rods are
used to space the turntables 42, 44 and keep the turntables 42, 44
from dishing at the stub shafts 58, 60. This allows the mold clamp
assemblies 100 to be fully assembled prior to insertion of the mold
clamp assemblies 100 into the blow molding machine 20. The fully
assembled mold clamp assemblies 100 are then mounted in the blow
molding machine 20 using the hardware described. This modular
aspect of the wheel 24 and mold clamp assemblies 100 provides many
advantages, as will be more fully described.
[0044] Each modular mold clamp assembly 100 includes rods 124
mounted on base member 112 of frame 110. The rods 124 extend
essentially parallel to the longitudinal axis of the base member
112. As best shown in FIGS. 3 and 6, rods 124 extend through
openings in mounting brackets 114, 116, 118, 120. In the embodiment
shown, the mounting brackets 114, 116, 118, 120 are fixed to the
base member 112 by bolts or other mounting hardware. Mold platens
126 and 128 are mounted on the rods 124 by slides 130 which permit
movement of the platens toward and away from each other during
closing and opening of mold halves 132 and 134 mounted on platens
126 and 128, respectively. FIG. 3 illustrates assembly 100 with the
mold halves closed.
[0045] Pin 142 extends through a portion of end member 113. The
adjacent ends of rods 124 are secured to the pin. Pivot arm 144 is
rotatably mounted on pin 142 between the rods 124. The outer end
146 of arm 144 away from the mold halves extends through an opening
in end member 113 and is connected to follower slide 148 by links
150 (FIG. 9). The follower slide 148 is mounted on the outside
surface of the end wall 113 by slide 152 to permit movement of the
car back and forth in the direction of arrow 154, shown in FIGS. 5
and 6. Car 148 carries cam follower roller 156, which extends into
circumferential fixed cam slot 196 of the blow molding machine.
Rotation of wheel 24 moves follower 156 into and around the cam
slot 196 to follower slide 148 inwardly and outwardly and rotate
arm 144 between the positions shown in FIGS. 3 and 4.
[0046] Shift member 162 is located between mold platen 126 and end
member 113. A cylindrical rod 167 extends from an upper end 164 of
member 162 and is bolted directly to mold platen 126 so that
movement of member 162 toward end member 113 moves the mold platen
126 and mold half 132 toward the end member 113. The lower end 166
of shift member 162 extends from the lower end of bracket 120 and
extends below mold halves 132 and 134. The shift member is slidably
mounted on rods 124 and 168.
[0047] Link 160 is pivotally connected to the inner link end 145 of
arm 144 and to mold shift member 162. The pivot connection between
link 160 and member 162 is located halfway between the upper end
164 and lower end 166 of member 162 to balance forces. Shift rod
168 is parallel to the longitudinal axis of the base member 112 and
extends freely through the base member 112. The shift rod 168 is
connected to the lower end 166 of member 162. The link 160 and
inner link end 145 of arm 144 form a two-link extendable and
retractable drive 163 for opening and closing platens 126, 128 and
mold halves 132, 134.
[0048] Cross pin 170 is fixedly mounted on the ends of rods 124
extending past platen 128 and mold half 134 and rotatably supports
pivot arm 172. The lower end 174 of arm 172 is connected to the
adjacent end of shift rod 168 by pivot link 176 and rod end clevis
177. The upper end 178 of arm 172 is connected to mold clamp rod
180 by pivot link 182 and rod end clevis 183. Clamp rod 180 is
connected to platen 128 through dished washer spring pack 184. Rod
168, clevis 177, link 176, arm 172 and rod 180 are part of a mold
shift mechanism 165 for opening and closing platen 128 and mold
half 134. Mechanism 165 is connected to drive 163 through member
162.
[0049] In operation, the modular mold clamp assemblies 100 are
assembled to the turntable 42, 44 of the wheel 24, as previously
described. The assemblies 100 have fluid couplings which are
connected via hoses to the respective fluid manifolds 210. The
fluid is supplied through the fluid manifolds 210 to cool the mold
halves, as is known in the industry. As best shown in FIGS. 16 and
17, fluid manifold 210 located proximate turntable 42 delivers
fluid to the assemblies 100, while fluid manifold 210 located
proximate turntable 44 draws fluid away from the assemblies 100.
Alternatively, the respective manifolds 210 may be reversed or
positioned in other locations. The manifolds 210 have four pipes
212 which extend radially outward from and are rotatably mounted on
the stub shaft 58. Fluid is delivered to the pipes 212 through a
main conduit 214 which extends through the shaft 58. Hoses (not
shown) are connected, at one end, to fluid outlets 216 of pipes 212
and, at the opposite end, to assemblies 100. The assemblies 100 are
pre-assembled to transport the fluid to the mold halves 132, 134.
Similarly, fluid is removed through respective pipes 212 through
main conduit 218 which extends through shaft 60. The assemblies 100
are pre-assembled to transport the fluid away from the mold halves
132, 134. As the manifold operates in a known manner, a more
detailed description will not be provided.
[0050] The assemblies 100 have air couplings which are connected
via hoses to the respective air manifolds 220. The air is used to
blow air into the mold cavities and to operate the required devices
with the container as it is removed from the cavity, both of which
are known in the industry. As best shown in FIGS. 16 and 17, air
manifold 220 located proximate turntable 42 delivers air to the
assemblies 100. Alternatively, the manifold 220 may be positioned
on the opposite turntable or in other locations. The manifold 220
has eight assemblies 222 which extend radially outward from and are
rotatably mounted on the stub shaft 58. Air is delivered to the
assemblies 222 through a main conduit 224 which extends through the
shaft 58. Hoses (not shown) are connected, at one end, to air
outlets 226 of assemblies 222 and, at the opposite end, to
assemblies 100. The assemblies 100 are pre-assembled to transport
the air to the mold halves 132, 134. As the manifold operates in a
known manner, a more detailed description will not be provided.
[0051] With the mold halves 132 and 134 in the open position and
drive 163 retracted as shown in FIG. 4, rotation of wheel 24 moves
the open mold halves 132, 134 past the extrusion station to either
side of a number of parisons extruded from an extrusion head.
Rotation of the wheel 24 also moves follower 156 along a radially
outward portion of a cam slot 196 (FIG. 15) to move follower slide
148 radially outwardly from the position of FIG. 4 to the position
of FIG. 3. This movement rotates arm 144 counterclockwise from the
position of FIG. 4 to the position of FIG. 3. Movement of the
actuating means to affect such opening and closing movements of the
mold die is achieved by mold-actuating cam means now to be
described.
[0052] Referring to FIG. 15, an exemplary cam unit 198 or assembly
with cam slot 196 is illustrated. The cam unit 198 is positioned
proximate a respective turntable 42 and is secured to the base 22.
Cam unit 198 has the cam slot 196 formed in one face thereof. The
slot 196 has a dwell portion 200 of substantial length and an
actuating portion 202, which, when engaged by the cam followers
156, operates the mold clamp assemblies 100 to move the mold halves
132, 134 to closed position. The fully closed position thereof is
effected when the cam followers are moved outwardly beyond the
terminal end of the mold actuating portion 202 of the cam slot
196.
[0053] The outer or entrance end 204 of cam slot 196 is funnel-like
and of appreciable width at the entrance end to insure the ready
reception of cam followers 156 as they progressively move clockwise
relative to the cam unit, as viewed in FIG. 15. The fully opened
position is effected when the cam followers 156 are moved and
engage a declining portion 206 of slot 196.
[0054] Rotation of arm 144 from the position of FIG. 4 to the
position of FIG. 3 extends drive 163 to move shift member 162 away
from end member 113. Movement of the shift member moves mold half
132 from the open position to the closed position. Movement of the
shift member also actuates mold shift mechanism 165 to move shift
rod 168 away from end member 113, rotate arm 172 and move mold half
134 from the open position to the closed position. The connection
between rod 180 and spring pack 184 is adjusted so that spring pack
184 is compressed when the mold is closed.
[0055] During and after closing of the mold, the clamp force
exerted on mold half 134 is transmitted directly to drive 163
through mechanism 165. An equal and oppositely-directed clamp force
exerted on mold half 132 is transmitted to the drive directly
through member 162. Clamping forces are transmitted through rods
124 between cross pins 170 and fixed pin 142 which in turn is
attached to end frame 113. Clamping forces are not transmitted
through frame member 110. The end of the mechanism 165, cross pin
170, adjacent end member 111 floats on the frame 110. As a result,
the frame 110 is not subjected to bending moments by the high clamp
forces holding mold halves 132 and 134 closed. The frame 110 need
not be strengthened against bending moments. Smaller, more
efficient motors may be used to operate the machine due to weight
reduction.
[0056] After closing of the mold to capture the parison, rotation
of wheel 24 moves the closed mold halves away from the extrusion
station to a blow station where the parisons are blown, and, after
cooling of the blown parisons, to an ejection station where the
mold is opened for ejection of blow-molded containers. During
rotation to the ejection station, follower 156 is moved radially
inwardly by the cam track so that arm end 146 is moved radially
inwardly about fixed pin 142, drive 163 is retracted as shown in
FIG. 4, and the platens 126, 128 and mold halves 132, 134 are
opened by movement of the shift member 162 and mechanism 165.
Platen 126 and mold half 132 are connected directly to shift member
162 and are opened in response to movement of the member. Platen
128 and mold half 134 are opened by movement of shift rod 168
toward side member 113, which corresponds to rotation of arm 172
and movement of rod 180 away from side member 113 and toward side
member 111.
[0057] During the operation of the wheel 24, it is not uncommon to
have problems with a particular mold clamp assembly. It is also
common to have scheduled maintenance. In the prior state of the
art, in order to repair or perform maintenance on a particular mold
clamp assembly, the operation of the wheel is stopped and the
repair or maintenance is performed on the mold clamps as the mold
clamps are attached to support rods of the wheel. This can cause
significant downtime for the entire operation and dramatically
affects the productivity of the operation. Alternatively, the
operation of the wheel is stopped and the respective mold clamp is
removed from the support rods and turntables of the wheel and
replaced with another mold clamp assembly. However, as the mold
clamp assemblies are attached at numerous points to the structure
of the wheel, this process takes a good deal of time and expertise
to accomplish, thereby dramatically affecting the productivity of
the operation and requiring the services of a skilled operator to
accomplish the transfer.
[0058] In contrast, the wheel 24 and the modular mold clamp
assembly 100 described herein overcome the problems associated with
the prior art. As all of the components of the modular mold clamp
assembly 100 are mounted to the frame 110, the mold clamp assembly
100 is self-contained or modular, i.e., it is not mounted to
integral support rods of the wheel. Therefore, the removal of the
self-contained modular mold clamp assembly 100 from the wheel 24 is
greatly facilitated. In order to repair or perform maintenance on a
particular mold clamp assembly 100, the operation of the wheel 24
is stopped and the modular mold clamp assembly 100 is removed and
replaced with another modular mold clamp assembly 100. As all of
the components of the assembly 100 are pre-assembled and supported
by the assembly frame 110, rather than by structural members of the
wheel 24, the maintenance personnel simply unscrews the hardware
which attaches the frame 110 of the modular mold clamp assembly 100
to the wheel 24, removes the modular mold clamp assembly 100,
inserts a new modular mold clamp assembly 100, and attaches the
frame 110 to the wheel 24 by use of the hardware. This allows the
repair or maintenance to be accomplished with minimal downtime for
the wheel, thereby minimizing the impact to the productivity of the
operation. Additionally, the replacement of the modular mold clamp
assembly 100 can be accomplished with maintenance level personnel
rather than factory technicians, thereby minimizing the cost.
[0059] The method of molding parts in the blow molding apparatus 20
allows for productivity to be increased. The modular mold clamp
assemblies 100 are inserted into the movable member 24. The movable
member 24 is rotated about a rotational axis of the base 22. The
components 42, 44 of the movable member 24 are supported through
the modular clamp assemblies 100. The mold halves 132, 134, which
are supported by the modular mold clamp assemblies 100, are clamped
around extruded material. The material is cured in the mold halves
132, 134 and the parts are ejected from the mold halves 132, 134.
This allows the productivity of the molding apparatus 20 to be
increased, as the repair and maintenance downtime of the blow
molding apparatus 20 is minimized.
[0060] The structure of the wheel 24 is also greatly simplified. As
each modular member assembly 100 is self-contained, the various
components of the modular mold clamp assembly 100 are not mounted
to support rods, shafts or plates which extend between the
turntables 42, 44 of the wheel 24. In addition, the base member 112
and the end members 111, 113 are made of materials that have the
structural strength and integrity to act as supports when installed
in the wheel 24. Therefore, the wheel 24 used with the modular mold
clamp assemblies 100 described herein is greatly simplified from
the wheels currently in use. The support rods and shafts previously
required are eliminated, as the modular mold clamp assemblies 100
provide the structural support necessary between the turntables 42,
44 of the wheel 24.
[0061] As described herein, the modular mold clamp assemblies 100
provide the structure and rigidity between the turntables to help
maintain the turntables in position relative to each other. This
allows the wheel 24 of the blow molding machine to have more open
spaces, making any repair to the blow molding machine easier. The
use of the modular mold clamp assemblies 100 as supports also
reduces the overall cost of the blow molding machine, as it is less
expensive to have structural modular mold clamp assemblies than to
have structural shafts upon which mold clamps are assembled.
[0062] While the base member 112 and end members 111, 113 must be
made of material which has sufficient strength characteristics to
support the components and provide the structural integrity
required for the wheel 24, the frame 110 does not need to be made
of material which can withstand the bending moments exerted by the
high clamp forces holding molds 132 and 134 closed, as the bending
moments are not transferred to the frame 110, as was previously
described. Therefore, the frame 110 need not be strengthened
against bending moments, thereby allowing the frame 110 to be made
of relatively lightweight material. This facilitates the removal
and replacement of the modular mold clamp assembly 100 and reduces
the material costs to manufacture the frame 110. This also allows
the turntables to be made of relatively lightweight material. As
the bending moments are not transferred through the assemblies 100
to the turntables 42, 44, the turntables need not be strengthened
against bending moments.
[0063] Depending upon the type of container to be manufactured
using the blow molding machine, the number of molding stations may
vary. Consequently, it is known in the art to have wheels with
different numbers of mold stations. Currently, each of the wheels
must be manufactured according to the desired application, with the
appropriate number of shafts extending between the turntables to
provide support to the turntables and to provide the mounting
structure for the mold clamp assemblies. Consequently, as each
wheel is designed for a particular number of mold stations, the
inventory associated with meeting the needs of applications can be
extensive.
[0064] According to the invention described herein, the inventory
required to accommodate various configurations is minimized. As the
wheels do not require support rods or continuous shafts, etc., the
wheels can be manufactured to accommodate different configurations.
An array of mounting openings 25 may be provided on the turntables
42, 44 of the wheels 24. The mounting openings 25 can be configured
to accommodate multiple mold clamp assembly configurations. The
modular mold clamp assemblies 100 may be used to accommodate
various configurations of the wheel. The end members 111, 113 are
positioned in line with the appropriate openings 25 of the
turntables 42, 44 of the wheel 24 and mounted thereto using the
mounting hardware. This allows the same modular mold clamp
assemblies 100 to be used in various machines, thereby reducing the
need to manufacture specific mold clamp assemblies for specific
machines.
[0065] The modularity of the rotary blow molding machine reduces
the cost of the machine. The turntables 42, 44 can be easily
removed from the stub shafts 58, 60 by removing the mounting plate
provided thereon. This allows the first respective turntables 42,
44 to be removed from the base 22 and ring gear 26 and replaced
without the need to replace the ring gear 26, fluid manifold 210,
air manifold 220, etc. As the shafts 58, 60 are not continuous, the
turntables 42, 44 can be removed from the shafts 58, 60 by moving
the turntables 42, 44 inward of the wheel. As the shaft 58, 60 is
not continuous, the removal of the turntables does not require the
removal of the shaft. Consequently, different sized turntables 42,
44 may be used without the need to change other parts of the rotary
blow molding machine. In addition, the cam followers 156 may be
positioned in different openings of the follower slide 148. This
allows the cam followers 156 to be positioned at the same diameter,
whether the mold clamp assemblies 100 to be used with turntables
42, 44 have a large diameter or small diameter. Consequently, the
same mold clamp assemblies 100 can be used with large or small
turntables. This allows the same components to be used in various
machines, thereby reducing the need to manufacture specific
components for specific machines. Only the different sized
turntables 42, 44 would be changed.
[0066] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
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