U.S. patent application number 10/844618 was filed with the patent office on 2005-11-17 for toggle press.
Invention is credited to Sawdon, Edwin G., Sprotberry, Steven J..
Application Number | 20050252269 10/844618 |
Document ID | / |
Family ID | 35308122 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050252269 |
Kind Code |
A1 |
Sawdon, Edwin G. ; et
al. |
November 17, 2005 |
Toggle press
Abstract
A press for translating a tool includes a first member, a second
member and a plurality of retention members. The first member is
drivingly coupled to an actuator. The first member is axially
moveable between first and second positions in response to movement
of the actuator. The first member includes a first end surface
having a plurality of circumferentially spaced apart detents. The
second member is threadably engaged with the first member. The
first and second members define an assembly having a length. The
retention members are positioned between the first and second
members. Each retention member is biasedly engaged with one of the
detents to provide resistance to relative rotation between the
first and second members. The resistance to relative rotation may
be overcome to adjust the length of the assembly.
Inventors: |
Sawdon, Edwin G.; (St.
Clair, MI) ; Sprotberry, Steven J.; (Marysville,
MI) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
35308122 |
Appl. No.: |
10/844618 |
Filed: |
May 12, 2004 |
Current U.S.
Class: |
72/451 |
Current CPC
Class: |
B21D 39/031 20130101;
B21D 28/002 20130101; B30B 1/10 20130101; B21J 9/18 20130101; B30B
1/16 20130101; B21D 28/24 20130101; B30B 15/0088 20130101 |
Class at
Publication: |
072/451 |
International
Class: |
B21J 009/18 |
Claims
What is claimed is:
1. A press for translating a tool, comprising: a press body
defining a cavity; a piston disposed within said cavity, said
piston being pivotable between a first position and a second
position, said piston including a trunnion defining a trunnion face
and a plurality of pin recesses aligned on an arc; a sensor pin
disposed in one of said plurality of pin recesses substantially
flush with said trunnion face; and a sensor supported by said press
body and substantially axially aligned with said trunnion, said
sensor being operable to detect the presence of said sensor pin
when said piston is in said first and second positions.
2. The press of claim 1 wherein said trunnion face further includes
an arcuate slot surrounding said plurality of pin recesses.
3. The press of claim 1 wherein said plurality of pin recesses each
include a threaded blind bore for receiving said sensor pin.
4. The press of claim 1 wherein said sensor is a proximity sensor
having a sensing element disposed substantially flush with said
trunnion face.
5. The press of claim 1 wherein said sensor includes a magnetic
device and said sensor pin is constructed of a ferromagnetic
material.
6. The press of claim 1 wherein said sensor is operable to output a
first signal when said piston is in said first position and a
second signal when said piston is in said second position.
7. The press of claim 1 wherein said trunnion further defines a
substantially cylindrical bearing surface in sliding rotational
engagement with said press body.
8. The press of claim 7 wherein said trunnion further includes a
network of internal cavities in fluid communication with said
bearing surface for containing and dispensing a lubricant
thereto.
9. The press of claim 8 wherein said press body includes a first
lubrication port in fluid communication with said network of
internal cavities for injecting a lubricant therein.
10. The press of claim 1 wherein said press includes a first
pneumatic port in communication with said cavity for selectively
supplying pressurized fluid to one side of said piston.
11. A press for translating a tool, comprising: a press body having
a cavity; a piston rotatably positioned within said cavity and
moveable between a first position and a second position; a press
link including a first yoke and having a first leg defining a first
aperture and a second leg defining a second aperture, wherein said
second aperture includes a rotation limiting surface; and a first
link pin drivingly interconnecting said first yoke and said piston,
said first link pin including: a first end engaging said first
aperture; a body portion having a substantially cylindrical bearing
surface rotatably engaging said piston; a second end engaging said
second aperture such that said rotation limiting surface prevents
said first link pin from rotating relative to said first yoke; and
a network of internal cavities in fluid communication with said
bearing surface, said network adapted to contain and dispense a
lubricant to said bearing surface.
12. The press of claim 11 wherein a portion of said second aperture
includes a curved wall portion and a substantially planar wall
portion.
13. The press of claim 12 wherein a portion of said second aperture
is substantially D-shaped.
14. The press of claim 13 wherein said second end of said first
link pin is substantially D-shaped.
15. The press of claim 11 wherein said network of internal cavities
includes an axial cavity and a plurality of radial cavities in
fluid communication with said axial cavity.
16. The press of claim 11 wherein said press link further includes
a second yoke opposite said first yoke.
17. The press of claim 16 further comprising a second link pin,
wherein said second yoke includes a third leg defining a third
aperture and a fourth leg defining a fourth aperture, said second
link pin extending through said third and fourth apertures of said
second yoke wherein said second link pin is prevented from rotating
relative to said second yoke.
18. A press for translating a tool, comprising: a first member
drivingly coupled to an actuator, said first member being axially
moveable between first and second positions in response to movement
of said actuator, said first member including a first end surface
having a plurality of circumferentially spaced apart detents; a
second member threadably engaging said first member, said first and
second members defining an assembly having a length; a plurality of
retention members positioned between said first and second members,
each retention member biasedly engaging one of said detents,
thereby providing resistance to relative rotation between said
first and second members, wherein said resistance to relative
rotation may be overcome to adjust said length of said
assembly.
19. The press of claim 18 wherein said second member includes a
plurality of axially extending bores in receipt of said retention
members.
20. The press of claim 19 further including a plurality of biasing
members positioned within said bores between said retention members
and said second member.
21. The press of claim 20 wherein said plurality of detents
includes eight detents.
22. The press of claim 21 wherein said plurality of engaging
members includes eight pins.
23. The press of claim 18 further including a press body and a
strain gauge mounted to said press body, said strain gauge being
operable to indicate an overload condition and provide a signal to
discontinue the application of force by said actuator.
24. The press of claim 18 wherein said plurality of detents are
equally spaced apart and aligned substantially in a circle.
25. The press of claim 18 wherein said second member includes an
annular surface substantially parallel to and axially spaced apart
from said first end surface, said annular surface including a
plurality of bores alignable with said detents, said bores
receiving at least a portion of said plurality of retention
members.
26. The press of claim 18 wherein said plurality of retention
members each include a first end having a longitudinal bore in
receipt of a biasing member.
27. The press of claim 26 wherein said plurality of retention
members each include a second end that is curved and received by
said detents.
28. The press of claim 27 wherein said plurality of detents are
conically shaped.
29. The press of claim 18 wherein one of said first and second
members includes a marking on an outer surface thereof to provide a
datum for said length of said assembly of said first and second
members.
30. The press of claim 18 further including a retainer aligning
said retention members in a spaced apart relation to one
another.
31. The press of claim 30 wherein said retainer is axially
translatable to allow said retention members to enter and exit said
detents during adjustment of said length of said assembly.
32. The press of claim 31 further including a spring biasedly
loading said retainer toward said first member.
33. The press of claim 32 wherein said first member includes eight
equally spaced apart detents and said retainer aligns four
retention members in an equally spaced apart relation.
34. The press of claim 30 wherein said retainer and said retention
members are positioned within a cavity formed in one of aid first
and second members.
35. A press for translating a tool, comprising: a press body; an
actuator supported by said press body; a ram assembly drivingly
coupled to said actuator, said ram assembly linearly moveable in an
advancing direction and a retracting direction; a tool assembly
coupled to an end of said ram assembly opposite said actuator; and
a quick release mechanism including a pin removably attaching said
tool assembly to said ram assembly wherein a load being transferred
to said tool assembly during movement in said advancing direction
bypasses said pin, said tool assembly being disconnectable from
said ram assembly by removal of said pin without the use of hand
tools.
36. The press of claim 35 wherein said tool assembly includes a
punch having a transverse aperture extending therethrough.
37. The press of claim 36 wherein said ram assembly includes an
elongated tube having a pair of transverse apertures substantially
aligned with said transverse aperture in said punch.
38. The press of claim 37 wherein said pin extends through said
apertures in said punch and said elongated tube to limit axial and
rotational movement of said punch relative to said elongated
tube.
39. The press of claim 38 wherein a clearance exists between said
pin and said punch aperture such that load travels through said
punch to said ram assembly without loading said pin during movement
of said ram assembly in said advancing direction.
40. The press of claim 37 further including a stripper at least
partially surrounding said punch, said stripper being biased in a
direction away from said elongated tube.
41. The press of claim 40 wherein said stripper includes a pair of
spaced apart axially extending slots in receipt of said pin.
42. The press of claim 41 wherein said ram assembly further
includes an annular collar threadably engaging said elongated tube
to retain a spring in a cavity of said elongated tube, said spring
being operable to provide said biasing load to said stripper.
43. The press of claim 42 wherein said annular collar includes a
pair of axial slots aligned to receive said pin.
44. A press for translating a tool, comprising: a press body having
an upper jaw and a lower jaw; an actuator supported by said press
body; a ram assembly drivingly coupled to said actuator and
slidably positioned within said upper jaw; a lower tool assembly
supported by said lower jaw of said press body axially below said
ram assembly, said lower tool assembly including a shoulder portion
engaging said lower jaw and a shank portion including a transverse
aperture engaging an axial bore extending through said lower jaw;
and a quick release mechanism including a pin removably attaching
said lower tool assembly to said press body, said lower tool
assembly being disconnectable from said press body by removal of
said pin without the use of hand tools.
45. The press of claim 44 wherein said lower jaw portion defines a
first axial bore receiving said lower tool assembly.
46. The press of claim 45 wherein said lower tool assembly includes
a tool holder positioned in said first axial bore.
47. The press of claim 46 wherein said press body defines a
transverse bore extending through said first axial bore
substantially aligned with said transverse aperture in said shank
portion of said tool holder.
48. The press of claim 47 wherein said press body further includes
a second axial bore substantially parallel to said first axial bore
and intersecting said transverse bore, said second axial bore
receiving a locking portion of said quick release mechanism.
49. The press of claim 48 wherein said detent pin is disposed
through said transverse bore and transverse aperture, thereby
restricting relative rotational displacement of said tool assembly
and press body.
50. The press of claim 49 wherein said locking portion of said
quick release mechanism includes a spring biased detent retained on
said pin.
51. The press of claim 47 wherein said tool holder includes an
axial recess for receiving a tool.
52. The press of claim 51 wherein said tool includes a die for
forming a workpiece compressed between said ram assembly and said
lower assembly.
53. The press of claim 52 wherein said tool holder further includes
a fastener bore for receiving a fastener to secure said tool in
said tool holder, said fastener bore extending substantially
coaxially to and in communication with said axial recess.
54. A press for translating a tool, comprising: a press body; a
first actuator coupled to said press body; a tool assembly coupled
to said first actuator and supported by said press body for
drivingly engaging a workpiece; a second actuator attached to said
press body and adapted to translate said press body relative to a
mounting member; a guide assembly interconnecting said mounting
member and said press body, said guide assembly including a
translation limiting mechanism operable to adjust a range of
translation of said press body between various extended and
retracted positions; and a sensor fixedly attached to said guide
assembly and operable to detect the position of said press body
when located at said extended and retracted positions.
55. The press of claim 54 wherein said actuator includes a cylinder
fixedly attached to said press body and a piston fixedly attached
to said mounting member.
56. The press of claim 55 wherein said mounting member slidably
engages a stop adjust rod, wherein said stop adjust rod is fixedly
attached to said press body.
57. The press of claim 56 wherein said translation limiting
mechanism includes a stop collar selectively positioned on said
stop adjust rod.
58. The press of claim 57 wherein said translation limiting
mechanism further includes a screw for selectively fixing said stop
collar to said stop adjust rod in said plurality of positions.
59. The press of claim 58 wherein said sensor includes a sensing
element disposed in a plane substantially parallel to a peripheral
edge of said translation limiting mechanism.
60. The press of claim 59 wherein said sensing element is a
magnetic device and said stop collar is constructed of a
ferromagnetic material.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to sheet metal
forming devices and, more particularly, to a sheet metal forming
press incorporating unique force generating and translating
mechanisms.
BACKGROUND OF THE INVENTION
[0002] In the manufacture of products, there is often a need to
join several pieces of material such as sheet metal to build
various assemblies and subassemblies. There are many different
means for accomplishing this joining task. For example, there is
adhesive bonding, welding, or cold deformation. Both bonding and
welding processes require the introduction of a foreign material to
the assembly. The foreign material can tend to fail, thereby
weakening the assembly. In cold deformation, several pieces of
sheet material are plastically deformed in such a manner that they
are locked together. Depending on the thickness, strength, and/or
the number of pieces of material to be joined, a great amount of
force is required to accomplish this task.
[0003] Traditional presses for providing this force include in-line
hydraulic presses and accordion-type toggle presses. Such presses,
however, are often heavy and include many intricate parts making
maintenance difficult and time consuming.
SUMMARY OF THE INVENTION
[0004] A press for translating a tool and drivingly engaging a
workpiece is provided. The press generally includes a press body, a
piston, a sensor pin, and a sensor. The press body defines a
cavity. The piston is disposed within the cavity and is pivotable
between a first position and a second position. The piston includes
a trunnion defining a trunnion face and a plurality of pin
recesses. The sensor pin is disposed in one of the plurality of pin
recesses. The sensor is supported by the press body substantially
axially aligned with the trunnion. The sensor is operable to detect
the presence of the sensor pin and determine when the piston is in
the first and second positions.
[0005] Another aspect of the present invention provides a press
body containing an actuation device including a piston, a press
link, and a link pin. The piston is movable between a first
position and a second position. The press link includes a first
yoke receiving the piston. The first yoke includes a first leg and
a second leg. The first leg includes a first aperture. The second
leg includes a second aperture. The first aperture is substantially
circular and the second aperture includes a rotation limiting
surface. The first link pin extends through the first and second
legs and the piston. The first link pin includes a first end, a
body portion, a second end, and a network of internal cavities. The
first end engages the first aperture. The body portion has a
substantially cylindrical bearing surface rotatably supporting the
piston. The second end engages the second aperture and has a
rotation limiting surface engaging the rotation limiting surface of
the second aperture. This prevents rotation of the first link pin
relative to the press link. The internal cavities of the network
fluidly communicate with the bearing surface and are adapted to
contain and dispense a lubricant.
[0006] Another aspect of the present invention provides a press for
translating a tool including a first member, a second member and a
plurality of retention members. The first member is drivingly
coupled to an actuator. The first member is axially moveable
between first and second positions in response to movement of the
actuator. The first member includes a first end surface having a
plurality of circumferentially spaced apart detents. The second
member is threadably engaged with the first member. The first and
second members define an assembly having a length. The retention
members are positioned between the first and second members. Each
retention member is biasedly engaged with one of the detents to
provide resistance to relative rotation between the first and
second members. The resistance to relative rotation may be overcome
to adjust the length of the assembly.
[0007] Another aspect of the present invention provides a press for
translating a tool including a press body, an actuator, a ram
assembly, a tool assembly and a quick release mechanism. The
actuator is supported by the press body. The ram assembly is
drivingly coupled to the actuator. The ram assembly is linearly
moveable in an advanced direction and a retracting direction. The
tool assembly is coupled to an end of the ram assembly opposite the
actuator. The quick release mechanism includes a pin removably
attaching the tool assembly to the ram assembly. A load being
transferred to the tool assembly during movement of the ram
assembly in the advancing direction bypasses the pin. The tool
assembly is disconnectable from the ram assembly by removal of the
pin without the use of hand tools.
[0008] Another aspect of the present invention provides a press for
translating a tool including a press body, an actuator, a ram
assembly, a lower tool assembly and a quick release mechanism. The
press body has an upper jaw and a lower jaw. The actuator is
supported by the press body. The ram assembly is drivingly coupled
to an actuator and slidably positioned within the upper jaw. The
lower tool assembly is supported by the lower jaw of the press body
axially below the ram assembly. The lower tool assembly includes a
shoulder portion engaging the lower jaw and a shank portion
including a transverse aperture engaging an axial bore extending
through the lower jaw. The quick release mechanism includes a pin
removably attaching the lower tool assembly to the press body. The
lower tool assembly is disconnectable from the press body by
removing the pin without the use of hand tools.
[0009] Another aspect of the present invention provides a press for
translating a tool including a press body, a first actuator, a tool
assembly, a second actuator, a guide assembly and a sensor. The
first actuator is coupled to the press body. The tool assembly is
coupled to the first actuator and supported by the press body for
drivingly engaging a workpiece. The second actuator is attached to
the press body and adapted to translate the press body relative to
a mounting member. The guide assembly interconnects the mounting
member and the press body. The drive assembly includes a
translation limiting mechanism operable to adjust the range of
translation of the press body between various extended and
retracted positions. The sensor is fixedly attached to the guide
assembly and operable to detect the position of the press body when
located at the extended and retracted positions.
[0010] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0012] FIG. 1 is a perspective view of a press in accordance with
the principles of the present invention;
[0013] FIG. 2 is a side view of the press of FIG. 1 with a cover
plate removed to illustrate an exemplary actuation device and ram
assembly in a first position;
[0014] FIG. 3 is a side view of the press of FIG. 2 illustrating
the actuation device in a second position;
[0015] FIG. 4 is an exploded perspective view of the press of FIG.
1;
[0016] FIG. 5 is an exploded perspective view of the actuation
device and a portion of the cover plate of the press of FIG. 1;
[0017] FIG. 6 is a cross-sectional view of a ram assembly of the
press of FIG. 1;
[0018] FIG. 7 is an exploded perspective view of the ram assembly
of FIG. 6;
[0019] FIG. 8 is a cross-sectional view of a punch assembly of the
press of FIG. 1;
[0020] FIG. 9 is an exploded perspective view of the punch assembly
of FIG. 8;
[0021] FIG. 10 is a cross-sectional view of a lower tooling
assembly of the press of FIG. 1;
[0022] FIG. 11 is an exploded perspective view of the lower tooling
assembly of FIG. 10;
[0023] FIG. 12 is a perspective view of the press of FIG. 1 coupled
to an equalizer assembly in a first position;
[0024] FIG. 13 is a perspective view of the press and equalizer
assembly of FIG. 12 in a second position;
[0025] FIG. 14 is an exploded perspective view of the equalizer
assembly and a portion of the press of FIGS. 12 and 13;
[0026] FIG. 15 is an exploded perspective view of an alternate
embodiment ram assembly;
[0027] FIG. 16 is a top view of the ram assembly of FIG. 15;
[0028] FIG. 17 is a cross-sectional view of the ram assembly of
FIG. 15; and
[0029] FIG. 18 is another cross-sectional view of the ram assembly
depicted in FIG. 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The following description of the preferred embodiments is
merely exemplary in nature and is in no way intended to limit the
scope of the invention, its application, or its uses.
[0031] With reference to FIGS. 1-4, a press 10 in accordance with
the present invention is described. The press 10 generally includes
a press body 12, an actuation device 14, a ram assembly 16, and a
lower tooling assembly 18. The actuation device 14 (shown in FIGS.
2-4) is operable to axially reciprocate the ram assembly 16 between
a retracted position (shown in FIG. 2) and an extended position
(shown in FIG. 3). The ram assembly 16 is adapted to engage a
workpiece against the lower tooling assembly 18 to form a desired
joint.
[0032] The press body 12 includes an actuation cavity 20, a ram
bore 21, first and second cover plates 22, 24, an upper pneumatic
port 26, an upper lubrication port 27, a lower pneumatic port 28, a
lower lubrication port 29, a throat 30, and a set of apertures
comprising a mounting pattern 31. The actuation cavity 20 includes
a pair of radial walls 20a, 20b and a semi-circumferential outer
wall 20c. The radial walls 20a, 20b are spaced apart from one
another and define a swept arc length of approximately 90.degree..
The first and second cover plates 22, 24 are removably fixed to
opposite sides of the press body 12 with a plurality of fasteners
25 such as screws or bolts. The cover plates 22, 24 provide an
airtight seal to the actuation cavity 20. The cover plates 22, 24
also ensure that the actuation device 14 remains substantially
protected from dust and debris during operation of the press 10.
The upper 26 and lower 28 pneumatic ports extend through the press
body 12 and are in communication with the actuation cavity 20. In
an exemplary embodiment, a compressor (not shown), or similar
device, is operable to selectively supply pressurized air to the
upper 26 and lower 28 pneumatic ports and provide a pneumatic
impetus to the actuation device 14. The upper and lower lubrication
ports 27, 29 are adapted to carry a lubricant to the actuation
device 14 and ram assembly 16, respectively. The throat 30 defines
an upper jaw 32 and a lower jaw 34. The throat 30 is adapted to
receive a workpiece prior to and during a joining operation.
[0033] With specific reference to FIGS. 2-5, the actuation device
14 generally includes a piston 36, a press link 38, an upper link
pin 40, a lower link pin 42, and a proximity sensor 44. The piston
36 includes a one-piece member defining a trunnion 46, a wiper arm
48, and a link ring 50. The piston further includes a groove 51 for
receipt of two substantially rectangular seals (not shown). The
rectangular seals are V-shaped in cross-section and sealingly
engage inner surfaces of the cover plates 22, 24 as well as the
walls of cavity 20. The wiper arm 48 of the piston 36 is adapted to
pivot between a first position adjacent the first radial wall 20b
of the cavity 20 (shown in FIG. 2) and a second position adjacent
the second radial wall 20a of the cavity 20 (shown in FIG. 3). It
is envisioned that in an alternative embodiment, a stroke wedge 52
(shown in phantom in FIG. 3) may be inserted into the actuation
cavity 20 adjacent the first radial wall 20b. The stroke wedge 52
provides a third position for the wiper arm 48 of the piston 36.
The third position would provide a shortened stroke for the ram
assembly 16. A shortened stroke for the ram assembly 16 enables
larger dimensioned workpieces to be joined. It is further
envisioned that stroke wedges 52 of different circumferential
dimensions could be implemented to provide multiple stroke
variations.
[0034] FIG. 5 depicts the press link 38 as including an upper yoke
54 and a lower yoke 56. The upper yoke 54 includes a first leg 58
and a second leg 60. The first leg 58 includes an aperture 62
having a generally circular cross-section. The second leg 60
includes an aperture 61 having generally cylindrically shaped
portion 63 and an adjacent portion 64 having a generally D-shaped
cross-section. The aperture portion 64 in the second leg 60 defines
a rotation limiting surface 64a and an arched surface 64b. The
arched surface 64b has a radius that is larger than the radius of
the aperture 62 in the first leg 58. The lower yoke 56 includes a
third leg 66 and a fourth leg 68. The third leg 66 includes an
aperture 70 having a generally circular cross-section. The fourth
leg 68 includes an aperture 72 having a generally D-shaped
cross-section. The D-shaped portion of aperture 72 in the fourth
leg 68 defines a rotation limiting surface 72a and an arched
surface 72b. The arched surface 72b has a radius larger than the
radius of the aperture 70 in the third leg 66. The upper link pin
40 drivingly couples the press link 38 to the piston 36 through the
link ring 50 and the upper yoke 54. The lower link pin 42 drivingly
couples the press link 38 to the ram assembly 16 as will be
discussed in more detail below.
[0035] The upper link pin 40 includes a first end 74, a second end
76, a bearing surface 78, and a network of internal cavities 80.
The first end 74 is generally circular in cross-section. The first
end 74 engages aperture 62 in the first leg 58 of the upper yoke
54. The second end 76 has a generally D-shaped cross-section
defining a rotation limiting surface 76a and an arched surface 76b.
The arched surface 76b has a smaller radial dimension than the
bearing surface 78. The second end 76 engages aperture 64 in the
second leg 60 of the upper yoke 54. The rotation limiting surface
64a of upper yoke 54 engages rotation limiting surface 76a of upper
link pin 40 to maintain the rotational position of the upper link
pin 40 relative to the press link 38. Lastly, a first snap ring 75
engages a groove (not shown) in the aperture 62 of the first leg
58. The snap ring 75 maintains the axial position of the first link
pin 40 in the upper yoke 54. The bearing surface 78 rotationally
engages an inner circumferential surface 77 of the link ring 50 of
the piston 36. In an exemplary embodiment, the bearing surface 78
has a diameter in close tolerance to the inner circumferential
surface 77 of the link ring 50. The network of internal cavities 80
includes an axial bore 80a and a plurality of radial bores 80b in
fluid communication with one another. The radial bores 80b are
further in fluid communication with the bearing surface 78. The
network of internal cavities 80 contains a lubricant, such as oil
or grease, and are adapted to dispense the lubricant to the bearing
surface 78. This ensures proper lubrication between the bearing
surface 78 and the link ring 50.
[0036] The lower link pin 42 is constructed substantially similarly
to the upper link pin 40. The lower link pin 42 includes a third
end 82, a fourth end 84, a bearing surface 86, and a network of
internal cavities 88. The third end 82 is generally circular in
cross-section. The third end 82 engages the aperture 70 in the
third leg 66 of the lower yoke 56. The fourth end 84 is generally
D-shaped in cross-section. The fourth end 84 defines a rotation
limiting surface 84a and an arched surface 84b. The arched surface
84b has a smaller radial dimension than the bearing surface 86. The
fourth end 84 engages the aperture 72 in the fourth leg 68 of lower
yoke 56. The rotation limiting surfaces 72a, 84a of the lower yoke
56 and the lower link pin 42 engage to maintain the rotational
position of the lower link pin 42 relative to the press link 38.
Lastly, a second snap ring 85 engages a groove (not shown) in the
aperture 70 in the third leg 66. The snap ring 85 maintains the
axial disposition of the lower link pin 42. The arched surface 84b
has a smaller radial dimension than the bearing surface 86. The
network of internal cavities 88 in the lower link pin 42 are
substantially similar to the network of internal cavities 80 in the
upper link pin 40. The network of internal cavities 88 operate to
provide lubrication to the interface between the bearing surface 86
of the lower link pin 42 and the ram assembly 16. Therefore, it
should be appreciated that the present design provides the
advantages of preventing relative rotation between the link pins
40, 42 and the press link 38, while enabling lubricated rotation
between the upper link pin 40 and the piston 36 as well as between
the lower link pin 42 and the ram assembly 16.
[0037] With continued reference to FIG. 5, the interrelationship
between the piston 36 and proximity sensor 44 of the actuation
device 14 is described. The proximity sensor 44 is attached to the
first cover plate 22 and is axially aligned with the trunnion 46 of
the piston 36. The trunnion 46 includes a cylindrical bearing
surface 90, a trunnion face 92, and a network of internal cavities
94. The trunnion face 92 includes an upper arcuate slot 96 and a
lower arcuate slot 98. The upper arcuate slot 96 includes a
plurality of pin recesses 100 (shown in FIGS. 2 and 3). The network
of internal cavities 94 are in fluid communication with the bearing
surface 90 and adapted to contain and dispense a lubricant such as
oil or grease.
[0038] The proximity sensor 44 includes a sensor body 102, a first
sensor probe 104, a second sensor probe 106, and a sensor pin 108
(FIGS. 2 and 3). The sensor body 102 is adapted to be attached to
an output device. It is envisioned that the output device may
provide an audible, visual, or combination of audible and visual
signal. The first and second sensor probes 104, 106 include end
portions 104a, 106a that extend through apertures in the first
cover plate 22. The end portions 104a, 106a are disposed
substantially flush with the trunnion face 92 and aligned with the
upper and lower arcuate slots 96, 98. The sensor pin 108 is
selectively positioned in one of the plurality of pin recesses 100
in the upper arcuate slot 96 of the trunnion 46. In FIGS. 2 and 3,
the sensor pin 108 is located in the clockwise most pin recess 100.
In this position, the sensor probe 106 detects the sensor pin 108
when the wiper arm 48 is positioned adjacent the first radial wall
20b. Sensor probe 104 detects sensor pin 108 when the wiper arm 48
is positioned adjacent to the second radial wall 20a. The sensor
pin 108 may be positioned in the middle pin recess 100. In this
position, the sensor probe 104 detects the sensor pin 108 when the
wiper arm 48 is positioned adjacent the stroke wedge 52 (shown in
phantom). Thus, it should be appreciated that this configuration
provides a versatile sensing system for the press 10. The present
design enables the sensor 44 to detect the position of the piston
36, even when the stroke of the ram assembly 16 is altered via a
stroke wedge 52. The proximity sensor 44 is operable to detect the
presence of the sensor pin 108 and output a signal indicating the
position of the piston 36. In an exemplary embodiment, the sensor
pin 108 is a metal screw and the first and second sensor probes
104,106 include magnetic devices.
[0039] With reference now to FIGS. 6 and 7, the ram assembly 16 is
described in detail. The ram assembly 16 includes a ram base 110, a
press ram 112, a biasing mechanism 114, a punch holder 115 and a
punch assembly 116 (shown in FIGS. 8 and 9). The ram base 110 and
press ram 112 are threadably coupled together to enable adjustments
to the axial overall length of the ram assembly 16. The biasing
mechanism 114 acts to secure the ram assembly 16 from involuntary
adjustments.
[0040] The ram base 110 includes a substantially cylindrical member
disposed in the ram bore 21 of the press body 12 (shown in FIGS. 2
and 3). The ram base 110 includes a transverse bore 117, an
external threaded portion 118, and an end surface 120. The
transverse bore 117 receives the lower link pin 42 of the actuation
device 14, as described above. The end surface 120 includes a
plurality of indentations 122 circumferentially spaced apart from
one another. In the embodiment illustrated, the plurality of
indentations 122 includes eight indentations. Each indentation 122
has a conical geometry and may be formed using a drill point.
[0041] The press ram 112 includes a first end 112a and a second end
112b. The first end 112a includes a bore 124, an internal threaded
portion 126, and a plurality of blind bores 128. Each blind bore
128 contains at least a portion of the biasing mechanism 114. The
second end 112b includes a tool bore 130, a pair of transverse
apertures 132a, 132b, and a marking 134. A fastener bore 133
interconnects bore 130 with bore 124. The internal threaded portion
126 of the first end 112a threadably engages the external threaded
portion 118 of the ram base 110. This provides for an overall
length adjustment of the ram assembly 16, as will be described in
more detail below. The tool bore 130 is stepped to align the punch
holder 115 with a longitudinal axis of the press ram 112. A
fastener 135 threadingly engages punch holder 115 to couple the
punch holder to press ram 112.
[0042] The biasing mechanism 114 includes a plurality of pins 138,
and a plurality of biasing members 140. In the embodiment
illustrated, the plurality of biasing members 140 include coil
springs. Each coil spring 140 is positioned within a corresponding
blind bore 128. The plurality of pins 138 each include a first end
138a and a second end 138b. The first ends 138a include
longitudinal bores receiving the biasing members 140, as shown in
FIG. 6. The second ends 138b are rounded and received by the
plurality of indentations 122 in the end surface 120 of the ram
base 110. The biasing members 140 provide an axial load on the
plurality of pins 138 to maintain their engagement with the
plurality of indentations 122. Accordingly, relative rotational
displacement of the ram base 110 and the press ram 112 is somewhat
restricted.
[0043] In an exemplary embodiment, the external and internal
threaded portions 118, 126 include a predetermined thread pitch
such that one revolution of the press ram 112 relative to the ram
base 110 provides a predetermined axial adjustment of the ram
assembly 16. In the embodiment illustrated, the external threaded
portion 118 includes a diameter of one and one-eighth inch and
thirty-two threads per inch. One revolution of the press ram 112
relative to the ram base 110, therefore, provides an axial
displacement of approximately 0.032 inches. Additionally, because
there are eight equally spaced apart pins 138, a single click
between pins 138 equates to a rotational angle of approximately 45
degrees. This rotational amount provides an axial displacement of
the ram assembly 16 of approximately 0.004 inches. It should be
appreciated that such simple and accurate axial adjustment of the
ram assembly 16 is highly advantageous when using the press 10 for
multiple joining applications.
[0044] Furthermore, as stated above, a marking 134 is included on
the press ram 112. The marking 134 provides a datum line for
adjusting the axial dimension of the ram assembly 16. For example,
with the ram assembly 16 in the retracted position (as shown in
FIG. 2), the press ram 112 can be rotated relative to the ram base
110 such that the marking 134 is substantially flush with the upper
jaw 32 of the press body 12. When this situation exists, the axial
dimension of the ram assembly 16 is known to be some predetermined
length. The press ram 112 can then be rotated to adjust the length
in 0.004 inch increments. It is envisioned that the press ram 112
may also include further markings to establish datum lines for the
ram assembly 16 when a stroke wedge 52 is utilized, as discussed
above in reference to FIG. 3. Furthermore, it should be appreciated
that the threads and numbers of pins 138 utilized can be altered to
achieve alternative incremental adjustments for the ram assembly
16.
[0045] FIGS. 8-9 depict the punch assembly 116 including a collar
142, a punch 144, a stripper 146, a spring spacer 148, a biasing
member 150, and a quick release mechanism 152. The collar 142 is a
substantially annular member including a shoulder portion 142a and
a shank portion 142b. The shank portion 142b includes external
threads 154 and a plurality of U-shaped recesses 156. The shoulder
portion 142a includes a plurality of transverse bores 158. The
external threads 154 threadably engage the internal threaded
portion 136 of the second end 112b of the press ram 112. The
apertures 132a, 132b in the press ram 112 are substantially aligned
with a pair of the U-shaped recesses 156 in shank portion 142b of
the collar 142.
[0046] The punch 144 includes an elongated cylindrical member
having a transverse bore 160 and a tool portion 162. The punch 144
is disposed through the collar 142 and extends into a bore 163 of
the punch holder 115. The transverse bore 160 in the punch 144 is
substantially aligned with the U-shaped recesses 156 in the collar
142 and the apertures 132a, 132b in the press ram 112. The tool
portion 162 is adapted to engage a workpiece.
[0047] The stripper 146 includes a shoulder portion 146a and a
sleeve portion 146b. The shoulder portion 146a includes a hollow
cylindrical member defining a pair of vertical slots 164. The
sleeve portion 146b includes a hollow cylindrical member defining a
stripper aperture 166. The stripper 146 receives the punch 144 such
that the vertical slots 164 are substantially aligned with the
transverse bore 160 in the punch 144 and the U-shaped recesses 156
in the collar 142. The biasing member 150 includes a compression
spring disposed within the tool bore 130 of the press ram 112. The
spring spacer 148 includes a solid annular member disposed within
the tool bore 130 axially between the biasing member 150 and the
stripper 146. The biasing member 150 is adapted to bias the
stripper 146 away from the ram assembly 16.
[0048] The quick release mechanism 152 includes a detent pin 168
having a spring biased detent 170. The detent pin 168 extends
through the apertures 132a, 132b in the press ram 112, the pair of
U-shaped recesses 156 in the collar 142, the transverse bore 160 in
the punch 144, and the vertical slots 164 in the stripper 146. In
this manner, the detent pin 168 prevents rotation of the punch
assembly 116 relative to the press ram 112. It should be
appreciated that the detent pin 168 does not carry any load created
by the actuation device 14 through the ram assembly 16. Rather, the
axial load is transferred through the ram assembly 16 via the punch
holder 115 to punch 144. An advantage of this design lies in the
quick release mechanism 152. The detent pin 168 includes a ring
172. A user of the press 10 can simply grasp the ring 172 and
extract the detent pin 168 from the ram assembly 16. This enables
the punch 144 and stripper 146 to be removed without tools.
Therefore, the punch 144 can be quickly and easily swapped out for
another punch and stripper designed to provide a different
joint.
[0049] FIGS. 10 and 11 show the lower tooling assembly 18
statically supported by the lower jaw 34 of the press body 12. The
lower jaw 34 includes an axial bore 174, a pair of axially aligned
transverse bores 176, and a locking bore 178. The axial bore 174
receives a portion of the lower tooling assembly 18. The lower
tooling assembly 18 includes a tool holder 180, a die assembly 182,
and a quick release mechanism 184. The tool holder 180 includes a
generally cylindrical member having a shoulder portion 180a, a
shank portion 180b, a tool bore 186, a fastener bore 188, and a
pair of transverse apertures 192. The tool bore 186 extends axially
through the shoulder portion 180a and partly into the shank portion
180b. The fastener bore 188 is radially conjoined with the tool
bore 186. The fastener bore 188 also includes a threaded blind bore
190 for receiving a fastener 200 and a washer 201.
[0050] The die assembly 182 generally includes a cylindrical column
194 supporting a tool die 196. The die assembly 182 is disposed in
the tool bore 186 of the tool holder 180. The tool die 196 includes
a die for providing a TOG-L-LOC.RTM. type joint between two
workpieces. Such a die is described in greater detail in U.S. Pat.
No. 6,092,270, the entire disclosure of which is hereby
incorporated by reference herein. The cylindrical column 194
further includes a pocket 198 formed on an outer cylindrical
surface of the column. The pocket 198 is aligned with the fastener
bore 188 in the tool holder 180. The screw 200 includes a head 202
positioned in the fastener bore 188. The washer 201 is positioned
below the head 202 and engages the pocket 198 in the column 194 to
prevent undesired removal of the die assembly 182 from the tool
bore 186. The shoulder portion 180a of the tool holder 180 engages
the lower jaw 34 of the press body 12 to support the lower tooling
assembly 18. The transverse apertures 192 in the tool holder 180
are substantially aligned with the transverse bores 176 in the
lower jaw 34.
[0051] The quick release mechanism 184 includes a detent pin 204
having a spring biased detent 206 and a ring 208. The detent pin
204 extends through the transverse bores 176 in the lower jaw 34
such that the spring biased detent 206 engages the locking bore
178. As such, the detent pin 204 extends through the transverse
apertures 192 in the tool holder 180 to maintain the tool holder
180 in the axial bore 174. This design provides for toolless
removal of the lower tooling assembly 18 from the press body 12.
The ring 208 is simply grasped by a user and the detent pin 204 can
quickly and easily be removed to interchange the tool holder 180
with an alternative tool holder.
[0052] During operation, a plurality of workpieces (not shown) are
placed over the lower tooling assembly 18 when the actuation device
14 is in its retracted position, as shown in FIG. 2. Then, a
compressor, or similar device, provides pressurized fluid to the
upper pneumatic port 26. The wiper arm 48 of the piston 36 travels
from the first radial wall 20b to the second radial wall 20a.
Simultaneously with the piston 36 traveling as just described, the
press link 38 drives the ram assembly 16 toward the lower tooling
assembly 18. The tool portion 162 of the punch 144 engages the
workpiece before the wiper arm 48 of the piston 36 engages the
second radial wall 20a of the actuation cavity 20. This initiates
the forming process. Once the wiper arm 48 of the piston 36 reaches
the second radial wall 20a, upper pneumatic port 26 is exhausted to
atmosphere and pressurized fluid is supplied to the lower pneumatic
port 28 to force the piston 36 back toward the first radial wall
20b. This, in turn, retracts the ram assembly 16 to the position
shown in FIG. 2. The joined workpieces are then removed.
[0053] The press 10 of the present invention provides an override
feature during the above-described process. A sensor 210, such as a
strain gauge, is positioned on the press body 12 adjacent the
throat 30. The sensor 210 is positioned here because this is the
point of the press body 12 that experiences the most stress during
the above-described process. The sensor 210 is operable to detect
stress applied to the press body 12 and output a signal
accordingly. In an exemplary embodiment, the sensor 210
communicates with a controller operable to control the supply of
pressurized air from the compressor. For example, if the sensor 210
detects a stress level greater than a predetermined threshold, the
sensor instructs the controller to discontinue the press operation.
This function provides for an override feature for the press 10 in
situations when the punch may be broken or when piston 36 or ram
assembly 16 have become obstructed.
[0054] FIGS. 12-14 illustrate an alternative embodiment of the
present invention, wherein the press 10 further includes an
equalizer assembly 212. The equalizer assembly 212 is adapted to be
mounted to a working surface such as a workbench or a robot arm.
The equalizer assembly 212 is operable to translate the press 10
along a linear axis between a first position (shown in FIG. 12) and
a second position (shown in FIG. 13).
[0055] The equalizer assembly 212 generally includes an actuator
214, a guide assembly 216, and a sensor 218. The actuator 214
includes a cylinder 220 and a piston 222, wherein the piston 222 is
driven by a pneumatic source (not shown) applied to the cylinder
220. The cylinder 220 is fixed to the press body 12 via threaded
fasteners 223. The piston 222 is drivingly coupled to the guide
assembly 216 by a pin 225.
[0056] The guide assembly 216 includes a stop adjust rod 224, an
equalize block 226, an equalize mount block 228, a lower stop
collar 230, an upper stop collar 232, a plurality of slide brackets
234, and a plurality of slides 236. The equalize block 226 is
mounted to the press body 12 via threaded fasteners 227 and
includes a threaded bore 226a. The stop adjust rod 224 is a
substantially cylindrical elongated member having an external
thread over its entire length 224a threadably engaging the threaded
bore 226a in the equalize block 226. The equalize mount block 228
includes an aperture 238, a guide cavity 240, and a plurality of
threaded bores constituting a mounting pattern 242. The aperture
238 is in communication with the guide cavity 240. The aperture 238
receives the stop adjust rod 224. The guide cavity 240 contains the
equalize block 226. The mounting pattern 242 mates with the
mounting pattern 31 on the press body 12. The mounting patterns 31,
242 include an ISO Standard 125 millimeter diameter Weld Gun
Mounting Pattern. The mounting pattern 31 is machined through the
side of the press body 12. This enables the equalizer assembly 212
to be mounted on either the right hand or left hand side of the
press body 12. Additionally, for ease of assembly, the mounting
pattern 242 is provided such that fasteners can be installed from
the opposite side of the press body 12 from which the equalizer
assembly 212 is being mounted.
[0057] The lower 230 and upper 232 stop collars are disposed on
opposite ends of the stop adjust rod 224. The lower 230 and upper
232 stop collars include steel rings and a screw. The screws can be
loosened and/or tightened to position the stop collars 230, 232 as
desired on the stop adjust rod 224. Such positioning enables a user
to adjust the stroke of the press 10 relative to the equalize mount
block 228 of the equalizer assembly 212. Additionally, the stop
adjust rod 224 may be threadably adjusted relative to the equalize
block 226 to adjust the stroke of the ram assembly 16 of the press
10.
[0058] The plurality of slide brackets 234 includes four slide
brackets 234a-234d. The slide brackets 234 each include channels
244. The slide brackets 234 are mounted to a backside of the
equalize mount block 228 via threaded fasteners 235. The plurality
of slides 236 include two slides 236a and 236b. The two slides 236a
and 236b are fixedly attached to the press body 12 via fasteners
237. The first slide 236a is slidably engaged by the channels 244
of slide brackets 234a and 234b. The second slide 236b is slidably
engaged by the channels 244 of slide brackets 234c and 234d. As the
actuator 214 operates to translate the piston 222 within the
cylinder 220, the press 10 translates linearly relative to the
equalize mount block 228 between the first position (shown in FIG.
12) and the second position (shown in FIG. 13).
[0059] The sensor 218 includes a sensor body 246, an upper probe
248, and a lower probe 250. The sensor body 246 is disposed on a
side of the equalize mount block 228 adjacent the guide cavity 240.
The upper 248 and lower 250 sensor probes extend through the
sidewall of the equalize mount block 228 and have ends 248a, 250a
disposed substantially flush with a plane common to the peripheral
edges of the lower 230 and upper 232 stop collars. In an exemplary
embodiment, the upper 248 and lower 250 sensor probes include
magnetic devices operable to detect the presence of either the
lower stop collar 230 or the upper stop collar 232. In either
event, it should be appreciated that the sensor 218 remains fixed
in a single position on the equalize mount block 228, regardless of
the position of the stop collars 230, 232. It should further be
appreciated that the sensor 218 is operable to output a first
signal when detecting the presence of one of the stop collars 230,
232 and output a second signal when the sensor fails to detect the
presence of a stop collar 230, 232.
[0060] FIGS. 15-18 depict an alternate embodiment ram assembly 300.
Ram assembly 300 is substantially similar to ram assembly 16,
previously described. As such, like components will retain the
reference numerals previously introduced. Ram assembly 300 includes
ram base 110 threadingly engaged with a press ram 301. A biasing
mechanism 302 allows incremental adjustment of the overall length
of ram assembly 300 by rotating press ram 301 relative to ram base
110.
[0061] Biasing mechanism 302 includes a plurality of balls 304, a
retainer 306 and a coil spring 308. Coil spring 308 is positioned
within a bore 310 of press ram 301. A bore 312 interconnects bore
310 and a punch holder bore 314. The remaining lower portion of
press ram 301 is substantially similar to the lower portion of
press ram 112 and is not depicted in FIG. 17. As in the previous
embodiment, fastener 135 couples holder 115 (FIG. 6) to the press
ram.
[0062] The retainer 306 is a substantially cylindrical member
having a bore 316 axially extending therethrough. A counterbore 318
is in communication with bore 316 and is sized to receive coil
spring 308. The retainer 306 includes an end face 320. A plurality
of recesses 322 are positioned on end face 320 and
circumferentially spaced apart from one another. The recesses 322
are sized to receive a portion of balls 304 and allow a remaining
portion of each ball to protrude outwardly from end face 320. As
mentioned earlier, ram base 110 includes eight circumferentially
spaced apart indentations 122 positioned on the end surface 120.
Each of the indentations 122 are sized to receive a portion of the
balls 304. One skilled in the art will appreciate that biasing
mechanism 302 functions substantially similarly to biasing
mechanism 114 in that eight distinct rotational positions exist
between ram base 110 and press ram 301.
[0063] Retainer 306 is positioned within bore 310 and is free to
axially translate within the bore. A series of flats 324 are formed
on an outer surface of retainer 306. Flats 324 engage
correspondingly flat wall portions 326 to restrict rotation of
retainer 306 relative to press ram 301. In operation, coil spring
308 biasedly loads retainer 306 and balls 304 into engagement with
ram base 110 to somewhat restrict relative rotational movement
between ram base 110 and press ram 301. As mentioned previously,
the overall length of ram assembly 300 may be adjusted by rotating
press ram 301 relative to ram base 110 with sufficient force to
overcome coil spring 308 and move balls 304 into the next set of
indentations 122. Because ram base 110 includes eight equally
spaced indentations, the exact change in overall length may be
calculated knowing the thread pitch of the connection between ram
base 110 and press ram 301 in view of a rotational angle of 450. In
the embodiment disclosed, 450 of rotation changes the overall
length of ram assembly 300 by approximately 0.004 inches.
[0064] Furthermore, the foregoing discussion discloses and
describes merely exemplary embodiments of the present invention.
One skilled in the art will readily recognize from such discussion,
and from the accompanying drawings and claims, that various
changes, modifications and variations may be made therein without
department from the spirit and scope of the invention as defined in
the following claims.
* * * * *