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Title:
Anti-Vibration Die Holder Technology for Fabricating Press
Kind Code:
A1
Abstract:
The invention involves an anti-vibration die holder for a press, such as a metal-fabricating press. The anti-vibration die holder preferably includes at least one resilient surface adapted to contact a die when the die is mounted operatively on the die holder.


Inventors:
Lee, Brian J. (Elk River, MN, US)
Shimota, Jon M. (Stillwater, MN, US)
Timp, Richard L. (Vadnais Heights, MN, US)
Application Number:
12/163536
Publication Date:
12/31/2009
Filing Date:
06/27/2008
Primary Class:
Other Classes:
72/55, 72/467
International Classes:
B21J13/00; B21C3/00; B21D22/00
View Patent Images:
Related US Applications:
Attorney, Agent or Firm:
INTELLECTUAL PROPERTY GROUP;FREDRIKSON & BYRON, P.A. (200 SOUTH SIXTH STREET, SUITE 4000, MINNEAPOLIS, MN, 55402, US)
Claims:
What is claimed is:

1. A die holder for a fabricating press, the die holder having an interior recess that is bounded by at least one interior wall and that is configured to receive a die, the die holder having an anti-vibration system comprising a resilient surface adapted to engage the die when the die is mounted operatively in the die holder's interior recess, the construction of the die holder and its anti-vibration system allowing no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.

2. The die holder of claim 1 wherein the construction of the die holder and its anti-vibration system allow no more than 0.01 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.

3. The die holder of claim 1 wherein the construction of the die holder and its anti-vibration system allow no more than about 0.005 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.

4. The die holder of claim 1 wherein the resilient surface is defined by material having a Shore A durometer of between about 20 and about 95.

5. The die holder of claim 1 wherein the die holder is devoid of set screws adapted to rigidly engage the die during a clamping operation.

6. The die holder of claim 1 wherein the die holder includes at least one spring component, wherein during a clamping operation the die holder applies a clamping force on the die, and wherein the spring component generates at least part of the clamping force.

7. The die holder of claim 1 wherein the die holder includes a clamp portion and a wall portion, wherein the clamp and wall portions are adapted to be positioned in an open configuration or a closed configuration, the clamp and wall portions together surrounding said interior recess when in the closed configuration, wherein the die holder can be adjusted from a clamped configuration to an unclamped configuration by performing an unclamping operation, wherein when the die is received in said interior recess and the die holder is in the clamped configuration the die is clamped securely by the die holder, the die holder being provided with a single-motion actuator that allows the unclamping operation to be performed in response to a single motion of the actuator.

8. The die holder of claim 7 wherein the actuator is a tool-free actuator that allows the unclamping operation to be a tool-free operation.

9. The die holder of claim 7 wherein said interior recess has a generally circular configuration, the clamp portion has a concave interior surface and the wall portion has a concave interior surface, said interior surfaces being adapted to engage the die when the die holder is clamped securely on the die.

10. The die holder of claim 7 wherein the clamp portion is a concave clamp portion and the wall portion is a concave wall portion, and when the clamp and wall portions are positioned in the closed configuration the die holder has a generally annular configuration.

11. The die holder of claim 1 wherein the die holder is mounted on a horizontal table of the fabricating press, the fabricating press being a turret press having a turret with a plurality of stations adapted to receive respective tool holders, the die holder being mounted removably to the turret.

12. A method of using a fabricating press equipped with at least one active die holder and at least one inactive die holder, the inactive die holder having an interior recess bounded by at least one interior wall, wherein a die is mounted operatively in said interior recess, the inactive die holder having an anti-vibration system comprising a resilient surface engaged with said die, the method comprising operating the fabricating press to perform a plurality of strokes adjacent to the active die holder, the construction of the inactive die holder and its anti-vibration system being such that during the plurality of strokes said die experiences no more than 0.032 inch of upward die displacement relative to the inactive die holder.

13. The method of claim 12 wherein during the plurality of strokes said die experiences no more than 0.02 inch of upward die displacement relative to the inactive die holder.

14. The method of claim 12 wherein during the plurality of strokes said die experiences no more than 0.01 inch of upward die displacement relative to the inactive die holder.

15. The method of claim 12 wherein the plurality of strokes is at least 10,000 strokes.

16. The method of claim 12 wherein the construction of the inactive die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the inactive die holder after 10,000 punch strokes of the fabricating press adjacent to the active die holder.

17. The method of claim 12 wherein the resilient surface is defined by material that has a Shore A durometer of between about 20 and about 95 and that bears against said die during the plurality of strokes so as to dampen vibrations.

18. The method of claim 12 wherein the die holder is devoid of set screws adapted to rigidly engage the die during a clamping operation, such that during the plurality of strokes said die is not engaged by any set screw.

19. A die holder for a fabricating press, the die holder having an interior recess that is bounded by at least one interior wall and that is configured to receive a die, the die holder having an anti-vibration system comprising a plurality of resilient surfaces adapted to contact the die when the die is mounted operatively in said interior recess, the resilient surfaces being spaced-apart about said interior wall(s).

20. The die holder of claim 19 wherein the resilient surfaces have an anti-stiction arrangement characterized by the resilient surfaces covering between about 180 degrees and about 300 degrees of a perimetrical extent of said interior wall(s).

21. The die holder of claim 19 wherein the resilient surfaces are constructed to provide slide-resistant engagement between the die holder and the die.

22. The die holder of claim 19 wherein the resilient surfaces are defined by resilient non-lubricating material.

23. The die holder of claim 19 wherein the die, when mounted operatively in said interior recess, contacts both the resilient surfaces and said interior wall(s) of the die holder.

24. The die holder of claim 23 wherein the resilient surfaces are defined by resilient bodies each having a height that is less than a height of said interior wall(s).

25. The die holder of claim 23 wherein said interior wall(s) comprise metal, and said resilient surfaces are defined by material having a Shore A durometer of between about 20 and about 95.

26. The die holder of claim 19 wherein, when the interior recess of the die holder is unloaded, the resilient surfaces project from the die holder's interior wall(s) by at least about 0.001 inch, and wherein when the die holder is clamped on the die the resilient surfaces are compressed such that an exterior sidewall of the die simultaneously contacts both the resilient surfaces and the die holder's interior wall(s).

27. The die holder of claim 26 wherein, when the interior recess of the die holder is unloaded, the resilient surfaces project from the die holder's interior wall(s) by between about 0.001 inch and about 0.005 inch.

28. The die holder of claim 19 wherein a body defining at least one of the resilient surfaces has a grooved front section adapted to engage the die when the die is mounted operatively in said interior recess.

29. The die holder of claim 19 wherein a plurality of bodies define the resilient surfaces, and wherein each such body has a grooved front section adapted to engage the die when the die is mounted operatively in said interior recess.

30. The die holder of claim 19 wherein at least one of the resilient surfaces is defined by an elongated band mounted in a recess extending circumferentially about said interior wall(s).

31. The die holder of claim 30 wherein a plurality of grooves are formed in the elongated band, the grooves extending along a length of the band.

32. The die holder of claim 30 wherein the die holder carries a plurality of spaced-apart grooved elongated bands defining the resilient surfaces.

33. The die holder of claim 19 wherein the die holder includes at least one spring component, wherein during a clamping operation the die holder applies a clamping force on the die, and wherein the spring component generates at least part of the clamping force.

34. The die holder of claim 19 wherein the die holder includes a clamp portion and a wall portion, wherein the clamp and wall portions are adapted to be positioned in an open configuration or a closed configuration, the clamp and wall portions together surrounding said interior recess when in the closed configuration, wherein the die holder can be adjusted from a clamped configuration to an unclamped configuration by performing an unclamping operation, wherein when the die is received in said interior recess and the die holder is in the clamped configuration the die is clamped securely by the die holder, the die holder being provided with a single-motion actuator that allows the unclamping operation to be performed in response to a single motion of the actuator, at least one of the resilient surfaces being mounted on the die holder's wall portion, and at least one of the resilient surfaces being mounted on the die holder's clamp portion.

35. The die holder of claim 34 wherein the actuator is a tool-free actuator that allows the unclamping operation to be a tool-free operation.

36. The die holder of claim 34 wherein said interior recess has a generally circular configuration, the clamp portion has a concave interior surface and the wall portion has a concave interior surface, said interior surfaces being adapted to engage the die when the die holder is clamped securely on the die.

37. The die holder of claim 34 wherein the clamp portion is a concave clamp portion and the wall portion is a concave wall portion, and when the clamp and wall portions are positioned in the closed configuration the die holder has a generally annular configuration.

38. The die holder of claim 19 wherein the die holder is mounted on a horizontal table of the fabricating press.

39. The die holder of claim 19 wherein the die holder is mounted removably within an opening defined by a table of the fabricating press.

40. The die holder of claim 19 wherein the fabricating press is a turret press having a turret with a plurality of stations adapted to receive respective tool holders, the die holder being mounted removably to the turret.

41. A combination of a die and a die holder for a fabricating press, the die holder having an interior recess bounded by at least one interior wall, the die being mounted operatively in the die holder's interior recess, the die holder having an anti-vibration system comprising a resilient surface defined by a resilient face in which at least one groove or other recess is formed, wherein the grooved or otherwise recessed resilient face is engaged with an exterior sidewall of the die.

42. The combination of claim 41 wherein a plurality of generally parallel grooves are formed in the resilient face.

43. The combination of claim 41 wherein the die holder is provided with a plurality of resilient surfaces that are spaced-apart about the die holder's interior wall(s) and that are in contact with the die, the resilient surfaces being defined by grooved bands or other grooved elongated bodies, the grooves on each band or elongated body being arranged so as to be generally parallel to one another and to extend along a circumferential extent of an exterior sidewall of the die.

44. The combination of claim 43 wherein the grooved bands or other elongated bodies contact between about 180 degrees and about 300 degrees of a circumferential extent of an exterior sidewall of the die.

45. The combination of claim 41 wherein the resilient surface is defined by material having a Shore A durometer of between about 20 and about 95.

46. The combination of claim 41 wherein, when the interior recess of the die holder is unloaded, the resilient surface projects from the die holder's interior wall by at least about 0.001 inch

47. The combination of claim 41 wherein the die holder's interior wall is formed of metal, and the die is in contact with both the resilient surface and the metal interior wall of the die holder.

Description:

FIELD OF THE INVENTION

The present invention is in the field of die holders for machine tools. More particularly, this invention relates to die holders for fabricating presses.

BACKGROUND OF THE INVENTION

Metal-fabricating presses, such as turret presses, single-station presses, etc., are used to fabricate sheet metal and other sheet-like workpieces. Commonly, each press includes an upper table and a lower table, and at least one die holder adapted for holding a die securely between the upper and lower tables. In many cases, the die holder is adapted to tightly hold the die with a plurality of set screws. In order to change out a die, the set screws must be loosened before the old die can be removed. Then, the new die can be loaded into the die holder (e.g., after moving the new die into the space between the upper and lower tables). The upper and lower tables of many presses are relatively close together. Thus, replacing dies can be a difficult and time consuming process. In addition, after a pressing operation, the die can be hard to remove from the die holder due to stiction. Stiction occurs when the die becomes stubbornly stuck in the die holder (e.g., due to a close fit between the die and the die holder, and any lubrication present). Stiction causes additional difficulty because the die must be forced from the die holder.

SUMMARY OF THE INVENTION

In certain embodiments, the invention provides a die holder for a fabricating press. The die holder has an interior recess that is bounded by at least one interior wall and that is configured to receive a die. In the present embodiments, the die holder has an anti-vibration system comprising a resilient surface adapted to engage the die when the die is mounted operatively in the die holder's interior recess. Preferably, the construction of the die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of the fabricating press.

Some embodiments of the invention provide a method of using a fabricating press equipped with at least one active die holder and at least one inactive die holder. The inactive die holder has an interior recess bounded by at least one interior wall. In the present embodiments, a die is mounted operatively in this interior recess, and this inactive die holder has an anti-vibration system comprising a resilient surface engaged with the die. The present method comprises operating the fabricating press to perform a plurality of strokes adjacent to the active die holder. The construction of the inactive die holder and its anti-vibration system are such that during the plurality of strokes the die experiences no more than 0.032 inch of upward displacement relative to the inactive die holder.

Certain embodiments of the invention provide a die holder for a fabricating press. The die holder has an interior recess that is bounded by at least one interior wall and that is configured to receive a die. In the present embodiments, the die holder has an anti-vibration system comprising a plurality of resilient surfaces adapted to contact the die when the die is mounted operatively in the interior recess. In the present embodiments, the resilient surfaces are spaced-apart about the interior wall(s).

In some embodiments, the invention provides a combination of a die and a die holder for a fabricating press. The die holder has an interior recess bounded by at least one interior wall. In the present embodiments, the die is mounted operatively in the die holder's interior recess. In the present embodiments, the die holder has an anti-vibration system comprising a resilient surface defined by a resilient face in which at least one groove or other recess is formed. Preferably, the grooved or otherwise recessed resilient face is engaged with an exterior sidewall of the die.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, broken-away perspective view of a fabricating press in accordance with an embodiment of the invention.

FIG. 2 is a perspective view of a die and a die holder in accordance with an embodiment of the invention.

FIG. 3 is a perspective view of the die holder of FIG. 2 in an open configuration in accordance with an embodiment of the invention.

FIG. 4 is a perspective view of the die and die holder of FIG. 2 in an open configuration in accordance with an embodiment of the invention.

FIG. 5 is a perspective view of a die and a die holder in accordance with another embodiment of the invention.

FIG. 6 is a perspective view of the die and die holder of FIG. 5 in an open configuration in accordance with an embodiment of the invention.

FIG. 7 is a perspective view of the die holder of FIG. 5 in an open configuration in accordance with an embodiment of the invention.

FIG. 8 is a side detail view of a portion of the die holder of FIG. 5 in accordance with an embodiment of the invention.

FIG. 9 is a perspective view of a die and a die holder in accordance with another embodiment of the invention.

FIG. 10 is a perspective view of the die and die holder of FIG. 9 in an open configuration in accordance with an embodiment of the invention.

FIG. 11 is a perspective view of the die holder of FIG. 9 in an open configuration in accordance with an embodiment of the invention.

FIG. 12 is a partially broken-away side view of a portion of the die and the die holder of FIG. 9 in accordance with an embodiment of the invention.

FIG. 13 is a perspective view of a die holder in accordance with another embodiment of the invention.

FIG. 14 is a perspective view of a die holder in accordance with another embodiment of the invention.

FIG. 15 is a perspective view of the die holder of FIG. 14 in a disassembled configuration in accordance with an embodiment of the invention.

FIG. 16 is a perspective view of a die holder in accordance with another embodiment of the invention.

FIG. 17 is a perspective view of a die holder in accordance with another embodiment of the invention.

FIG. 18 is a perspective view of a press table with a plurality of die holders in accordance with another embodiment of the invention.

FIG. 19 is a perspective view of a die holder with a removable handle in accordance with another embodiment of the invention.

FIG. 20 is a perspective view of a die holder with a die cassette and a plurality of dies in accordance with another embodiment of the invention.

FIG. 21 is a perspective view of a die holder with a die-release mechanism in accordance with an embodiment of the invention.

FIG. 22 is a perspective view of a die holder with a die-release mechanism in accordance with another embodiment of the invention.

FIG. 23 is a top plan view of the die holder of FIG. 22.

FIG. 24 is a schematic, broken-away top plan view of a portion of a die holder having a die-release mechanism in accordance with certain embodiments of the invention.

FIG. 25 is a broken-away hidden line perspective view of a die holder having a die-release mechanism in accordance with certain embodiments of the invention.

FIG. 26 is a broken-away partial side cut-away view of a die holder with a die-release mechanism in accordance with another embodiment of the invention.

FIG. 27 is a broken-away partial perspective cut-away view of the die holder with the die-release mechanism of FIG. 26 in accordance with an embodiment of the invention.

FIG. 28 is a broken-away partial perspective view of the die holder with the die-release mechanism of FIG. 26 in accordance with an embodiment of the invention.

FIG. 29 is a perspective view of a die holder in a disassembled configuration in accordance with certain embodiments of the invention.

FIG. 30 is a broken-away, schematic cross-sectional side view of a fabricating press involved in certain embodiments of the invention.

FIG. 31 is a schematic broken-away top view of a turret press involved in certain embodiments of the invention.

FIG. 32 is a schematic broken-away perspective view of one exemplary manner in which a die holder can be mounted on a table of a fabricating press.

FIG. 33 is a perspective view of a die holder in a closed and clamped configuration in accordance with certain embodiments of the invention.

FIG. 34 is a perspective view of the die holder of FIG. 33 in an open configuration.

FIG. 35 is a perspective view of a clamp portion of the die holder of FIG. 34.

FIG. 36 is a broken-away schematic cross-sectional side view of the die holder of FIG. 33.

FIG. 37 is a perspective view of a de holder and die in accordance with certain embodiments of the invention.

FIG. 38 is a perspective view of the die holder and die of FIG. 37, with the die holder clamped on the die.

FIG. 39 is a perspective view of a multiple-track die holder and two dies in accordance with certain embodiments of the invention.

FIG. 40 is a perspective view of the die holder and dies of FIG. 39, with the die holder clamped on the dies.

FIG. 41 is an exploded perspective view of a die holder in accordance with certain embodiments of the invention.

FIG. 42 is a perspective view of a portion of the die holder of FIG. 41.

FIG. 43 is a broken-away partial perspective view of the die holder of FIG. 41, showing an actuator of the die holder in a locked position.

FIG. 44 is a broken-away partial perspective view of the die holder of FIG. 43, showing the actuator in an unlocked position.

FIG. 45 is a front perspective view of a die holder in accordance with certain embodiments of the invention.

FIG. 46 is a back perspective view of the die holder of FIG. 45.

FIG. 47 is a side perspective view of the die holder of FIG. 45.

FIG. 48 is a grooved band adapted for defining resilient surfaces of a die holder in accordance with certain embodiments of the invention.

FIG. 49 is a perspective view of a die holder in accordance with certain embodiments of the invention.

FIG. 50 is a perspective view of another die holder in accordance with certain embodiments of the invention.

FIG. 51 is a perspective view of still another die holder in accordance with certain embodiments of the invention.

FIG. 52 is a perspective view of yet another die holder in accordance with certain embodiments of the invention.

FIG. 53 is a cross-sectional view of a die and a die holder in accordance with certain embodiments of the invention.

FIG. 54 is a partially broken-away cross-sectional detail view of an engagement between the die and the die holder of FIG. 53.

FIG. 55 is a partially broken-away cross-sectional perspective view of a die holder in accordance with certain embodiments of the invention.

FIG. 56 is a schematic perspective view of an upwardly displaced die in a die holder.

FIG. 57 is a side view of the die holder and the upwardly displaced die of FIG. 56.

FIG. 58 is a cross-sectional view of the die holder and the upwardly displaced die of FIG. 56.

FIG. 59 is a flowchart exemplifying certain methods of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following detailed description is to be read with reference to the drawings, in which like elements in different drawings have like reference numerals. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the given examples have many useful alternatives, which fall within the scope of the invention.

Some embodiments of the invention provide a die holder for a fabricating press, such as a metal-fabricating press. In some cases, the press has an upper table and a lower table. A gap between the upper and lower tables is adapted to receive sheet metal or another sheet-like workpiece. In some cases, the upper table may be omitted. The lower table preferably is adapted to have mounted thereon at least one die holder (a wall portion 140 of the die holder may be mounted fixedly on the table, and a clamp portion 130 of the die holder may, in some cases, be adapted for being removably attached to the wall portion). The lower table commonly has a horizontal surface on which the die holder can be mounted and/or defining a mount opening in which the die holder can be mounted. The mount opening in such a press can optionally have a generally circular configuration. In other cases, the mount opening is adapted to receive a polygonal (e.g., generally square) die holder.

One type of fabricating press is shown in FIG. 1. Here, the press 10 is a turret press, although the fabricating press 10 can be a single-station press or any other fabricating press. The fabricating press 10 can include any machine useful for the fabrication of sheet-like workpieces, such as sheet metal or other metal parts. The fabrication process itself can include any work step, such as punching holes, creating bends, various forms, etc.

In some embodiments, the fabricating press 10 includes (e.g., is) a turret press 20. In such embodiments, the turret press 20 can include an upper table (e.g., an upper turret) 30 and a lower table (e.g., a lower turret) 40. The upper table 30 and lower table 40 can be separated by a turret gap 50 adapted to receive sheet-like workpieces. The turret press 20 can include a plurality of stations (reference is made to FIG. 31), at least one of which is adapted to receive a die holder 70. In some embodiments, the die holder 70 is adapted for being removably mounted in an opening 80 defined by a table of the fabricating press 10. (The embodiment shown in FIG. 1 has such openings in the lower table 40, but they are not visible because die holders 70 have been mounted therein). In other cases, the die holder is not potted in an opening defined by the lower table, but is bolted or otherwise anchored removably to the table (such as in the same general manner shown in FIG. 32). A wall portion 140 of the die holder 70 can optionally be mounted in a stationary position on the table. Metal sheets and/or other workpieces (including non-metal sheets and other non-metal workpieces requiring bends, holes, forms, or other fabrication) can be placed between the upper and lower turrets, and a punch or other tool mounted on the upper turret (see FIG. 30) may be caused to act against the workpiece, forcing the workpiece against the die for fabrication. The lower and upper tables may be adapted to rotate together to allow any desired tool set to be moved into position to act on the workpiece. In such presses, the dies are changed periodically to accommodate different fabrication operations, and to replace worn dies.

For embodiments involving a turret press (or other presses with upper and lower tables separated by a gap), to mount a die 90 within the die holder 70, the die can be moved into the gap and mounted in the die holder.

In some embodiments, the die can be moved into the die holder through an open side of the die holder. The open side (which preferably can be closed once the die is mounted on the die holder) may optionally be bounded underneath by an opening base OB of the die holder. The opening base OB, when provided, desirably has a smaller height than the wall portion 140 of the die holder. Preferably, the opening base OB forms part of the die holder's shelf 110 and defines a portion of the support surface 120 that is adapted to support the bottom of a die. When the clamp portion 130 of the die holder is in a closed configuration, the clamp portion preferably is carried against (e.g., positioned on top of) at least part of the opening base OB.

One exemplary embodiment of a die 90 mounted in a die holder 70 is shown in FIG. 2. Here, the clamping operation results in the die holder clamping a single die, although other embodiments involve the clamping operation causing the die holder to simultaneously clamp on at least two dies. FIGS. 39 and 40, for example, depict a multiple-track die holder embodiment wherein the clamping operation causes the die holder to simultaneously clamp on two dies.

In some cases, the die holder is used on a single-station fabricating press. In embodiments of this nature, the press typically does not involve turrets, although the press may still have upper and lower tables (or at least a lower table), as is well known in the present art.

The die holder 70 can include any apparatus useful for holding a die 90. Preferably, the die holder 70 has an interior recess 100. The interior recess 100 may have a generally circular configuration (and/or it may be adapted to receive a die having a generally circular configuration). This, however, is not the case in all embodiments. For example, other embodiments involve a polygonal die 90 and a polygonal interior recess 100. Polygonal dies of the Salvagnini style are known, and the present die holder can be configured to accommodate such dies. FIGS. 37 and 38 depict one embodiment of a die holder 70 adapted to retain a polygonal (e.g., generally square) die. Embodiments like that of FIGS. 37 and 38 are described below in more detail.

The die holder preferably has a shelf 110 adapted to support a bottom (e.g., a planar base) of a die 90. Reference is made to FIG. 3. The shelf, for example, can have (e.g., can define) a support surface 120 on which the bottom of a die is adapted to rest (e.g., when the die is operably mounted in the die holder). In some embodiments, the die holder has a shoulder 150 defining at least part of the die holder's interior side surface 160, which optionally extends at least generally (e.g., substantially) orthogonally from the shelf 110. The shoulder 150 can bound the interior recess 100. When the die holder is in a closed configuration, the die holder's interior side surface 160 (at least part of which preferably is defined by the shoulder 150) can optionally entirely surround the interior recess 100. Further, the die holder 70 can have a central opening 170 (optionally one through which slugs of workpiece material can drop during certain metal fabrication operations), and the shelf 110 can encompass (e.g., can optionally entirely surround) the central opening 170. In some cases, the die holder has an opening base OB one side of which bounds the central opening 170 and another side of which defines an outer perimeter of the die holder.

In some embodiments, the die holder 70 includes a clamp portion 130 and a wall portion 140. The clamp portion 130 can optionally comprise (e.g., can be) a concave clamp portion (i.e., it can optionally have a concave interior surface). The clamp portion, for example, can have a generally C-shaped configuration as shown in many of the drawings. Additionally or alternatively, the wall portion 140 can optionally comprise (e.g., can be) a concave wall portion.

In some embodiments, the clamp portion 130 and wall portion 140 cooperate to allow the die holder 70 to have a closed configuration, embodiments of which are shown in FIGS. 1, 2, 5, 8, 9, 12, 13, 17, 20, 21, 33, 36, 38, 40, 43, and 44, and an open configuration, embodiments of which are shown in FIGS. 3, 4, 6, 7, 10, 11, 14-16, 22, 23, 34, 37, 39, and 41. Preferably, in the closed configuration, the clamp 130 and wall 140 portions together surround the interior recess 100 (optionally entirely surrounding the interior recess, substantially entirely surrounding the interior recess, or surrounding the interior recess to such an extent that a die cannot be mounted in the die holder by simply sliding the die sideways through any side opening). In the open configuration, the die holder 70 preferably is configured to allow a die 90 to be placed in the die holder 70 or removed from the die holder 70. In some embodiments, when the clamp 130 and wall 140 portions are positioned in the closed configuration, the die holder 70 has a generally annular configuration (and/or at least has a generally circular interior side surface 160 surrounding the interior recess 100). In some embodiments, the die holder has configurations like those shown in FIGS. 18, 19, or 37-40. Other die holder configurations can also be provided with the features of any embodiment described in the present disclosure.

The terms “concave clamp portion” and “concave wall portion” do not require the whole of either component to be concave. Preferably, though, a concave clamp portion 130 has a concave interior surface 180, and a concave wall portion 140 has a concave interior surface 190. Those interior surfaces desirably are adapted to surround, abut, and/or engage a die 90 when the die is mounted in the die holder 70 and the die holder is in the closed configuration.

In some embodiments, a concave interior surface 180 of the clamp portion 130 bounds at least 30 degrees, at least 35 degrees, or at least 40 degrees of the interior recess 100 when the clamp and wall portions are in the closed configuration. FIGS. 33-36 and 41-44 exemplify embodiments wherein the die holder 70 has a clamp portion 130 (optionally defining a concave interior surface 180) that encompasses more than 180 degrees of the interior recess 100. Embodiments of this nature can be particularly advantageous. For example, such a clamp portion 130 can be sized to press fit on, or otherwise embrace, a die such that the clamp portion retains the die when the clamp portion is pulled off (e.g., moved sideways apart from) the wall portion 140. In such embodiments, when the clamp portion is pulled apart from the wall portion (at such time as a die is mounted in the die holder), the clamp portion holds the die (e.g., holds an exterior sidewall of the die) such that the die and the clamp portion move together away from the die holder's wall portion. The present invention covers any die holder that has this functionality, regardless of the details on how the die holder is able to embrace the die.

In certain embodiments, the die holder 70 also has a clamped configuration, embodiments of which are shown in FIGS. 1, 2, 5, 8, 9, 12, 13, 20, 21, 33, 36, 38, 40, and 43, and an unclamped configuration, embodiments of which are shown in FIGS. 3, 4, 6, 7, 10, 11, 14-16, 22, 23, 34, 37, 39, and 41 (also in the open configuration) and in FIGS. 17 and 44 (also in the closed configuration). The clamped configuration is useful for securely clamping a die 90 in the die holder 70. The unclamped configuration is useful for allowing the die holder 70 to be reversibly placed in either the open configuration or the closed configuration. In some embodiments, the die holder can be adjusted from an unclamped configuration to a clamped configuration by performing a clamping operation, and the die holder 70 can be adjusted from the clamped configuration to the unclamped configuration by performing an unclamping operation.

In certain embodiments, the die holder 70 includes at least one spring component. Preferably, the spring component is adapted to generate at least part of the clamping force the die holder places on the die. In some cases, the spring component comprises at least one compression spring CSP, optionally provided on the clamp portion 130. Reference is made to FIGS. 41-44. These figures exemplify embodiments wherein the die holder includes at least one engagement body (e.g., at least one axially-moveable locking pin) that is moveable between locked and unlocked positions. When provided, the engagement body preferably is in the locked position when the die holder is in a clamped position, and the engagement body preferably is in an unlocked position when the die holder is in an unclamped position. In some cases, the (or each) engagement body is resiliently biased (e.g., by a compression spring or other spring component), optionally toward the locked position. For example, the (or each) engagement body may be extendable and retractable, and may be resiliently biased toward an extended position.

In FIGS. 41-44, there are two engagement bodies (it may be desirable to have a plurality of engagement bodies). The engagement bodies shown in FIGS. 41-44 comprise locking pins adapted to move axially, e.g., between extended and retracted positions (such as between locked and unlocked positions). Here, the illustrated locking pins are adapted to move along a vertical axis, i.e., if the die holder is mounted on a horizontal plane. This, however, is not required. For example, it may be desirable to have one or more locking pins or other engagement members tipped at an angle. This may provide advantages, including stronger clamping force or a more secure clamp. Thus, in some embodiments, at least one locking pin or other engagement member is adapted to move along an axis that is oblique to vertical.

In certain embodiments, the die holder includes a spring component having a body comprising (e.g., formed of) spring steel. For example, a spring steel body (optionally having an arcuate shape) can form at least part of the die holder's clamp portion 130. During a clamping operation, the die holder 70 can apply a clamping force on a die 90 (when the die is in the die holder's interior recess 100) and the optional spring steel body may generate at least part of the clamping force. In such embodiments, when the clamp and wall portions are in the closed configuration, a clamping operation preferably can be performed so as to decrease a dimension, such as a diameter, of the interior recess (more generally, this can optionally be the case for various embodiments described in this disclosure).

In many embodiments, the die holder includes an actuator 210. In some of these embodiments, the actuator is adapted to be moved (e.g., manually, or in some cases robotically or otherwise using hydraulics, pneumatics, electronics, magnetics, or the like) in such a way as to move the die holder between clamped and unclamped configurations. In some cases, the actuator is adapted to be moved in one manner (e.g., in one direction) so as to adjust the die holder from an unclamped position to a clamped position, and the actuator can be moved in a different manner (e.g., in a different direction) so as to adjust the die holder from a clamped position to an unclamped position. This, however, is not the case for all embodiments.

In one group of embodiments, the die holder is provided with an actuator 210 comprising a body that moves relative to the clamp portion 130 and/or wall portion 140 during clamping and/or unclamping operations. This moveable body can optionally be a pivotable body that moves pivotally (e.g., about at least one hinge) during the clamping and/or unclamping operations. The pivotable body, for example, can be a handle or a latch. FIGS. 33-36 and 41-44 depict exemplary embodiments involving a latch.

In certain embodiments, the actuator 210 is a tool-free actuator that allows the unclamping operation, the clamping operation, or both to be tool-free operations (or at least operations that do not involve rotating a set screw or any other threaded fastener). The clamping and/or unclamping operations, for example, may be performed without a wrench or screw driver. Components of the die holder itself, even if removable (e.g., a removable handle actuator), are not considered tools for purposes of the present disclosure.

As described below, some embodiments provide a die holder (which can optionally be a tool-free die holder) that can be clamped and unclamped, and/or adjusted between open and closed configurations, without requiring any assembly or disassembly of the die holder. These embodiments, for example, may involve the die holder having a clamp portion that is pivotally (e.g., hingedly) connected to the die holder's wall portion.

In certain embodiments, the actuator 210 is a single-motion actuator that allows the die holder 70 to be unclamped in response to a single motion of the actuator. (In some of these embodiments, the unclamping operation is also a tool-free operation.) Additionally or alternatively, the actuator 210 can be one that allows the die holder to be clamped in response to a single motion of the actuator 210. In some embodiments of this nature, the die holder must be partially assembled (e.g., the clamp portion may need to be joined to the wall portion, and/or a removable handle may need to be joined to the die holder) before the single-motion clamping can be performed. However, the actual clamping in such embodiments preferably occurs in response to a single motion of a single-motion actuator (the same may be true of the actual unclamping). Exemplary single motions can be pivoting, pressing, sliding, squeezing, or rotating the actuator 210.

In some embodiments, the die holder 70 is provided with an actuator 210 comprising a body (e.g., a handle) that is moved in one direction (once or repeatedly) during the clamping operation and in another direction (optionally an opposite direction) during the unclamping operation. In embodiments involving a die holder 70 with a shelf 110 defining a support surface 120 on which the bottom of a die 90 is adapted to rest, the handle or other body can optionally be moveable in a plane that is at least generally parallel (or at least substantially parallel) to the shelf's support surface (such that the handle or other body moves in that plane to cause the clamping and unclamping operations). If such a die holder 70 is on, for example, a horizontal table (optionally a lower table 40, as shown in FIG. 1) of a fabricating press 10, then during clamping and unclamping operations the handle or other body may be adapted to move horizontally. If such a die holder is mounted on a turret press (or another press having a gap between upper and lower tables), then the gap 50 can be a generally horizontal gap, and the single-motion actuator 210 can optionally comprise a handle that is moved at least generally horizontally during clamping and unclamping. Other examples include moving the actuator (optionally a latch or handle thereof) generally orthogonally to the generally horizontal gap (e.g., in a generally upward or downward direction) or at an oblique angle. FIGS. 41-44, for example, show a latch that is moved in a plane (e.g., a vertical plane) substantially perpendicular to the die holder's support surface 120 during unclamping operations. In FIGS. 33-36, the latch is moved in a plane substantially perpendicular to the die holder's support surface 120 during both clamping and unclamping operations. However, this is not the case in all embodiments.

In certain embodiments, when the clamp and wall portions 130, 140 are in an open configuration, a die 90 can be mounted in the die holder 70 by moving the die sideways (in some cases, horizontally) through an open side 220 of the die holder. Reference is made to FIGS. 3, 4, 6, 7, 10, 11, 14, 15, 16, 22, 23, 34, 37, 41, and 42. Preferably, the clamp and wall portions 130, 140 can then be moved toward a closed configuration and a clamping operation can be performed to securely clamp the die holder on the die, as shown in FIGS. 1, 2, 5, 9, 12, 20, and 38.

In some embodiments, the die holder can be adjusted (e.g., moved) from an unclamped, open configuration to a closed, clamped configuration by pushing together the clamp and wall portions. For example, in embodiments like that of FIGS. 41-44, this can be done (e.g., in a single step) by pushing the die holder's clamp portion onto the wall portion. Preferably, this is a tool-free operation. More will be said of this later.

In certain embodiments, the die holder is mounted on a table (optionally a horizontal table) of a fabricating press in such a way that when the clamp and wall portions 130, 140 of the die holder 70 are in the open configuration, an open side of the die holder faces an exterior perimeter 224 of the metal-fabricating press 20. Reference is made to FIG. 1. Such embodiments facilitate easy changing of dies in the press by minimizing the amount of work that must be done in the gap between the upper and lower tables. Various embodiments of the die holder 70 will now be described in more detail.

As shown in FIGS. 2-4, some embodiments include a die holder 70 with a clamp portion 130 that is hingedly joined (e.g., about a hinge 228) to a wall portion 140 such that the clamp and wall portions can be moved between the closed configuration, as shown in FIG. 2, and the open configuration, as shown in FIGS. 3 and 4, by pivoting the clamp portion 130 relative to the wall portion 140. Here (as in other embodiments), the clamp portion 130 can optionally be a concave clamp portion, the wall portion 140 can optionally be a concave wall portion, or both.

In the embodiment shown, the clamp portion 130 includes a latch 230, and the latch is hingedly joined to the clamp portion and has a free end 240 that can be hooked onto a catch 250 on the wall portion 140. The illustrated latch 230 has a generally arcuate shape, although this is not required. The clamp portion also includes an actuator 210 connected to the latch 230 (optionally connected pivotably) and adapted to pull the free end 240 of the latch 230 tight against the catch 250 on the wall portion 140 as part of the clamping operation. This exemplifies embodiments where the die holder 70 is adapted for being clamped and unclamped without any assembly or disassembly of the die holder. Thus, one group of embodiments provides a die holder adapted for being clamped and unclamped without any assembly or disassembly. Another embodiment of this nature is shown in FIG. 17.

In other cases, the closed configuration involves the clamp portion 130 being attached removably to the wall portion 140, as exemplified in FIGS. 5, 8, 9, 12, 13, 33, 40, 43, and 44, and the open configuration involves the clamp portion being removed from (e.g., completely separated from) the wall portion, as exemplified in FIGS. 6, 7, 10, 11, 16, 34, 39 and 41. Thus, even though the clamp and wall portions may be completely separated from each other when the die holder is in an open configuration, the die holder in some embodiments can be adjusted from the open configuration to a closed configuration, and vice versa, without using any tool.

In the embodiment shown in FIGS. 5-8, the clamp portion 130 has two clamp posts 260 extending respectively from each of its two ends 270, 280. The illustrated wall portion 140 has corresponding clamp post apertures 290 adapted to receive the clamp posts 260 when the die holder 70 is placed in the closed configuration. This arrangement can optionally be reversed (e.g., the clamp posts can extend from the ends of the wall portion, and the post-receipt apertures can be formed in the ends of the clamp portion), or one end of the clamp portion can have a post while the other end of the clamp portion has a post-receipt aperture adapted to receive a post extending from the wall portion. Other variations of this nature are anticipated.

In some embodiments, one or more pinch plates (e.g., a stack of contiguous pinch plates) 300 can be included in the die holder's wall portion 140, as shown best in FIG. 8. The pinch plates 300 can have pinch plate apertures 310 aligned with the clamp post apertures 290. In such embodiments, when a clamp post 260 is inserted through a clamp post aperture 290, the post moves into a pinch plate aperture 310. First and second pinch plate springs 320, 322 can movably hold the pinch plates within a recess defined by the wall portion 140. In an unbiased configuration (e.g., when the die holder 70 is in the open configuration), the pinch plate springs 320, 322 hold the illustrated pinch plates 300 in a substantially perpendicular orientation relative to an axis of the clamp post apertures 290 such that the clamp post apertures 290 are aligned (e.g., share a common axis) with the respective pinch plate apertures 310. Preferably, the pinch plate apertures 310 are positioned and sized to receive respective posts 260. For example, when the pinch plates are in a substantially perpendicular orientation relative to the axis of the clamp post aperture 190, the clamp posts can be readily moved through the clamp post apertures 290 and into the pinch plate apertures 310. To then place the die holder 70 in the clamped configuration, significant binding forces are applied on the clamp posts 260 when the pinch plates 300 are moved into a skewed position relative to the clamp posts. During the process of applying binding force on the clamp posts, the pinch plates can optionally pull the clamp portion 130 tighter against the wall portion 140 so as to clamp the die holder securely on a die mounted therein. The binding forces preferably are large enough to retain the die within the die holder during metal fabrication operations.

The pinch plates 300 can be placed into a significantly skewed position relative to the clamp posts in any suitable manner. In the embodiment shown in FIGS. 5-8, the die holder 70 includes an actuator (optionally comprising a handle) 210 that is pivotably coupled to the die holder. As the actuator is pivoted, it forces an actuating member 330 to articulate along (e.g., through) a wall of the die holder. The actuating member 330 has an end portion 340 that exerts force against the pinch plates 300 as the actuator 210 is pivoted in a desired direction. In more detail, the actuator 210 is pivoted in the desired direction to cause end portion 340 to exert force against the pinch plates 300 so as to bind the clamp posts 260 to the wall portion 140 of the die holder 70. When it is desired to unclamp the die holder, the actuator 210 can be pivoted in an opposite direction so that the end portion 340 of the actuating member 330 moves away from the pinch plates 300, allowing the springs 320, 322 to move the pinch plates 300 back to their default position (preferably a non-skewed position). In the embodiment of FIGS. 5-8, the actuator 210 causes two actuating members to move respectively toward two stacks of pinch plates, as is perhaps best appreciated with reference to FIG. 6.

A binding-force mechanism like that in FIGS. 5-8 can be provided with a variety of different actuator types. For example, a powered solenoid can be used to push a stack of pinch plates into a skewed position. Alternatively, a ratchet-type handle can be adapted for being cranked repetitively in such a way that pneumatic or hydraulic pressure builds within a chamber of the die holder, causing a piston or the like to move the pinch plates into a skewed position. Electromagnetic actuators could also be used to push such pinch plates into a skewed position. Other embodiments involve such pneumatic, hydraulic, or electromagnetic actuators being adapted to move a moveable body mounted on the clamp portion or wall portion directly against the die to effect clamping.

Another embodiment is shown in FIGS. 9-12. FIG. 9 shows the die holder 70 in the closed and clamped configurations, with a die 90 clamped securely in the interior recess 100 of the die holder 70. FIG. 10 shows the die holder of FIG. 9 in the open and unclamped configurations (here, the die 90 is still mounted on the die holder). FIG. 11 shows the die holder of FIGS. 9 and 10 in the open and unclamped configurations after the die has been removed.

In the embodiments of FIGS. 9-12, the clamping operation decreases a dimension, such as a diameter, of the die holder's interior recess 100. (This is preferably a result of clamping the die holder in various embodiments.) The clamp portion 130 (or a component or section thereof) preferably is forced against the die 90 during the clamping operation.

FIGS. 9-12 and 13 exemplify a group of embodiments wherein the die holder has a clamp portion 130 comprising two arcuate bodies (e.g., bars) 210, 360 pivotally joined to each other. The two arcuate bodies 210, 360 preferably are resiliently biased so as to assume an expanded configuration unless they are forced to pivot to a compacted configuration. Here, the die holder's clamping operation involves one of the two arcuate bodies 210, 360 pivoting relative to the other. This pivoting action can optionally be about an axis at least generally parallel to the die holder's support surface 120. When such a clamp portion 130 is mounted on the wall portion 140 and clamped, it ends-up being in its compacted configuration (and stays in this configuration when the die holder is in the clamped configuration).

In FIGS. 9-12, the clamp portion 130 includes an actuator 210 adapted to actuate a clamp cam 350, shown best in FIG. 12. The clamp cam 350, for example, can be proximate an end portion 270, 280 of the clamp portion 130. In the illustrated embodiment, each end portion of the clamp portion 130 has a clamp cam 350. The illustrated actuator 210 is pivotably joined to a clamp bar 360. In some embodiments, the clamp bar 360 comprises (e.g., is) a spring steel bar. The clamp bar 360 can have one or more clamp protrusions 370 extending from each end, as shown best in FIG. 12. (FIG. 13 depicts another useful configuration for such a protrusion.) The die holder 70 can have a clamp shoulder 380 corresponding to each clamp cam 350, and a clamp protrusion receiver (e.g., a recess) 390 corresponding to (e.g., adapted to receive) each clamp protrusion 370.

In such embodiments, the die holder is placed in its closed configuration by placing the clamp protrusions 370 in (or proximate to) the corresponding clamp protrusion receivers 390, and then placing (e.g., securing) each clamp cam 350 against its corresponding clamp shoulder 380. In more detail, the clamping operation here includes applying a force (optionally in a generally downward direction) to the actuator 210 so that it tends to pivot relative to the clamp bar 360 in such a manner that each clamp cam 350 articulates against its corresponding clamp shoulder 380 and forces each clamp protrusion 370 further into its corresponding clamp protrusion receiver 390. In some embodiments, the clamp cam 350 is curved so that, during clamping, it can be articulated to such an extent that an apex 400 of the curve has been articulated against, and forced downwardly past, the contact point with cam shoulder 380. At this point, the die holder will not release the die until a substantial external force is applied to the actuator 210 in the opposite direction (e.g., in a generally upward direction) to articulate the apex 400 of the clamp cam 350 upwardly past the contact point with the cam shoulder 380.

FIG. 13 shows another embodiment of a die holder 70 that includes a clamp portion 130 having a cam 410 with an engagement portion 414. In this embodiment, the clamp portion 130 includes an actuator 210 that has (e.g., defines) the cam 410. The illustrated cam 410 has a generally hook-shaped configuration. The actuator is pivotably coupled to a clamp bar 360. Here again, the clamp bar 360 can optionally comprise (e.g., can be) a spring steel bar. The wall portion 140 includes a receiver portion (e.g., a recess) 430 adapted to receive the engagement portion 414 of the clamp portion 130 and a camming surface 420 adapted for articulation against the cam 410. To place the die holder in its closed configuration, the clamp portion 130 is placed against the wall portion 140 such that the engagement portion 414 is proximate (or within) the receiver portion 430 and the cam 410 is proximate or against the camming surface 420. To then clamp the die holder, a force is applied (e.g., in a generally downward direction) to the actuator 210 to pivot the actuator relative to the clamp bar 360, which causes the cam 410 to articulate against the camming surface 420 so as to force the engagement portion 414 fully into its corresponding recess 430. In some embodiments, the engagement portion 414 and recess 430 are shaped such that they will not disengage until a substantial force is applied to the actuator in a generally opposite direction (e.g., a generally upward direction).

FIG. 14 shows another die holder embodiment. This embodiment includes a clamp portion 130 pivotably coupled with one end of a wall portion 140. An actuator 210 is pivotably joined to another end of the wall portion 140. To place the die holder 70 in a closed configuration, the clamp portion 130 is pivoted relative to the wall portion 140 until the free end of the clamp portion abuts (or is simply adjacent to) the wall portion. To then place the die holder in a clamped configuration, the actuator 210, formed with a latch 230, is pivoted from the opposite end of the wall portion until its latch 230 engages a catch 250 on the clamp portion. Alternatively, the catch 250 could be on the actuator 210 and the latch 230 could be on the clamp portion. The latch 230 and catch 250 can respectively include or operate as a cam and camming surface. The present embodiment is a doubled-hinged die holder 70. Here, the clamp portion 130 is detachable from the wall portion 140, as shown in FIG. 15. Optionally, the actuator 210 can also be detachable from the wall portion 140. Further, it is anticipated that the clamp portion could be attached to the right side of the wall portion (as seen in FIG. 14) and the actuator could be attached to the left side.

FIG. 16 shows an embodiment of a die holder 70 having a clamp portion 130 with an actuator 210 adapted to cause a cam 410 to cam directly against a surface of a die 90 (not shown in FIG. 16) so as to clamp the die. In the embodiment of FIG. 16, the die holder 70 can have shoulders 440, and the clamp portion can have corresponding shoulder receivers (not shown in FIG. 16). In such an embodiment, to place the die holder in a closed configuration, the clamp portion 130 is set on the die holder 70 such that the shoulders 440 are received within the shoulder receivers. To then clamp the die holder, the actuator 210 can be actuated (e.g., a handle thereof can be moved) to articulate the cam 410 directly against a surface of the die. The cam 410, for example, can be curved to allow it to retain the die within the die holder after it has been articulated to such an extent that an apex of the curve has been articulated against, and forced past, the contact point with the die surface. A force can be applied to the actuator in a generally opposite direction to place the die holder in the unclamped configuration. Such embodiments can optionally be provided with a removable handle. For example, the cam 410 can have an opening (not shown) into which a removable handle can be inserted removably when it is desired to rotate the cam (rather than having the handle be integral to the cam 410 as shown in FIG. 16).

FIG. 17 shows an embodiment of a die holder 70 having a clamp portion 130 hingedly connected to the wall portion 140. The embodiment of FIG. 17 also includes an actuator 210 coupled to a latch 230. A free end 240 of the latch 230 can engage a portion of (e.g., a pin or other catch on) the wall portion, and the actuator 210 can then be pivoted relative to the latch 230 to perform the clamping operation. In the embodiment of FIG. 17, a base end of the latch 230 can be coupled to a rod 450 proximate the actuator 210. The rod 450 can be received within a spring 460. As the actuator 210 is closed during the clamping operation, the end of the latch 230 pushes the rod 450 to compress the spring 460. The spring 400 serves to hold the actuator in both the open and closed configurations.

FIG. 18 shows an embodiment of a table 40 of a press 20 carrying a plurality of die holders. The middle die holder 70 has a concave clamp portion 130, a concave wall portion 140, and a single-motion actuator 210. This embodiment illustrates that the outer surface 470 of the die holder can take any shape. Thus, the terms “concave wall portion” and “concave clamp portion” refer to the concave interior surfaces of those components: the exteriors of those components need not be concave.

FIG. 19 shows an embodiment of a die holder 70 having an actuator 210 with a removable handle portion 480 and a base portion 490. In use, the handle portion 480 can be received removably within the base portion 490, and the actuator 210 can be actuated to perform the clamping operation. A removable handle can be provided for other embodiments as well. For example, the handle in FIG. 16 can be removable in much the same manner as the handle in FIG. 19.

FIG. 20 shows a die holder 70 with its clamp portion 130 and wall portion 140 in the closed and clamped configurations holding a die 90 that is a die cassette 500. The die cassette 500 is adapted to receive a plurality of smaller dies 190. It should be noted that the die cassette 500 can be utilized with any embodiment of the present invention. Thus, a die cassette is considered to be a “die” for purposes of this disclosure.

In connection with the die 90, some embodiments involve an opening 390 that extends entirely through the die. This, however, is not the case in all embodiments.

FIGS. 33-36 depict advantageous die holder features that are provided in certain embodiments of the invention. These figures exemplify embodiments wherein the die holder is designed to reduce or eliminate the stiction problem. The die holder in such embodiments preferably has one (or any combination) of the following features: (1) a shelf 110 adapted to support the bottom of a die, where the shelf has one or more recesses RE, such as grooves or channels (optionally at least one annular groove or channel, and/or a plurality of concentric grooves or channels), pockets, valleys, or other contouring that reduces the extent of contact between the shelf 110 and the bottom of a die mounted operably on the die holder, (2) one or more relief areas RL on the interior surface 160 of the die holder, the relief area(s) being contoured so as to be spaced from a die operably mounted on the die holder, and (3) an interior corner between the die holder's shelf 110 and shoulder 150 having a relief contour (e.g., a radiused or otherwise curved surface extending between shoulder surface 160 and shelf surface 120, where all or part of the radiused or otherwise curved surface is separated from a die operably mounted on the die holder). For embodiments involving one or more of these features, the die holder can have any design described in the present disclosure. More generally, the invention covers any die holder having one or more of these advantageous features.

In embodiments where grooves, channels, or other recesses RE are provided in the die holder's shelf 110, the recesses optionally have a depth of at least 0.0015 inch (such as at least about 0.04 mm), or at least 0.0019 inch (such as at least about 0.05 mm). In some cases, the recesses RE reduce the amount of surface area (of the shelf) that contacts a die operably mounted on the die holder by at least 20%, at least 35%, or at least 40% (compared to an entirely flat shelf). In the embodiment of FIGS. 33-36, the shelf 110 has a plurality of concentric grooves and a plurality of annular contact surfaces 120. Many other recess RE arrangements can be used.

In embodiments where the interior surface 160 of the die holder is provided with one or more relief areas RL, a relief area RL may be located circumferentially between two contact areas COA of the interior surface 160. The interior surface 160 may have one or a plurality of these relief areas RL. Preferably, when a die is clamped by the die holder, contact area(s) COA of the interior surface 160 contact the die, but relief area(s) RL do not. When provided, the relief area(s) may extend from the die holder's shelf all the way up to the top of the die holder's shoulder 150. This, however, is by no means required. In some embodiments, relief areas RL occupy at least 10%, at least 15%, or at least 20% of the die holder's interior side surface 160.

In embodiments where interior corner relief RS is provided, the relief contour can optionally extend along the entire perimetrical extent (e.g., the entire circumferential extent) of the wall portion 140. This, however, is by no means required. For example, other embodiments involve one or more sections of corner relief RS spanning a total of at least 10 degrees, at least 30 degrees, at least 45 degrees, at least 90 degrees, or at least 120 degrees about the die holder. The present invention covers any die holder (of any design described herein, or of any other design) with an interior corner relief RS.

FIGS. 37 and 38 depict exemplary embodiments wherein the die holder is adapted to hold a polygonal die. Here, the illustrated die 90 has a generally square configuration. Likewise, the die holder's interior recess 100 has a generally square configuration. Virtually any desired configurations can be used for the die holder's interior recess 100 and the die 90.

The die holder 70 of FIGS. 37 and 38 has a wall portion 140 and a clamp portion 130. The illustrated clamp portion 130 is joined pivotally to the wall portion 140. When it is desired to mount the die 90 in the die holder 70, the die can be moved through the die holder's open side 220 into the interior recess 100. The clamp portion 130 can then be pivoted relative to the wall portion 140 until the die holder reaches its closed configuration. At that point, a latch 230 on the clamp portion 130 is extended so as to attach a hook 240 on the free end of the latch to a catch (e.g., a post, pin, or other suitable structure) 250 on the wall portion 140. An actuator 210 on the die holder is operably coupled (e.g., pivotably attached) to the latch 230. Thus, by pivoting the actuator 210 in a desired direction, the latch 230 is pulled tight against the catch 250 on the wall portion 140, thereby causing the clamp portion 130 to clamp on the die 90. FIG. 38 shows the die 90 in the resulting clamped position.

FIGS. 39 and 40 depict an exemplary embodiment wherein the die holder 70 is adapted to clamp a plurality of dies 90 simultaneously. FIGS. 39 and 40 also exemplify embodiments wherein the die holder 70 has a configuration that can be characterized as being generally pie-shaped. Again, the die holder 70 has a clamp portion 130 and a wall portion 140. The die holder 70 here has an actuator 210, which when actuated is adapted to cause the clamp portion 130 to simultaneously clamp two dies 90 mounted on the die holder. In more detail, the clamp portion 130 has two generally opposed concave surfaces 180, which are adapted to respectively engage the two dies 90 mounted on the die holder. The clamp portion 130 has a generally T-shaped cross-sectional configuration (e.g., in a cross-section taken parallel to the die holder's shelf 110 and/or support surface 120). Other configurations can alternatively be used.

The actuator 210 on the die holder 70 of FIGS. 39 and 40 comprises a handle (on the clamp portion) that moves pivotally to effect clamping and unclamping. The actuator 210 here comprises a bar 910, a first end 902 of which is adapted to be received axially in a corresponding recess 810 in the die holder's wall portion 140. The first end 902 of the bar 910 is equipped with a transverse pin, which is adapted to be received in a corresponding recess 805 open to recess 810. Once the bar 910 has been inserted into recess 810, the actuator 210 can be pivoted to clamp the die holder. In more detail, pivoting the actuator 210 causes the bar 910 to rotate about its axis. This in turn causes the transverse pin 905 on the first end 902 of the bar 910 to cam with a sloped surface in a recess (not shown) open to recess 805. The resulting camming action forces the clamp portion n130 to move tightly against the two dies mounted on the die holder 70. A spring or the like (not show) may provide extra means for keeping the actuator in the clamped position. The illustrated actuator 210 is a handle. However, a rotatable knob or the like could alternatively be used.

In some embodiments, the die holder is moved between open and closed configurations, and/or between clamped and unclamped configurations, automatically (i.e., without manually manipulating the die holder, or without any direct human contact). For example, an automatic actuator actuated by electrical, hydraulic, and/or pneumatic power can be utilized for automatically configuring the die holder. Controls for such an automatic actuator can be included with the fabricating press or a control panel. In some embodiments, a programmable robot (e.g., a robotic arm) can be utilized to automatically actuate the actuator. For example, the various die holder embodiments described above can be configured on a press such that they can be clamped and/or unclamped pneumatically, hydraulically, etc.

Some embodiments of the fabricating press include a table (optionally a turret table) with a plurality of die holders. In those cases (or any other cases), each die holder can optionally be an independently-operable die holder such that performing a clamping operation clamps a single die holder alone and does not simultaneously clamp any other tool holder (e.g., any other die holder), and/or such that performing an unclamping operation unclamps the die holder alone and does not simultaneously unclamp any other tool holder.

Further, any of the fabricating presses or die holders described herein can include means to indicate that the die is received within, and securely clamped in, the die holder. For example, two electrical contacts can be included within the interior recess and a voltage potential can be applied between the two contacts. The contacts can be configured to allow the circuit to be completed only upon successful clamping of the die within the die holder. The completed circuit could be used to signal an indication light (or other means) on the die holder, on a fabricating press, or on a control panel to indicate the die is either clamped or unclamped. If desired, the press, a controller thereof, etc. can be set-up such that it will not initiate pressing operations unless the die holder registers that a (or each) die therein is securely clamped. Further, the system can be adapted to indicate whether the correct die is received in the die holder. If the correct die is not in the die holder, the controller can be set-up such that it will not initiate pressing. Any signals transmitted among the die holder, a press (e.g., a controller thereof), and a die can be sent by wire or by wireless RF means.

In some embodiments, the invention provides a die holder 70 having a die-release mechanism 520. Preferably, the die-release mechanism 520 is useful for overcoming the above-referenced stiction problem. Several exemplary embodiments, which will be discussed in detail below, are shown in FIGS. 21-28. The present embodiments extend to any die holder having a die-release mechanism of any type described below. In the present embodiments, the die holder itself may be any one of the types described in this disclosure, or it may have any other desired construction, provided it has a die-release mechanism.

The die-release mechanism is useful for facilitating removal of the die 90 from the die holder 70 by applying a separation force to the die (e.g., so as to overcome stiction force created by lubricant between the die and die holder). In some embodiments, actuating the die-release mechanism 520 involves a contact portion 530 of that mechanism moving at least generally toward a central axis CA of the interior recess (and/or moving at least generally radially inward). Additionally or alternatively, actuating the die-release mechanism 520 may involve a body 524 with a contact portion 530 moving at least generally parallel to (or at least substantially parallel to) a plane in which the shelf's support surface 120 lies. This may involve the body 524 moving horizontally (e.g., if the die holder is mounted on a table of a press). In certain embodiments, actuation of the die-release mechanism 520 involves a contact portion 530 of that mechanism moving at least generally toward (or directly toward) an open side 80 of the die holder. In some cases, actuation of the die-release mechanism 520 involves a contact portion 530 of that mechanism emerging from an opening OP in the die holder's interior surface 160 (the opening OP can optionally be in a concave interior surface of the die holder).

In the embodiment shown in FIG. 21, the die-release mechanism 520 includes a body 524 having a contact portion 530 that is constantly biased to act against a die mounted on the die holder. Here, the body 524 (or at least its contact portion 530) is under a constant spring bias, regardless of whether the die holder 70 is in a closed and/or clamped configuration or an open and/or unclamped configuration. In such embodiments, the body 524 can advantageously be mounted movably on the die holder's wall portion 140. Preferably, the body 524 is mounted in an opening (e.g., a bore) extending into the wall portion 140 and opening through interior surface 190. A resilient member, such as a spring (not shown in FIG. 21), can be used to constantly bias the body 524 in the desired direction (optionally toward a side of the die holder that is adapted to open). In FIG. 21, the die-release mechanism 520 comprises two such bodies 524, although one, three, or any other desired number can be used. In some of the present embodiments, the body 524 is adapted to move horizontally during actuation of the die-release mechanism (e.g., if the die holder is mounted on a table of a press).

In some embodiments, the body 524 is adapted to move radially (e.g., at least generally radially, or at least substantially radially) and/or at least generally toward a central axis CA of the interior recess so as to apply a separation force on the die 90, and the body 524 is resiliently biased toward (generally toward, substantially toward, or directly toward) the central axis CA of the interior recess. In such an embodiment, when a die 90 is moved into the die holder 70 and the die holder is moved into its closed configuration, the die 90 will exert sufficient force on the body 524 to retract the body 524 (overcoming the biasing force) into the die holder's wall portion. When the die holder 70 is placed in the open configuration, the body 524 will have sufficient biasing force (e.g., enough spring force) to overcome stiction and move the die 90 (e.g., so as to separate the die from at least one die holder surface to which the die was originally stuck due to the stiction).

In the embodiment of FIGS. 22 and 23, the die-release mechanism 520 is adapted to actuate in response to the die holder 70 being moved from its closed configuration to its open configuration. In the embodiment of FIGS. 22 and 23, the clamp portion 130 is hingedly connected to the wall portion 140. As the clamp portion 130 pivots open relative to the wall portion 140, an actuating ring AR moves circumferentially on (e.g., within) the wall portion 140. Preferably, the actuating ring has a cam 540 that cams with the body 524 defining the contact portion 530, thereby forcing the body 524 and its contact portion 530 to move (optionally radially and/or at least generally toward a central axis of the interior recess) so as to apply a separation force on a die mounted on the die holder.

Thus, in some embodiments, at least a portion of the actuator (e.g., an actuating ring AR thereof) moves along a curved path during actuation of the die-release mechanism.

With continued reference to FIGS. 22 and 23, when the illustrated die holder is in the closed configuration, the actuator ring AR is positioned such that the cam 540 does not force the body 524 to bear forcibly against a die mounted on the die holder (e.g., at such times, the illustrated body 524 is free to retract fully inside an opening OP in the die holder's wall portion). If desired, the die holder can include a spring (not shown) biased to return the body 524 (e.g., to its fully retracted position) and/or the actuating ring when the die holder 70 is moved from its open configuration to its closed configuration. In other embodiments, simply placing a die within the die holder 70 will cause the body 524 to retract into the die holder's wall portion. The present embodiment is useful for allowing selective actuation of the die-release mechanism.

One or more keys 544 (e.g., useful for aligning the die within the die holder) can optionally be provided in any embodiment described in the present disclosure. The key can optionally be rigidly fixed to the wall portion, and can be a pin or any other key structure.

An actuating ring AR like that shown in FIG. 24 may or may not rotate in response to a clamp portion 130 of the die holder being moved to its open position. FIG. 29 shows an actuator comprising an actuating ring AR with a reduced-height portion RH and an enlarged height portion EH. This type of actuator ring AR is also shown in FIG. 25. Here, the enlarged height portion EH defines a cam 540 on which a rear end of body 524 cams when the actuating ring is rotated so as to actuate the die-release mechanism. The ring in such camming embodiments need not have the enlarged EH and reduced RH height portions (the ring can have uniform height, etc.). In FIG. 29, the actuating ring AR can be made to rotate by manually pushing a shoulder SH on the ring (alternatively, this can be done hydraulically, pneumatically, etc.). The actuating ring AR in this embodiment can optionally extend entirely about a perimeter of the die holder (and/or it can optionally be configured to entirely encompass the interior recess). Alternatively, it may extend only partway about the perimeter (optionally encompassing at least 25°, 30°, 45°, 90°, 180°, 270°, or 300°). Preferably, rotating the actuating ring AR in a desired direction causes a body 524 of the die-release mechanism to move forcefully (e.g., so as to apply a positive force) against a die mounted on the die holder. This can be done by camming, as has been described, or by other means. The actuating ring AR may have an annular configuration, as shown. However, this is not required.

Another embodiment that allows for selective actuation of the die-release mechanism 520 is shown in FIGS. 26-28. When the die 90 is received in the interior recess 100 of the die holder 70, the die-release mechanism 520 can be actuated at a desired time to apply a separation force on the die 90 (e.g., so as to urge the die 90 away from at least a portion of the die holder 70). In the embodiment shown in FIGS. 26-28, the die-release mechanism comprises a wedge member 550 with a contact portion 530, where actuating the die-release mechanism involves the wedge member 550 moving (e.g., at least generally radially) such that the contact portion 530 wedges beneath a die 90 in the die holder's interior recess.

In the embodiment of FIGS. 26-28, the wedge member 550 can optionally be biased away from the die holder's central recess 170 (and/or toward the adjacent outer perimeter of the die holder) by a wedge spring 570. To actuate this die-release mechanism 520, a force can be applied (optionally manually) to move the wedge member 550 toward the central recess 170 and into lifting contact with a die in the interior recess 100. The wedge member 550 can have a slot 580 sized to receive a fastener (e.g., a bolt, peg, etc.) 590 adapted to allow the wedge member 550 to articulate relative to the central recess (e.g., relative to the die holder wall on which it is mounted) without detaching from the die holder 70. In the present embodiment (and in the embodiments of FIGS. 22-25 and 29), the separation force involves a positive, physical push of the die away from at least a portion of the die holder 70. This is contrary to embodiments wherein the die is biased by a spring-loaded body, as the separation force here is a positive force. Embodiments of this nature are particularly desirable for overcoming stiction. Thus, one embodiment group extends to any die holder (e.g., of any design disclosed herein) having a die-release mechanism adapted to apply a positive separation force to a die mounted on the die holder.

In some embodiments, an operator wishing to remove or exchange a die 90 from a fabricating press 10 may do so by first adjusting the die holder 70 from a clamped to an unclamped configuration and from a closed to an open configuration. The die 90 can then be removed from the die holder 70. Another die 90 can be then be placed within the die holder 70, and the die holder can be adjusted to a closed and clamped configuration.

In some embodiments, an operator may use a die-release mechanism 520 to overcome stiction in the process of removing a die 90 from the die holder 70. For example, a constantly biased member (e.g., a spring-loaded body) can be provided (and used) to release the die 90 when the die holder 70 is adjusted from the clamped configuration to the unclamped configuration and/or from the closed configuration to the open configuration. Alternatively, a die-release mechanism 520 may be selectively actuated, e.g., in response to an operator moving the die holder 70 from the closed configuration to the open configuration. In certain embodiments, the operator can selectively actuate the die-release mechanism 520 by moving a wedge member 550 so as to cause the wedge member to bear forcibly against the die 90 (optionally, so as to separate a bottom surface of the die from a support surface of the die holder, which may involve the wedge member lifting the die away from the die holder's shelf/support surface).

FIGS. 41-44 exemplify various die holder embodiments. Here, the actuator 210 allows the die holder to be unclamped in response to a single motion of the actuator. The actuator shown here is a latch, although any other single-motion actuator can be used. Once this die holder has been clamped on a die, the unclamping operation can be performed by simply pulling the latch outwardly, e.g., moving it from the latch position shown in FIG. 43 to the latch position shown in FIG. 44. This movement of the latch causes the two engagement bodies (which are locking pins in the illustrated embodiment) to move from their locked position to an unlocked position. The latch 210 here is mounted pivotally (e.g., on a pivot pin PP) on the clamp portion 130 of the die holder. The illustrated locking pins are resiliently biased (e.g., by respective compression springs CSP) such that when they are aligned with corresponding locking recesses LOR, they move into locking engagement with those recesses. As the springs CSP move the locking pins LP in this manner, cam surfaces PCS on the locking pins LP bear against (e.g., cam with) corresponding camming surfaces 750 bounding the locking recesses LOR, such that the clamp portion 130 is urged toward the wall portion 140. When this occurs at such time as a die is mounted on the die holder, it causes the clamp portion to bear forcibly against the die. Later, when it is desired to unclamp the die, the latch can be moved to the latch position shown in FIG. 44. As the latch is moved in this manner, part of the latch (e.g., an actuating portion 222) bears against the locking pins LP, lifting them out of their locked position (in the process overcoming the bias of the springs CSP). In FIGS. 43 and 44, it can be appreciated that the actuating portion 222 (which is shown as being an actuating pin) of the latch lifts upwardly against a lifting surface 313 on each locking pin LP during the unclamping process. To keep the latch in the position shown in FIG. 43 during use, it may be desirable to provide at least one return spring 601 (see FIG. 41) that bears against a portion of the latch so as to provide resistance against the latch inadvertently moving to its open position. Since the die holder may spin/rotate during use, it may be desirable to provide a return spring 601 or some other mechanism that prevents centrifugal force and/or gravity from moving the latch into the position shown in FIG. 44.

Referring to FIG. 43, the angle of the cam surfaces PCS on the locking pins LP and that of the corresponding camming surfaces 750 bounding the locking recesses LOR may range from 1 to 20 degrees from vertical, perhaps optimally being from 2 to 10 degrees from vertical. This, however, is by no means required in other embodiments. Moreover, the noted angle contemplates the die holder being mounted on a horizontal plane, and that is not required.

FIGS. 41-44 exemplify embodiments wherein the die holder is adapted to be adjusted from an unclamped, open configuration to a closed, clamped configuration by performing a single step that comprises pushing together the clamp and wall portions. In the illustrated design, the single step is a tool-free operation, although this is not strictly required. The wall portion 140 of the die holder may be mounted on a table of a press. Once a die is placed on the die holder's support surface 120, the clamp portion 130 can be pushed (e.g., in a sideways manner, such as in a horizontal direction) onto the wall portion 140 until the locking pins LP move into locking engagement with the locking recesses LOR. During this process, the camming action (described above) causes the clamp portion to bear forcibly against the die. To make it easy to push the clamp portion onto the wall portion, a bottom surface ACS of each locking pin LP can be tapered, and corresponding angled ramp surfaces RMP can be provided between the outside edge of the die holder's opening base OB and the locking recesses LOR. Thus, when the clamp portion is pushed together with the wall portion, angled bottom surfaces ACS of the locking pins LP ride easily over the angled ramp surfaces RMP to prevent the locking pins from getting hung-up on the outside edge of the die holder's opening base. These features, however, are optional.

FIGS. 41-44 show the angle of the ramp (from horizontal) being about 25 degrees. More generally, a range of about 20-30 degrees may be suitable. In FIGS. 41-44, the angle (from horizontal) of the bottom surface ACS of each locking pin LP also has an of about 25 degrees, and a range of about 20-30 degrees may be suitable. In FIG. 41, two springs CSP are shown respectively on the two locking pins LP. In one practical example, these springs have a total rate of 6 pounds. More generally, a range of about 5-20 pounds may be suitable. The embodiment of FIG. 41 also shows a return spring ACS (although multiple return springs may be desirable). The illustrated return spring 601 may have a rate of about 2-10 pounds, such as about 2 pounds in a practical example.

Referring to FIGS. 41-44, the opening base OB can be made from a hardenable tool steel such as A2 or pre hard tool steel material such as 4130, then turned on a lathe or turning center to the approximate inner and outer diameters, and then either heat treated for hardness or if a prehard material is used hardening is not required, in either case the unit can be placed in a milling machine after the lathe operation and the front opening portion can be milled, then the pocket features and finish details can be added to the part. An added surface preparation, such as nitrocarburizing, may be added for surface hardening and or lubricity. The illustrated locking recesses LOR may be heat treated with either induction hardening or laser hardening for added durability. The opening base OB can be made on a multi axis machine center to avoid costly set up. The clamp portion 130 can be made in a similar fashion as the opening base OB, although multiple set-ups may be required to achieve the recess area on the top surface and the pocket openings for the illustrated actuator 210 and lifting pins LP. The clamp Portion 130 can be made from a hardenable spring steel such as S2 to enable the clamp portion 130 to spring open to engage the die then embrace a die for removal. The actuator 210 can be made with conventional machines such as a mill or can be made by wire EDM (electrical discharge machining) or waterjet. The actuator 210 could also be made by metal injection molding, plastic injection molding or casting. The lifting pins LP can be made from hardenable tool steel such as A2 or D2, and can be turned on a turning center then milled to the correct shape and angle on the ends that engage the locking recesses LOR. The lifting pins LP can be hardened after the lathe and mill work is complete, and then ground to a proper fit in the clamp portion 130. These options, however, are only provided for purposes of example: they are by no means limiting. Rather, the die holder in any embodiment can be manufactured in a various different ways.

The present invention also provides embodiments wherein a die holder (e.g., a die holder in accordance with any design shown or described herein, or a die holder of any other design) is provided with an anti-vibration system. It is to be understood, for example, that any of the anti-vibration features, systems, methods, and/or embodiments described below (and/or referenced in FIGS. 45-59) can be provided on (and/or used with) any die holder apparatus or method embodiment described in the paragraphs preceding this one (and/or referenced in FIGS. 1-44).

It has been discovered that providing a die holder with an anti-vibration system can eliminate or substantially reduce such problems as die creep and die bounce. Die creep occurs when, due to the vibrations that occur during punching operations, one or more inactive dies (i.e., dies at non-punching positions) gradually move upwardly relative to the inactive die holders in which they are mounted. If the problem is not addressed and the die creep becomes significant, then subsequent punching operations will be inaccurate (or the sheet could crash into a raised die in a non-punching location destroying the workpiece). FIGS. 56-58 show an upwardly-displaced die on a die holder (the upward displacement is exaggerated here for purposes of illustration). A similar phenomenon, die bounce, can also be caused by the vibrations that occur during punching operations. Die bounce involves one or more dies in non-punching positions bouncing up and down relative to their die holders during punching operations. The die bounce can be such that a die becomes elevated and gets stuck in the elevated position because the bottom of the die gets above a ball detent. To address these problems, certain embodiments of the invention provide an anti-vibration die holder.

Preferably, the die holder is provided with an anti-vibration system, and the construction of the die holder and its anti-vibration system allow no more than 0.032 inch of upward die displacement relative to the die holder after 10,000 test strokes of a fabricating press. This 10,000 stroke test involves mounting the die holder in question at a non-punching location on a fabricating press, then performing 10,000 strokes of the press at a punching location (i.e., adjacent to an active die holder), and then measuring the upward displacement of the die on the die holder in question. The test is performed at the highest possible tonnage rating for the fabricating press with the die holder in a position 160 to 180 degrees from the punching station. By way of example, the test strokes can be performed on Finn-Power punch presses, or on other turret style presses (the die holder 70, of course, can be used on other types of fabricating presses, such as single-station presses). Preferred embodiments limit any upward die displacement to no more than 0.03 inch, preferably no more than 0.02 inch, and perhaps optimally no more than 0.01 inch after 10,000 test strokes. The embodiment of FIGS. 45-47, for example, allows from 0.000 to no more than about 0.005 inch of upward die displacement relative to the die holder after 10,000 test strokes. The noted displacement limits are achieved when using a 20-ton fabricating press as the standard, and in preferred embodiments the noted displacement limits are achieved when using a 30-ton fabricating press as the standard.

One group of embodiments provides a die holder with an anti-vibration system comprising at least one resilient surface adapted to contact a die when the die is mounted operatively in an interior recess of the die holder. In preferred embodiments, the die holder has a plurality of resilient surfaces, which can advantageously be spaced-apart about the die holder's interior wall(s). It has been discovered that arrangements of this nature (where the resilient surface or surfaces do not entirely surround the die) are advantageous in that they eliminate or significantly reduce stiction. Stiction occurs when, after a die has been mounted operatively in a die holder, the die becomes stuck in the die holder. Stiction is problematic because the die must be forced from the die holder, taking additional time and cutting into the efficiency of the manufacturing process.

In certain embodiments, the die holder includes a plurality of resilient surfaces 700 that cover between about 180 degrees and about 300 degrees of a perimetrical (e.g., circumferential) extent of the die holder's interior wall(s). Reference is made to FIGS. 45-47, which illustrate one embodiment of this nature. Here, the resilient surfaces 700 are defined by a plurality of resilient bands BA mounted on the die holder at locations spaced-apart about the die holder's interior walls. This is representative of a broader group of embodiments wherein a die holder has one or more resilient surfaces 700 defined by bands, strips, or other elongated bodies.

Many types of bodies can be used to provide suitable resilient surfaces 700. Some embodiments employ one or more resilient plugs PL (optionally cylindrical or generally cylindrical bodies), which are adapted to contact the die when the die is operatively mounted in the die holder. Such a plug can have its axis generally parallel, perpendicular, or oblique to the die holder's interior wall. FIG. 50, for example, depicts an embodiment wherein the die holder has a plurality of resilient plugs PL each with its axis perpendicular to the die holder's interior wall, such that a generally planar end (which can optionally be grooved or otherwise recessed) of each plug is adapted to contact the die. FIGS. 51 and 52 depict embodiments wherein the die holder has a plurality of resilient plugs PL each with its axis parallel to the die holder's interior wall, such that a curved side of each plug is adapted to contact the die. Many variants of this nature will be apparent to skilled artisans given the present teaching as a guide.

Thus, the bands, plugs, or other bodies defining the resilient surfaces can take many different forms. For example, they can be provided as buttons, spheres, cubes, or the like. Further, the bodies defining the resilient surfaces need not be entirely resilient. For example, a base portion of each body could be rigid, while a die-contacting portion is resilient. Many other useful alternatives will be apparent to skilled artisans given the present teaching as a guide.

Preferably, each resilient surface 700 is defined by a resilient body that protrudes into the die holder's interior recess 100 a sufficient distance to engage the die when the die is operatively mounted in the die holder. Reference is made to FIGS. 53-55. For embodiments where the die holder is adapted to perform a clamping operation on the die (in order to place the die in an operatively mounted position), the resilient body or bodies preferably protrude into the die holder's interior recess 100 a sufficient distance that, during clamping, the resilient body or bodies are compressed until the die is in contact with both the die holder's interior wall(s) and the resilient body or bodies. Thus, when the interior recess 100 of the die holder is unloaded (i.e., has no die in it), the resilient surfaces preferably project from the die holder's interior wall(s). In some embodiments of this nature, the resilient surfaces 700 project from the die holder's interior wall(s) by at least about 0.001 inch, e.g., by between about 0.001 inch and about 0.005 inch. In one practical embodiment, the projection distance is about 0.003 inch. These exemplary dimensions, however, are by no means limiting to the invention. Rather, these dimensions will vary with different embodiments.

If desired, an adhesive or other fixation means can be employed between the walls of the resilient bodies and recesses in which they are received. The bands, for example, can glued to the holder, or the bands can be shaped to fit a dove tail type slot. The bands can alternatively be adhered by double sided tape. These, however, are merely non-limiting examples.

The resilient surfaces preferably are constructed to provide a slide-resistant engagement between the die holder and the die. Thus, during operation, the die preferably is maintained in a constant (or at least substantially unchanging) position relative to the die holder.

The resilient surfaces can be formed of a resilient non-lubricating material (i.e., a resilient material that is not self-lubricating). Preferred materials include Neoprene (i.e., polychloroprene) and other synthetic rubber compounds. Natural rubber and other resilient materials may also be used. As other examples, polyurethane and other resilient plastics may be used.

In certain embodiments, the resilient surfaces 700 are defined by material having a Shore A durometer of between about 20 and about 95. In one practical example, Neoprene having a Shore A durometer of about 50 is used.

Preferably, when a die is mounted operatively in the die holder's interior recess, the die contacts both the die holder's resilient surfaces 700 and the die holder's interior wall(s). This can be accomplished, for example, by providing the die holder with at least one resilient body having a height that is less than a height of the die holder's interior wall(s). Reference is made to FIGS. 53 and 54. In some embodiments of this nature, the die holder's interior wall(s) comprise metal (e.g., steel), and the resilient surfaces 700 are defined by material (e.g., Neoprene) with a Shore A durometer of between about 20 and about 95.

In some embodiments, a body defining at least one resilient surface 700 has a grooved or otherwise recessed front section adapted to engage the die when the die is mounted operatively in the interior recess 100. Reference is made to FIGS. 45-51. In these figures, a plurality of grooved bodies define resilient die-contact surfaces, and each such body has a grooved front section adapted to contact an exterior sidewall of the die when the die is mounted operatively in the interior recess 100. These figures are representative of a broader group of embodiments wherein the die holder has at least one resilient surface 700 defined by an elongated band BA mounted in a recess extending perimetrically (e.g., circumferentially) about the die holder's interior wall(s). FIG. 28 shows a resilient band wherein a plurality of grooves are formed in the elongated band, and the grooves extend along a length of the band. In some embodiments, the die holder carries a plurality of grooved elongated bands defining the resilient surfaces 700.

As just one example, grooves can be formed in a band of Neoprene (or another resilient material) by grinding the grooves into the band. The grinding can be done using automatic or manual surface grinding equipment. For example, the Neoprene can be placed on a vacuum plate or double side taped to a steel surface so it can be magnetically secured to the equipment. Alternatively, the neoprene can be extruded with the desired grooves and simply cut to the proper lengths. The preferred depth for the grooves will depend on such variables as the size of the die holder, the size of the die, the type of resilient material used, the size and shape of the resilient bodies, etc. In some practical embodiments, the grooves have a depth of between about 0.005 inch and about 0.030 inch. In one practical embodiment, the grooves have a depth of about 0.015 inch. These dimensions, however, are not limiting to the invention.

By providing suitable grooves or other recesses in the resilient body or bodies that engage the die, one can provide enough compression to get the die to seat firmly against both the die holder's interior wall and the resilient body or bodies. It has been discovered that this is a good way to overcome limitations in the manufacturing tolerances associated with certain resilient materials. This is believed to be particularly advantageous when using material of the noted durometer range. This combination of softness range and grooves or other recesses is believed to give excellent anti-vibration properties.

In one practical embodiment, the die holder has the general construction illustrated in FIGS. 45-47, the wall portion 140 has three spaced-apart grooved bands of Neoprene (the middle one having a height of about 8 mm and a length of about 75 mm, with a projection of about 0.003 inch, the two outer ones having a height of about 8 mm and a length of about 25 mm, with a projection of about 0.003 inch), and the clamp portion 130 has two spaced-apart grooved bands of Neoprene (each having a height of about 6 mm and a length of about 25 mm, with a projection of about 0.003 inch). Here, the grooves in each band have a depth of about 0.15 inch, each of the three bands on the wall portion 140 has eight grooves and eight ribs, and each of the two bands on the clamp portion 130 has six grooves and six ribs. In this example, the Neoprene has a Shore A durometer of about 50. It is to be understood, however, that these details are by no means limiting to the invention; they are merely examples.

As is best shown in FIGS. 47, 49, and 51-52, certain embodiments provide a die holder having a clamp portion 130 and a wall portion 140, wherein at least one resilient surface 700 is adjacent to an attachment point between the clamp 130 and wall 140 portions. Here, there are two attachment points between the clamp 130 and wall 140 portions, and at least one resilient surface 700 is adjacent to each attachment point. In FIGS. 45-47, for example, a grooved band is adjacent to each attachment point. In FIGS. 51-52, at least one resilient plug is (e.g., a plurality of resilient plugs are) adjacent to each attachment point.

As is best shown in FIGS. 45, 49, and 50, certain embodiments provide a die holder wherein at least one resilient surface 700 is (optionally a plurality of resilient surfaces 700 are) adjacent to a key KY protruding from the die holder's interior wall. The key KY here is adapted to engage and properly orient a die mounted operatively on the die holder.

Certain embodiments provide a die holder having a clamp portion 130 and a wall portion 140 wherein at least one resilient surface 700 is (optionally a plurality of spaced-apart resilient surfaces 700 are) provided on each of the clamp portion 130 and the wall portion 140. FIGS. 45-47 exemplify embodiments wherein the die holder has a clamp portion 130 with a plurality of resilient grooved bands, and the wall portion 140 also has a plurality of resilient grooved bands. The illustrated bands are spaced-apart so as to eliminate or substantially reduce stiction.

Certain embodiments provide a die holder having an exterior wall (e.g., a wall adapted to be engaged by a die shoe on which the die holder can be mounted) on which there is at least one exterior resilient body. FIG. 49 depicts one exemplary embodiment wherein a plurality of exterior resilient plugs PL are spaced-apart about an exterior perimeter (e.g., a circumference) of the die holder. Here, the resilient plugs are adapted to absorb vibration transmitted from a die shoe to the die holder. Thus, some embodiments provide a die holder mounted operatively on a die shoe, and at least one resilient body (optionally a plurality of resilient bodies) on the die holder engages the die shoe. In the embodiment of FIG. 49, the die holder has a generally circular exterior configuration, and resilient plugs PL are spaced-apart about at least part of the die holder's circumference. Many variants of this nature can also be used.

As noted above, an anti-vibration system can be provided advantageously on many different types of die holders. The die holders described above and exemplified in FIGS. 1-44 derive particular benefit from having an anti-vibration system, e.g., they preferably do not require set screws to secure the die on the die holder. Thus, in certain embodiments the anti-vibration die holder is devoid of set screws adapted to rigidly engage the die.

The invention also provides methods of using an anti-vibration die holder. In certain embodiments, these methods involve mounting a die operatively in the anti-vibration die holder. In some cases, this involves positioning the die in the interior recess 100 of the die holder 70, and then performing a clamping operation on the die holder so as to forcibly clamp the die in the die holder. Depending upon the particular embodiment, this clamping may result in one or more resilient bodies/surfaces 700 being compressed between an exterior sidewall of the die and an interior wall of the die holder.

Other methods involve using an anti-vibration die holder in the process of performing punching operations on a fabricating press. FIG. 59 is a flowchart depicting certain method embodiments wherein a fabricating press is equipped with at least one active die holder and at least one inactive die holder (reference is also made to FIGS. 30 and 31). As will be readily understood by skilled artisans, each active die holder is at a punching location, and each inactive die holder is at a non-punching location. In the present methods, the inactive die holder has an interior recess bounded by at least one interior wall, and a die is mounted operatively in this interior recess. Here, the inactive die holder has an anti-vibration system comprising at least one resilient surface 700 engaged with the die. The present method involves operating the fabricating press to perform a plurality of strokes adjacent to (e.g., at) the active die holder. Preferably, the construction of the inactive die holder and its anti-vibration system are such that during the plurality of strokes the die in the inactive die holder experiences no more than 0.032 inch of upward die displacement relative to the inactive die holder. More preferably, the upward die displacement is no more than 0.03 inch, no more than 0.02 inch, or no more than 0.01 inch. For embodiments like that exemplified in FIGS. 45-47, the upward displacement is no more than 0.005 inch relative to the inactive die holder after 10,000 strokes at the active die holder. Thus, in some cases, the method involves performing at least 10,000 strokes of the fabricating press at the punching location(s). In such cases, the construction of the inactive die holder and its anti-vibration system preferably allow no more than 0.032 inch (more preferably no more than 0.03 inch, no more than 0.02 inch, no more than 0.01 inch, or perhaps optimally from 0.000 to no more than about 0.005 inch) of upward die displacement relative to the inactive die holder after 10,000 punch strokes of the fabricating press at the active die holder(s). In some of the present methods, the/each resilient surface is defined by material that has a Shore A durometer of between about 20 and about 95 and that bears against the die during the plurality of strokes so as to dampen vibrations. Additionally or alternatively, the present die holder can advantageously be devoid of set screws adapted to rigidly engage the die during a clamping operation, such that during the plurality of strokes the die is not engaged by any set screw.

While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.





 
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