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A method and apparatus for forming cup-shaped members used in conjunction with a single-acting or a double-acting press having an outer punch assembly, an inner punch assembly and a base. A draw pad and a cutting edge are carried on the outer punch assembly, a draw horn is carried on the inner punch

A method and apparatus for forming cup-shaped members used in conjunction with a single-acting or a double-acting press having an outer punch assembly, an inner punch assembly and a base. A draw pad and a cutting edge are carried on the outer punch assembly, a draw horn is carried on the inner punch assembly and a blank and draw die is carried on the base. The draw pad and the draw horn oppose the blank and draw die such that the draw pad clampingly engages the blank and draw die in order to exert a clamping pressure on the pressure piston system having first and second pistons vertically stacked with respect to one another. The pressure piston system includes a damping member located within the pressure piston system for continuously increasing the clamping pressure during advancement of the outer punch assembly toward the base of the press.

대표청구항 ▼

What is claimed is: 1. A cup-shaped member forming apparatus for use in a single acting press or a double-acting press having an outer punch assembly, an inner punch assembly and a base, comprising: a) a draw pad and a cutting edge carried on said outer punch assembly; a draw horn carried on said i

What is claimed is: 1. A cup-shaped member forming apparatus for use in a single acting press or a double-acting press having an outer punch assembly, an inner punch assembly and a base, comprising: a) a draw pad and a cutting edge carried on said outer punch assembly; a draw horn carried on said inner punch assembly; a blank and draw die carried on said base, said blank and draw die generally opposing said draw pad and said draw horn, said cutting edge configured to engage a sheet material disposed between said draw pad and said blank and draw die for cutting a disk from said sheet material, said draw pad configured to engage said disk and said blank and draw die for exerting a clamping force on said disk and said blank and draw die during operation of said press; and b) a pressure piston system carried by said outer punch assembly, said pressure piston system being operatively connected to a pneumatic air supply and including at least a first piston and a second piston, said first and second pistons being vertically stacked with respect to one another, said first piston being operatively mounted on a first cylinder and said second piston being operatively mounted on a second cylinder, said pressure piston system further including a damping member, said first piston operatively engaged with said draw pad such that when said outer punch assembly is advanced toward said base said clamping force of said draw pad on said disk and said blank and draw die is continuously increased. 2. The apparatus of claim 1, said damping member being disposed between said first piston and said second piston. 3. The apparatus of claim 1, said damping member having a stiffness rating of between about 55 A and 95 A Durometer. 4. The apparatus of claim 1, said damping member is formed from urethane. 5. The apparatus of claim 1, whereby said damping member being compressed about 0.010 to about 0.015 inches is capable of directing a force on said second piston equivalent to or greater than a force of the second piston on the damping member during operation of said press. 6. The apparatus of claim 1, said pressure piston system further comprising a third piston, said third piston mounted on a third cylinder and disposed in a stacked relationship above said second piston, said second and third pistons having a second damping member disposed therebetween for continuously increasing said clamping force during operation of the press. 7. The apparatus of claim 1, wherein said damping member further comprises a plurality of button-shaped inserts spaced apart and imbedded into a top surface of said first piston. 8. The apparatus of claim 1, wherein said damping member is ring-shaped and imbedded within a top surface of said first piston. 9. The apparatus of claim 1, wherein said damping member is ring-shaped and disposed on a top surface of said first piston. 10. The apparatus of claim 1, said damping member having a stiffness rating of between about 55 A and 95 A Durometer. 11. A method of forming a cup-shaped member from a metal sheet in a single-acting or a double-acting press having an inner punch assembly, an outer punch assembly, and a base, comprising the steps of: a) providing a draw pad and a cut edge carried on said outer punch assembly; b) providing a draw horn carried on said inner punch assembly; c) placing a sheet material between a blank and draw die mounted on said base of said press and said draw pad, said cut edge, and said draw horn; d) advancing said cut edge and said draw pad toward said sheet material and said blank and draw die by moving said outer punch assembly toward said base; e) blanking a disk from said metal sheet by advancing said cut edge; f) providing a pressure piston system including a first and a second piston, said first piston engaged with said second piston and with said draw pad, said pressure piston system further including a damping member, said pistons operatively connected to a pneumatic air supply; g) applying a continuously increasing clamping pressure on said metal sheet by advancing said outer punch assembly and the pistons toward said base; and h) drawing the cup-shaped member from said disk by advancing said draw horn toward said base. 12. The method of claim 11, wherein said damping member is disposed between said first piston and said second piston. 13. The method of claim 11, wherein a pneumatic pressure applied to each piston is about 2,000 pounds. 14. The method of claim 11, wherein said damping member is formed from urethane. 15. The method of claim 11, wherein said damping member has a cross-sectional height of about 0.125 to 0.50 inches. 16. The method of claim 11, whereby said damping member being compressed about 0.010 to about 0.015 inches is capable of directing a force on said second piston equivalent to or greater than a force of the second piston on the damping member during operation of said press. 17. The method of claim 11, wherein a third piston is disposed above and in a stacked relationship with said first and second pistons, said third piston connected to said pneumatic air supply, a second damping member being disposed between said third piston and said second piston.