Apparatus and method for cushioning the action of draw dies operating in a stamping press and the like
US6068245A · kind A · utility
Inventor
Key dates
| Filing date | Sep 16, 1998 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Sep 16, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D24/14
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A draw die operable within a straightside press includes a lower die shoe with a lower die; pressurized lift cylinders each having an upwardly extending piston rod and an axial resistance to compression; a generally ring-shaped cushion defining a central hole and a plurality of lock beads extending upwardly in spaced-apart relation surrounding the central hole, wherein the cushion surrounds the punch, is sized and configured to support a blank atop the beads and over the punch for draw forming the blank over the punch, and is supported by the lift cylinders; a plurality of cushion units held by the shoe and each having an upwardly extending piston rod and an axial resistance to compression; an upper die defining a second stamping shape which mates with the first stamping shape; a plurality of hydraulic shock absorbers held by the upper die and having an axial resistance to compression and a piston rod that extends downwardly toward the cushion. A ram mechanism moves the upper die downwardly where the shock absorbers engage the cushion and accelerate it downwardly, depressing the lift cylinders somewhat. Upon further downward movement of the upper die and cushion, the cushion cylind…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.