Apparatus for stripping a drawn article from a punch
US5542277A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 10, 1995 |
| Grant date | Aug 6, 1996 |
| Priority date | — |
| Expiry date | Jan 10, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D45/06
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In a press comprising at least one die (3), a hollow punch (1) and ram (2) assembly movable through the die, and a bottom forming tool (13) having a convex surface portion (14) axially aligned with the punch, said punch and ram assembly having a valve seat (24) in the ram hollow and a valve member (21) which has a valve body engageable with the valve seat and a stem extending through the valve seat towards the free end of the punch so that as the punch approaches the convex surface portion of the bottom forming took, the valve member is lifted off the valve seat to permit compressed air to pass from the punch hollow, the valve stem is supported in a bearing between the valve seat and the extremity of the punch, and said valve stem and interior surface of the punch define a cavity of prechosen volume between the valve seat (24) and extremity of the punch (1) so that as the punch approaches the bottom forming tool (5) cooperation of the convex surface portion (14) of the bottom forming tool and valve stem (20) lifts the valve body of the valve seat to permit compressed air to fill the cavity with a prechosen volume of compressed air before inertia forces close the valve again on the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.