Means and method of forming sheet metal
US3934440A · kind A · utility
Inventor
Key dates
| Filing date | Sep 4, 1973 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Sep 4, 1993 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D26/02
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A means of and method of forming sheet metal by use of fluid pressure wherein an initially flat sheet metal work piece is placed on a backing plate with its margins clamped between the plate and a peripheral clamping ring. The clamping ring is clamped against the margin of the work piece by a plurality of fluid operated clamping units. the side of the work piece opposite from the backing plate and within the clamping ring is free to expand or distend without restraint except that provided by the metal comprising the work piece itself. Pressure fluid is introduced between the metal work piece and its backing plate to cause the work piece to distend away from the backing plate. A set of freely movable feeler strips engage the edge of the work piece at spaced points. The feeler strips control sensing units which, in turn, control the pressure exerted by the clamping units so as to permit predetermined slippage of the margin of the work piece with respect to the clamping rings. If the dimensions of the work piece are critical and the undulated zone of the work piece is within the boundaries of the finished product, the work piece is placed on the same or second backing plate so that th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.