Drawing device for a press with control device for maintaining pressure during press stoppage
US5979210A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1998 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Mar 18, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D24/14
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A drawing device for a press is provided with a drawing slide, with a sheet holder having a sheet held therein, and with a pressure cheek which is arranged under the sheet holder and is connected with a piston rod which can be displaced in parallel to the drawing direction. The piston rod is operatively connected with a preacceleration piston of a preacceleration cylinder. The drawing cylinders are applied to the pressure cheek by way of drawing rods, in which case the drawing cylinders have drawing pistons with first and second piston spaces. The first piston space directed to the drawing rod is pressure controlled during the drawing operation for the sheet forming. In the event of a press stoppage during a sheet forming, a control valve device can be activated so that, for maintaining the pressure existing in the first piston space at the start of the press stoppage during the time of the press stoppage, pressure medium can be charged into the first piston space by way of a pressure medium generator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.