Method of and apparatus for fabricating spiral wrapped cartridge cases
US4183124A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1977 |
| Grant date | Jan 15, 1980 |
| Priority date | — |
| Expiry date | Nov 21, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D51/54
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Method of and apparatus for fabricating spiral wrapped cartridge cases or the like, in which an expandable bladder positioned within the interior of the cartridge case is initially expanded by application of hydraulic fluid at relatively low hydraulic pressure levels and at relatively high flow rates until the bladder substantially fills the cartridge case and then is pressurized at relatively high hydraulic pressure levels to form the cartridge case within a die cavity. Hydraulic pressure is applied to the bladder by a hydraulic pressure generator which is powered solely by the closure of the platens of a conventional industrial press between which the die and the pressure generator are mounted. The pressure generator shifts automatically from its low pressure to its high pressure mode of operation as the press platens close.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.