Automatic shut-off valve for power tools
US4243111A · kind A · utility
14Cited by
9References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1979 |
| Grant date | Jan 6, 1981 |
| Priority date | — |
| Expiry date | Jan 31, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/145
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A fluid-actuated shut-off valve for a fluid-powered tool such as a wrench including a spool valve urged to open position by a spring and having respective valve-operating surfaces subject to both regulated inlet and exhaust pressures in the tool. The valve operating surfaces and spring are arranged so the valve is thrown to its closed position by a combination of a constant regulated control pressure and the drop in exhaust pressure as the tool motor slows down and stalls under load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.