Reduced-impact sliding pressure control valve for pneumatic hammer drill
US8176995B1 · kind B1 · utility
1Cited by
8References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2009 |
| Grant date | May 15, 2012 |
| Priority date | — |
| Expiry date | Jan 16, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7834
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and means of minimizing the effect of elastic valve recoil in impact applications, such as percussive drilling, where sliding spool valves used inside the percussive device are subject to poor positioning control due to elastic recoil effects experienced when the valve impacts a stroke limiting surface. The improved valve design reduces the reflected velocity of the valve by using either an energy damping material, or a valve assembly with internal damping built-in, to dissipate the compression stress wave produced during impact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.