Impact tool
US4143585A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 5, 1977 |
| Grant date | Mar 13, 1979 |
| Priority date | — |
| Expiry date | Aug 5, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25D2209/005
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An impact tool is described which is capable of developing percussive forces for rock drilling, pile driving, seismic exploration and other repetitive high force applications. The tool contains a hammer and a valve which may be hydraulically actuated so as to oscillate; repetitively executing forward and return strokes during each cycle of oscillation. The valve is actuated in the forward stroke direction by being engaged by the hammer, and in the return stroke direction by fluid pressure means so as to switch the pressure in a cavity in which both the valve and the hammer are disposed for developing forces on the hammer so as to sustain its oscillation. A fluid filled pocket is provided into which the valve enters as it moves in the forward stroke direction, after having switched the pressure in the cavity. A passage is provided on the hammer which is dimensioned so that fluid in the cavity is either connected to a channel, the cavity, or entrapped in the pocket, depending on the position of the hammer. A control valve in the channel determines the flow through the channel, and thus the displacement of the valve into the pocket. The displacement is maintained until communication b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.