Hydraulic control system for a rock drill
US4440236A · kind A · utility
9Cited by
6References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 5, 1983 |
| Grant date | Apr 3, 1984 |
| Priority date | — |
| Expiry date | May 5, 2003 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B44/06
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A rock drill having a hydraulic system for controlling striking, rotating and advancing movements of a drilling rod. The advancing or forward feeding conduit for a feed actuator is provided with a relief valve which is responsive to the pressure in the positive rotating conduit for a rotary actuator so that the pressure in the forward feeding conduit is relieved to weaken the advancing force when the load on the rotary actuator is increased. A further relief valve is also provided for relieving the pressure in the striker conduit to weaken the striking force.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.