Drill boom with hydraulic parallel motion means
US4158393A · kind A · utility
3Cited by
1References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1977 |
| Grant date | Jun 19, 1979 |
| Priority date | — |
| Expiry date | Jul 25, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/022
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In a drill boom pivotally supporting a rock drilling apparatus, hydraulic parallel motion means is provided which includes a hydraulic pilot cylinder for sensing the setting of the elevation angle of the drill boom. During elevating of the drill boom the hydraulic pilot cylinder is furthermore used as an additional elevating cylinder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.