Mobile drilling apparatus
US4703812A · kind A · utility
12Cited by
5References
12Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 25, 1983 |
| Grant date | Nov 3, 1987 |
| Priority date | — |
| Expiry date | Oct 25, 2003 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A mobile drilling apparatus having a support structure, a mast positioned on the support structure, a drill head and a hydraulic assembly vertically operable on and guided by the mast. The hydraulic assembly moves the drill head and includes lower hydraulic cylinders rigidly connected to the mast and upper cylinders, each mounted inside and connected rigidly to a tube. A piston rod with connected upper and lower pistons is movable within the upper and lower hydraulic cylinders. The drill head is connected to the lower portion of the tube.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.