Steep angle raise bit
US4186809A · kind A · utility
0Cited by
5References
2Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 6, 1978 |
| Grant date | Feb 5, 1980 |
| Priority date | — |
| Expiry date | Nov 6, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/28
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A raise bit for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations that surround the pilot hole is provided with a cutter arrangement that provides a continuous angle bottom configuration in the range of 134.degree. to 60.degree..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.