Rock drill
US4296825A · kind A · utility
15Cited by
15References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 4, 1979 |
| Grant date | Oct 27, 1981 |
| Priority date | — |
| Expiry date | Oct 4, 1999 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/56
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rock drill for percussion drilling comprising a central button insert and a row of outer button inserts. The central button insert extends beyond the outer inserts. For purposes of increasing the drilling rate and the life of the rock drill the ratios of respectively this extent (X) to the diameter (D) of the hole; X:D, and the transverse distance (Y) between the central insert and one of the outer inserts and the diameter (D); Y:D, shall be within predetermined limits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.