Percussive drilling apparatus
US6164392A · kind A · utility
4Cited by
5References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1999 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Apr 26, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/0426
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A percussive drill for extension drilling includes a drill bit, a tube having a male screw thread attached to a female screw thread of the drill bit, and a rod having a male screw thread attached to a female screw thread of the tube. Central passages of the rod and tube are aligned with one another to conduct flushing fluid to the drill bit. The drill bit drills a hole whose diameter is from 60-170 mm and at least twice the outer diameter of the rod. A total area of a cross-sectional surface of the tube is within 100-125% of a total area of a cross sectional surface of the rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.