Rock drill
US4540200A · kind A · utility
5Cited by
13References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 17, 1982 |
| Grant date | Sep 10, 1985 |
| Priority date | — |
| Expiry date | Sep 17, 2002 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16D1/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drilling assembly for use in percussion drilling comprising a drill bit and a drill rod having cooperating conical surfaces, one of said surfaces being provided with a helically extending thread. For purposes of ensuring a reliable connection the thread meets certain geometrical demands and is designed as a left hand thread. Further, the conical surface being provided with the thread is harder than the other conical surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.