Roof drill bit
US4189013A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1978 |
| Grant date | Feb 19, 1980 |
| Priority date | — |
| Expiry date | May 18, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/0465
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A roof drill assembly comprising a roof drill having a drill bit of a cylindrical configuration when used with a specifically designed drive rod and a means for retaining the drill bit within the drive rod enables a better dust removal during drilling and an increased load carrying ability of the shank. The drill bit body has two opposing symetrical lands including a web of uniform width extending across the diameter of the cylinder. The configuration forms a specific point angle, a chisel edge angle and a rake angle. The web contains a refractory metal carbide as a cutting surface and a shank extends from the body to engage a drive rod. The drive rod contains a tubular portion having an outer portion diameter compatible with the drill bit and an inner diameter to provide dust removal. A transition portion contains two channels that communicate from the opposing walls of the transition portion to the inner opening in the tubular drive portion that extends from the tubular portion. The transition portion extends to a drill bit receiving portion which has flat sides and is compatible to receive the insertion of the shank of the drill bit and retain it within the drive rod. A tubular …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.