Drill tool
US4440244A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1981 |
| Grant date | Apr 3, 1984 |
| Priority date | — |
| Expiry date | Feb 25, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/66
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drill tool for rotary and/or percussion drilling with drill rod means (14) within casing tube means (15) comprises a centric cutting bit (11) and an eccentric reamer cutter (12), both provided with hard metal inserts. For purposes of obtaining a life of the drill tool as long as possible the first frontal insert (23) on the reamer cutter (12) is positioned in front of the first peripheral insert (18) when seen in the rotational direction (D) during drilling, and the centric cutting bit (11) provided with more inserts on the half (38) of its front surface opposed to the reamer cutter (12) during drilling than on the other half (39).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.