Rotary drill bit shank, rotary drill bits so equipped, and methods of manufacture
US7472764B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2005 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Feb 11, 2026 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/42
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.