Drill bit
US7849939B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2008 |
| Grant date | Dec 14, 2010 |
| Priority date | — |
| Expiry date | Aug 7, 2028 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/1092
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention recites a drill bit comprising a main body having an axis about which it is rotated in use, a cutting face, a connecting means for attaching the bit to a source of rotary motion, a gauge region intermediate said cutting face and the connecting means. Additionally the gauge region comprises at least one member movable between a first position in which the gauge region is bounded by an imaginary tubular surface of constant cross-section co-axial to the axis of rotation and a second position in which a portion of the member is located radially inwards, with respect to the axis of rotation, of its position when said member is in said first position. In accordance with the present invention, the gauge region whilst said member is in said second position being bound by an imaginary three dimensional conical sectional surface; and at least one actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.