Drag bit and cutters
US4593777A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1984 |
| Grant date | Jun 10, 1986 |
| Priority date | — |
| Expiry date | Feb 8, 2004 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/567
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drill bit comprises a bit body having an operating end face. A plurality of self-sharpening cutters are mounted in the bit body and extend through the operating end face. The cutters have cutting faces adapted to engage an earth formation and cut the earth formation to a desired three-dimensional profile. The cutting faces define surfaces have back rake angles which decrease with distance from the profile. The individual cutting faces may be inwardly concave in a plane parallel to the intended direction of motion of the cutter in use. Each of the cutting members has a stud portion disposed in a respective recess in the bit body and defining the inner end of the cutting member, the cutting face being generally adjacent the outer end and having an outer cutting edge. The centerline of the stud portion is rearwardly inclined, from the outer end to the inner end, with respect to the direction of movement in use, taken at the midpoint of the cutting edge, at a first angle from 80.degree. to 30.degree. inclusive. The cutting face is oriented such that the tangent to the cutting face at the midpoint of the cutting edge and in the center plane of the cutting member is disposed at a secon…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.