Rotary drill bits
US5649604A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1995 |
| Grant date | Jul 22, 1997 |
| Priority date | — |
| Expiry date | Oct 3, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/5673
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary drill bit comprises a bit body having a shank for connection to a drill string, a plurality of cutters mounted on the bit body, each cutter having a cutting face, and means for supplying drilling fluid to the surface of the bit body to cool and clean the cutters. At least some of the cutters are lateral cutters located to act sideways on the formation being drilled, and the cutting faces of such lateral cutters are orientated to exhibit negative side rake and negative top rake with respect to the surface of the formation. The negative side rake angle is greater than 20.degree. and may be as much as 90.degree., and the negative top rake angle is also more than 20.degree.. A single cutter may include two cutting faces at different negative side rake angles, e.g. the cutter may comprise a generally cylindrical substrate formed at one end with two oppositely inclined surfaces meeting along a ridge, a facing table of polycrystalline diamond being bonded to the substrate surfaces and extending over the ridge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.