Rotary drill bit
US4640374A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 3, 1985 |
| Grant date | Feb 3, 1987 |
| Priority date | — |
| Expiry date | Sep 3, 2005 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary drill bit includes a cutting face having a peripheral edge and a central recess. A plurality of fluid discharge nozzles are mounted in bores in the cutting face. A plurality of cutter elements are mounted in the peripheral edge and in the recess to fracture an earthen core formed as the drill cuts through a formation. A plurality of lateral discharge passages extend radially through the bit body from said recess and extend longitudinally to the peripheral edge to form circumferential interruptions in the peripheral edge. Each passage includes leading and trailing edges at the cutting face. A convex protrusion is disposed centrally at a longitudinally inner end of the recess and includes a convex deflecting surface arranged to contact and fracture the earthen core and deflect the cuttings to the lateral discharge passages. The outer periphery of the cutting face is radially recessed to accommodate the flow of drilling fluid. The cutting face includes a groove extending from one side of the outer end of each nozzle bore and terminating at the nearest one of the trailing edges to conduct debris from the bore to the nearest discharge passage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.