Means for retaining roller cutters on rotary drill bit
US4911255A · kind A · utility
11Cited by
6References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Mar 27, 1990 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A roller cutter (28) of a drill bit (10) is retained on a journal (24) for rotation by a retainer ring (82) having external screw threads (88) which are threaded onto mating screw threads (108) on the roller cutter (28) for rotation therewith. The retainer ring (82) is mounted within a semicircular groove (68) on the journal (24) and has an inner periphery formed of a smooth arcuate surface contacting the annular groove at a position spaced at least 10.degree. from the entrance opening of the groove thereby to reduce bending stresses exerted against the root (74) of the groove (68).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.