Rock bit insert
US4869329A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1988 |
| Grant date | Sep 26, 1989 |
| Priority date | — |
| Expiry date | Aug 31, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/52
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A new and improved tungsten carbide insert for rock bits is disclosed, in which the inserts are subject to extended vibratory tumbling in order to increase their fracture toughness. More specifically the vibratory finishing or tumbling of the inserts has been increased from a typical time of 30-60 minutes to time periods of at least 90 minutes and preferably a minimum of 225 minutes. A marked improvement in toughness is obtained by this process because the size and distribution of surface flaws of the inserts were greatly reduced, and because the surface hardness of the inserts was increased, thereby resulting in an increase in the stress required to cause fracture, and a consequent increase in resistance to breakage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.