EP 0546725 A1 19930616 - Improvents in or relating to cutting elements for rotary drill bits.
Title (en)
Improvents in or relating to cutting elements for rotary drill bits.
Title (de)
Schneideinsätze für Bohrkronen.
Title (fr)
Eléments de coupe pour trépan.
Publication
Application
Priority
GB 9125558 A 19911130
Abstract (en)
A preform cutting element for a rotary drill bit includes a cutting table (18) of polycrystalline diamond material having a front cutting face, a peripheral surface, and a rear face bonded to a substrate of cemented tungsten carbide. The cutting table includes an outer peripheral portion (20), defining at least a part of the peripheral surface, which is formed of a first form of diamond, for example of larger grain size, which is of greater impact resistance than a second form of diamond forming other portions (19) of the cutting table. This protects the cutting edge of the cutting element against impact damage in use, particularly before a significant wear flat has formed. <IMAGE>
IPC 1-7
IPC 8 full level
E21B 10/52 (2006.01); E21B 10/56 (2006.01); E21B 10/567 (2006.01)
CPC (source: EP)
E21B 10/52 (2013.01); E21B 10/5676 (2013.01)
Citation (search report)
- [X] EP 0453426 A1 19911023 - SANDVIK AB [SE]
- [XP] EP 0462091 A1 19911218 - SANDVIK AB [SE]
- [A] EP 0312281 A2 19890419 - DE BEERS IND DIAMOND [ZA]
- [A] US 4854405 A 19890808 - STROUD DONALD S [US]
- [A] GB 2168404 A 19860618 - ELFGEN GERD
Designated contracting state (EPC)
BE DE FR IE NL
DOCDB simple family (publication)
GB 2261894 A 19930602; GB 2261894 B 19950705; GB 9224750 D0 19930113; DE 69214100 D1 19961031; DE 69214100 T2 19970417; EP 0546725 A1 19930616; EP 0546725 B1 19960925; GB 9125558 D0 19920129; ZA 929178 B 19931004
DOCDB simple family (application)
GB 9224750 A 19921126; DE 69214100 T 19921126; EP 92310836 A 19921126; GB 9125558 A 19911130; ZA 929178 A 19921126