EP 0032428 A1 19810722 - Rotary drill bits.
Title (en)
Rotary drill bits.
Title (de)
Drehbohrmeissel.
Title (fr)
Trépan pour forage rotary.
Publication
Application
Priority
GB 8000606 A 19800110
Abstract (en)
In a rotary drilling bit having preform cutting elements, a partial or total structural discontinuity is disposed between the elements and the underlying structure or within the underlying structure to reduce the bending strain upon the preform cutting elements. In this way there is a reduction in the fracture or damage of preform cutting elements.
IPC 1-7
IPC 8 full level
E21B 10/56 (2006.01); E21B 10/573 (2006.01); E21B 10/62 (2006.01)
CPC (source: EP)
E21B 10/573 (2013.01); E21B 10/62 (2013.01)
Citation (search report)
US 4168923 A 19790925 - VEZIRIAN EDWARD
Designated contracting state (EPC)
BE CH DE FR GB LI NL SE
DOCDB simple family (publication)
EP 0032428 A1 19810722; EP 0032428 B1 19860827; AU 547017 B2 19851003; AU 6618681 A 19810716; DE 3175194 D1 19861002
DOCDB simple family (application)
EP 81300062 A 19810108; AU 6618681 A 19810113; DE 3175194 T 19810108