EP 0187971 A3 19870819 - DRILL BIT
Title (en)
DRILL BIT
Publication
Application
Priority
DE 3500202 A 19850105
Abstract (en)
[origin: US4696355A] A drilling tool for percussion drilling machines is proposed which has an increased endurance strength or fatigue strength when used in percussion drilling machines having a high striking speed. For this purpose, the carbide cutting tip (11) is arranged transversely to the flute runout (12, 13) so that the effective moment of resistance area in the area of the groove root (22) of the recessed groove (14) is not weakened by flute runout surfaces.
IPC 1-7
IPC 8 full level
E21B 10/44 (2006.01); E21B 10/58 (2006.01)
CPC (source: EP US)
E21B 10/445 (2013.01 - EP US); E21B 10/58 (2013.01 - EP US); Y10T 407/1924 (2015.01 - EP US); Y10T 408/9097 (2015.01 - EP US)
Citation (search report)
- [X] FR 1118255 A 19560604
- [A] DE 856589 C 19521124 - WALLRAM HARTMETALLWERK, et al
- [A] EP 0048908 A1 19820407 - HAWERA PROBST KG HARTMETALL [DE]
Designated contracting state (EPC)
CH DE FR GB IT LI
DOCDB simple family (publication)
EP 0187971 A2 19860723; EP 0187971 A3 19870819; EP 0187971 B1 19910313; DE 3500202 A1 19860710; DE 3582147 D1 19910418; US 4696355 A 19870929
DOCDB simple family (application)
EP 85115973 A 19851214; DE 3500202 A 19850105; DE 3582147 T 19851214; US 81657786 A 19860106