EP 0402624 B1 19940720 - Rotation-percussion drill bit for a portable drilling machine.
Title (en)
Rotation-percussion drill bit for a portable drilling machine.
Title (de)
Drehschlagbohrer für ein von Hand führbares Bohrgerät.
Title (fr)
Trépan à rotation percussion pour un appareil de forage portatif.
Publication
Application
Priority
DE 3919264 A 19890613
Abstract (en)
[origin: EP0402624A2] Anchored in cylindrical location bores of the drill head (10) are at least two carbide pins (11') which project radially beyond the adjacent circumferential surface (10a) of the drill head (10). The carbide pins (11') have a polygonal cross-sectional profile. They are centred on the inner circumferential surface of their location bore (12) by means of their longitudinal edges (11a). The rotational resistance which the drill bit has to overcome during the drilling work is thereby reduced. At the same time, increased drilling advance can be noted. On the other hand, the risk of the carbide pins (11') fracturing in the wake of the rhythmic axial blows is reduced. <IMAGE>
IPC 1-7
IPC 8 full level
E21B 10/40 (2006.01); E21B 10/44 (2006.01); E21B 10/56 (2006.01)
CPC (source: EP)
E21B 10/40 (2013.01); E21B 10/445 (2013.01); E21B 10/56 (2013.01)
Designated contracting state (EPC)
CH DK FR LI NL
DOCDB simple family (publication)
EP 0402624 A2 19901219; EP 0402624 A3 19910731; EP 0402624 B1 19940720; DE 3919264 A1 19901220; DE 3919264 C2 19970123
DOCDB simple family (application)
EP 90108763 A 19900510; DE 3919264 A 19890613