EP 0003815 B1 19811014 - DRILL BIT FOR A ROTARY PERCUSSION DRILLING MACHINE
Title (en)
DRILL BIT FOR A ROTARY PERCUSSION DRILLING MACHINE
Publication
Application
Priority
DE 2807197 A 19780220
Abstract (en)
[origin: US4243113A] An exhaust channel in a rock drilling head of a rotary impact drill has an opening which extends over the front face of the drill shaft and over the adjoining peripheral surface of the drill shaft. Clogging of the exhaust channel is prevented by providing clearances between the forward and peripheral surfaces of the drilling head and the bored hole which are too small to permit the passage of rock particles large enough to block the exhaust channel.
IPC 1-7
IPC 8 full level
E21B 10/38 (2006.01); E21B 21/16 (2006.01)
CPC (source: EP US)
E21B 10/38 (2013.01 - EP US); E21B 21/16 (2013.01 - EP US)
Designated contracting state (EPC)
BE CH FR GB NL SE
DOCDB simple family (publication)
EP 0003815 A1 19790905; EP 0003815 B1 19811014; DE 2807197 A1 19790830; US 4243113 A 19810106
DOCDB simple family (application)
EP 79100475 A 19790219; DE 2807197 A 19780220; US 1257579 A 19790215