EP 0543806 B1 19960117 - HYDRAULIC DOWN-THE-HOLE ROCK DRILL
Title (en)
HYDRAULIC DOWN-THE-HOLE ROCK DRILL
Title (de)
GESTEINSBOHRGERÄT MIT HYDRAULISCHEM ANTRIEB IM BOHRLOCH
Title (fr)
PERFORATRICE HYDRAULIQUE A ROCHE POUR LE FOND DU TROU
Publication
Application
Priority
SE 9000490 W 19900712
Abstract (en)
[origin: WO9201138A1] A hydraulic down-the-hole rock drill is adapted to be driven by pressure water. The spent drive fluid is utilised as a flushing medium to flush the debris out of the borehole. The piston hammer (20) is guided at its front and rear ends and a continuously pressurized chamber (28) extends around the piston hammer all the way between the two guiding portions (22, 27). The front guiding portion (22) has a smaller diameter than the rear guiding portion (27) so that the piston hammer will have a differential piston area in the chamber (28). Thus, the pressure in the chamber (28) will provide a continuous force backwards on the piston hammer and cause the return stroke of the piston hammer when a valve controlled cylinder chamber (34) at the rear end of the piston hammer is depressurized.
IPC 1-7
IPC 8 full level
B25D 9/12 (2006.01); B25D 9/16 (2006.01); E21B 4/14 (2006.01)
CPC (source: EP)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB IT LI LU NL SE
DOCDB simple family (publication)
WO 9201138 A1 19920123; AT E133233 T1 19960215; DE 69024978 D1 19960229; DE 69024978 T2 19961212; DK 0543806 T3 19960506; EP 0543806 A1 19930602; EP 0543806 B1 19960117; ES 2084033 T3 19960501
DOCDB simple family (application)
SE 9000490 W 19900712; AT 90911460 T 19900712; DE 69024978 T 19900712; DK 90911460 T 19900712; EP 90911460 A 19900712; ES 90911460 T 19900712