EP 0161227 A1 19851113 - Hydraulic percussive machine.
Title (en)
Hydraulic percussive machine.
Title (de)
Hydraulisches Schlaggerät.
Title (fr)
Appareil hydraulique de percussion.
Publication
Application
Priority
SE 8402232 A 19840424
Abstract (en)
In a hydraulic percussive rock drill, the bistable distribution valve (31) for controlling the reciprocation of the piston hammer (13) has control chambers (41, 42) which, when pressurized urge the distribution valve to switch over. The control chambers (41, 42) are pressurized through control passages (43, 44; 47, 48) that end in the cylinder for the piston hammer (13). An auxiliary valve (54) controls the control passages (43, 44; 47, 48). As soon as the distribution valve (31) has shifted its position, the one of the control chambers (43, 44; 47, 48) that effected the movement of the distribution valve (31) is drained through the auxiliary valve (54) so that the distribution valve (31) is prepared for the next movement. The rapid operation of the auxiliary valve (54) permits for the selection of very short piston hammer strokes and high impact frequencies.
IPC 1-7
IPC 8 full level
CPC (source: EP)
Citation (search report)
- [A] US 4172411 A 19791030 - MATSUDA MAKOTO [JP], et al
- [A] FR 1007678 A 19520508
- [A] FR 2004864 A1 19691205 - KRUPP GMBH
- [A] US 2517243 A 19500801 - ROSE HOWARD E
- [A] DE 2849292 A1 19790927 - DOBSON PARK IND
Designated contracting state (EPC)
CH DE FR LI
DOCDB simple family (publication)
EP 0161227 A1 19851113; SE 442100 B 19851202; SE 8402232 D0 19840424; SE 8402232 L 19851025
DOCDB simple family (application)
EP 85850135 A 19850422; SE 8402232 A 19840424