Rock drill
AssigneeSandvik Tamrock Oy
InventorTimo Muuttonen
Life of this patent
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Abstract
A rock drill includes a shank. A percussion piston is arranged to hit the back end of the shank. Further, a pulling element is arranged around the shank, to which a pulling force can be directed in such a manner that the shank can, by the pulling force, be moved toward the percussion piston, when stuck drilling equipment is freed. During rock drilling, a push force is arranged to act on the pulling element, the push force being opposite with respect to the pulling force. The push force is designed in such a manner that during drilling the pulling element moves due to the push force toward the front section of the drill to be at a predefined distance from the position corresponding to the impact point of the shank.
Claims10
A rock drill comprising:
- a frame;
- a shank that is arranged in the front section of the drill and that is axially movable;
- a percussion device having a reciprocating percussion piston on the same axis with the shank and arranged to hit the back end of the shank to provide impact pulses in drilling equipment to be fastened to the shank, the percussion piston having an absorber to absorb the percussion piston impacts that extend to the front side of a designed impact point;
- a pulling element that is a sleeve-like piece arranged around the shank, the drill having means for exerting a pulling force to the pulling element and for moving the pulling element by a pulling force axially toward the percussion piston, the pulling element further having a first bearing surface that is arranged to act on a second bearing surface on the shank to move the shank by said pulling force to the designed impact point, and wherein:
- during rock drilling, a push force is arranged to act on the pulling element, the push force being stronger than the pulling force exerted to the pulling element during drilling;
- and
- during rock drilling, due to said push force, the pulling element is positioned toward the front section of the drill at a predefined distance from the position corresponding to the impact point of the shank.
Dependencies are inferred from the claim text.