Method and device for damping the recoil of a work tool connected to a rock drilling machine
AssigneeAtlas Copco Aktiebolag
InventorsKurt Holger Andersson, Carl Gosta Bernhard Ekwall, Bo Erik Forsberg
Life of this patent
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Abstract
A recoil damping device for a percussive tool comprises a retard piston which is movable in a cushioning chamber. The feeding force and/or the pressure in the supply passage to the cushioning chamber is regulated so that the retard piston is axially free relative to the machine housing.
Claims27
A method for damping the recoil of a work tool comprising:
- applying a feeding force to a percussive tool (10),
- transmitting the feeding force to the work tool (18) over a retard piston member (36), said retard piston member being axially movable in a cushioning chamber,
- continuously supplying said cushioning chamber with pressurized fluid through a passage in the machine housing of the percussive tool, said machine housing being subjected during operation to a rearwardly acting force which includes a force caused by the recoil of the work tool, and
- providing a floating impact position of said retard piston member by regulating at least one of the feeding force and the pressure in said passage relative to said rearwardly acting force so that said retard piston member during operation is maintained out of axial contact with said machine housing.
A method in a percussive rock drilling for damping the recoil of a work tool comprising:
- applying a feeding force to a rock drilling machine (10),
- transmitting the feeding force to the work tool (18) over a retard piston member (36) and a sleeve member (31), said retard piston member being axially movable in a cushioning chamber, and said sleeve member being adapted to non-rotatably engage said work tool,
- supplying said cushioning chamber with pressurized fluid through a passage in the machine housing of the rock drilling machine, said machine housing being subjected during operation to a rearwardly acting force which includes a force caused by the recoil of the work tool, and
- providing a floating impact position of said retard piston member and sleeve member by regulating at least one of the feeding force and the pressure in said passage relative to said rearwardly acting force so that said retard piston member and said sleeve member are maintained out of axial contact with said machine housing.
A recoil damping device for a percussive tool such as rock drilling machines and chiselling machines which includes a work tool (18), a machine housing (10) coupled to said work tool and adapted to apply a feeding force to said work tool in a working direction, a hammer piston (13) reciprocating in the machine housing and adapted to deliver impacts to said work tool, said impacts generating shock wave reflexes in said work tool, said shock wave reflexes causing a recoil force on said machine housing, a guide member (31) adapted to guide said work tool, said recoil damping device damping said recoil force and comprising:
- an annular cushioning chamber (40) in said machine housing, a passage (37) in said machine housing to admit pressure fluid into said cushioning chamber,
- a retard piston member (36) axially movable in said cushioning chamber, and
- isolating means for isolating said retard piston member from the work pressure of said hammer piston rearwardly of said guide member,
- said retard piston member being adapted to damp the recoil force transmitted over said guide member.
A method in percussive working such as rock drilling and chiselling for damping the recoil of a work tool comprising:
- applying a feeding force to a percussive tool (10) in a forward direction,
- transmitting the feeding force to the work tool (18) over a retard piston member (36) and a sleeve-shaped guide member (31) adapted to guide said work tool, said retard piston member being arranged rearwardly of said guide member and being axially movable in a cushioning chamber,
- continuously supplying said cushioning chamber with pressurized fluid through a passage in the machine housing of the percussive tool,
- additionally applying impacts to said work tool by means of a hammer piston, said impacts generating shock wave reflexes in said work tool, said shock wave reflexes causing a recoil force on said machine housing,
- providing a floating impact position of said retard piston member and guide member by regulating at least one of the feeding force and the pressure in said passage relative to said recoil force so that said retard piston member and guide member instantaneously is maintained out of axial contact with said machine housing, and
- bounding said cushioning chamber and isolating said retard piston member from the work pressure of said hammer piston rearwardly of said guide member.
A recoil damping device for a percussive tool such as rock drilling machines and chiselling machines which includes a work tool (18), a machine housing (10) coupled to said work tool and adapted to apply a feeding force to said work tool in a working direction, a hammer piston (13) reciprocating in the machine housing and adapted to deliver impacts to said work tool, said impacts generating shock wave reflexes in said work tool, said shock wave reflexes causing a recoil force on said machine housing, a guide member (31) adapted to guide said work tool, said recoil damping device damping said recoil force and comprising:
- an annular cushioning chamber (40) in said machine housing,
- a passage (37) in said machine housing to admit pressure fluid into said cushioning chamber,
- a retard piston member (36) axially movable in said cushioning chamber and located rearwardly of said guide member, and
- a sleeve-shaped member (16) firmly attached in said machine housing and adapted to radially inwardly bound said cushioning chamber for isolating said retard piston member from the work pressure of said hammer piston rearwardly of said guide member,
- said retard piston member being movably guided relative to said sleeve-shaped member around the outer side thereof and being adapted to damp the recoil force transmitted over said guide member.
Dependencies are inferred from the claim text.