This percussion apparatus includes a striking piston, a control distributor arranged to control a reciprocating movement of the striking piston, and a control device arranged to vary the striking stroke of the striking piston. The control device comprises a plurality of control channels, a control channel connected to the control distributor, a control slide movably mounted between a plurality of control positions, and an adjusting slide mounted in a receiving housing delimited by the control slide, the control slide and the adjusting slide delimiting a first adjusting chamber connected to the control channel and a second adjusting chamber connected to a the high-pressure fluid supply circuit. The control slide is movably mounted between a first position in which the first control chamber and the second adjusting chamber are connected and a second position in which the first control chamber and the second adjusting chamber are isolated.

A hydraulic hammer is disclosed having a piston and an accumulator membrane disposed external and co-axial to the piston. Additionally, a sleeve is disposed between the piston and accumulator membrane, wherein the sleeve has a plurality of radial passages formed therein that fluidly connect the accumulator membrane with the piston.

A hydraulic hammer is disclosed having a piston and an accumulator membrane disposed external and co-axial to the piston. Additionally, a sleeve is disposed between the piston and accumulator membrane, wherein the sleeve has a plurality of radial passages formed therein that fluidly connect the accumulator membrane with the piston.

A hydraulic hammer includes a housing defining a cutout and a power cell slidably received within the housing. The power cell includes a valve assembly extending from a side of the power cell. The valve assembly is at least partially received within the cutout of the housing. The hydraulic hammer further includes a pair of wear plates at least partially disposed around the valve assembly of the power cell. Each of the pair of wear plates is coupled to at least one of the power cell and the housing.

A hydraulic hammer includes a housing defining a cutout and a power cell slidably received within the housing. The power cell includes a valve assembly extending from a side of the power cell. The valve assembly is at least partially received within the cutout of the housing. The hydraulic hammer further includes a pair of wear plates at least partially disposed around the valve assembly of the power cell. Each of the pair of wear plates is coupled to at least one of the power cell and the housing.

This percussion apparatus includes a striking piston mounted so as to be displaced inside a piston cylinder and arranged to strike a tool; and a guide bearing comprising a guide surface configured to guide the striking piston during the displacements of the striking piston in the piston cylinder. The guide bearing includes a centering device configured to center the striking piston in the piston cylinder, the centering device comprising centering chambers formed in the guide surface and distributed around the striking piston, each centering chamber being fluidly connected to a high pressure fluid supply circuit; and at least one discharge groove formed in the guide surface of the guide bearing and located proximate to at least one of the centering chambers, the at least one discharge groove being fluidly connected to a low pressure circuit.

This percussion apparatus includes a striking piston mounted so as to be displaced inside a piston cylinder and arranged to strike a tool; and a guide bearing comprising a guide surface configured to guide the striking piston during the displacements of the striking piston in the piston cylinder. The guide bearing includes a centering device configured to center the striking piston in the piston cylinder, the centering device comprising centering chambers formed in the guide surface and distributed around the striking piston, each centering chamber being fluidly connected to a high pressure fluid supply circuit; and at least one discharge groove formed in the guide surface of the guide bearing and located proximate to at least one of the centering chambers, the at least one discharge groove being fluidly connected to a low pressure circuit.

A pneumatic tool includes: a drive mechanism which is configured to be driven by compressed air of a first pressure: and a valve mechanism which is configured to be actuated by compressed air of a second pressure, which is higher than an atmospheric pressure and lower than the first pressure, and which is configured to switch whether or not to supply the compressed air of the first pressure to the drive mechanism.

A pneumatic tool includes: a drive mechanism which is configured to be driven by compressed air of a first pressure: and a valve mechanism which is configured to be actuated by compressed air of a second pressure, which is higher than an atmospheric pressure and lower than the first pressure, and which is configured to switch whether or not to supply the compressed air of the first pressure to the drive mechanism.

A hydraulic hammer is provided. The hydraulic hammer includes a fluid inlet configured to receive a pressurized fluid for running the hydraulic hammer and a fluid outlet for discharging hydraulic fluid from the hydraulic hammer. A bypass passage fluidly connects the fluid inlet and the fluid outlet, the bypass passage has a bypass inlet fluidly connected to the fluid inlet and a bypass outlet fluidly connected to the fluid outlet. An automatic shut-off valve is disposed in the bypass passage between the bypass inlet and the bypass outlet and is configured to open or close the bypass passage. The automatic shut-off valve is configured to open the bypass passage under pressure of the pressurized fluid on continuous running of the hydraulic hammer for a set time to stop the hammer.