A percussion apparatus including a pressure regulating device comprising a regulating cylinder; a connecting channel opening into the regulating cylinder; a pressure regulating slide mounted movable in translation within the regulating cylinder and delimiting, with the regulating cylinder, a connecting passage having a passage section which varies according to the regulating position occupied by the pressure regulating slide; a biasing element configured to exert a prestress on the pressure regulating slide; and a prestress setting device configured to set a prestress exerted by the biasing element on the pressure regulating slide.

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.

Disclosed is a fluid driven pulsating, hammering tool operational when pressurized fluid is pumped into the tool's upper sub, having a poppet valve which can seal the upper end of a slidable outer valve assembly when closed; an inner valve assembly slidable within the outer valve assembly; wherein the inner and outer valve assemblies remain in selective fluid communication with the poppet valve even when the poppet valve is closed, wherein interruption of said fluid communication occurs from movement of the inner and/or outer valve assemblies to particular positions along their sliding paths; and further including a lower valve which is preferably a Tesla valve having channels which are also in fluid communication with the poppet valve.

Provided is a two-piston hydraulic striking device that has stable operativity. This two-piston hydraulic striking device includes two striking mechanisms for striking one transfer member. Each striking mechanism has a pressure receiving area ratio between the front and rear of a piston thereof set in such a way that the two striking mechanisms have the same cycle time.

Provided is a hydraulic striking device in which a reverse operation circuit and a forward operation circuit can switch connection states to a high pressure circuit and a low pressure circuit by means of an operation switching valve. Further, the hydraulic striking device is configured to be selectable between a reverse operation mode or a forward operation mode by operating the operation switching valve. A high/low pressure switching portion is provided with a shortening portion for reducing the time required for high/low pressure switching operation in piston front and rear chambers in association with retraction of a valve to be shorter than the time required for high/low pressure switching operation in the piston front and rear chambers in association with advancement of the valve.

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.

An impact tool includes a housing having a handle portion defining a first axis, a motor supported by the housing and defining a motor axis, and a rotary impact mechanism arranged on a second axis that is perpendicular to the first axis. The rotary impact mechanism is configured to convert a continuous rotational input from the motor to consecutive rotational impacts upon a workpiece. The rotary impact mechanism includes a chamber containing a hydraulic fluid, an anvil positioned at least partially within the chamber, and a hammer for imparting the consecutive rotational impacts upon the anvil. The hydraulic fluid is configured to attenuate a noise of the rotary impact mechanism that is created by the hammer impacting the anvil. The impact tool further includes a gear train that receives torque from the motor and includes a rotational input that transfers torque to the rotary impact mechanism.

A power tool including an impact tool, a body and an actuator. The actuator is operable to move the body along an operational axis from an impact position, at which the body is operable to transfer impact energy to a head end of the impact tool, to a retracted position spaced apart from the impact position along the operational axis.

A method of retaining a hammer tool in the front head of a powercell assembly of a hammer assembly includes biasing a hammer tool retaining pin such that a portion of the tool retaining pin extends into a tool receiving bore of the front head of the powercell assembly, holding a hammer tool in the tool receiving bore of the front head of the powercell assembly via the tool retaining pin, and releasing the hammer tool remotely from the hammer assembly.

The percussion apparatus includes a striking piston and a piloting device configured to make a striking stroke of the striking piston vary, the piloting device comprising a piloting cylinder, a piloting slide mounted movable in translation within the piloting cylinder according to a direction of displacement and mounted movable in rotation within the piloting cylinder, and a main piloting chamber delimited by the piloting slide and the piloting cylinder. The percussion apparatus further includes a setting device configured to set a range of variation of the striking stroke of the striking piston, the setting device including a setting member configured to set the angular position of the piloting slide in the piloting cylinder, and at least one fluidic communication passage formed on the piloting slide and configured to hydraulically limit the translational displacement stroke of the piloting slide according to the direction of displacement according to the angular position occupied by the piloting slide.