The rotary percussive hydraulic perforator comprises a body; a fitting; a striking piston configured to strike the fitting; a stop piston including a front face facing the fitting and a rear face situated opposite to a rear wall of a cavity receiving the piston stop; and a main hydraulic supply circuit including a high pressure fluid supply conduit and a low pressure fluid return conduit. The body and the stop piston delimit a first control chamber permanently connected to the high pressure fluid supply conduit and configured to bias the stop piston forwards, and a second control chamber configured to bias the stop piston forwards and permanently connected to a low pressure accumulator connected to the low pressure fluid return conduit.

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.

Provided is a two-piston hydraulic striking device that has stable operatively. 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.

A hydraulic percussion device comprising a piston mounted for reciprocal motion within a cylinder to impact a percussion bit and a control valve to control reciprocation of the piston. A valve pilot line is arranged to switch the control valve based on the position of the piston within the cylinder, wherein the valve pilot line is alternately connected, by the reciprocal movement of the piston, to high and low pressure lines (P, T) via an undercut in the piston. The undercut is located at a portion of the piston having a diameter less than the maximum sealing diameter of the piston.

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.

An apparatus including an accumulator and a drive mechanism. The accumulator includes an energy storage apparatus with a first piston face configured to reversibly compress an energy storage medium and a second piston face forming at least part of an inner surface of a corresponding second fluid chamber reversibly expandable by movement of the second piston face. A third piston face forms at least part of an inner surface of a corresponding third fluid chamber reversibly expandable by the third piston face. The first, second and third piston faces are coupled together.

A hydraulic hammer for a machine is provided. The hydraulic hammer includes a housing and a piston disposed within the housing and adapted to reciprocate along a longitudinal axis of the housing. The hydraulic hammer further includes a first chamber and a second chamber defined within the housing. The hydraulic hammer further includes a primary passage extending from an inlet and branching into a first passage and a second passage. The first passage fluidly communicates the primary passage with the first chamber and the second passage fluidly communicates the primary passage with the second chamber. The hydraulic hammer further includes a flow control device coupled to the first passage. The flow control device includes a valve element adapted to move between a first position and a second position based on an input signal indicative of a pressure of charge in the first chamber.

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.

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 hammer including a housing and a piston arranged for reciprocating movement within the housing is disclosed. The hammer further includes a head assembled on the housing and defining a chamber for holding a pressurized gas and a wall configured to abut the housing and defining a gas discharge passage extending between the chamber and the housing. A plug is positioned in the gas discharge passage and configured to move or deform under pressure of the pressurized gas in the chamber.