Percussion apparatus equipped with a pressure regulating device

A percussion apparatus including:

• a body delimiting a piston cylinder,
• a striking piston mounted displaceable in a reciprocating manner inside the piston cylinder, and configured to hit a tool during each operating cycle of the percussion apparatus,
• a first control chamber delimited by the striking piston and the piston cylinder, the first control chamber being permanently connected to a high-pressure fluid supply circuit,
• a second control chamber which is delimited by the striking piston and the piston cylinder, and which is antagonist to the first control chamber,
• a control distributor configured to control a reciprocating movement of the striking piston inside the piston cylinder in a reciprocating manner along a striking stroke and a return stroke, the control distributor being configured to connect the second control chamber in a reciprocating manner to the high-pressure fluid supply circuit and to a low-pressure return circuit, and
• a pressure regulating device configured to regulate an operating pressure of the percussion apparatus to a predetermined value, the pressure regulating device comprising:
• a regulating cylinder,
• a connecting channel opening into the regulating cylinder and configured to be connected to the second control chamber during the return stroke of the striking piston,
• a pressure regulating slide mounted movable in translation within the regulating cylinder in a direction of translation and configured to occupy a plurality of regulating positions shifted from one another in the direction of translation, the pressure regulating slide and the regulating cylinder being configured to delimit a connecting passage having a passage section which varies according to the regulating position occupied by the pressure regulating slide, the connecting passage being configured to fluidly connect the connecting channel to the low-pressure return circuit,
• a biasing element configured to exert a prestress on the pressure regulating slide and to bias the pressure regulating slide to a regulating position in which the passage section of the connecting passage is minimal,
• wherein the pressure regulating device includes a prestress setting device configured to set a prestress exerted by the biasing element on the pressure regulating slide, the prestress setting device including:
• a blanking plug configured to blank off an open end of the regulating cylinder,
• an actuating member disposed in the regulating cylinder and configured to cooperate with the biasing element, the actuating member being displaceable in a direction of displacement substantially parallel to the direction of translation, and
• an setting member mounted movable in rotation relative to the actuating member around an axis of rotation, the setting member including a setting part configured to be accessible from the outside of the percussion apparatus and to be driven in rotation by a user, and a drive part disposed in the regulating cylinder and mechanically connected to the actuating member, the blanking plug including a passage opening configured to make the setting part accessible from the outside of the percussion apparatus,
• the setting member and the actuating member being configured such that a rotation of the setting member about the axis of rotation and in a first direction of rotation causes a displacement of the actuating member towards the pressure regulating slide so as to increase the prestress applied by the biasing element on the pressure regulating slide and such that a rotation of the setting member about the axis of rotation and in a second direction of rotation, opposite to the first direction of rotation, causes a displacement of the actuating member away from the pressure regulating slide so as to reduce the prestress applied by the biasing element on the pressure regulating slide,
• and in that the pressure regulating device includes an indexing mechanism configured to define, for the setting member, a plurality of angular indexing positions in each of which the setting member occupies, relative to the actuating member, a respective angular position which is stable.