Damping device for a percussion device of a hydraulic rock drilling machine (1) with a striking direction (R), including a damping piston (5) for action in an axial direction against a tool, wherein the damping piston (5) exhibits a first piston portion (6), which is received in a first damping chamber (7) and a second piston portion (8), which is received in a second damping chamber (9). In operation, in a normal striking position of said percussion device, the damping piston (5) is set against a fixed stop (19) against movements in the striking direction. A damping slot (10) is established between the first (7) and the second (9) damping chamber in all axial positions of the damping pistons, and the first damping chamber (7) is pressurized with a hydraulic pressure. The invention also concerns a percussion device and a rock drilling machine.

The handheld power tool has a tool receptacle for accommodating a tool on a working axis (11) and an electric motor (5). A pneumatic percussion mechanism (6) has an exciter, which is moved back-and-forth by the motor (5) periodically in parallel to the working axis (11), a striker (14), which is movable on the working axis (11) and is coupled via a pneumatic spring (18) to the exciter, and an anvil (19), which is situated movably on the working axis (11) and is situated downstream from the striker (14) in the percussion direction (12). The anvil (19) has a cylindrical anvil section (22) having a diameter and multiple channels (30) extending over the entire length (31) of the anvil section (22). A cross-sectional area of the anvil section (22) is at most 5% less than a circular area defined by the diameter.

A hydraulic hammering device is capable of sufficiently transmitting blow energy to bedrock while further strengthening cushioning action and suppressing damage to equipment. The device includes a pushing piston disposed behind a transmission member and having a smaller propulsive force than that of a main body, a damping piston positioned behind the pushing piston to slide reciprocally forwards and backwards and having a greater propulsive force than that of the main body, a direction-restrictor in a high-pressure circuit between pushing and damping chambers, to which hydraulic fluid is supplied for providing the pistons with propulsive forces, and a fluid supply source. The direction-restrictor restricts an outflow from the chambers side to the fluid supply source side while allowing fluid inflow from the fluid supply source side to the chambers and the pushing chamber sides. A throttle in a drain circuit discharges leaked fluid from a sliding contact location to a tank.

A cushion device is used for a cylinder of a pneumatic tool, and the pneumatic tool contains: a body, a cylinder, a valve unit, a piston member, a cushion washer, and at least one spring. The body includes a grip and a fitting sleeve having a chamber, a closing element, and an opening. The cylinder is fitted in the chamber and includes a room and an abutting portion. The valve unit is mounted between the room and the abutting portion. The piston member is accommodated in the room and slides along a movement axis. The cushion washer and the at least one spring are mounted in the chamber, and the cushion washer abuts against the closing element and the pressing face. The cushion washer includes at least one open segment which has at least one air groove each having a mouth parallel to the movement axis.

A method of regulating the disassembly of a component from a powered tool assembly that uses a pressurized fluid and a locking member that is in operative association or communication with the fluid is provided. The method comprises biasing the locking member into a locked configuration using the pressurized fluid, preventing movement of the component in a first predetermined direction.

A hydraulic hammer includes: a cylinder having a first cylinder end and a second cylinder end opposite the first cylinder end; a piston disposed within the cylinder, the piston having a first piston end, the piston being reciprocatingly movable with respect to the cylinder along an axial direction; a valve body disposed on the first cylinder end so as to define a valve body cavity; and a seal carrier sealingly arranged between the first piston end and the first cylinder end and being reciprocatingly movable with respect to the cylinder along the axial direction. The piston is reciprocatingly movable with respect to the seal carrier along the axial direction.

Rock drilling machine (10) comprising a piston that is arranged to move back and forth in a chamber (12a, 12b) when the rock drilling machine (10) is in use, a cavitation-sensitive component (14), and an oil channel that is arranged to extend between the chamber (12a, 12b) and said cavitation-sensitive component (14). The oil channel comprises a series of restrictions (18) and oil volumes (20) to hinder the movement of cavitation bubbles through said oil channel.

The invention concerns a rock breaking device comprising a striking cell having at least one actuation chamber, a striking piston, and a hydraulic circuit comprising a hydraulic supply source having a High Pressure circuit and a Low Pressure circuit, and an actuator configured to connect the High Pressure circuit or the Low Pressure circuit to the actuation chamber so as to move the piston in translation in the striking cell in a normal movement area of which the limits are variable depending on the pressure difference between the High Pressure circuit and the Low Pressure circuit, the striking cell comprising depressurizing means configured to control the establishment of hydraulic communication between the High Pressure circuit and the Low Pressure circuit when the striking piston exits a predefined movement area.

The invention relates to a hydraulic percussion device intended to be fitted on a base vehicle, the device comprising: a housing comprising a closing plate; a power cell mounted in the housing; and a damper connecting the power cell and the closing plate, the damper comprising a body rigidly connected to the power cell opposite the closing plate; a chamber provided inside the body; and a closing piston which is movable inside the chamber and capable of abutting against the closing plate in order to seal the chamber, the chamber being intended to contain a compressible fluid for damping the movements of the power cell in relation to the housing.

Systems and methods for reducing vibration in power tool. One system includes a power tool that includes a housing and a motor. The power tool further includes a magnetically susceptible fluid located within the housing. The power tool further includes an inductor configured to introduce a magnetic field to the magnetically susceptible fluid. The power tool further includes a sensor configured to indicate an amount of vibration experienced by the power tool. The power tool further includes an electronic processor coupled to the sensor and to the inductor. The electronic processor is configured to receive a user-selected sensitivity level for vibration control, to receive an input signal from the sensor indicating the amount of vibration, to generate a control signal based on the input signal, and to provide the control signal to the inductor to control the magnetic field.