A vibration reducing structure of pneumatic hammer includes a handle having a concave room with a bottom wall and an air inlet channel communicating with the concave room. A control valve is disposed in the air inlet channel. A movable inner tube shell is accommodated in an outer tube shell coupled with the concave room and extends a rear end into the concave room. A movable hammer member, an air inlet valve for activating the hammer member and a hole communicating the air inlet channel to the air inlet valve are disposed in the inner tube shell. A sealed air room is formed between the bottom wall and an end wall of the inner tube shell. A communicating channel communicates the air inlet channel to the air room for air with high pressure entering the air room.

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.

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 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.

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.

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.

An impact tool for machining workpieces has an impact mechanism which is arranged in a housing and is suitable for transmitting an oscillating movement to a machining tip arranged in an axial direction, wherein the impact mechanism can be displaced against the housing between a lower stop point and an upper stop point in the axial direction, wherein a device for generating a constant or variable contact pressure of the machining tip is arranged between the housing and the impact mechanism, such that after a prestressing path of the impact mechanism from the lower stop point, the machining tip is additionally subjected to the contact pressure.

A machine tool is disclosed. A magneto-pneumatic striking mechanism has a primary actuator arranged around an axis of movement and includes a first magnetic coil and a second magnetic coil. The striking mechanism has, on the axis of movement within the magnetic coils, a striker and a die. Furthermore, the striking mechanism has an air spring acting on the striker in a direction of impact. The air spring may be entirely or partially within the first magnetic coil. The air spring has a ventilation opening that is open to the environment if the striker is less than 10% of its stroke away from the die, and otherwise the ventilation opening is closed. An exchange of air with the environment is therefore only possible when the striker is near the die or is near the impact position.

The present disclosure provides a pneumatic tool with shock absorber. The pneumatic tool has a main body which is adapted for an air supply to be connected thereto. With the air supply, a striker disposed in the main body reciprocates to generate impulse and vibration. A damper, including an elastic member and an airtight compartment, is disposed at the rear end of the reciprocation path of the striker. Therefore, the elastic member and the airtight compartment can absorb the shock produced backwardly by the striker. The vibration and the noise can be reduced for avoiding occupational injury caused thereby.

The invention relates to a pneumatically operated drill hammer, comprising a piston and a distributor axially arranged relative to each other in a housing, the piston being arranged to be moved axially between a first position and a second position. The drill hammer further includes a pneumatic drive system, including a drive chamber, a return chamber and a plurality of channels for distribution of drive gas in said drive system. The return chamber is arranged at a lower side of the piston and the drive chamber is arranged at an upper side of the piston, wherein the drive chamber is defined by a variable space enclosed by at least the housing, the piston and the distributor. The drive chamber includes at least one inlet port and at least one exhaust port arranged at a circumference of the drive chamber.