A pneumatic impact tool having a vibration reducing structure includes a handle with a bucket member and a directional control valve. A tube member including a cylindrical wall and a chamber is coupled with the bucket member. The chamber is divided into a front and a rear chamber portion by a hammer member. Gas may be guided into the front or the rear chamber portion by the directional control valve. A vent is disposed on the cylindrical wall. An exhaust channel which communicates with the front chamber portion and not communicates with the rear chamber portion is disposed on an outer peripheral surface of the hammer member. The hammer member is pushed to return if gas is guided into the front chamber portion. Gas in the front chamber portion is exhausted when the exhaust channel communicates with the vent.

The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

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.

The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

An air impact tool includes an inner tubular member that is connected to the barrel. The inner tubular member has an annular wall and a cavity. The annular wall has exhaust hole. An air flow channel communicating with the air flow control valve and the cavity is defined inside the annular wall. The air flow channel is formed with a first air inlet. A hammer is in the cavity. The hammer is in close contact with the annular wall. A cylindrical gap is defined between a middle section of the hammer and the annular wall. The hammer has an exhaust passageway communicating with the cavity and the cylindrical gap. When the compressed air is injected into the cavity from the first air inlet, the hammer is pushed back, and the compressed air is exhausted via the exhaust passageway, the cylindrical gap and the exhaust hole in sequence.

An electric impact hammer includes an output shaft, a cylinder and a piston arranged in the cylinder. The piston defines an accommodating groove running through the rear end surface and a pair of through holes communicating with the accommodating groove and running through the outer periphery, and the front end of the output shaft is inserted in the accommodating groove, and the output shaft defines a corrugated groove on the outer periphery of the front end and a steel ball partially accommodated in the corrugated groove, the corrugated groove is connected end to end along the outer periphery of the output shaft and has an axial front end and an axial rear end; the other part of the steel ball is accommodated in the through hole, and the output shaft drives the piston to reciprocate in the axial direction by means of the steel balls.

A power tool includes a motor, a drive mechanism, and an impact mechanism. The drive mechanism is capable of driving a tip functional element to rotate about an output axis. The impact mechanism is capable of abutting against the tip functional element and capable of driving the tip functional element. The impact mechanism includes an impact rod, an impact power piece, and an impact block. The impact rod abuts against the tip functional element. The impact power piece is used for generating impact power. The impact block is disposed between the impact rod and the impact power piece, capable of forming a gas space with the impact power piece, and capable of reciprocating when impacted by the impact power generated by the impact power piece. A minimum length of the gas space in a direction of the output axis is less than or equal to 13 mm.

A percussion piston for a rock drill machine having a pilot cylinder, a distributor and a pressure medium includes a control edge configurable to cause a change in the position of the distributor in a direction parallel to the axial direction of the percussion piston as the percussion piston moves in the impact direction (A) in relation to the pilot cylinder. The control edge of the percussion piston includes at least one notch provided on the outer periphery of the control edge and arranged to cause a start of a state change for the distributor before the control edge of the percussion piston passes by a corresponding control edge provided on the distributor or pilot cylinder.

An impact mechanism for use in a power tool having a motor and adapted to impart axial impacts to a tool bit. The impact mechanism includes a piston configured to reciprocate in response to receiving torque from the motor, a striker that is selectively reciprocable within the spindle in response to reciprocation of the piston, and an anvil that is impacted by the striker when the striker reciprocates towards the tool bit. The anvil imparts axial impacts to the tool bit. The striker includes a body portion formed of a first material and an insert portion within the body portion. The insert portion is formed of a second material that is more dense than the first material.

A bearing device includes at least one bearing element. The at least one bearing element has at least one bearing running surface and at least one lubricant pocket. The at least one lubricant pocket is configured to lubricate at least a portion of the bearing running surface of the at least one bearing element. A method of producing the at least one bearing element includes forming the at least one lubricant pocket in the at least one bearing element at least partly by a non-cutting production method.