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.

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 rotary power tool includes a housing, a spindle defining a working axis, and a motor supported by the housing. The motor is operable to drive the spindle. The rotary power tool also includes a handle movably coupled to the housing and a vibration isolating assembly disposed between the housing and the handle. The vibration isolating assembly attenuates vibration transmitted from the housing to the handle. A battery pack is removably coupled directly to the handle and configured to provide power to the motor.

A rotary power tool includes a housing, a spindle defining a working axis, and a motor supported by the housing. The motor is operable to drive the spindle. The rotary power tool also includes a handle movably coupled to the housing and a vibration isolating assembly disposed between the housing and the handle. The vibration isolating assembly attenuates vibration transmitted from the housing to the handle. A battery pack is removably coupled directly to the handle and configured to provide power to the motor.

The hand-held power tool has a tool holder (2) for holding a tool (4) along a working axis (12). A hammer mechanism (6) has a striker (15) that is moved periodically along the working axis at an impact rate. A drive control (18) of the hammer mechanism (6) sets the impact rate to a set point value. A vibration absorber (19) has an oscillator (21) that moves along the working axis (12) about a resting position and one or multiple springs (20) that drive the oscillator (21) back into the resting position. A calibration phase comprises the following steps: detection of an acceleration using the acceleration sensor (24); determination of a minimum of the acceleration by varying the impact rate in a range of between 90% and 110% of the set point value; and adjusting the set point to the impact rate associated with the ascertained minimum.

The hand-held power tool has a tool holder (2) for holding a tool (4) along a working axis (12). A hammer mechanism (6) has a striker (15) that is moved periodically along the working axis at an impact rate. A drive control (18) of the hammer mechanism (6) sets the impact rate to a set point value. A vibration absorber (19) has an oscillator (21) that moves along the working axis (12) about a resting position and one or multiple springs (20) that drive the oscillator (21) back into the resting position. A calibration phase comprises the following steps: detection of an acceleration using the acceleration sensor (24); determination of a minimum of the acceleration by varying the impact rate in a range of between 90% and 110% of the set point value; and adjusting the set point to the impact rate associated with the ascertained minimum.

A shock absorption structure of a pneumatic tool, the pneumatic tool contains: a body, a cylinder, a gas valve unit, an impact element, and an elastic unit. The body includes an air channel and a cavity having a closing face, an opening, and an air chamber. The body also includes a first orifice and a second orifice. The cylinder includes a sliding room, a contacting fringe, a defining cutout, and an air inlet. The gas valve unit is fixed between the sliding room and the contacting fringe. The impact element is disposed in the sliding room and is pushed by the high pressure gas to reciprocately move. The elastic unit includes an elastic pushing force and is secured in the air chamber so as to push against the closing face and the contacting fringe and to push the cylinder to move away from the grip handle.

A shock absorption structure of a pneumatic tool, the pneumatic tool contains: a body, a cylinder, a gas valve unit, an impact element, and an elastic unit. The body includes an air channel and a cavity having a closing face, an opening, and an air chamber. The body also includes a first orifice and a second orifice. The cylinder includes a sliding room, a contacting fringe, a defining cutout, and an air inlet. The gas valve unit is fixed between the sliding room and the contacting fringe. The impact element is disposed in the sliding room and is pushed by the high pressure gas to reciprocately move. The elastic unit includes an elastic pushing force and is secured in the air chamber so as to push against the closing face and the contacting fringe and to push the cylinder to move away from the grip handle.

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, and a cushion washer. The body includes a grip and a fitting sleeve having a chamber, a closing face, and an opening. The cylinder is slidably fitted in the chamber, partially extends out of the fitting sleeve from the opening, 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 is made of a flexible rubber, is mounted in the chamber, and abuts against the closing face 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 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, and a cushion washer. The body includes a grip and a fitting sleeve having a chamber, a closing face, and an opening. The cylinder is slidably fitted in the chamber, partially extends out of the fitting sleeve from the opening, 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 is made of a flexible rubber, is mounted in the chamber, and abuts against the closing face 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.