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 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 rotary impact tool includes a housing, an electric motor supported in the housing, and a drive assembly. The drive assembly includes an anvil having a longitudinal bore for selectively receiving a tool bit, and a plurality of radial slots extending from the longitudinal bore through the anvil. The rotary impact tool further includes a bit holding device including a plurality of ball detents received in the respective radial slots, and a collar slidably disposed on the anvil having an interior surface for maintaining a portion of the ball detents within the longitudinal bore, and collar spring for biasing the collar rearward to a first collar position. The bit holding device further includes a helical detent spring surrounding the anvil having a continuous helical structure with a plurality of protrusions extending into the radial slots, the protrusions are for biasing the ball detents toward an open end of the bore.

In a hammer drill, a coil spring that urges a first clutch and a second clutch in directions away from each other is held between a first change plate that engages with the first clutch to be slidable in the axial direction of an intermediate shaft and a second change plate that engages with the second clutch to be slidable in the axial direction of the intermediate shaft. The first change plate is slidably guided by a gear housing.

A blade mounting device allows a blade of a pushing cut tool that cuts a workpiece by pushing a cutting edge forward to be mounted on an impact tool. This blade mounting device has a blade mounting portion for mounting the blade on the blade mounting device and a tool mounting portion secured to the blade mounting portion in order to mount the blade mounting device on the impact tool. The blade mounting portion has a front end portion where an inverted tapered hole complementary to an inclined shape surface formed on a tang of the blade is formed. The tool mounting portion is provided with a through hole perpendicular to the center axis and a center hole that reaches a through hole from a front side end surface of the tool mounting portion along the center axis.

An object of the invention is to provide an impact tool improved in vibration-proofing structure of a handle. A representative impact tool has a tool body and handle. The handle has a handle body and pair of grips that extend in a direction crossing an axial direction of a tool accessory, designed to be held by user's right and left hands. The handle body has a first part to which the grips are connected in a fixed manner and a second part that is connected to the tool body in a fixed manner. The first part is supported against the tool body via an elastic member and is allowed to move with respect to the tool body and the second part while being biased by an elastic force of the elastic member. A current supply cable, supplying current to a motor, is installed on the second part.

In an impact tool, a vibration absorbing body is fitted on the outside of an outer periphery of an operating body, and the vibration absorbing body is interposed between the operating body and the cover body. The vibration absorbing body includes a tubular main body, and ring bodies attached to be fitted into recessed grooves formed on an inner peripheral surface and an outer peripheral surface of the tubular main body along the circumferential direction and elastically deformed to expand or contract the outside diameter. The ring bodies are maintained in a state where the ring bodies are elastically contracted in a freely expanding or contracting manner.

A chisel holder has an outer sleeve, a holding member, multiple positioning members, a resilient member, and a limiting ring. The outer sleeve has an assembling space, a receiving chamber, and an abutting rib. The receiving chamber is defined in the outer sleeve at a position adjacent to the top of the outer sleeve and is conical. The holding member is mounted in the outer sleeve and has a central hole, a limiting rib, and multiple holding holes. The positioning members are mounted respectively in the holding holes in the holding member, selectively extend into the central hole in the holding member, and abut an inner surface of the receiving chamber. The resilient member is mounted in the assembling space in the outer sleeve and abuts the bottom of the holding member.

A hydraulic hammer assembly is provided. The hydraulic hammer assembly includes a housing and a piston is arranged for reciprocating movement along a longitudinal axis within the housing. A head disposed along the longitudinal axis on an end of the housing and defines a chamber for holding a pressurized gas. The hydraulic hammer assembly further includes a locking mechanism to lock the head on the housing. The locking mechanism includes at least one first flange extending radially from the end of the housing and at least one second flange extending radially from the head, wherein the head is retained on the housing by blocking axial movement of the second flange against the first flange when in a locked position.

Reciprocating power tool is provided which is improved in vibration isolation of the handle. The reciprocating power tool has a tool body and a handle connected to the tool body. When an axial direction of a tool bit is defined as a longitudinal direction, the handle extends in a vertical direction crossing the longitudinal direction. Further, an upper region of the handle is connected to the tool body via an elastic member and a lower region of the handle is connected to the tool body via a support shaft that it can rotate around an axis of the support shaft in a transverse direction crossing both the longitudinal direction and the vertical direction with respect to the tool body. When the handle rotates around the support shaft with respect to the tool body, the elastic member reduces vibration which is caused in the tool body and transmitted to the handle.