Abstract: An impact force is transmitted to a tip end tool due to the changes of the air pressure within an air chamber generated by the reciprocal operation of the piston within a striker. The attachment portion of a tip end tool holding member for holding the tip end tool to a cylinder casing is sandwiched between buffers disposed in the two directions of the axial direction of the tool thereby to elastically support the tip end tool holding member to be movable in the two directions of the axial direction of the tool.

Abstract: It is an object of the invention to provide a technique that contributes to improvement of the vibration reducing performance of a dynamic vibration reducer in a power tool while realizing reduction in size of the dynamic vibration reducer. A representative power tool which linearly drives a tool bit to perform a predetermined operation on a workpiece includes a tool body and a dynamic vibration reducer. The dynamic vibration reducer has a weight and an elastic element. The weight has an internal space that extends in the axial direction of the tool bit from at least one end of the weight in said axial direction. One end of the elastic element is inserted and received in the internal space, while the other end of the elastic element is placed on the tool body directly or via the body side member.

Abstract: A power tool includes a striking cylinder, a striking piston slidably housed in the striking cylinder, a driver coupled to a bottom surface of the striking piston, and a cushioning mechanism configured to absorb an impact of striking a fastener with the driver when the striking piston is driven. The cushioning mechanism includes a housing formed below the striking cylinder, and a bumper housed in the housing to receive the bottom surface of the striking piston. The bumper is formed in a tubular shape, a wall thickness of a central section of the bumper is greater than wall thicknesses of an upper section and a lower section of the bumper, and the wall thicknesses of the upper section and the lower section are substantially the same.

Abstract: An electrical power tool (1) includes a housing (10,20,30), an electrical motor (21), a motion conversion mechanism (36), a counterweight holding member (73), a counterweight (74), and support members (71,72). The electrical motor (21) is accommodated in the housing (10,20,30). The motion conversion mechanism (36) is configured to convert a rotary motion of the electrical motor (21) into a reciprocation motion. The counterweight holding member (73) extends in a direction perpendicular to directions of the reciprocation motion and is capable of being elastically deformed in the directions of the reciprocation motion. The counterweight (74) is supported by the counterweight holding member (73) and is capable of reciprocating in the directions of reciprocation motion together with the counterweight holding member (73). The support members (71,72) are positioned away from the counterweight (74) by a predetermined distance for supporting the counterweight holding member (73) to the housing (10,20,30).

Abstract: An apparatus and method of installing a hardwood floor employs a pneumatic or other impact fastener tool to drive staples, cleats, nails or other fasteners at a prescribed angle into and through the tongue of a solid or engineered hardwood flooring board having a standard profile and into a subfloor. The tool and method employs at least one inertia braking member, such as pads formed of rubber, foam, cork or other materials, that cushion the impact of a driving blade on the fastener and slow the final insertion of the fastener into the wood. Damage to the wood, such as splitting, shearing, pinching or puckering is prevented and overwood-underwood problems that are related to pinching and puckering do not arise. The inertia braking members are positioned inside a cylinder in which the driving piston and blade move and are easily replaceable when worn.

Abstract: A breaking apparatus (1) which includes; a housing (3); a striker pin (4) having a driven end and an impact end, locatable in said housing (3) in at least one retaining location to protrude said impact end through the housing (3); a moveable mass (2) for impacting on the driven end of the striker pin (4), and a shock-absorber (7a, b) coupled to the retaining locations. The shock-absorber (1) also includes at least two elastic (12) and at least one inelastic (13) layer in a first shock-absorbing assembly (7a) located internally within the housing about the striker pin (2) between the retaining location and the striker pin impact end. The shock-absorbing assembly (7a) is configured to allow movement of the shock absorber parallel to, or co-axial with the striker pin longitudinal axis during use.

Abstract: The invention of this application provides a pneumatic tool with a simple structure. The tool has a tubular housing, a stationary shaft, a first piston slidable along the stationary shaft, a second piston, a tool attachment member drivingly connected to the second piston, a compressed air supply path extending through the stationary shaft to supply compressed air between the first and second pistons, and an air discharge path for discharging the compressed air supplied between the first and second pistons to the outside of the housing when the first and second pistons are separated by a predetermined distance. The compressed air supply path has an axial portion in the stationary shaft and a radial portion, a compressed air inlet recess in the inner wall surface of a shaft sliding hole, and a supply outlet extending forward from the forward end of the compressed air inlet recess and communicating with a portion between the first and second pistons.

Abstract: An impact drill for boring a workpiece includes a main frame, a motor housed in the main frame, a spindle movably supported by the main frame and rotatable by the motor and movable in its axial direction, a first ratchet positioned fixedly with respect to the spindle, a second ratchet positioned with respect to the first ratchet, a spring biasing the second ratchet toward the first ratchet. The spring has at least one of a spring constant and a biasing force which prevents the second ratchet and the spindle from abutting against the main frame at least one of when a force ranging from 15 to 25 kg is applied to the main frame for boring the workpiece and when the spindle is moved to a retracted position.

Abstract: A resilient stop assembly for an impact tool includes first and second resiliently deformable parts, and a substantially rigid part situated between the deformable parts. Each of the first and second resiliently deformable parts and the substantially rigid part comprises: first and second opposite impact surfaces, at least one peripheral surface joining the impact surfaces, and an aperture extending entirely through the part between exit openings in the impact surfaces. The first impact surface of the second resiliently deformable part is separated from the second impact surface of the first resiliently deformable part by contact of those first and second impact surfaces with the substantially rigid part.

Abstract: An electrical power tool includes a housing, an electrical motor, a motion conversion mechanism, a weight-supporting member, a counterweight, and a first supporting member and a second supporting member. The first supporting member and the second supporting member are each provided on the housing for supporting the weight-supporting member to the housing. The weight-supporting member has a first connecting part and a second connecting part supported by the first supporting member and the second supporting member, respectively; and an elastically deforming part. The elastically deforming part is positioned between the first connecting part and the second connecting part and has a mounting part for mounting the counterweight. The elastically deforming part includes a portion having a smaller cross-sectional area than each cross-sectional area of the first connecting part and the second connecting part.

Abstract: The present invention provides a breaker mounting bracket a breaker mounting bracket for mounting a breaker body on a distal end of an arm of a working machine or the like. The breaker mounting bracket includes left and right side plates which are arranged to face each other in an opposed manner, an end plate which is provided between proximal end portions of both side plates and forms a connecting portion with a distal end of the arm of the working machine, and resilient bodies which come into contact with and support the breaker body and are mounted on inner sides of the left and right side plates and the end plate.

Abstract: A rock drilling machine includes a frame, and arranged inside the frame is a drill rod. A hammer gear is arranged to hammer the drill rod rear end. There is arranged around the drill rod a position sleeve and an arrangement to move position sleeve in an axial direction against hammering piston so that a counter surface of the position sleeve meets the counter surface whereby, on continuing the positioning, the drill rod is movable to the point desired. The counter surface by use of a spring element is arranged to flex in regard to the other structure of the position sleeve so that in the drilling position the sleeve is arranged to be freely backing against the front side of the drilling machine, and when in the drilling operation the positioning impact on the position sleeve against the hammering piston is removed.

Abstract: A portable power tool includes a housing, and an impact mechanism movably supported in the housing and having a front opening for receiving a working implement and a hammer piston for delivering hammer blows to the working implement. The impact mechanism is supported in the housing by a pivot device in a point located between the forward and rear ends of the impact mechanism and allowing longitudinal and pivotal movements but preventing in the support point radial and rotational movements of the impact mechanism relative to the housing. A resilient device is located at a distance from the pivot device and is arranged to bias the impact mechanism to a neutral position relative to the housing and to absorb vibration movements of the impact mechanism to protect the housing against such vibration movements.

Abstract: A hand-held power tool includes a spring-mounted decoupling device (16) for supporting a tool handle (14) on the tool housing (4) and having a first spring-mounted support (18) and a second spring-mounted support (20) that is spaced from the operational axis (A) in a second direction (y) perpendicular to the first direction (z) further away than the first spring-mounted support (18) that has a smaller spring stiffness along the second direction (y) than along the first direction (z).

Abstract: A powered hand tool comprising a pneumatic motor including a cylinder, a main body formed as a hollow tube member, a main body rear end being formed with a fluid inlet and a fluid outlet, the main body being axially disposed for engagement with the pneumatic motor, a main body front end with an interior surface fitted for engagement with a lock nut, the pneumatic motor having a rotary shaft axially extending out of the main body front end wherein the diameter of the pneumatic motor is smaller than the diameter of the hollow tube member, an internal isolation layer composed of a vibration isolation material placed in the hollow tube member so that the vibration isolation material is engaged with and adjacent the ends of the hollow tube member and the pneumatic motor.

Abstract: A power tool capable of performing vibration damping action in working operation, without an increase in size. The working tool includes a motor, a housing in which an internal mechanism driven by the motor is stored, a tool bit disposed on one end of the housing, a hand grip continuously connected to the other end of the housing, and a dynamic damper. The dynamic damper is disposed by utilizing a space between the housing and the internal mechanism so that the damping direction of the dynamic damper faces the longitudinal direction of the tool bit.

Abstract: A hand-held power tool (1;101) includes a drive (6;110) located in the power tool housing (2;102) for driving a working tool (111), and a torsional pendulum (4; 120; 220; 320; 420; 520) at least partially mounted on the housing (2; 102) for compensating vibrations generated by the drive (6; 110).

Abstract: A vibration isolation assembly is provided for use with a backfill tamper. In use, the vibration isolation assembly can be disposed between a handle and a percussion mechanism of the tamper and absorbs kickback forces from the percussion mechanism during backfill tamper operation. In one embodiment, the assembly includes an elongated conduit member that defines a passageway that allows compressed air to pass through the member to the percussion mechanism and a vibration dampening piston arrangement for absorbing feedback forces from the percussion mechanism during backfill tamper operation. The assembly may further include a spring arrangement for dampening vibration emanating from the piston.

Abstract: A portable power tool, particularly a hammer drill and/or chipping hammer, comprising a main element (12) which is provided with a tool axis (30), a center of gravity (32) and a normal axis (34) extending perpendicularly to the tool axis (30) and through the center of gravity (32), wherein the tool axis (30) and the normal axis (34) define a plane of movement, comprising a handle (14), which is mounted displaceably relative to the main element (12) in the plane of movement, and comprising a spring unit (46) connecting the handle (14) to the main element (12), the unit being provided with at least one spring element (48). It is proposed to provide the spring unit (46) so as to define at least substantially a path of movement (110) for at least a portion of the handle (14) in the plane of movement when a load (102) occurs that prompts the handle (14) to leave an idle position and approach the idle main element (12).

Abstract: A counterforce-counteracting device for a nailer comprises an active device, a rotating member, and a weight device. The active device drives the rotating member and the weight device to move. After the active device moves, the weight device is driven by the rotating member to produce a counterforce, so as to counteract the counterforce of the nailer. Thereby, such a device is secure and is easy to assemble.

Abstract: The present invention provides a reciprocating pneumatic tool mechanism, including a casing, pneumatically-operated control module, control switch, actuating module and vibration-absorbing member. The plates of the actuating module are combined into a single body by the perforating locator. The periphery of the plates can be slidably abutted with the inner wall of the tank. The air inlet of actuating module is adapted air-tightly with air supply end of pneumatically-operated control module. At a front end of the actuating module, a protruding tube is screwed into a punch hole in front of the casing. The vibration-absorbing member includes a built-in buffer between actuating module and pneumatically-operated control module, and a front-mounted buffer between the front ends of actuating module and casing. With the invention, the vibration-absorbing members of reciprocating pneumatic tool is saved, improving the assembly efficiency, reducing assembly cost and volume with better economic efficiency.

Abstract: A rotary-percussion hand-held power tool includes a vibrating percussion mechanism (2) for applying blows along a percussion axis (A), a guiding handle (4) vibrationally decoupled from the percussion mechanism (2) and provided with a motor switch (5) displaceable in switching region (X) for blocking the motor switch (5), an operational mode selection switch (3) arranged in the percussion mechanism (2), and a switching bar (9) displaceable by the operational mode selection switch (3) and having a stop (10) that projects into the switching region (X) of the locking switch (7) in the drilling operational mode.

Abstract: It is an object of the invention to provide a technique for further improving the vibration reducing performance in an impact tool. A representative impact tool includes a tool body, a cylinder housed within the tool body, a dynamic vibration reducer having a weight that linearly moves under a biasing force of an elastic element, wherein the dynamic vibration reducer reduces vibration of the tool body during hammering operation by the movement of the weight in the axial direction of the tool bit, and a mechanical vibration mechanism that actively drives the weight by applying external force other than vibration of the tool body to the weight via the elastic element. The weight and the elastic element are disposed on the axis of the tool bit and between an inner wall surface of the tool body and an outer wall surface of the cylinder in such a manner as to cover at least part of the outer wall surface of the cylinder in the circumferential direction.

Abstract: It is an object of the invention to provide a technique that contributes to rationalization of a mechanism relating to reduction of vibration in an impact tool. Representative impact tool includes a tool body, a hammer actuating member, a dynamic vibration reducer and a positioning elastic element. The positioning elastic element contacts the hammer actuating member and thereby positions the tool body with respect to the workpiece so as to absorb a reaction force caused by rebound from the workpiece and acts on the hammer actuating member when the hammer actuating member performs the hammering operation on the workpiece. The positioning elastic element includes the elastic element formed as a component part of the dynamic vibration reducer.

Abstract: It is an object of the invention to provide an effective technique for further enhancing the effect of reducing a reaction force inputted during hammering operation. Representative impact tool comprises a tool body, a hammer actuating member, a cylinder and a compression coil spring. The compression coil spring contacts the hammer actuating member and thereby positions the tool body with respect to the workpiece when the hammer actuating member is pressed against the workpiece and pushed rearward in advance of the hammering operation. In such position, the compression coil spring absorbs a reaction force that is caused by rebound from the workpiece and acts upon the hammer actuating member when the hammer actuating member performs the hammering operation on the workpiece. The cylinder is inserted into the tool body from the front along the axial direction of the hammer actuating member and thereby housed within a predetermined housing part of the tool body.

Abstract: A shock attenuating coupling device is provided for a rotary impact tool for drivingly connecting a hammer mechanism to a drive anvil. The shock attenuating coupling device includes a first coupling member, a second coupling member, a drum, a shoe, and a body of resilient material. The first coupling member has a first drive portion. The second coupling member has a second drive portion. The drum is provided proximate the first drive portion and the second drive portion and has a radially inner engagement surface. The shoe is provided within the drum and between the first drive portion and the second drive portion. The shoe has a radially outer surface capable of being expanded in a radially outer direction. The body of resilient material is interposed between the drum and the shoe.

Abstract: It is an object of the invention to provide a technique for a reduction of an impact force cased by rebound of a tool bit after its striking movement in an impact power tool. The representative impact power tool includes a tool body, a hammer actuating member, a striker, a weight and an elastic element. A reaction force is transmitted from the hammer actuating member to the weight and the elastic element is elastically deformed when the weight moves ward by the reaction to absorb the reaction force. The invention is characterized in that the mass of the weight is set to about 40% or more of the mass of the stiker.

Abstract: An impact tool comprising a motor, a hammer 8 that is rotated and axially moved by a drive force of the motor, an anvil 3 that repeats engagement/disengagement from the hammer 8 accompanying rotation and axial movements of the hammer 8, and a tip tool 4 mounted to the anvil 3, the anvil 3 comprising a first split piece 3A, which includes pawls 3c (first concave-convex part) on an opposite side to the hammer and repeats engagement/disengagement from the hammer 8, a second split piece 3B, which includes pawls 3f (second concave-convex part) engageable with the pawls (first concave-convex part) 3c of the first split piece 3A in a direction of rotation, and to which the tip tool 4 is mounted, and a rubber damper (elastic body) 13 interposed between the first and second split pieces 3A, 3B to prevent direct contact between the pawls (first concave-convex part) 3c and the pawls (second concave-convex part) 3f in the direction of rotation and in an axial direction.

Abstract: A pneumatic hammer drill includes a handle body, a pneumatic cylinder, a piston, a tool, and a damping member. The handle body has an upper part that defines a front cavity and that has a rear end. The pneumatic cylinder has a cylinder rear end fitted in the front cavity, a front tool-connecting end, and a pressure chamber. The piston is disposed slidably in the pressure chamber. The tool is inserted into the pressure chamber through the front tool-connecting end. The damping member is made of a vibration-damping material, and is attached to the rear end of the handle body.

Abstract: A ground rod driver that uses an industry standard connecting plate to physically attach the driver to Skid Steer type equipment. The driver has a hydraulic, impact driving hammer connected to an alignment beam that enables vertical movement of the hammer. Operation of the driving hammer, as well as up and down motion of the driving hammer is derived from the accessory hydraulic system and connections of the Skid Steer. Simple operating control valves, flow control valve and hydraulic hoses, and an operating station are mounted directly to the driver.

Abstract: A hand-held power tool includes a pneumatic percussing mechanism (3) located in the power tool housing (2) and having an anvil (5) and a percussion piston (4) for applying blows to the anvil (5), and at least one oscillation damper (6, 6?) including an oscillation damping mass (7, 7?), at least one spring (8a, 8a?) for compressively preloading the damping mass (7, 7?) against the power tool housing (2), and an axially displaceable excitation member (9) for actively exciting the oscillation damper (6, 6?) in response to the anvil (5) occupying an operational position.

Abstract: A powered hand tool comprising a pneumatic motor including a cylinder, a main body formed as a hollow tube member, a main body rear end being formed with a fluid inlet and a fluid outlet, the main body being axially disposed for engagement with the pneumatic motor, a main body front end with an interior surface fitted for engagement with a lock nut, the pneumatic motor having a rotary shaft axially extending out of the main body front end wherein the diameter of the pneumatic motor is smaller than the diameter of the hollow tube member, an internal isolation layer composed of a vibration isolation material placed in the hollow tube member so that the vibration isolation material is engaged with and adjacent the ends of the hollow tube member and the pneumatic motor.

Abstract: A power tool including a gear unit provided with a load moderating mechanism capable of reducing noise and prolonging service life. A coupling is force fitted with a spindle at a predetermined pressure allowing the spindle and the coupling to rotate relative to each other when a load exceeding a predetermined load is applied therebetween. A gear has a surround section having a convex and surrounding the coupling. The coupling has an abutment projection abutable against the convex and a damper projection. An elastic member is interposed between the damper projection and the surround section. Rotation of the gear is transmitted to the spindle through the elastic member and the coupling.

Abstract: An ice chopper having a blade for initially engaging ice with a small force followed by an impact of a larger force to break up the ice. The ice chopper has a tube for a handle having a second tube inside with a compression spring. The second tube has a blade attached, which engages ice and pushes the second tube up inside the tube simultaneously compressing the compression spring. When a stop is reached the second tube stops retracting and the impact force of the downward movement of the tube is absorbed by the blade for breaking the ice. The ice chopper is then lifted off the ice, the compression spring pushes the second tube and the blade downward and the ice chopper is ready for another stroke. An ergonomic handgrip is attached at the top of the tube for gripping the ice chopper.

Abstract: Disclosed herein is a powder actuated setting tool piston retainer arrangement which includes a housing and firing mechanism and a piston having a piston retaining ring in operable communication with the housing and firing mechanism. Further the arrangement includes a barrel within which the piston is slidably disposable. A cantilevered retainer is disposed at the barrel, the retainer being pivotally articulated with the barrel such that the retaining ring is contactable thereby to retain the piston in a selected position. Further disclosed herein is a method for retaining a piston of a powder actuated setting tool in position. The method includes urging a cantilevered retainer radially inwardly of a barrel of the setting tool for the purpose of contacting a retaining ring of the piston of the setting tool. Such contact frictionally retains the piston in a selected position.

Abstract: An impact drill includes a first ratchet together with a spindle and movable in an axial direction, and a second ratchet engageable with the first ratchet. The second ratchet can be moved in the axial direction, and rotated with a predetermined range in a rotational direction.

Abstract: An impact tool enables a front cover part to be easily attached to and detached from a housing body, with a device having a simplified structure. The front cover part has an annular fastening portion clamped to the outer peripheral surface of a front edge portion of the housing body, a cylindrical portion extending from the front end of the housing to the region of the fastening portion, and a connecting portion connecting together the cylindrical portion and the fastening portion. The fastening portion is split at a circumferential part thereof to form a pair of circumferentially opposing tongue-shaped portions. A clamping device is provided between the tongue-shaped portions, which is movable between a clamping position where it pulls the tongue-shaped portions toward each other and an unclamping position where the tongue-shaped portions are released from being pulled toward each other.

Abstract: A nail driver bumper comprises an inner pad and an outer pad which are made of heat-resisting elastomer material. A plurality of axial ribs is arranged between the inner pad and the outer pad. An axial slot is formed between two adjacent axial ribs. A top of each axial slot is communicated to the lower chamber of the cylinder. An axial channel and a radial channel are formed at the lower end of each axial slot. The entire axial channels and the radial channels are communicated with the axial slots and the central hole of the inner pad so as to communicate to the lower chamber. Thus, a plurality of air paths is informed between the inner pad and the outer pad so as to increase the surface area for an ability of preferred heat dissipating, and prolong the lifetime of the bumper.

Abstract: An engine breaker includes a vertically extending cylindrical main body (1), a work member (2) supported by a lower portion of the main body for up and down movement, an engine (5) mounted to an upper portion of the main body and having an output shaft arranged to extend horizontally, and a striker (30) incorporated in the main body (1) for successively striking an upper end of the work member (2) through rotation of a horizontally extending rotary shaft (6) to which rotation output of the engine (1) is transmitted. The engine (5) includes a housing (5a) supported by the main body (1) via a resilient member (8), and a flexible coupling (9, 9A, 9B) for absorbing vibration in a direction crossing the rotary shaft (6) is interposed between the output shaft (52) and the rotary shaft (6).

Abstract: A power tool includes vibration isolation material positioned between an engine shroud and a drive shaft housing. The vibration isolation material isolates the drive shaft housing from engine vibration for radial, axial, and torsional movement without utilizing intermediate components.

Abstract: A jackhammer system for reducing the vibration and noise experienced by an operator of the jackhammer. The jackhammer system includes a housing, a chisel movably positioned within a lower neck of the housing, a pair of flywheels rotatably attached to a pair of support brackets, a ram slidably positioned within a guide channel and engageable by the flywheels to engage the chisel, a plurality of elastic members attached to the ram, and an actuator mechanically connected to the support brackets for controlling a position of the flywheels. An upper sensor and a lower sensor determine the position of the ram within the guide channel. An engaging plate supported by a plurality of compression springs receives the downwardly impact of the ram when driving the chisel downwardly. A recoil absorber having a recoil spring is attached to an upper portion of the housing for absorbing the recoil of the ram.

Abstract: The invention relates to a control system for a percussion drive of an earth drilling unit having a housing, a drilling tool, a pulling or thrusting drive, a percussion piston, a pressure chamber belonging to the percussion piston and a pressure medium feed, which can be connected and disconnected, for the operation of the percussion piston, wherein the connecting and disconnecting of the pressure medium feed occurs when the pulling or thrusting drive exceeds or falls below a specific pull or thrust.

Abstract: An apparatus for providing percussion action in a rotary power tool having a rotary output shaft, the apparatus comprising at least one moveable mass adapted to have a component of movement parallel to the axis of the rotary output shaft to cause impacts to be applied to a working member of the tool; and a device for intermittently converting rotary movement of the rotary output shaft into movement of at least one the moveable mass to cause the impacts to be applied to the working member.

Abstract: Percussion device, includes a housing and two movable bodies, an impact body for an impact pin protruding from the housing, and a balancing body for counterbalancing impact motions of the impact body. The housing includes springs, which constantly strive to bring the bodies towards each other and against the action of which the bodies may be separated axially. The balancing body is rotatable, via a drive spindle connected to a driving source the spindle being mounted in a bearing member, at least one of the bodies including an oblique surface, which, by contact against the other body, transforms the rotary motion of the balancing body into axial motions of the impact body. Rotation of the bearing member is prevented by a helical pressure spring attached to the bearing member and the housing. In this way, tangential vibrations cannot be transferred from the drive spindle to the housing.

Abstract: A tool for a powered machine, having vibration damping member. A method of providing a tool having a vibration damping member arrangement, applicable to different tools, is described. Estimated antinode positions along the tool in use are determined and a vibration damping member arrangement is located to cover at least one selected antinode position.

Abstract: An impact tool enables a front cover part to be easily attached to and detached from a housing body, with a device having a simplified structure. The front cover part has an annular fastening portion clamped to the outer peripheral surface of a front edge portion of the housing body, a cylindrical portion extending from the front end of the housing to the region of the fastening portion, and a connecting portion connecting together the cylindrical portion and the fastening portion. The fastening portion is split at a circumferential part thereof to form a pair of circumferentially opposing tongue-shaped portions. A clamping device is provided between the tongue-shaped portions, which is movable between a clamping position where it pulls the tongue-shaped portions toward each other and an unclamping position where the tongue-shaped portions are released from being pulled toward each other.

Abstract: An attachment for an impact hammer for translating the hammer's typical forwardly directed impact force into a rearwardly directed pulling force while still allowing the user to maintain a conventional orientation of the hammer relative to the work piece intended to be pulled. The attachment comprises a housing defining a cavity with a hammer bit axially movable therein and having an impacting head urged rearwardly by a bias structure which responds to a forward impact force by the impact hammer to cause the hammer bit head to exert impact force on the work piece in a rearward direction.

Abstract: It is, accordingly, an object of the present invention to provide an electric hammer with improved construction, while ensuring the vibration reduction performance. According to the present invention, a representative electric hammer may include a hammer bit, a driving motor, a crank mechanism and a counter weight. The crank mechanism drives a striker by converting a rotating output of the driving motor to linear motion in the axial direction of the hammer bit. The counter weight is detachably mounted to the crank mechanism and serves to reduce vibration of the striker. According to the representative hammer, because the counter weight is detachably mounted to the crank mechanism, it is possible to switch between the mode in which the counter weight is mounted on the hammer body in order to reduce and alleviate vibration and the mode in which the counter weight is removed from the hammer so that the operation can be performed with the hammer having a lighter weight and slimmer appearance.

Abstract: A combustion-engined setting tool, including a housing (11), an axially displaceable piston guide (13) and a firing pin guide (12) provided on a side of the piston guide (13) facing in the direction opposite the setting direction and axially displaceable relative to the housing (11), damping element (20) supported against a stop (17) provided in the housing (11) and cooperating with the firing pin guide (12), and a locking device (30) having a locking position (28) in which it prevents a press-on force, which is generated upon the setting tool (10) being pressed against a construction component, from acting on the damping element (20), so that the damping element (20) remains inactive during a press-on process, and having a release position (29) in which the damping element (20) becomes active and is capable of absorbing recoil forces.

Abstract: An explosively operated tool (1) for driving a fastener into a substrate such as steel or concrete has a resetting mechanism (12) for resetting a piston (10) of the tool into a rear part of a barrel assembly (8) of the tool after each firing of the tool. The barrel assembly (8) is mounted for axial movement within the tool housing (2) and co-operates with a mass mounted for rearwards movement relative to the housing (2) in opposition to a biasing force to absorb recoil on firing of the tool. The resetting mechanism (12) for resetting the piston (10) into a rear part (2a) of the barrel assembly after firing is powered in response to displacement of the mass on recall.