Abstract: A ram assembly comprises a top plate defining one or more clamp openings and one or more top plate lift openings, a bottom plate defining one or more anchor openings, a lift plate defining one or more lift plate ram cable openings, and one or more ram wire rope assemblies. Each ram wire rope assembly extends through one lift plate ram cable opening and between one clamp opening and one anchor opening to inhibit movement of the top plate, the bottom plate, and the lift plate relative to each other. The top plate lift opening is sized and dimensioned to allow at least a portion of the actuator rod assembly to extend through the top plate. The lift plate is adapted to be secured relative to the actuator rod assembly.

Abstract: A pile driving method for driving a pile, e.g. a hollow and open ended pile, e.g. a large diameter pile having an outer diameter of at least 5 meters, e.g. a monopile of an offshore wind turbine, into the soil, e.g. into the seabed. Use is made of a pile driving system which comprises a drive head member that is configured to engage the pile, and a solid mass drop weight assembly comprising a support structure and comprising solid drop weight elements supported by said support structure, preferably solid steel drop weight elements being composed of steel elements, e.g. stackable steel elements, which drop weight elements have a total mass of at least 100 tonnes, e.g. more than 500 tonnes. e.g. more than 1000 tonnes, e.g. more than 2000 tonnes, which drop weight assembly is vertically mobile relative to, e.g. above, the drive head member.

Abstract: A machine for retreading tires includes a rotatable hub that includes a moveable conical element, and an expandable rim disposed around the rotatable hub. The expandable rim includes a plurality of shoes. Each shoe of the plurality of shoes may have a base portion and a rim portion. The base portion may have a two-piece construction that allows for replacement of a worn interface that may include a channel and a ramp. A method for assembling an expandable rim for use in a tire retreading machine, and a method for servicing a machine having an expandable rim are also disclosed.

Abstract: An impact tool includes a housing, a motor supported within the housing, an anvil extending from the housing, and a drive assembly configured to convert a continuous rotational input from the motor to intermittent applications of torque to the anvil. The anvil includes a body rotatable about a longitudinal axis, a driving end portion configured to receive a tool element over a distal end thereof, and a bore extending through the driving end portion of the anvil in a direction transverse to the longitudinal axis. The driving end portion includes a groove located between the bore and the distal end. The groove includes a curved portion converging toward the distal end and is configured to receive a friction ring such that the friction ring follows a contour of the groove.

Abstract: An impact tool includes a motor, a driving mechanism, a tool body, an elastically-connected part elastically connected to the tool body to be movable at least in a front-rear direction relative to the tool body, a detecting mechanism configured to detect pressing of a tool accessory against a workpiece, and a control part configured to control driving of the motor based on a detection result of the detecting mechanism. The detecting mechanism includes a movable member that is provided in one of the tool body and the elastically-connected part and configured to be moved by relative movement of the other of the tool body and the elastically-connected part in the front-rear direction, and a detector that is provided in the one of the tool body and the elastically-connected part and configured to detect rearward pressing of the tool accessory by detecting movement of the movable member.

Abstract: An impact tool is provided with vibration isolators to reduce vibrations felt by the operator gripping the handle of the tool. The impact tool has a hammer and an anvil that impact against each other during use. The impacts create undesirable vibrations in the tool housing and noise in the work area. The isolators are useful in minimizing such vibrations and noise.

Abstract: 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.

Abstract: A driving tool including a driver configured to drive out a fastener, a piston to which the driver is connected, a cylinder in which the piston is disposed so as to be reciprocated, a head valve which is slidably mounted to an outer circumferential side of the cylinder and controls a flow of compressed air into the cylinder, and a seal portion which is provided to face an opening edge of the head valve. The seal portion includes a lip portion protruding along an outer circumferential surface of the head valve.

Abstract: A machine tool that can be guided manually has an outer housing that extends along a longitudinal axis and has a hand grip region. An electrical drive unit and a tool unit are accommodated in the outer housing and are mechanically uncoupled relative to the outer housing. The outer housing has a center of mass that, with respect to the length of the outer housing, is arranged along the longitudinal axis in a section that extends toward the rear from the geometric center of the outer housing.

Abstract: A plate spring is attached to the distal-end portion of a piston. The distance L1 between the distal-end portion of a plunger and a core (recessed portion) that faces the distal-end portion of the plunger is set to be shorter than the distance L2 between the distal-end portion (plate spring) of the piston and the projecting end surface of a valve main body that faces the distal-end portion of the piston with drive of a solenoid portion stopped. Consequently, when the solenoid portion is driven, the plate spring collides against the projecting end surface of the valve main body so that the plunger does not collide against the core. As a result, a shock applied to the piston can be absorbed by the elastic force of the plate spring, which suppresses generation of a sound of collision.

Abstract: Disclosed are methods and devices utilizing magnetized components to assist operation of an internal mechanism of a tool. Magnetic fields can assist a power tool comprising internal mechanisms that cycle very quickly. Magnetized components can assist in a load/reset action relative to internal components of the power tool. In one example, one or more hammers of a hammer drill/driver can be reset more efficiently when various magnetized elements are oriented in certain ways relative to one another. Additionally, friction between components can be reduced by repulsive magnetic fields between two or more components. Utilizing the magnetic fields can improve the overall function of internal components of the tool. In another example, a tool such as a nailer or stapler can utilize magnetism to assist its internal components. In a nailer or stapler the magnetism can assist, for example, acceleration and deceleration of components utilized to drive the nail/staple.

Abstract: A bumper sized to fit a cylinder of a fastener driving tool includes a side profile of the bumper defined by a plurality of flat regions and a plurality of convex regions around an outer periphery of the bumper. Included in the bumper are an inner peripheral surface and an outer peripheral surface. The flat and convex regions are disposed on the outer peripheral surface of the bumper in an alternating pattern.

Abstract: A power tool comprising: a body (103); a dust catching attachment (120) attachable to the body (103); an engagement mechanism portion (151) which engages the body (103) with the dust catching attachment (120); and a spacing member that biases the body (103) and the dust catching attachment (120) in a state that the body (103) and the dust catching attachment (120) are engaged to each other by the engagement mechanism portion (151).

Abstract: A breaking apparatus (1) with a housing (3), striker pin (4), moveable mass (2) and shock absorber. The striker pin (4) has a driven end and an impact end and a longitudinal axis extending between the two ends. The striker pin (4) is locatable in the housing (3) such that the impact end protrudes from the housing (3). The moveable mass (2) impacts on the driven end of the striker pin (4) and the shock-absorber is coupled to the striker pin (4) by a retainer (8) interposed between a first (7b) and second (7a) shock-absorbing assemblies located internally within the housing (3) along, or parallel to, the striker pin longitudinal axis. The first shock-absorbing assembly (7b) is positioned between the retainer (4) and movable mass (2) and is formed from a plurality of un-bonded layers including at least two elastic layers (12) interleaved by an inelastic layer (13).

Abstract: A hammer drill includes, in a cylinder accommodated in a housing, a piston configured to advance and retract and an impact element to operate together with the piston with an air chamber interposed therebetween, and a bit mounted in a front part of a tool main body so that an impact operation can be transmitted to the bit by advancing and retracting movement of the impact element. Vent holes are provided in the cylinder, and configured to discharge air in the air chamber to outside of the cylinder, and to introduce the air outside the cylinder into the air chamber by the movement of the piston. One of the vent holes is located at a center of an upper half of a periphery of the cylinder and the other vent hole is located in a lower half of the periphery of the cylinder.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism includes: a flying mass; an impact surface which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston which limits a movement of the flying mass opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; and a drive for periodically moving the exciting piston with a stroke along the impact axis.

Abstract: A pneumatic percussion tool (1) for demolition and/or breaking work is connectable to an insert tool (2). The percussion tool has a percussion cylinder (4), a piston (5), arranged to travel in the bore of the cylinder (4), a buffer (8), and a valve unit (6), acting on the piston (5) during operation to produce a repetitive reciprocating motion in the bore of the cylinder (4) by alternately applying pressure to the upper or lower end of the cylinder (4) while the insert tool (2) is influenced by the stroke of the piston (5) at its dead center at the lower end of the cylinder (4). The percussion tool prevents the reciprocating motion of the piston when the buffer (8) reaches a predetermined degree of wear and the tool is not pressed against any object being worked.

Abstract: A rotary tool includes a drive device, a driven member configured to be rotatably driven by the drive device, a spindle rotatably supported within a housing, an impact attenuation mechanism disposed between the driven member and the spindle and transmitting rotation of the driven member to the spindle while an impact applied to the driven member being attenuated, and a driven member support bearing rotatably supporting the driven member, so that the driven member can rotate relative to the spindle.

Abstract: A representative power tool according to the invention performs a predetermined operation on a workpiece at least by axial linear movement of a tool bit 119 coupled to a front end region of a housing 103. The power tool includes driving mechanisms 113, 115 that are housed within the housing 103 and linearly drives the tool bit 119, and a dynamic vibration reducer 151 that has a weight 153 which is allowed to linearly move under a biasing force of an elastic element, and reduces vibration caused during operation, by movement of the weight 153 in the axial direction of the tool bit. A dynamic vibration reducer housing space 149 for housing the weight 153 and the elastic element of the dynamic vibration reducer 151 is integrally formed with the housing 103.

Abstract: A hydraulic breaker hammer casing assembly for converting a hydraulic breaker hammer to a pile driving apparatus for driving piles into the ground. A hydraulic breaker hammer is immovably retained in a support housing. The hydraulic breaker hammer is fitted with a blunt working implement for transmitting blows to a drive cap supported on top of a pile. A pile guiding assembly is secured at an open bottom end of the support housing for guiding, in axial alignment with the working implement, the pile being driven in the ground. The casing assembly protects the hydraulic breaker hammer secured therein and provides access thereto as well as displaceable connection to a boom of a pile driving rig.

Abstract: An impact tool includes a bit holding device with an elongate tool holder having a bit holding hole with a tool bit, an outer shell component forming an outer shell of the bit holding device and mounted onto a front end portion of the tool holder, a stopper fitted onto the tool holder and prevented from moving in a longitudinal direction of the tool holder, and prevents the outer shell component from becoming detached from the front end of the tool holder, and an opening prevention member disposed outward of a center position of the stopper in the longitudinal direction of the tool holder and opposed to an outer surface of the stopper in a direction transverse to the longitudinal direction of the tool holder, and prevents the stopper from opening in the direction transverse to the longitudinal direction of the tool holder.

Abstract: A power tool includes a body and a housing surrounding at least a portion of the body. The power tool also includes a first isolator positioned between the body and the housing and in contact with the body and the housing. The power tool also includes a first fastener connected to the housing to position the first isolator with respect to the housing.

Abstract: The invention is based on a hammer drill and/or chisel hammer, having an impact mechanism unit, an impact mechanism housing and at least one damping unit. The invention proposes that the damping unit is arranged on the impact mechanism housing along a main extension direction of the impact mechanism unit.

Abstract: A technique for reducing the costs of manufacturing an auxiliary handle provided separately from a main handle in a hand-held power tool is provided. A hand-held power tool includes a power tool body having a front end region to which a tool bit can be mounted, a main handle that is disposed on a rear end side of the power tool body opposite from the tool bit, an auxiliary-handle mounting member for mounting an auxiliary handle, and longitudinally elastic elements that are disposed between the power tool body and the auxiliary handle mounting member in the axial direction of the tool bit and can elastically deform in the axial direction. The auxiliary-handle mounting member is allowed to move with respect to the power tool body in the axial direction of the tool bit by elastic deformation of the longitudinally elastic elements, so that transmission of vibration from the power tool body to the auxiliary-handle mounting member in the axial direction is reduced.

Abstract: A demolition hammer is provided that includes a housing that is reversible and a plurality of interchangeable wear plates. The demolition hammer may include a housing a housing having a first wall and a second wall opposite the first wall, and a power cell disposed within the housing, the power cell having a front face, wherein the housing is reversible such that the housing can be used with the power cell in a first orientation in which the front face faces the first wall and a second orientation in which the front face faces the second wall.

Abstract: A hammer drill equipped with a main body part; a drive motor; a motion conversion mechanism, and a vibration absorber which are housed in the main body part; and a handgrip which is provided as a continuation of the main body part at a position closer to the rear end side of the tool than the drive motor and used for gripping the tool. The vibration absorber is in a configuration where vibrations of the main body part are suppressed during a machining operation.

Abstract: A hydraulic, pneumatic, or electric tool may include a spindle that is adapted for rotational movement. A swing arm may be coupled to the spindle such that the rotational motion of the spindle is transferred to the swing arm. The swing arm may make contact with an anvil such that the rotational motion of the swing arm causes the anvil to move along a linear path. A piston may be operatively coupled to the anvil to follow the linear movement of the anvil. The piston may be adapted to interact with an energy storage medium when the swing arm moves the anvil in the first direction, causing energy to be stored. As the swing arm continues to rotate, the swing arm may lose contact with the anvil, thus allowing the energy storage medium to urge the piston and the anvil in a second direction opposite the first direction.

Abstract: A rock drilling machine and an axial bearing module. The rock drilling machine is equipped with an axial bearing having at least one axial piston for axially positioning a drill shank and for damping stress pulses returning from the rock. The axial bearing includes a module that is detachable in one piece from one installation direction. The axial bearing module includes the required pressure medium channels, seals, bearing surfaces, and a module frame having at least bearing housing in connection therewith.

Abstract: A fluid powered percussion tool 1 has a housing 2 with a supply channel for pressurized fluid 3, a percussion mechanism 4, a swing joint 5 arranged to carry the percussion mechanism 4 relative to the housing 2 at a point situated between the forward end A and the rear end B of the percussion mechanism 4, at least one elastically resilient element 6 arranged between the housing 2 and the percussion mechanism 4 at a distance from the swinging joint 5 and arranged to load the percussion mechanism 4 against a neutral position in the housing 2 and to absorb the vibrational movements of the percussion mechanism 4, and a flexible connection for pressurized fluid 7 for distribution of pressurized fluid from the supply channel for pressurized fluid 3 to the percussion mechanism 4. The elastically resilient element 6 includes a conical spring 8. The flexible connection for pressurized fluid 7 includes a hose 11.

Abstract: The cover is provided with engaging pieces that engage with a recessed groove provided on the outer peripheral surface of a hammer case and hold the cover on the hammer case to prevent the cover from being detached. The cover is also provided with bumper receiving portions extending from the front end of the cover and allowing the bumper to be externally attached to the cover, and engaging claws formed on the bumper receiving portions and engaging with engaged recessed portions formed on the inner peripheral surface of the bumper for holding the bumper to prevent the bumper from being detached from the cover. The cover with the bumper attached to the bumper receiving portions is provided to the hammer case.

Abstract: A motorized hammer has a body and a tool holder which is mounted on the front of the body and is capable of imparting impacts via the tool in the holder. A rear handle is, moveably mounted to the rear of the body via at least one movement control mechanism which is capable of moving towards or away from the body. A biasing mechanism biases the rear handle away from the body and each movement control mechanism includes a first mount. A rod having a longitudinal axis is rigidly connected at one of it ends to the first mount. A second mount slidingly engages with the rod at two distinct points only along its length to allow the rod to slide relative to the second mount in a direction parallel to the longitudinal axis. The second mount prevents the rod from moving in a direction perpendicular to the longitudinal axis.

Abstract: A hand-held power tool (1) is provided. The hand-held power tool has a housing, a linear drive for moving a tool along a working axis (9) and an absorber (20). The absorber (20) is formed by layers stacked in a structuring direction (23) perpendicular to the working axis (9) consisting of a baseplate (24) made of plastic, a spring element (21) comprising an elastomer, a support plate (25) made of a plastic, a spring element (21) comprising an elastomer and a mass element (22) fastened onto the support plate (25). The spring element (21) is joined to the baseplate (24) and/or to the support plate (25) with a material bond.

Abstract: The invention relates to a method for fitting a breaking device tool with a bearing, a breaking device and a tool bushing. The tool of the breaking device is fitted with a bearing with at least one bearing bushing manufactured of bearing material and arranged in a bearing space. There is a clearance fit between the bearing bushing and the bearing space, whereby the bearing bushing is insertable into the bearing space by manual force. During the use, compression stress pulses are given to the tool with a percussion device, whereby stress waves travel in the tool, which waves generate on the tool surface a movement in the direction of its perpendicular. This movement is transmitted to the bearing bushing, and it deforms the bearing bushing in the radial direction in such a way that the bearing bushing is pressed against the bearing space.

Abstract: A bumper of a driving tool has a cylindrical overall shape and also has a space portion expanding downward therein. The bumper is provided with an upper portion, an intermediate portion, and a lower portion. A normal inclined-surface, in which an outer diameter becomes larger from an upper end of a full height of the bumper toward a slightly upper position of the intermediate portion, is formed at a periphery of the upper portion. A bulging-out portion haying the largest outer diameter in the bumper is bulged out, at a periphery of the intermediate portion. A reverse inclined-surface, in which the outer diameter becomes smaller toward downward, is formed at the periphery of the lower portion.

Abstract: The invention relates to a gearing, in particular for portable electric power tools, preferably for angle grinders, comprising an automatic locking device (6, 15). According to the invention, provision is made for damping elements (20) to be integrated in the locking device module.

Abstract: The Force-Barrier is a very fast force applier and remover on or from a reciprocating body. The Force-Barrier is a completely passive device. It needs no control, and switches the force always at the same location regardless the orientation and gravity. In case the reciprocating body is driven by pressurized liquid or compressed gas, the Force-barrier is a substitute to a directional valve, or on-off valve, but faster, consuming less energy, and not being in need of control. The Force-Barrier enables the use of at least one spring and/or at least one electro motor in rebound-effectors and other reciprocating devices. The Force-Barrier may be implemented as a disk placed in between a cylinder and a piston, wherein the cylinder has two internal diameters, and the piston has two external diameters, and wherein there is a step between the two diameters of the piston and the two diameters of the cylinder.

Abstract: A hammer drill has a transmission housing 280 is formed from two clamshell halves of durable plastics or cast metal material. The transmission housing 280 is mounted on first and second damping springs 284 and 286 at its rearward end. The transmission housing 280 is also mounted on parallel rails (not shown) disposed within the tool housing 222 such that the transmission housing 280 can slide a small distance relative to the tool housing 222. The forward end of the transmission housing 280 has a generally part conical portion 290, which abuts a corresponding part conical portion 292 formed on the tool housing 222. The interface defined by conical portions 290 and 292 defines a stop against which the transmission housing 280 rests against the tool housing 222 in the inoperative condition of the hammer drill 220.

Abstract: It is an object of the invention to reduce noise caused by run-out of a tool bit in an impact tool. The representative impact tool according to the invention includes a tool holder 137 that houses a tool bit 119 in such a manner that the tool bit can linearly move in its axial direction, and a barrel 108 that is integrally connected to the tool holder 137 The impact tool further includes an elastic element 155 that is disposed between an inner circumferential surface of the tool holder 137 and an outer circumferential surface of the tool bit 119 in an end region of the tool bit 119 on the barrel side and connected in close contact with the tool holder 137 and the tool bit 119 over a predetermined length of the tool bit 119 in the axial direction. The elastic element 155 applies a biasing force to prevent a run-out of the tool bit 119 in a direction transverse to the axial direction. Further, an intermediate element 145 comes in point contact with the tool bit 119 on its axial center line.

Abstract: A power tool includes a grip, a connecting part, an elastic element, an electrical switch and an operating member. The connecting part connects the grip to the power tool body. The elastic element is disposed between the connecting part and the power tool body. The operating member is switched by a user between an energizing position and a de-energizing position. The operating member is retained in the position to which it is switched. The operating member is disposed in the connecting part in such a manner as to be slidable in a direction transverse to the longitudinal direction of the power tool body and to the extending direction of the grip.

Abstract: An oscillating tool comprises a housing that accommodates a motor which for driving a tool is coupled with a drive shaft via an oscillation drive, for driving it about its longitudinal axis rotatingly oscillatingly. For reducing vibrations, there is provided an inertial mass that is movably held on the housing via at least one spring element.

Abstract: A setting tool for driving in fastening elements includes a setting piston (20) axially displaceable in a piston guide (13) which is adjoined by a bolt guide (12), and a piston stop device (30) for the setting piston (20) and arranged at an end region of the piston guide (13) adjacent to the bolt guide (12) and having a damping element (31) supported against a stop (15), and a stop member (32) for the setting piston (20) and adjoining the damping element (31) in a direction toward the piston guide (13), with the damping element (31), the stop member (32) and the stop (15) having respective surfaces (33, 34; 35, 36) arranged axially opposite each other at least one of which is formed as an inclined surface (S) forming with a respective opposite surface an angle of from 2° to 20°.

Abstract: The present invention relates to a drill comprising a shank adapter (3), a damping piston (5) with a forward end surface (18), a stop end surface (14) for the damping piston (5), a rotation chuck bushing (4) with a forward end surface (16), a stop end surface (17) for the rotation chuck bushing, a impact piston (2) with a brake land (10) with a forward end surface (19), and a brake chamber (8) for braking of the impact speed of the impact piston (2) during idle impacts, which brake chamber (8) has a rear edge (21). According to the invention, the actual idle impact stroke length (L1, L2) of the damping piston is greater than the idle impact braking distance (L3) of the impact piston, where the actual idle impact stroke length (L1, L2) of the damping piston is the shorter of the idle impact stroke length (L1) of the damping piston and the idle impact stroke length (L2) of the rotation chuck bushing.

Abstract: A mobile drill rig has a drill mast, a carriage mounted to the drill mast for vertical movement, and a vibratory drill head having a sine generator and a rotation mechanism for imparting vibration and rotation to a drill rod string. An elastomeric torsion coupler couples the rotation mechanism to the sine generator to transmit rotational force to the drill rod string while isolating vibrations of the sine generator from the rotation mechanism. Another coupler connects the drill head to the carriage in a manner that allows floating vertical movement of the drill head relative to the carriage while isolating vibrations of the sine generator from the carriage. Elastomeric bumpers limit the vertical movement of the drill head relative to the carriage. Elastomeric spacers located between the rotation mechanism and the sine generator handle the vertical loading and maintain the proper spacing between the sine generator and the rotation mechanism.

Abstract: It is an object of the invention to reduce noise caused by run-out of a tool bit in an impact tool. The representative impact tool according to the invention includes a tool holder 137 that houses a tool bit 119 in such a manner that the tool bit can linearly move in its axial direction, and a barrel 108 that is integrally connected to the tool holder 137 The impact tool further includes an elastic element 155 that is disposed between an inner circumferential surface of the tool holder 137 and an outer circumferential surface of the tool bit 119 in an end region of the tool bit 119 on the barrel side and connected in close contact with the tool holder 137 and the tool bit 119 over a predetermined length of the tool bit 119 in the axial direction. The elastic element 155 applies a biasing force to prevent a run-out of the tool bit 119 in a direction transverse to the axial direction. Further, an intermediate element 145 comes in point contact with the tool bit 119 on its axial center line.

Abstract: A drill hammer for the three operation modes of drilling, chiseling, and hammer-drilling has a motor with a motor shaft; a gear with an intermediate shaft, a driving gear wheel, a toothed slaving shaft , a shifting hub, and a driven gear wheel; a percussion mechanism with a wobble disk and a wobble gear wheel; and a driven shaft with a driving gear wheel and a drill chuck. The gear is configured to be changed over easily without axial displacement of running gears that mesh with one another so that the drill hammer is more robust, shorter or more compact, and lighter in weight. The drill hammer is thus simply and economically constructed and whose efficiency is not impaired by the gear shifting mechanism.

Abstract: A tool bit for a chisel or a hammer drill, in particular, a insertable chisel or insertable drill for power-driven drill and chisel hammers, has an insertion end, with a chisel shank or drill shank, and a chisel head or drill shank located opposite the insertion end. The diameter of the shank increases in the direction of the chisel head at least once from a first, small diameter to a second, large diameter and decreases again from this to a small diameter or forms at least one bead.

Abstract: A pulse drilling machine (1;1?) for the generating of shock wave pulses in a tool direction (R) has an impulse piston (4;4?) with a housing (2), and a device (8) for abruptly changing fluid pressure influencing the impulse piston to achieve a force resultant on the impulse piston in the tool direction to generate a shock wave pulse in a drill string (13; 13?) which is connected to the machine, a first fluid chamber (14;3?) inside the housing which in operation is arranged to exert a pressure in the tool direction on the impulse piston. The machine has a fluid flow channel (11; 18; 19), which includes a device for damping fluid flow flowing from the first fluid chamber through the fluid flow channel obtained when influencing the impulse piston (4; 4?) in a direction opposite to the tool direction (R) by rock reflexes in the drill string during drilling.

Abstract: A demolition hammer is provided that may include a housing having a distal end, a power cell disposed in the housing, an end plate attached to the distal end of the housing, and a damper disposed in the housing between the power cell and the end plate, wherein the damper is spaced apart from the power cell by a gap. The damper may also support and align a plurality of wear plates interposed between the housing and power cell. The damper may have generally rectangular first portion having a planar upper surface and a planar lower surface generally parallel to the upper surface and a generally circular second portion extending from the lower surface, wherein the first portion and the section portion define a central through bore.

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: A power tool according to the invention includes a dynamic vibration reducer having a body, a weight and elastic elements. The body is formed by a plurality of cylindrical members which are coaxially disposed to face each other. The elastic elements exert biasing forces on the cylindrical members such that the cylindrical members are held apart from each other. The cylindrical members are fixed to the tool body side under the biasing forces of the elastic elements. Venting members for forced vibration are provided on the cylindrical members and protrude radially outward from the cylindrical members, respectively. The venting members are mounted by inserting into venting member mounting parts on the tool body side in a direction transverse to the longitudinal direction of the cylindrical members. At least one of the venting members can move with respect to the cylindrical member in the longitudinal direction.