Abstract: An anchor installation tool has an elongated member with a body portion and a head portion. The body portion includes an internal bore to receive a drill bit. The head portion projects from and has a diameter smaller than the body portion. The head portion is coaxial with the body portion. An anchor guide has a sleeve-shaped body with a bore throughout the body. The bore has a portion sized to fit over the body portion and a portion to fit over the head portion. The guide slides on the body and head portions. A mechanism retains the anchor guide onto the body portion. The retaining mechanism enables sliding of the anchor guide and prohibits removal of the anchor guide from the body portion.

Abstract: A rock breaking device employs a falling weight and a striker pin or other tool held within a tool holding structure supported by a recoil assembly includes a number of isolator structures that protect the rock breaking device by absorbing excess forces that may be applied to the recoil assembly. Each isolator structure includes a front plate that extends below a lower side of a recoil tube flange. In new rock breaking devices, the front plates may be incorporated as part of the isolator structures. Alternatively, an existing rock breaking device can be retrofitted by welding a heavy plate onto the front of an existing front plate of the isolator structures. The heavy plate extends beyond the lower side of the recoil tube flange to provide greater strength.

Abstract: A shock-absorbing element is disposed frontward of an interjacent element within a housing of an impact tool, and a washer is disposed rearward of and adjacent to the shock-absorbing element. The interjacent element is configured to come in contact with the washer when the interjacent element is caused to advance by an impactor's strike under no-load conditions. A sleeve disposed rearward of and adjacent to the washer is configured to position the shock-absorbing element and the washer, and to allow the interjacent element to move rearward and frontward inside the sleeve.

Abstract: The invention is to provide a hammer drill which is to be capable of restricting rotation of a bit in a hammer mode, and improve usability. A hammer drill includes a lock plate 51 in a housing 2, and the lock plate 51 engages with a second gear 31 so as to lock rotation of the second gear. The lock plate 51 is provided to be slidable between an engaging position with the second gear 31 and a non-engaging position, and is biased to the engaging position by a coil spring. The hammer drill further includes a restriction part 50 on an outer peripheral side of a holding tube 46 in a mode switching knob 44. The restriction part 50 abuts the lock plate 51 in one of two phases for engaging a clutch 37 with only a boss sleeve 32 so as to hold the lock plate 51 at the non-engaging position, and cancels the abutment with the lock plate 51 in the other phase to slide the lock plate 51 to the engaging position.

Abstract: A stake driver for driving wood stakes into a soil has a rectangular hollow housing having an open top and an open bottom. The bottom portion is configured for receiving at least a part of the wood stake therein, while an elongated driving shaft extends from an interior of the housing upwardly above a top edge of the housing. The upper part of the driving shaft is configured for engagement by a power transmitting tool, such as for instance a jack hammer. A driving pad is secured to a bottom end of the driving shaft transversely to the longitudinal axis of the housing. At least one hammer plate is secured, through connection to a shaft sleeve, to the driving shaft above the driving pad. The hammer plate and the driving pad are each configured to move in an axial direction inside the housing and transmit a hammering force to the wood stake. The hammering force is partially absorbed by a compression spring positioned between the hammer plate and the driving pad.

Abstract: The present disclosure relates to an anvil, an anvil and socket combination and an anvil attached to a power tool. The anvil structure includes a drive head with an end and a body portion having a channel spaced there between. A friction ring is retained in the channel. Flats are provided on the end and on the sides of the end and the square portion in a coordinating alignment such that the flats generally lie in the same plane. The ring retained in the channel between the end and the portion at least partially extends relative to the flap. A transition cone is provided on the anvil for distributing impact load. Additional, relief grooves are provided on corners of the polygon portion to help further relieve stress in the anvil structure.

Abstract: An impact adaptor to convert a rock drill to an impact driver is described. The impact adapter has a boom coupling for securing the adapter in co-operating alignment with the shank of a drifter. The adapter has a casing for slidingly receiving and guiding an anvil therein from a top open end of the casing. The casing has an open bottom end adapted for receiving a top end section of a pile, tube or rod in the casing. Anvil supports are provided in the casing for retaining the anvil captive therein in the absence of the top end section of the pile, tube or rod. The casing has a predetermined length above the anvil supports to permit captive displacement of the anvil and displacement of the top section of the pile, tube or rod therein. The impact adapter is secured to the drifter in a movable or immovable manner and compensates for wear of the shank.

Abstract: An improved valve for a portable post driver. The post driver has an inner hollow cylinder open at both ends and adapted to receive a post through a lock clamp located at its lower end. An outer hollow cylinder having a closed upper end, and slightly larger in diameter than the inner cylinder, is located in sliding engagement over the inner cylinder. First and second power cylinders are attached to upper and lower surfaces of the outer cylinder in alignment with each other. A common piston rod connects the pistons of the power cylinders. A stationary fastening pin attached to the piston rod extends through a slot in the wall of the outer cylinder and is attached to the wall of the inner cylinder. The valve has a reciprocating valve piston which alternately communicates the two power cylinders to a source of fluid under pressure.

Abstract: A hand-held power tool includes a percussion power tool includes a percussion piston (5) for applying blows to an anvil (8) axially displaceable in a guide tube (6) within limits defined by two, spaced from each other, stops (9a, 9b) arranged in the guide tube (6), a pneumatic percussion mechanism (2) for driving the percussion piston (5), an air spring (3) for connecting the percussion piston (5) with the percussion mechanism (2), and an impact ring (12) arranged coaxially with the anvil (8) outwardly thereof and having spaced from each other, inner radical flanks (14) located on opposite axial sides of the outer radial collar (11) provided on the anvil (8), with the impact ring (12) freely axially displaceable, within limits, relative to the outer radial collar (11) and having an outer diameter smaller than a guiding inner diameter of the guide tuber (6), and with a mass ratio of the impact ring (12) to the anvil (8) being equal at least 0.25.

Abstract: An auto hammer having housing, a handle and a striking device, the striking device including a striking rod for striking nails or other components in a linear reciprocating manner and a clamping mechanism for clamping nails or other components. The clamping mechanism includes clamping elements and a sleeve and the sleeve is provided with slots along which the driving portions of the clamping elements may slide so that the clamping elements are movable between a closed position and an opened position. This clamping mechanism can reliably clamp nails or other components to facilitate the operation of the user.

Abstract: In a driving tool, a diameter of an intermediate member is enlarged to increase a mass of the intermediate member and an outside diameter of a cylinder at a position where the intermediate member is internally provided is enlarged in accordance with the enlarged diameter of the intermediate member. Further, in the driving tool, a bearing thickness of a ball bearing is reduced correspondingly to a dimension of the enlarged outside diameter of the cylinder and a washer is provided at a part where the ball bearing abuts on the cylinder in the forward and backward moving direction thereof.

Abstract: An anvil assembly for a tool includes an anvil having a body with an outer periphery and a head formed on a distal end of the body. The anvil assembly also includes a sleeve surrounding at least a portion of the outer periphery of the body. The sleeve has a distal end against which a tool element is abutted when the tool element is coupled to the head.

Abstract: A pneumatic impact wrench includes a handle assembly graspable by a user, a work attachment connected to the handle assembly, an inlet permitting air flow to drive the impact wrench, an outlet permitting air flow out of the impact wrench, a motor assembly positioned between the inlet and the outlet includes a rotor driven by the air flow between the inlet and the outlet. The motor assembly defines a longitudinal motor axis about which the rotor rotates. An output drive is connected to the motor assembly to selectively rotate in response to rotation of the rotor, the output drive defines a longitudinal output axis about which the output drive rotates, the longitudinal output axis is substantially perpendicular to the longitudinal motor axis, and an impact mechanism is positioned between the motor assembly and the output drive to selectively drive the output drive in response to rotation of the rotor.

Abstract: A tool assembly provided with a housing defining a chamber, and a reciprocating work tool arranged in the chamber, is disclosed. A tool retention member has an aperture through which the work tool extends. Engaging structure including mutually engaging protrusions on the housing and the tool retention member is configured to permit engagement of the tool retention member with the housing by relative rotation of the tool retention member and the housing. Retention structure on the work tool is configured to prevent removal of the work tool from the housing when the tool retention member is engaged with the housing. A locking structure is configured to lock the tool retention member and housing against relative rotation. A prestressing structure is located between the protrusions on the housing and a portion of the tool retention member and is configured to urge the tool retention member away from the housing.

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: 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: This apparatus is a steel driving cap for forcibly driving wooden stakes into the ground utilizing a sledgehammer for striking the driving cap. The apparatus is constructed of tubular steel of various dimensions to accommodate various sizes of wood stakes. The apparatus also has a flat steel surface of various thickness (depending on the size of the wood stake) welded to the top of the apparatus to form a cap, used for striking with a hammer or sledgehammer. The apparatus also has a steel handle welded to the back side of the apparatus, used by a second person for guiding the stake as it is being driven.

Abstract: A slide hammer for driving a probe into the ground includes a probe lifting and removal arrangement in which a slide hammer tube is pivoted away from the probe to function as a lever operating with a clutch arrangement to incrementally withdraw the probe from the ground. A biasing arrangement using a coil spring is operative to hold the anvil in a locked probe driving position, to facilitate release of the tube from the locking position for pivotal movement to the probe removal position, to bias a clutch disk to a release position with respect to the pin, to facilitate incremental lifting contact between the clutch disk and the pin, and to return the tube to a subsequent incremental lifting position.

Abstract: A striking mechanism includes a working space whose first section is surrounded by a first electromagnet and whose second section is surrounded by a second electromagnet; a striking element that can move along a striking axis inside the working space and that has a magnetizable material; an anvil whose striking surface delimits the working space in the striking direction and which protrudes into the first magnetic coil and which is made of a magnetically soft material. A spring element is provided which exerts a force onto the striking element in every position in the working space in the direction of the anvil.

Abstract: A control system for use in conjunction with a primary power system and operable to control a pneumatically powered hand-held tool broadly comprises an air delivery assembly operable to communicate with a pressurized air source; a control assembly including an exhaust line from the primary power system and to the control assembly, a spool valve in fluid communication with the supply line and the exhaust line, and a control line in fluid communication with the spool valve and the hand-held tool; a tool assembly comprising the hand-held tool for performing delicate hand working operations; and a housing for at least partial storage of the air delivery assembly and the control assembly. The primary power system and the control system operate in conjunction with each other to both power and precisely control a pneumatically powered hand-held tool.

Abstract: The Survey Hub Installation apparatus is principally comprises an elongated rod having a penetration point and penetration anvil at a first end and a Hub receptacle and Hub receptacle anvil at a second end. A hammer is tubularly received at the rod intermediate the penetration anvil and the Hub receptacle anvil. A feather receptacle and a feather hammer is formed at the second end.

Abstract: A number of cam-operated devices such as power tools (10) are described, the tools having a rotary drive device (24) for rotating a drive shaft (36) having a cylinder cam (42) mounted thereon. A pair of cam followers (54) are located within a cam track (44) provided on the cam member (42), such that rotation of the cam (42) causes axial movement of the cam followers (54), which may be attached to a drive shaft (48) and a tool bit (12). A range of shapes of cam track (44) are described, each of which is non-sinusoidal in shape. Various embodiments of the invention provide non-sinusoidal cam tracks having forward or rearward throw sections which are respectively steeper, shorter, or provide greater acceleration of the cam followers than sinusoidal cam tracks of equivalent wavelength and amplitude. Related piston and cylinder devices and reciprocal drive devices are also described.

Abstract: A power driven tool for rotating a mechanical element. The tool includes a housing and motor. The motor has an output shaft. The shaft rotates relative to the housing. The tool also includes an impact drive axially fixed within the housing. The impact drive includes a base and an anvil shaft having an anvil. The impact drive includes an annular hammer having opposite impact lands pivotally mounted on the base for movement between three positions, including a forward position in which the hammer is positioned so one impact land engages the anvil, a reverse position in which the hammer is positioned so another of the impact lands engages the anvil, and a disengaged position in which neither of the impact lands engages the anvil. Further, the tool includes a ratchet mechanism. The ratchet mechanism includes an output drive mounted for rotation relative to the housing for rotating a mechanical element.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.

Abstract: The present invention relates to a combustion-type pile-driving device, comprising a cylinder having a closed upper end and an open lower end, which cylinder is freely movable as a piston with respect to an anvil which seals the lower end of the cylinder, a ram which is freely movable as a piston with respect to the cylinder and the anvil in the cylinder, and an injection device for injecting a fuel into a combustion chamber formed between the ram and the anvil in the cylinder for driving the ram upward by combustion of the injected fuel, wherein a second injection device is provided for injecting fuel into a second combustion chamber formed in the cylinder between the ram and the closed upper end of the cylinder for driving the ram downward and driving the cylinder upward by combustion of the injected fuel. The invention further relates to a method for using such a pile-driving device.

Abstract: A rock drilling machine with a first control means (21, 22) within a second piston (6) and acting on a first piston (13) such that it counteracts displacement of the relative positions of a first and a second control device at the moment of contact of the second piston onto the drill rod or onto a part (9) connected to this. Furthermore, a rock drill rig comprising such a rock drilling machine and a method for counteracting the said displacement. Significant improvements in reproducibility for impact mechanism stability over long manufacturing series are achieved through the invention. In the same way, the lifetime of rock drilling devices manufactured according to the invention is extended through the impact mechanism acting in a more stable manner despite wear of component parts. It is furthermore possible to dimension for higher rates of impact without risking the impact mechanism stability.

Abstract: A device for a drilling hammer and/or percussive hammer has a tool holding fixture for holding a tool and for transmitting a torque to the tool. A component of the tool holding fixture consists of a hollow cylindrical tool holder, which has an insertion opening for an insertion end of the tool, and has an impact opening, via which a percussive action can be applied to the insertion end. A stopping surface, which is stationary with regard to the tool holder and which acts in an axial direction of the tool holder, is provided in the tool holder in the area of the impact opening. The tool holding fixture is particularly suited for insertion ends according to the SDS-max standard.

Abstract: A powered hammer includes a housing, a tool holder coupled to the housing and configured to hold a tool, a motor within the housing, a piston slideably mounted within the housing, a drive mechanism that converts rotary output of the motor into a reciprocating motion of the piston, a ram slideably mounted forward of the piston and that is reciprocatingly driven by the piston, and a beat piece support mounted in the housing forward of the ram. A beat piece is slideably supported by the beat piece support. The beat piece is repetitively struck by the ram and that in turn repetitively strikes an end of a tool when the tool is held in the tool holder to transfer the momentum of the ram to a tool. The beat piece support includes a seal that is slidingly engaged by the beat piece. The seal includes an absorbent material.

Abstract: An impact drill that includes a drive motor located in a motor housing, an impact mechanism, and a tool fitting. The tool fitting and the impact mechanism are components of a swivel device that is located such that the swivel device may swivel relative to the motor housing.

Abstract: A percussion device (5) for a rock drilling machine (1) including a percussive piston (6; 15) which is reciprocally movable inside a cylinder and an impact receiving element (7;16) with an impact surface (A;A?), against which the percussive piston is arranged to perform strikes in an impact direction for transferring of percussive energy through Shockwaves to a percussive tool. The percussion device is distinguished by the impact receiving element (7; 16) including a Shockwave modifying portion (9; 17) which extends in a direction opposite to the impact direction as seen from a plane (P; P?) through the impact surface (A; A?). The invention also concerns a rock drilling machine and a rock drilling rig.

Abstract: A pneumatic percussion mechanism for a hand-held power tool includes a percussion piston (23) displaceable in a guide tube (21) for applying impacts to an anvil (24), a driving member (22) reciprocating in the guide tube (21) for driving the percussion piston, and an air spring (25) for transmitting a driving torque from the driving member (22) to the percussion piston (23) and directly switchable on and off by the anvil (24).

Abstract: A powered hammer includes a housing, a tool holder coupled to the housing and configured to hold a tool, a motor within the housing, and a piston slideably mounted within the housing. A drive mechanism converts rotary output of the motor into a reciprocating motion of the piston. A ram is slideably mounted within the housing, forward of the piston, and is reciprocatingly driven by the piston. A beat piece is slideably mounted forward of the ram. The beat piece is repetitively struck by the reciprocating ram, which in turn repetitively strikes an end of the tool when held in the tool holder to transfer the momentum of the ram to the tool. A vibration dampener is coupled to the housing and is configured to remove metal splinters from lubricating fluid in the housing while counteracting vibration generated by movement of at least one of the piston, the ram, and the beat piece.

Abstract: A tool assembly such as a hammer assembly, includes a housing defining a chamber and a reciprocating piston arranged in the chamber for cyclical movement in a work stroke and a return stroke. The housing includes a lower housing member, an upper housing member and an engaging structure which permits the engagement of the upper housing member with the lower housing member by relative rotation of the upper and lower housing members, such that each of the lower and upper housing members defines a portion of the chamber. The upper housing member is a precision component which contains the hydraulic components or other drive components necessary to drive the piston, while the lower housing member can be manufactured separately since it does not need to be manufactured to the high tolerances required by the upper housing member. The resulting tool assembly may be more compact than a conventional tie rod tool assembly.

Abstract: A breaking apparatus (1) including a movable mass (3) for impacting on a striker pin (4), a housing (2) and a striker pin (4) configured to partially protrude through the housing (2), the apparatus (1) characterised in that the striker pin (4) is configured to be beatable in a plurality of retaining locations relative to the housing (2).

Abstract: A tool assembly provided with a housing defining a chamber, and a reciprocating work tool arranged in the chamber, is disclosed. A tool retention member has an aperture through which the work tool extends. Engaging structure including mutually engaging protrusions on the housing and the tool retention member is configured to permit engagement of the tool retention member with the housing by relative rotation of the tool retention member and the housing. Retention structure on the work tool is configured to prevent removal of the work tool from the housing when the tool retention member is engaged with the housing. A locking structure is configured to lock the tool retention member and housing against relative rotation. A prestressing structure is located between the protrusions on the housing and a portion of the tool retention member and is configured to urge the tool retention member away from the housing.

Abstract: A drop-hammer apparatus that can repeatedly lift and release a weighted hammer over a specified vertical distance by using a gear with teeth along less than its entire perimeter.

Abstract: A hand-held power tool a percussion mechanism (2) of which includes a percussion piston (4) displaceable by an air spring (3) of the power tool for applying blows to an anvil (5) that is dust-tightly and lubricant-tightly sealed with respect to its guide by two axially offset sealing elements (8) between which a lubricant chamber (9) for receiving a barrier lubricant (10) is formed.

Abstract: A driving mechanism for a powered hammer having a motor and a tool holder includes a ram mounted for reciprocation in a guide tube section. The ram has a radially outwardly projecting sealing portion and an outer circumferential surface that defines a helically shaped vent channel running from a front end portion of the circumferential surface to a rear end portion of the circumferential surface and being interrupted by the sealing portion. A piston is driven in reciprocating motion of the motor such that an air cushion is generated in a space between the ram and the piston to cause an impact on the tool bit by movement of the ram towards the tool bit. The space between the ram and the piston is temporarily connected with ambient air through the helical vent channel and a recess in the wall of the guide tube section after causing the impact on the tool bit.

Abstract: A tool assembly (10), for example a hydraulic or pneumatic hammer assembly, includes a housing (11) defining a chamber (16), a removable reciprocating work tool (20) arranged in the chamber, and a tool retention member (80) having an aperture through which the work tool extends. The housing (11) includes an engaging structure (50) which permits the engagement of the tool retention member (80) with the housing by relative rotation of the tool retention member and housing. The work tool (20) is provided with retention structure (44) such as a retaining flange which prevents the removal of the work tool from the housing when the tool retention member is engaged with the housing. At least some of the disclosed embodiments may eliminate the need for a retainer pin, thereby allowing the work tool to rotate, possibly avoiding wear, increasing tool life and simplifying tool replacement.

Abstract: A hand-held percussion power tool includes a pneumatic mechanism (20) having a guide (21) and a striking member reciprocating in the guide (21), and a braking device (30) for the striking member and including at least one braking member for breakingly engaging the striking member and formed as a pivot lever (31) a pivotal movement of which is controlled by the striking member.

Abstract: A pneumatic percussion mechanism for a hand-held power tool includes a percussion piston (23) displaceable in a guide tube (21) for applying impacts to an anvil (24), a driving member (22) reciprocating in the guide tube (21) for driving the percussion piston, and an air spring (25) for transmitting a driving torque from the driving member (22) to the percussion piston (23) and directly switchable on and off by the anvil (24).

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 hydraulic impact mechanism includes a housing with a cylinder bore, a forward working chamber and a rear working chamber, a hydraulic fluid supply passage connected to the forward working chamber and a drain passage connected to the rear working chamber, a hammer piston reciprocally guided in the cylinder bore for delivering blows to a working implement attached to the housing, a pressure accumulator pre-loaded to a certain pressure level, and a distribution valve for alternatingly connecting the rear working chamber to the supply passage and the drain passage to thereby reciprocate the hammer piston, wherein a sequence valve is provided in the drain passage to keep up the pressure in the rear working chamber so that the resulting forward directed force prevents the piston from being moved backwards in the cylinder bore at pressure levels in the supply passage below the pre-load pressure level of the accumulator.

Abstract: A pile driving control apparatus for a pile driving system includes a hydraulic control system that controls a throttle of a pile driving hammer, and thereby controls an impact velocity of the hammer with a pile. A controller provides a control signal to the hydraulic control system. Based on the control signal, the hydraulic control system controls an impact velocity of the hammer during a subsequent hammer stroke. The controller may determine one or more control parameters such as sound pressure at a sound control location during a hammer stroke, vibration at a vibration control location during a hammer stroke, an impact force imparted to the pile during a hammer stroke, and/or actual pile capacity of the pile, and provide to the hydraulic control system a control signal based on the determined control parameter(s).

Abstract: The invention is based on a portable power tool, in particular a hammer drill and/or a rotary demolition hammer, comprising a motor (10a, 10b, 10c) and a motor shaft (12a, 12b, 12c), comprising a percussion mechanism unit (14a, 14b, 14c) which can be driven by the motor (10a, 10b, 10c) for achieving an impulse in the direction of a percussion axis (16a, 16b, 16c) and which has an axial drive unit (18a, 18b, 18c) having an output means (20a, 20b, 20c), and comprising a transmission unit (22a, 22b, 22c) which is provided for transmitting a drive force 15 from the axial drive unit (18a, 18b, 18c) to a piston unit (24a, 24b, 24c). It is proposed that, in the region of the transmission unit (22a, 22b, 22c), the motor shaft (12a, 12b, 12c), as viewed in the longitudinal direction 20 of the percussion axis (16a, 16b, 16c), be directed laterally past at least one part of the transmission unit (22a, 22b, 22c).

Abstract: An impact handle for a shovel and other tools to assist the user or laborer in digging and/or moving material such as dirt or snow, or other compacted materials. An impact handle with a shovel attachment would have similar physical features as generic shovels on the market today. However, the impact handle includes an impact generator within the handle. As a user or operator applies his/her foot-pressure on the foot actuator located at the top of the scoop or blade, the impact generator using electro-magnetic principles produces impulses of 1 to 10 hertz of downward blows. These impulses reduce the effort required by the operator to force the tool scoop or blade to penetrate the material being excavated. The impact handle dramatically reduces time required to complete hand excavation projects. The impact handle can also be used, but is not limited to, to reduce the time required for chiseling, scraping, prying, nail pulling and carpet-stretching.

Abstract: A pneumatic hammer drill includes a tool connected to a pneumatic cylinder having an air valve assembly, return- and forward-stroke chambers, a piston, and a connecting passage interconnecting fluidly the return- and forward-stroke chambers. When the piston approaches the tool, the connecting passage permits air to flow from the return- to the forward-stroke chamber so that the pressure in the return-stroke chamber is reduced, and the speed of a forward stroke of the piston is increased. When the piston approaches the air valve assembly, the connecting passage permits air to flow from the forward- to the return-stroke chamber so as to reduce the pressure in the forward-stroke chamber so that the piston moves close to the air valve assembly during a return stroke thereof and the length of the forward stroke is increased.

Abstract: A power tool (1) having a striking means (5), by which a percussive tool (2) that can be driven at least partially along an axis (A) struck directly and having a flushing bore (4) extending at least partially longitudinally through a tool shank (3), and having a flushing head (6) having a radially inwardly open transverse bore hole (8) connected in a flow-through fashion with a fluid channel (7). The flushing head (6) has at least one hollow cylindrical sleeve-like guide surface (9), which is fitted for an insertion end (10) of the striking tool (2). The striking means (5) sealed by a seal (11a, 11b) is cup-like. The striking means (5) is moveably guided and made fluid tight by the seal (11a, 11b) to embrace the machine-side part of the insertion end (10) having the machine-side open flushing bore (4).

Abstract: A percussion bolt for a percussion mechanism of a power tool has a bolt element having a contact shoulder, said contact shoulder as seen in circumferential direction having a cross-section which varies.

Abstract: A wholly air-controlled impact mechanism invented for creating a more compact and powerful pneumatic wrench comprises a flying hammer, a pressure impulse generator and a pressure container containing the hammer and the generator. The main part of the flying hammer is a flywheel with 2 cavities and a number of air passages. A pilot valve and an impact pin are fitted in the cavities. The impact pin rests in its cavity during energy-accumulation phase and stretches out rapidly from the flywheel to finish an impact during impact phase. The generator transmits pressure impulse periodically, affecting the differential pressure acting on the pilot valve. The higher the differential pressure, the greater the impact torque developed. The unique design of the air passages of present invention results in a very reliable, powerful and durable energy-accumulating pneumatic wrench. Its production cost is much lower due to simplicity of its configuration.