Abstract: A hammer drill includes a motor; a spindle rotatingly driven by the motor and holding an output bit; a motion conversion member for converting rotational movement of the motor to reciprocating movement; a striker reciprocatingly driven by the motion conversion member for applying an axial striking force to the output bit; a striking-motion-releasing mechanism for releasing the striking force applying action exercised by the striker; and a tightening-torque adjusting clutch for interrupting the transfer of the rotational force to the output bit by increasing a load torque.

Abstract: A power tool having a rotary impact mechanism and a mode change mechanism. The impact mechanism is driven by an output member of a transmission and includes a hammer and an anvil. The mode change mechanism includes a mode collar that is movable between a first position, in which the mode collar directly couples the hammer to the transmission output member to inhibit movement of the hammer relative to the spindle, and a second position in which the mode collar does not inhibit movement of the hammer relative to the spindle. A power tool having an impact mechanism with an external adjusting member that can be moved to vary a trip torque of the impact mechanism is also provided.

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 invention relates to a hand-held power tool, in particular a hammer drill which has a hammer drive, a rotary drive, a switching device, and a main output element. The switching device has a slide mechanism, which is designed for switching between different operating modes. According to the invention, the slide mechanism has at least one coupling element, which in at least one operating mode is directly coupled to a coupling element, the latter being rotationally fixed to the main output element.

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 power tool including a drive assembly including a first clutch assembly having an engaged configuration, in which the first clutch assembly transfers a drive force from a motor shaft to a spindle, and a disengaged configuration, in which the first clutch assembly prevents the transfer of the drive force. The first clutch assembly can be movable toward the disengaged configuration when a torque exerted on the spindle exceeds a torque limit. The drive assembly can also include a second clutch assembly having an engaged configuration, in which the second clutch assembly transmits the drive force from the motor shaft to the spindle, and a disengaged configuration, in which the second clutch assembly prevents the transmission of the drive force. The second clutch assembly can be movable toward the engaged configuration when the tool element engages a workpiece.

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 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: It is an object of the invention to provide an improvement in ease of operation of a driving mode switching mechanism in a hammer drill. According to the invention, a representative hammer drill includes a driving mode switching mechanism which has an operating part, a first switching member and a second switching member. The operating part can be turned to at least three rotating positions in its circumferential direction, while the operating part can be turned 360° on the rotation axis in the both directions. Thus, the user can select the desired driving mode in the shortest turning distance without passing though an unnecessary driving mode position. Therefore, ease of operation in mode change can be enhanced.

Abstract: In a hammer drill, a coil spring is disposed rearward of a piston cylinder inside a housing so as to press the piston cylinder to an advanced position when the hammer drill operates in a drill mode, and a supporting plate is disposed at a rear end of the piston cylinder. The supporting plate includes a pair of side plates and a base portion connecting front ends of the side plates. The base portion is in contact with a rear surface of the piston cylinder, and rear ends of the side plates are in contact with a front end of the coil spring. Openings provided in the side plates are configured to hold a pin on which a connecting arm is pivoted.

Abstract: The invention relates to an impact wrench having a drive motor for driving a drive shaft (30) and an output shaft (10) that can be coupled to a tool holder, and having an impact mechanism, the impact mechanism comprising an anvil (14) coupled to the output shaft (10), and having a hammer (20), which is guided on the drive shaft (30) and rotates with the latter in the case of non-impact and, in the case of impact, executes a rotational movement relative to the drive shaft (30), an actuating means (23) being provided for switching the impact mechanism between an operating mode with the impact mechanism switched on and an operating mode with the impact mechanism switched off, the actuating means (23), in a first position, the impact mechanism having been switched on, being in rotationally fixed engagement with the drive shaft (30) or the hammer (20), or being without engagement with the hammer (20) or the drive shaft (30), and, in a second position, the impact mechanism having been switched off, being in rotatio

Abstract: The invention relates to an impact wrench having a drive motor for driving a drive shaft (10) and an output shaft (38) that can be coupled to a tool holder, and having an impact mechanism, the impact mechanism comprising an anvil (36) that has first impact cheeks (34) and that is coupled to the output shaft (38), and comprising a hammer, which is guided on the drive shaft (10), the hammer having second impact cheeks (24), which engage with the first impact cheeks (34) for the purpose of rotary transmission, wherein the hammer comprises a rotating mass (22) and a control part (20), the control part (20) carrying the second impact cheeks (24) and rotating with the drive shaft (10) in the case of non-impact and, in the case of impact, executing an axial and, preferably, additional, rotational oscillation relative to the drive shaft (10), the control part (20) transmitting the rotation of the drive shaft (10) to the rotating mass (22) and being movably guided in the axial direction in the rotating mass (22) for t

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 invention is an electric hand tool embodied as a hammer drill and/or slide hammer, with a work spindle, a striking tool, and an electric drive motor which can be connected to an intermediate shaft driving the work spindle and/or to a striking tool drive, via a transmission and coupling device. The transmission and coupling device have a transmission, and the transmission is-a multi-stage spur gear mechanism, the gears of which are shifted by axial displacement of the intermediate shaft.

Abstract: This invention discloses a percussion toggle device of a percussion driller. It includes bottom ratchet wheel that joggles the top ratchet wheel fixed in the output main shaft of the percussion driller, the locking ring used to lock the rotating direction of bottom ratchet wheel, the ejector rod to eject the locking ring, the slide rod that works with ejector rod to make it rise or fall, the percussion button connecting the slide rod, the positioning device to fixate the position of slide rod, and the reset device that works with the positioning device to remove the position limitation by the positioning device. This invention locks the rotating direction of bottom ratchet wheel through the independent percussion button, slide rod and ejector rod. In this way, the percussion toggle and the adjustment of torque force of the percussion driller can be separated. When using the percussion button, the user can toggle their operation between percussion and torque force.

Abstract: It is an object of the invention to provide an effective technique for improving the durability of a torque limiter utilized in a power tool. The object is achieved by a representative power tool comprising a tool bit, a driving mechanism and a torque limiter. The torque limiter includes first and second rotating members, a ball, a pressing member and an elastic member. The second rotating member includes a power transmitting region with a groove continuously formed from a deepest groove part to a shallowest groove part to allow torque transmission and a power transmission interrupted region with a groove shallower than the shallowest groove part of the power transmitting region to interrupts the torque transmission. According to this construction, when the ball is in the power transmitting region, the pressing member contacts the first rotating member and is held in a position in which the biasing force of the elastic member is prevented from acting upon the ball.

Abstract: A clutch device for an electric machine tool that is drivable in a fashion selected from the group consisting of a rotary fashion, a percussion fashion, and both with an impact mechanism deliberately disengageable from or engageable with a spindle that drives a plug-in tool, has an intermediate shaft arranged between the spindle and an armature shaft of a drive motor and configured for transmitting drive energy, the intermediate shaft being axially movable so that the electric machine tool is switchable between operating modes through an axial movement of the intermediate shaft.

Abstract: A power hand tool includes a housing; an electric motor mounted in the housing for provide a rotary motion; a transmission gear set is mounted in the housing and connected with the electric motor; a torsion control device having a first rotary knob, which can adjust the maximum torsion output of the transmission gear set while being turned, and a plurality of first dents formed on an internal periphery thereof; an impact device having a second rotary knob, which can switch on or off an impact motion generated on the transmission gear set while being rotated, and a plurality of second dents formed on an internal periphery thereof; and a locating device having a holder fixed to the torsion control device and a locating member mounted to the holder, the locating member having two resilient portions, each of which has a convexity engaged with the associated first dents or second dents.

Abstract: It is an object of the invention to provide a technique for further improving the vibration reducing performance in a power impact tool that linearly drives a tool bit by using a swinging mechanism. According to the invention, a representative power impact tool is provided with a motor, a rotating shaft, a swinging member, a tool driving mechanism and a counter weight. The swinging member is supported by the rotating shaft to swing in the axial direction of the rotating shaft by rotation of the rotating shaft. The counter weight is disposed in a region higher than a lower end region of the swinging member in the vertical direction to intersect with the axis of the rotating shaft, and a lower end of the counter weight is connected to the lower end region of the swinging member.

Abstract: An impact tool includes: a spindle disposed in a housing; an anvil disposed in front of the spindle and rotatably supported by the housing through a metal bearing, a rear surface of the anvil having a bearing hole in which a front end of the spindle is received; an impact mechanism configured to transmit a rotation of the spindle to the anvil; an outer groove formed on an outer periphery of the anvil and opposed to the metal bearing; and a connecting opening radially extending in the anvil and connecting the bearing hole and the outer groove to provide a communication therebetween. The outer groove is formed to have a depth in the range of 3-10% of an outer diameter of the anvil, and the connecting opening opens at a rear end of the outer groove in an axial direction of the anvil.

Abstract: A hand-held hammer drill has a housing, a tool spindle rotatingly driving a tool, a hammer action percussion-driving the tool, a swash plate drive driving the hammer action, and a countershaft driving as needed the tool spindle and the hammer action. A first bearing and an axial bearing are provided. The hub is rotatably supported in a cantilevered arrangement by the first bearing in the housing and coaxially surrounds the countershaft. The hub has a free cantilevered end and the axial bearing is disposed on the free cantilevered end, wherein the axial bearing axially supports the countershaft and has radial play relative to the countershaft.

Abstract: A handheld power tool has a housing, a tool receptacle, a motor having a motor shaft, an intermediate shaft, an element for transmitting a rotation of the motor shaft to a rotary motion of the intermediate shaft, a drive mechanism for a tool insertable into the tool receptacle, the drive mechanism being provided with an element for converting the rotary motion of the intermediate shaft into a rotary motion of the tool receptacle and an element for converting the rotary motion into the intermediate shaft into a hammering motion of the tool receptacle, wherein the motor shaft is coaxial with the intermediate shaft, and there is an element for coupling the motor shaft to the intermediate shaft.

Abstract: A power tool has a motor, a clutch device for adjusting torque, a percussion device which has two cam discs, and two adjusting rings for selectively setting four operating modes including a “screwdriving” operating mode, an “impacting” operating mode, a “drilling” operating mode and a “percussion drilling” operating mode. One of the two adjusting rings is a torque adjusting ring operable to select one of the “screwdriving” operating mode, the “impacting” operating mode, and the “drilling” operating mode while the other one of the two adjusting rings is a percussion ring operable to selectively set “percussion drilling” operating mode.

Abstract: A handle housing for a handle for a power tool, the handle housing having a first housing part; and a second housing part adapted to be mounted to the first housing part and subjected to a bending stress when mounted to said first housing part, the said first and second housing parts defining a chamber for accommodating one or more components of the power tool.

Abstract: A vibration reduction apparatus for use with a hammer tool having a hammer piston is disclosed. The hammer piston is caused to reciprocate in the cylinder by rotation of a gear wheel and crank drive. A cam is mounted around the gear wheel, a counterweight surrounds the piston cylinder, and a cam follower is provided on the counterweight. The cam follower on the counterweight is urged into contact with the cam by a biasing element. The external profile of the cam is such that rotation of the gear wheel causes oscillation of the counterweight in antiphase to motion of the hammer piston to counteract vibrations produced by operation of the hammer action of the tool. A mechanism is provided to deactivate the vibration reduction apparatus when the hammer action of the tool is deactivated.

Abstract: An intermediate shaft 3 operatively coupled to a motor and a tool holding sleeve 11 for holding a tip end tool 22 are disposed in a housing 1 in parallel with each other. A motion converting member 5 for converting rotary motion to reciprocating motion thereby to operate the tip end tool 22 to hammer is rotatably provided on the intermediate shaft 3. A first clutch 6 is provided between the intermediate shaft 3 and the motion converting member 5. A clutch sleeve 25 which is coupled to the intermediate shaft 3 by way of a rotation transmitting member, and a second clutch 27 which rotates integrally with the tool holding sleeve 11 and can move in a longitudinal direction of the tool holding sleeve are arranged on an outer periphery of the tool holding sleeve 11. The second clutch 27 is provided so as to be engaged with and disengaged from the clutch sleeve 25.

Abstract: A power tool includes a mode switching device that includes a mode switching member turned by manual operation, a linearly moving driven-side member and a mode switching mechanism actuated by linear motion of the driven-side member. The actuating member is disposed on the mode switching member such that the initial position of the actuating member is located in a position displaced in a radial direction from the rotation axis of the mode switching member. When the mode switching member is turned, the actuating member revolves in a circular arc movement in contact with the driven-side member to linearly move the driven-side member. The actuating member is structured to move radially inward of the mode switching member from the initial position toward the rotation axis of the mode switching member with respect to the mode switching member.

Abstract: A switching device for an impact power tool includes an input unit, a clutch unit, an output unit and a spring. The clutch unit is cooperated with the spring and located between the input unit and the output unit. The clutch unit includes a clutch disc connected to an input shaft of the input unit and a collar. The output unit includes an output shaft with struck blocks and a pounding member with striking blocks. When the collar is moved and connected with the clutch disc, the input shaft, the pounding member, the collar and the output shaft rotate simultaneously. The output shaft outputs rotation only. When the collar is moved and disengaged from the clutch disc, the input shaft drives the pounding member and the pounding member drives the output shaft to rotate. The output shaft outputs rotation with impact intermittently.

Abstract: Disclosed is a drill hammer (10) comprising a half shell-type housing (12) that accommodates the parts mentioned below, a motor (16) with an on-off switch (18) and a motor shaft (22) with a motor pinion (24), a gear mechanism (26) with an intermediate shaft (28), a driving gear (30), an entrained gear (32) with a shifting sleeve (34), and an output gear (35), an impact mechanism (36) with a swashplate (40), an eccentric gear (38) with an eccentric finger (42), and an impact element (44), as well as an output shaft (46) with a driving gear (48) and a drill chuck (50). The motor (16) meshes with the driving gear (30) of the intermediate shaft (28) via the motor pinion (24) thereof. The rotary movement of the motor (16) can be alternatively adjusted to an exclusively rotary movement, an exclusive lifting movement, or a rotary lifting movement of the output shaft (46) by means of the gear mechanism (26) by displacing the shifting sleeve (34) with the aid of shifting means (52).

Abstract: A portable power drill or hammer drill having a housing (12) which consists in particular of half shells (13, 14) and accommodates a manual gearbox (26), wherein a shift element (59) that can be rotated by hand converts its rotary movement into a shift movement, can be produced cost-effectively and can be easily operated, without lubricant escaping from the housing (12), by the shift element (59) consisting of a shell-like handle part (100) which can be joined together with a further, shell-like shift part (102) in a sealing manner from outside and inside relative to a housing shell (13).

Abstract: A power tool with a housing, an electric motor having an output shaft that provides a first output torque, a first gear reduction element driven by the output shaft to provide a second output torque, a second gear reduction element, which can be operated in active and inactive modes, driven by the first gear reduction element to receive the second output torque and to provide a third output torque, a third gear reduction element, which is operable in active and inactive modes, driven by the first gear reduction element to receive the second output torque and to provide a fourth output torque, an output spindle operably driven by the second gear reduction element or the third gear reduction element, and a shift actuator. The shift actuator is employed to position the second and third gear reduction elements to achieve at least three overall speed ratios.

Abstract: A shift bracket can be mounted on a shift rod for movement between a first, high-speed drilling mode and a second, low-speed drilling mode. Cooperating shift lock surfaces can be associated with the shift bracket and the shift rod, respectively. For example, a groove in the can create a shift lock surface on the shift rod. The shift bracket can be moved into a locked configuration where the cooperating shift lock surfaces can engage each other preventing movement of the bracket out of the high-speed drilling mode. The hammer mode can correspond to the high-speed drilling mode, but not to the low-speed drilling mode. A spring member can bias the bracket toward the locked position. An actuation member can be coupled to the shift bracket to overcome the biasing member and to rotate or perpendicularly move the bracket into an unlocked position. The actuation member can also move the shift member from the first mode to the second mode.

Abstract: A drill includes a housing with a motor coupled to an output spindle via a transmission. A mode collar can be rotatably mounted on the housing for movement that corresponds to different modes of operation. The mode collar can be coupled to an electronic switch to operate a movable member thereof. The coupling can include a switch housing including a slide member, an actuation spring member and a return spring member. The mode collar can have a cam surface and a cam follower in the form of a shift pin that moves the slide member, causing actuation of the switch. The actuation spring member provides a biasing force that is sufficient to overcome a biasing force of a switch spring member to move the movable member into the actuated position. The mode collar can also enable and disable contact between a fixed hammer member and a movable hammer member mounted around the output spindle.

Abstract: A drill housing supports an output spindle comprising a material that is relatively soft. The non-rotating hammer member can be mounted around the output spindle, adjacent its forward end, and adjacent the relatively soft material of the drill housing. The non-rotating hammer member can include support slots located along its edge. Support rods that are made of a relatively hard material can extend through the support slots to support the non-rotating hammer member. A plurality of recesses can be provided in the relatively soft material of the drill housing to support the non-rotating hammer member. A hammer mode shift mechanism can be configured to move the non-rotating hammer member along the support rods between a first position corresponding to a non-hammer mode and a second position corresponding to a hammer mode. The relatively hard support rods support the non-rotating hammer member to thereby resist damage to the relatively soft material of the housing member.

Abstract: A drill includes a housing and a motor coupled to an output member by a transmission. The transmission can selectively couple the output member to an output spindle through a low speed output gear or a high speed output gear for rotating the output spindle at a first speed or a second speed, respectively. Alternatively or additionally, a low speed mode can be provided by actuating an electronic switch that limits the speed of the motor. A rotatably fixed hammer member and a rotatable hammer member can be mounted around the output spindle. A mode collar can be rotatably mounted on the, housing and around the output member for movement to positions that correspond to various mode of operation, including a low speed mode, a high speed mode, and a hammer-drilling mode. In the hammer-drilling mode, the transmission operates in the high speed mode.

Abstract: A multi-mode drill can include a transmission to transfer torque from an output member of a motor to an output spindle. A transmission housing encloses the transmission in an interior cavity formed by a gear case shell and a cover plate. The cover plate can be coupled to the outer shell via screws. A static shift rod can be supported at one end by the cover plate. A shift bracket can be mounted on the shift rod and biased to a mode position by a biasing member exerting a force between the shift bracket and the cover plate. A shift pin can be supported adjacent one end by the cover plate and biased to a mode position by a biasing member exerting a force between the shift pin and the cover plate. A spindle biasing member can bias the output spindle against the cover plate. The shift pin can actuate an electronic switch. A motor housing can be coupled to the transmission housing with fasteners so that the cover fasteners are not accessible.

Abstract: When the mode change knob of a multi-mode hammer drill is moved to the hammer only position, an electronic sensor sends a signal to a control logic circuit. When the user then depresses the trigger mechanically closing the ON/OFF switch, the control logic circuit applies a voltage either to a holding relay or to the gate of a triac which enables the relay or triac to conduct, thus providing a parallel circuit by-passing the ON/OFF switch. Consequently, when the user releases the trigger and opens the ON/OFF switch, the parallel relay or triac maintains current flow to the motor. It can be seen that in hammer only mode the user can activate the hammer drill by simply tapping the trigger to depress it and does not need to hold down trigger during use of the hammer in operation.

Abstract: A vibration reduction apparatus for use with a hammer tool having a hammer piston is disclosed. The hammer piston is caused to reciprocate in the cylinder by rotation of a gear wheel and crank drive. A cam is mounted around the gear wheel, a counterweight surrounds the piston cylinder, and a cam follower is provided on the counterweight. The cam follower on the counterweight is urged into contact with the cam by a biasing element. The external profile of the cam is such that rotation of the gear wheel causes oscillation of the counterweight in antiphase to motion of the hammer piston to counteract vibrations produced by operation of the hammer action of the tool. A mechanism is provided to deactivate the vibration reduction apparatus when the hammer action of the tool is deactivated.

Abstract: When the mode change knob of a multi-mode hammer drill is moved to the hammer only position, an electronic sensor sends a signal to a control logic circuit. When the user then depresses the trigger mechanically closing the ON/OFF switch, the control logic circuit applies a voltage either to a holding relay or to the gate of a triac which enables the relay or triac to conduct, thus providing a parallel circuit by-passing the ON/OFF switch. Consequently, when the user releases the trigger and opens the ON/OFF switch, the parallel relay or triac maintains current flow to the motor. It can be seen that in hammer only mode the user can activate the hammer drill by simply tapping the trigger to depress it and does not need to hold down trigger during use of the hammer in operation.

Abstract: An impact tool is provided that can efficiently reduce the vibration resulting from the striker and that does not lead to a larger design even with the use of a counterweight mechanism. A counterweight mechanism is provided in a motion converter housing, facing the handle. The counterweight mechanism is positioned between a center of gravity of the impact tool and the grip of the handle and is positioned above the control substrate. The counterweight mechanism is equipped with a first support, a second support, a weight support member, and a counterweight.

Abstract: A hammer includes a housing; a motor mounted within the housing; and a tool holder rotatably mounted on the house for holding a cutting tool. A striker is mounted in a freely slideable manner within the housing, for repetitively striking an end of a cutting tool when a cutting tool is held by the tool holder. The striker is reciprocatingly driven by the motor, when the motor is activated, via a drive mechanism. The drive mechanism comprises: a pivoting drive arm pivotally mounted within the housing at one end and which is drivingly connected to the striker; a pivotal drive mechanism connected to the pivoting drive arm and which converts a rotary movement generated by the motor into an oscillating pivotal movement of the pivoting drive arm; and the amplitude of the oscillations of the pivoting drive arm can be adjusted.

Abstract: A hand held motor driven electrically powered tool, in particular a rotary hammer, comprising a spindle (40) for rotatingly driving a tool or bit (68), a spindle rotary drive train (14, 5, 10) for rotatingly driving the spindle (40) and an arrangement for detecting blocking events (16, 17). Blocking events occur when the tool or bit of the tool become rotationally fixed in the material being bored in which case the rotary drive on the spindle from the motor causes the tool housing to rotate in a user's grip.

Abstract: A power hand tool includes a housing; an electric motor mounted in the housing for provide a rotary motion; a transmission gear set is mounted in the housing and connected with the electric motor; a torsion control device having a first rotary knob, which can adjust the maximum torsion output of the transmission gear set while being turned, and a plurality of first dents formed on an internal periphery thereof; an impact device having a second rotary knob, which can switch on or off an impact motion generated on the transmission gear set while being rotated, and a plurality of second dents formed on an internal periphery thereof; and a locating device having a holder fixed to the torsion control device and a locating member mounted to the holder, the locating member having two resilient portions, each of which has a convexity engaged with the associated first dents or second dents.

Abstract: A power impact tool includes a main body accommodating a chuck at a front end portion thereof; a clutch handle for setting a torque applied to the chuck; a grip including a base portion; a free end portion; and a reinforcing connecting portion connected to the front end portion of the main body at the back of the clutch handle and to the free end portion of the grip. The reinforcing connecting portion is disposed in front of the grip; and a part protruded most forward among the reinforcing connecting portion is located directly in front of the trigger switch disposed at the base portion of the grip. A part of the reinforcing connecting portion disposed behind the clutch handle retreats backward toward the free end portion of the grip.

Abstract: A hand-held power tool, in particular a rotary hammer, is indicated that includes a machine housing (10) with a tool fitting (12) integrated therein, the tool fitting (12) being rotatably drivable in a first mode and being non-rotatably fixable on the machine housing (10) in a second mode, and that includes a duty-type switch (20) with a coupling element (21) capable of being displaced to activate the modes, and an actuating element (22) that induces its displacement. To prevent maloperation and resultant damage to the machine when the operator switches between modes, the actuating element is designed as an electrical actuator (23), preferably as an electromagnet (25) controlled by an electronic control unit (24) (FIG. 1).

Abstract: The invention relates to a method for controlling the operation of a pressure fluid operated percussion device and to a pressure fluid operated percussion device. The method comprises influencing the shape of a stress wave by setting a suitable clearance between a transmission piston and a tool. The percussion device is provided with means for setting the clearance between the transmission piston and the tool.

Abstract: Systems and methods for drilling a borehole are provided. One system includes a continuously variable transmission. An input shaft of the continuously variable transmission is coupled to a power supply. An output shaft of the continuously variable transmission is coupled to one or more system components such that the continuously variable transmission controls rotation of the one or more system components. One method for drilling a borehole includes supplying power to an input shaft of a continuously variable transmission. The method also includes controlling rotation of one or more system components using the continuously variable transmission during drilling of the borehole. The one or more system components are coupled to an output shaft of the continuously variable transmission. Also provided is a borehole that is drilled by this method.

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: A post driver has a housing of tubular form extending substantially vertically, and weight telescopically mounted within the housing for movement between an extended position raised above the housing and a lowered position. A strike pad projects from the weight to drive a post into a hole drilled in the ground. A fluid cylinder mounted within the housing extends from a lower part of the housing to the interior of the weight and is operable to raise the weight to its extended position whereby the weight can then fall to a lower position at which its strike pad engages the upper end of the post.

Abstract: A rotary hammer includes a spindle 18 which can be rotatably driven by an intermediate shaft 24 by way of a drive device. A tool holder 16 is arranged for rotation with the spindle 18, and for releasably holding a bit or tool for selective rotation and/or reciprocation. A pneumatic hammering arrangement facilitates repeated impacting of the bit or tool for reciprocation within the tool holder (16). A mode change mechanism includes a knob 18 for selectively operating the rotary hammer in any of three modes, identified as a rotary drive only mode, a hammer only mode and a rotary hammer mode.