Abstract: A switch assembly (1) for centrally arranged operating mode selection for an at least partially rotary and percussion combination hand tool device (2) is comprised of a first switch sleeve (11) for the switchable percussion drive (6) and a second switch sleeve (12) for the switchable rotary drive meshing with a tool spindle (4) via a countershaft (3) and a switch accessory (10) connecting both switch sleeves (11, 12) together, whereby the countershaft (3) and a percussion drive shaft (5) of the percussion drive (6) are arranged directly adjacent and parallel in a common axially extending zone (B) and rotationally-freely guide a driving gear pair (7) in direct meshing engagement with each other and which can be engaged by way of the switch sleeves (11, 12).

Abstract: The invention is based on a hand power tool, in particular a hammer drill, with a drivable drive mechanism (12) accommodated in a housing (10) and a mechanical hammer unit (14), which is for percussion-driving a tool (16) in a tool holding fixture (18) and has a hammer (20) that can be driven in its hammering motion by a driver unit (22), which has at least one annular curved path (24, 26) with raised areas and recessed areas oriented axially toward the tool and has a feeler unit (28), which is operationally connected to the hammer (20) and which, by at least one feeler element (30), can be brought into operational connection with the raised areas and recessed areas of the curved path (24, 26). The invention proposes that the feeler unit (28) has at least two feeler elements (30) that can be brought into operational connection with the curved path (24, 26).

Abstract: A power tool includes a housing, a fixed ratchet seat, a drive spindle, a rotatable ratchet, and an operating knob. The ratchet seat is disposed immovably in the housing. The drive spindle extends rotatably through the ratchet seat and is axially movable between front and rear limit positions. The rotatable ratchet is mounted on the drive spindle for co-rotation therewith, and disengages the fixed ratchet seat when the drive spindle is at the front limit position, and engages the fixed ratchet seat when the drive spindle is at the rear limit position. The operating knob is sleeved rotatably on the housing, and is rotatable to drive rotation of a switching ring in the housing. The switching ring is associated operably with a latching seat on the drive spindle to enable and disable movement of the drive spindle between the front and rear limit positions.

Abstract: A power tool includes a function control mechanism to control operation of a drive spindle in a selected one of a rotary drive mode and a hammering mode. The function control mechanism includes a first ratchet that is mounted to rotate with the drive spindle, a second ratchet that is slidable from a first position to a second position, and a ring controller. The second ratchet is disengaged from the first ratchet when the second ratchet is in the first position, and is engaged with the first ratchet when the second ratchet is in the second position. The ring controller is coupled to a push ring that abuts against the second ratchet such that rotation of the ring controller results in movement of the second ratchet between the first and second positions.

Abstract: A gear transmission assembly for an electrical power tool includes a housing (6), a multi-stage gear train (1) located in the housing and having a plurality of axially displaceable indexing gears (4a, 4b) associated with respective stages of the gear train (1) and a shift device (2) for shifting the gear train (1) from one stage to another and having a shifting slide (3) displaceable from one shift stage to another, and a plurality of springable shifting stirrups (5a, 5b) connected with the shifting slide (3) and cooperating with respective indexing gears (4a, 4b) for displacing same in response to displacement of the shifting slide (3) between shift stages.

Abstract: A drill hammer or riveter, includes a housing (11), in which a hammering mechanism (12) is accommodated that in an axially displaceably supported guide tube (13) has a reciprocating piston (16) and a striker (17), drivable by the piston (16) via an air cushion; the hammering mechanism (12) can be moved out of an idling position into a hammering position by an axial displacement of the guide tube (13); the guide tube (13) is urged by a restoring spring (27) in the direction of the idling position with a restoring force: and between the guide tube (13) and the housing (11), at least one damping and/or spring member (30, 36, 37) is provided, which in the hammering position of the guide tuber (13) has a spring or damping characteristic between the guide tube (13) and the housing (11) that deviates from the restoring spring (27) in the region of the idling position.

Abstract: The invention is based on a hand power tool, in particular a drill hammer and/or a chipping hammer, having a striking mechanism (14) capable of being driven in a housing (10) by an electric motor (12), via which an insertable tool (18) situated in a tool mount (16) is capable of being driven in an impacting manner, and having a sensor unit (30) via which a characteristic value for a no-load position can be detected.

Abstract: A combined electrical hand tool having an operating mode selection switch (1) with additional special functions that can be switched using a displaceable linkage (5) that can be displaced by the operating mode selection switch arranged between a lubricated assembly (2a) having a coupling (3a) and the external housing (4), wherein in at least two separate lubricant-tight assemblies (2a, 2b) at least one switchable coupling (3a, 3b) is present, which can be moved over an outwardly extending actuating means (6a, 6b) that is mounted lubricant-tight.

Abstract: An engaging portion, formed at an axial end of an intermediate member, is engageable with a slide sleeve. A cylinder has an elongated hole with an axial length longer than a shifting distance of the intermediate member. The slide sleeve includes an annular member and a slide member. The annular member has an inner cylindrical wall engageable with the engaging portion of the intermediate member and a projection extending in a radially outward direction passing through the elongated hole beyond an outer surface of the cylinder. The slide member is coupled around the outer surface of the cylinder and is slidable in the axial direction of the cylinder. One axial end of the slide member, positioned closer to a working tool, is engaged with the projection of the annular member. The other axial end of the slide member is urged toward the working tool by an urging member.

Abstract: A portable drill having an internal combustion engine and a shiftable gear mechanism is provided. The gear mechanism has an output shaft for driving a tool. An input shaft of the gear mechanism is driven by a crankshaft of the internal combustion engine. The gear mechanism is provided with a neutral speed or gear setting in which the output shaft is uncoupled from the input shaft.

Abstract: A transmission (1) for a hand tool device with two laterally spaced shafts (2, 2′) having parallel axes (A, A′). which can be switched using switch sleeves (3, 3′) arranged movable in an axially limited manner on the shafts, whereby both switch sleeves (3, 3′) are switchably coupled to one another by a switch transmission unit (4) in a rotationally free axially form-fitting manner and engaging into the switch sleeves and which are resiliently spring-biased along the axes (A, A′) by a spring arrangement (6).

Abstract: A device for switching operating modes for an at least partially rotational and percussive hand tool machine having an overload clutch, which is arranged between a hollow driving guide cylinder (3) containing an axially striking impact piston (2) and a rotating, driving crown gear (4) on the guide cylinder (3) and which can be switched into different operating modes using an externally manually switchable, axially displaceable switching member, wherein at least one operating mode is rotationally driven, wherein the axially displaceable switching member engages rotationally form-lockingly into a freely rotational coupling ring (6) of the overload clutch mounted relative to the guide cylinder (3).

Abstract: The invention is based on a hand power tool, in particular a drill- and/or chipping hammer, comprising a striking mechanism (10) that has a drivable pot-type piston (12) with at least one idle opening (14).

Abstract: A hand-held electrical combination hammer drill capable of being used both as a drilling hammer and as a chisel hammer, and including an actuation member (17) for actuating an electrical on-off switch of the hammer drill and located on the tool handle switching elements (3, 4) for switching between drilling and chiseling operations, stop elements (5-22) actuated by the switching means (3, 4) for retaining the actuation member (17) in a on-position of the on-off switch upon selection of the chiseling operation, and a stop switch (15) having, upon selection of the chiseling operation, a first position in which the stop switch provides for securing the actuation member (17) in its on-position with the stop elements (5-22), and a second position in which the stop elements occupies a non-operative position in which the actuation member, upon being released, automatically moves into its off-position under an action of a biasing force.

Abstract: The invention is based on a hand power tool having an electric motor (12) located in a housing (10), via which an insertable tool (16) situated in a tool mount (14) is capable of being driven in a rotating manner, and having a safety device (18) with which a characteristic value for an occurrence of uncontrolled blockage of the insertable tool (16) can be detected via a sensor unit (20), and the movement of the housing (10) can be decelerated.

Abstract: An engaging portion, formed at an axial end of an intermediate member, is engageable with a slide sleeve. A cylinder has an elongated hole with an axial length longer than a shifting distance of the intermediate member. The slide sleeve includes an annular member and a slide member. The annular member has an inner cylindrical wall engageable with the engaging portion of the intermediate member and a projection extending in a radially outward direction passing through the elongated hole beyond an outer surface of the cylinder. The slide member is coupled around the outer surface of the cylinder and is slidable in the axial direction of the cylinder. One axial end of the slide member, positioned closer to a working tool, is engaged with the projection of the annular member. The other axial end of the slide member is urged toward the working tool by an urging member.

Abstract: A hand-operated machine tool is disclosed that rotationally drills or percussively chips or both. An embodiment of the hand-operated machine tool includes a toolholder that is used to hold tools having a grooved shank. The toolholder has a toolholder body and at least one radially moving locking member, for example a locking sphere, that is insertable into a groove in the tool and the locking member is radially locked in position by a retaining element that may be displaced by an actuating element to a position that radially releases the locking member. In an embodiment of the invention, the toolholder has at least one sealing device that seals at least one chamber outwardly surrounding the locking member. The sealing device includes at least one sleeve-shaped component that is separate from the actuating element and at least partially defines the volume referred to as the chamber.

Abstract: A first switching member, having a claw portion engageable with a claw portion of a first gear, is slidably mounted on a crank shaft without causing any relative rotation therebetween. A first urging member resiliently urges the first switching member so that the claw portion of the first switching member is engaged with the claw portion of the first gear. A second switching member, having a claw portion engageable with a claw portion of a second gear, is slidably mounted on an intermediate shaft without causing any relative rotation therebetween. A second urging member resiliently urges the second switching member so that the claw portion of the second switching member is engaged with the claw portion of the second gear.

Abstract: A hammer is provided which enables the orientation of a tool or bit mounted within a spindle of the hammer to be rotated to the required orientation. The hammer comprises a housing part having an aperture therein in which a spindle that is mounted so that the spindle extends out of the housing through the aperture. The spindle is capable of being rotated about its axis to any of a plurality of orientations, so as to alter the orientation of a tool or bit mounted therein. A locking ring is located around the spindle which locking ring can be moved axially along the spindle into and out of engagement with the housing part, so that when the locking ring engages the housing, it prevents the spindle from rotating with respect to the housing. A grip ring is located around the spindle and can be rotated about the axis of the spindle from a first position in which it prevents disengagement of the locking ring from the housing.

Abstract: A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode.

Abstract: A hand-held electrical combination hammer drill capable of being used both as a drilling hammer and as a chisel hammer, and including an actuation member (17) for actuating an electrical on-off switch of the hammer drill and located on the tool handle switching elements (3, 4) for switching between drilling and chiseling operations, stop elements (5-22) actuated by the switching means (3, 4) for retaining the actuation member (17) in a on-position of the on-off switch upon selection of the chiseling operation, and a stop switch (15) having, upon selection of the chiseling operation, a first position in which the stop switch provides for securing the actuation member (17) in its on-position with the stop elements (5-22), and a second position in which the stop elements occupies a non-operative position in which the actuation member, upon being released, automatically moves into its off-position under an action of a biasing force.

Abstract: An electric combination hammer for use either as a drilling hammer or as a chisel hammer has a housing (10) and a handle (12) arranged on it, in which is arranged an on-off switch (16) having a pawl (14) and having a switch element (18) for manually switching from drilling operation to chisel operation and vice versa and having a catch device (20, 22) by which the pawl (14) may be engaged in chisel operation and which prevents a latched position from being engaged in drilling operation.

Abstract: A rotary switch for a hand-held tool and including a manually operated actuation member (3) rotatable over a predetermined angle (&phgr;) for switching from one operational mode to another immediately adjacent operational mode, a rotatable switching member (6) arranged coaxially with the actuation member (3), an overhanging spring (5) connected with the switching member (6) for joint rotation therewith, and an operating pin (4) connected with the actuation member (3) and arranged eccentrically with respect to its rotational axis for deflecting an arm of the overhanging spring to thereby rotate the switching member (6) over a predetermined angle to provide for a predetermined displacement of the switching element (12) of the hand-held tool.

Abstract: A hammer is provided which enables the orientation of a tool or bit mounted within a spindle of the hammer to be rotated to the required orientation. The hammer comprises a housing part having an aperture therein in which a spindle that is mounted so that the spindle extends out of the housing through the aperture. The spindle is capable of being rotated about its axis to any of a plurality of orientations, so as to alter the orientation of a tool or bit mounted therein. A locking ring is located around the spindle which locking ring can be moved axially along the spindle into and out of engagement with the housing part, so that when the locking ring engages the housing, it prevents the spindle from rotating with respect to the housing. A grip ring is located around the spindle and can be rotated about the axis of the spindle from a first position in which it prevents disengagement of the locking ring from the housing.

Abstract: An electrical hand-held tool having a plurality of operational modes and including a tool spindle (1) rotatably supported in the tool housing (5) for rotation about a rotational axis (A), an outer sleeve (2) arranged coaxially with the tool spindle (1) and connected thereto for joint rotation therewith, a bolt (6) supported in the housing without a possibility of rotation relative thereto and displaceable in a direction transverse to the rotational axis (A) for engaging in at least one opining (3) provided in the sleeve (2) at least in one of the operational modes of the electrical tool, and a sliding sleeve (12) supported on a drive shaft (13) of the electrical tool and connected with the bolt (6) for displacing same in response to actuation of a mode selection switch (4).

Abstract: The invention is based on a hand power tool, in particular a hammer drill, with a drivable drive mechanism (12) accommodated in a housing (10) and a mechanical hammer unit (14), which is for percussion-driving a tool (16) in a tool holding fixture (18) and has a hammer (20) that can be driven in its hammering motion by means of a driver unit (22), which has at least one annular curved path (24, 26) with raised areas and recessed areas oriented axially toward the tool and has a feeler unit (28), which is operationally connected to the hammer (20) and which, by means of at least one feeler element (30), can be brought into operational connection with the raised areas and recessed areas of the curved path (24, 26).

Abstract: A hand-held tool with more than two modes of operation and including a clutch pusher (4) at least partially located in the tool housing and fixedly connected with a bevel gear engaging a bevel gear (9) supported on the drive spindle (3), and at least one engagement cam (6) which connects the clutch pusher (4) with driving gears (11) with a possibility of axial displacement of the clutch pusher relative thereto in the first and second modes of operation, with the spindle, in the third mode of operation, being stopped without a possibility of rotation relative to the tool housing, and with the engagement cam (6) engaging in a recess (7) provided in the housing.

Abstract: A drilling and/or chiseling device has a drive spindle (19) for a drilling and/or chiseling tool with two ring gears (17, 18) of different sizes, a countershaft (1) with a drive pinion (15), a wobble drive (7) for a striking mechanism, mounted on the countershaft (1), and a switching sleeve (9), mounted on the countershaft (1) so that it can be shifted axially by a switching element (20). The switching element displaces the switching sleeve (9) into four different modes of operation of the drilling and/or chiseling device.

Abstract: An impact rotary tool includes an output shaft having an anvil at an end portion thereof, a hammer having a projecting portion applying an impact force to the anvil under a predetermined condition, a driving shaft connected to the hammer through a cam mechanism, and a changeover mechanism for changing the connection between the driving shaft and the output shaft. The mechanism is arranged along with a common axis defined by the driving shaft and the output shaft. The changeover mechanism includes a connecting member accommodated into the driving shaft in a first condition, and connecting the driving shaft and the output shaft in a second condition.

Abstract: A switch assembly (1) for centrally arranged operating mode selection for an at least partially rotary and percussion combination hand tool device (2) is comprised of a first switch sleeve (11) for the switchable percussion drive (6) and a second switch sleeve (12) for the switchable rotary drive meshing with a tool spindle (4) via a countershaft (3) and a switch accessory (10) connecting both switch sleeves (11, 12) together, whereby the countershaft (3) and a percussion drive shaft (5) of the percussion drive (6) are arranged directly adjacent and parallel in a common axially by extending zone (B) and rotationally-freely guide a driving gear pair (7) in direct meshing engagement with each other and which can be engaged by way of the switch sleeves (11, 12).

Abstract: A hammering electric hand tool device with idle strike cutoff for a pneumatic striking mechanism with an axially fixed guide pipe and a hammer member striking in the interior of a rotatable tool holder, wherein the tool holder encloses the guide pipe on the radial outer side at least partially, at least in an axial, partial area, and the tool holder is mounted so as to be movable in an axially limited manner.

Abstract: A first switching member, having a claw portion engageable with a claw portion of a first gear, is slidably mounted on a crank shaft without causing any relative rotation therebetween. A first urging member resiliently urges the first switching member so that the claw portion of the first switching member is engaged with the claw portion of the first gear. A second switching member, having a claw portion engageable with a claw portion of a second gear, is slidably mounted on an intermediate shaft without causing any relative rotation therebetween. A second urging member resiliently urges the second switching member so that the claw portion of the second switching member is engaged with the claw portion of the second gear.

Abstract: A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode.

Abstract: A rotary switch for a hand-held tool and including a manually operated actuation member (3) rotatable over a predetermined angle (&phgr;) for switching from one operational mode to another immediately adjacent operational mode, a rotatable switching member (6) arranged coaxially with the actuation member (3), an overhanging spring (5) connected with the switching member (6) for joint rotation therewith, and an operating pin (4) connected with the actuation member (3) and arranged eccentrically with respect to its rotational axis for deflecting an arm of the overhanging spring to thereby rotate the switching member (6) over a predetermined angle to provide for a predetermined displacement of the switching element (12) of the hand-held tool.

Abstract: An electrical hand-held tool having a plurality of operational modes and including a tool spindle (1) rotatably supported in the tool housing (5) for rotation about a rotational axis (A), an outer sleeve (2) arranged coaxially with the tool spindle (1) and connected thereto for joint rotation therewith, a bolt (6) supported in the housing without a possibility of rotation relative thereto and displaceable in a direction transverse to the rotational axis (A) for engaging in at least one opining (3) provided in the sleeve (2) at least in one of the operational modes of the electrical tool, and a sliding sleeve (12) supported on a drive shaft (13) of the electrical tool and connected with the bolt (6) for displacing same in response to actuation of a mode selection switch (4).

Abstract: A hand-held tool with more than two modes of operation and including a clutch pusher (4) at least partially located in the tool housing and fixedly connected with a bevel gear engaging a bevel gear (9) supported on the drive spindle (3), and at least one engagement cam (6) which connects the clutch pusher (4) with driving gears (11) with a possibility of axial displacement of the clutch pusher relative thereto in the first and second modes of operation, with the spindle, in the third mode of operation, being stopped without a possibility of rotation relative to the tool housing, and with the engagement cam (6) engaging in a recess (7) provided in the housing.

Abstract: A hammer is provided which enables the orientation of a tool or bit mounted within a spindle of the hammer to be rotated to the required orientation. The hammer comprises a housing part having an aperture therein in which a spindle that is mounted so that the spindle extends out of the housing through the aperture. The spindle is capable of being rotated about its axis to any of a plurality of orientations, so as to alter the orientation of a tool or bit mounted therein. A locking ring is located around the spindle which locking ring can be moved axially along the spindle into and out of engagement with the housing part, so that when the locking ring engages the housing, it prevents the spindle from rotating with respect to the housing. A grip ring is located around the spindle and can be rotated about the axis of the spindle from a first position in which it prevents disengagement of the locking ring from the housing.

Abstract: An apparatus is provided that allows a working element to undergo either rotary or reciprocation motion in a transmission system that is very compact in terms of the amount of space it requires to convert the rotary output of the motor into either rotary or reciprocating output of an output shaft operably connected to the working element. The transmission includes input and output members between which a clutch and cam mechanism are disposed for providing a rotary/reciprocating transmission system with a compact design. When the clutch is disengaged, the cam mechanism is operable to provide the output member and thus the output shaft connected thereto with reciprocating motion. Preferably, the output member is cylindrical with the input member, clutch and cam mechanism all disposed therein to provide the rotary/reciprocating tool with a so-called “barrel cam” transmission that is small to provide significant space saving in the tool housing.

Abstract: An improved vibration attenuator for reducing undesired vibrations generated by cutter bits being drawn across the faces of a rotating brake rotor. The attenuator has friction pads with engagement members that extend therefrom which are configured to cause force to exerted on the cutter bits in a direction parallel to the surface being machined and perpendicular to the direction of rotation of the rotor.

Abstract: A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode.

Abstract: A switching device for a power tool is provided. It comprises a housing, a rotary collar, an output axle with stepped portion, fixing gear wheel and a movable gear wheel. By the rotation of the rotary collar, the output axle can be retracted into the housing by an axial force to make contact of the movable gear wheel with the fixing gear wheel. Therefore, the switch collar device can adjust the output axle to switch between an position for simple rotation only and a position for rotation with impact. The whole structure of the present invention is more simple and cheaper than that of the conventional tool because it uses less parts.

Abstract: An electric machine tool for tools which operate by percussion, the electric machine tool having a machine housing; a rotatingly drivable work spindle seated in the machine housing; a tool receiver provided for receiving a tool and driven by the work spindle; a mechanical striking mechanism having a beater accelerated in an axial direction and actuating a shaft of the tool in the axial direction by blows; a driver unit which derives an acceleration of the beater from rotational movement, the driver unit having an axially displaceably arranged scanning member which rotates synchronously with the work spindle; two circular-shaped curved paths which guide the scanning member and are fixed in the housing, said circular-shaped curved paths having elevations and depressions, each of the elevations pointing in an axial direction of the work spindle in a direction of the scanning member.

Abstract: A manually operable drilling tool (1) wiht dual impacting funtion has a housing (2) containing a first striking mechanism (16) for producing axial impacts to be transferred to a drilling or chiseling tool bit (7), clamped in a chuck (6) of the tool (1). Within the housing (2), a second striking mechanism (20) is arranged for producing axial impacts, the axial impacts of which have an impact energy and an impact frequency different from the impact energy and the impact frequency of the axial impacts produced by the first striking mechanism (16). The drilling or chiseling tool bit (7), clamped in the chuck (6), can be acted upon with axial impacts produced either by the first (16) or the second striking mechanism (20) or by both striking mechanisms together. The axial impact striking, mechanisms (16, 20) can also be switched off completely for use in wood or metal.

Abstract: A hammer drill (1) includes an intermediate shaft (13), a clutch ring (25), a second gear (20), and a boss (15) all mounted on the intermediate shaft (13). Also included are a rotatable change lever (40) and a clutch plate (31) which has lock claws (36). When the change lever (40) is fully rotated in the clockwise direction, the hammer drill (1) is placed in a drill-only mode where the clutch ring (25) meshes only with the second gear (20). When the change lever (40) is rotated approximately 45 degrees counterclockwise from the foregoing position, the hammer drill (1) is placed in a hammer drill mode, where the clutch ring (25) meshes with the second gear (20) and the boss (15). When the change lever (40) is rotated approximately another 45 degrees counterclockwise, the hammer drill (1) is placed in a neutral position where tile second gear (20) is disengaged from the clutch ring (25), with the clutch ring (25) remaining in mesh with the boss (15).

Abstract: A power-driven hammer drill 1 includes a rotary lever 8 for transmitting and disabling the transmission of the rotation of a motor 5 to a tool bit 4 and a slide lever 9 for transmitting and disabling the transmission of hammer blows to the tool bit 4. The rotary lever 8 is formed with a chamfer 52, whereas the slide lever 9 is formed with a straight portion 54 and a cut-out 53 which conforms to the circular edge of the rotary lever 8. When the slide lever 9 is in the lowermost position with the rotary lever 8 fitted in the cut-out 53, the rotary lever 8 is in the position to disconnect the rotation of the motor 5 to the tool bit 4, and while in this position, the slide lever 9 cannot be slid to its uppermost position, in which hammer blows cannot be transmitted to the tool bit 4.

Abstract: A power-driven screwdriver with a torque-dependent release clutch having two clutch halves is disclosed. The screwdriver comprises additional entrainment elements provided on the clutch halves for bridging the release clutch. To this end, a motor-driven drive gear is mounted to rotate freely on a tool drive shaft and is secured against axial displacement on the housing side while a cam ring can be adjusted axially, together with the tool drive shaft, via an adjusting device. The clutch elements are formed on the respectively facing sides of the drive gear and the cam ring, and the entrainment element are likewise formed, as separate elements, on the respectively facing sides of the drive gear and the cam ring. As a result of the adjusting device axial displacement of the tool drive shaft results either in a rigid through drive, where the release clutch is nonfunctional, or in the torque-dependent release of the release clutch, where the entrainment elements are nonfunctional.

Abstract: A switch device for a screw button is disclosed. The switch device includes a slowdown box with a switch base, which consists of two sets of concave gears with appropriate spacing located on the axial plane around the outer brim, each set having a plurality of switch concave gears. The side on which the switch gears located is formed as a inclined surface, which is used to coordinate with a plurality of switch concave gears corresponding to the switch convex gears where the respective axial surface of the switch base in the switch block are set. The switch block thereby controls the switch convex gears to engage or disconnect with the switch concave gears when rotating. The motion of the output axis in radial direction is manipulated to determine whether the vibrating block fixed on the output axis can vibrate when the output axis is pressed and rotates to induce vibration because engaged with the vibrating base.

Abstract: A pair of stoppers (47) capable of moving back and forth in an axial direction of a spindle (5) are provided on an outer periphery of a tubular portion (9a) for supporting the spindle (5). As a pair of projections (49) provided on a first change ring (32) are moved in conjunction with the rotation of the first change ring (32) which is capable of changing over the operating mode of a percussion driver drill, the stoppers (47) move back and forth in the axial direction. During a percussion mode and a drill mode, the stoppers (47) abut against a flat washer (50) for fixing an internal gear (13) to restrict the forward movement of the flat washer (50), while, during a clutch mode provided in the first change ring (32) as a third changeover position, the stoppers (47) move away from the flat washer (50). A pair of washers (40, 41) superposed on each other in the axial direction of the spindle (5) are interposed between the first change ring (32) and a second change ring (39).

Abstract: A hammering screwdriver 1 for tightening and loosening screws offers the possibility of operating the rotating action alone when tightening the screws, and a rotation/hammering action when loosening the screws. This is primarily attained by the construction of the cam controller casing 2 between which and the hammering mechanism cage 6 a ball 10 is arranged. With this exclusively rotating motion, this ball 10 lies in a salient 16 below an elevation 8 on the head end 7 of the cam controller casing 2. With rotation/hammering motion, the ball 10 is moved over the track 3 to the head end 7 of the cam controller casing 7 until it reaches the elevation. Here the cam controller casing 2 moves forward in an axial direction owing to which hammering action occurs.

Abstract: A power tool has an application mechanism (300) for connection to the output of an epicyclic gearbox provided with a torque control ring. The mechanism has a body (310) journalling a chuck spindle (302). Outside the body is a clutch control arrangement comprising balls (334,336) pressed against the torque control ring by individual springs (330) controlled by a control ring (322) threaded on the body. The mechanism includes a hammer arrangement having rotary and fixed ratchet plates (378,376) and cam ring (308) operable to engage and separate the plates by a lever (360) which projects between the springs (330).