Abstract: A tool, which can be used in the manner of a pinion, contains two parts, whereof one serves as the drive and the other as the driven part. The two parts form a cavity in which is inserted a torque-limiting clutch. The latter is positioned in axially floating manner, so that the once set clutch release torque can be maintained independently of external influences.

Abstract: A powered, unidirectional output controlling apparatus mounted between the main shaft of an electrically powered tool and a power source is provided. The apparatus comprises a rotating seat, a plurality of flexible disc seats made from a rubber material, a locking seat, a plurality of locking rollers and a fixing ring. One end of the rotating seat is engaged with the power source output of a power transmission mechanism and the other end of the rotating seat is provided with a plurality of insertion shafts passing through the locking seat fastened by two flexible disc seats. The locking seat is first mounted into the fixing ring. The center of the rotating seat is provided with a bolt hole for the mounting of the main shaft. The external edge of the fixing ring is secured to the housing of the electrically powered tool. The perimeter portion of the locking seat is provided with a plurality of locking slots and the locking slots are mounted with a plurality of locking rollers.

Abstract: A surgical instrument having a locking mechanism for preventing an output shaft of the surgical instrument from rotating and a further locking mechanism for mounting a battery pack to a distal end of a housing of the surgical instrument. The surgical instrument further includes a clutch mechanism for limiting the torque of a drive shaft of the surgical instrument. The locking mechanism for preventing the output shaft from rotating includes a locking switch which mates with a locking cap disposed on the output shaft. The locking mechanism for mounting the battery pack to the housing includes a groove at the distal end of the housing and a retaining ring which engages the groove when the battery pack is mounted on the housing. The clutch mechanism includes a clutch plate that interfaces with both the output shaft and the drive shaft and prevents failure of the motor shaft.

Abstract: A power nut runner with a torque responsive shut-off capacity comprises a housing (11, 12, 13), a rotation motor (10) connected to an output shaft (28) via a torque responsive release clutch (26) in which torque is transferred via a cam mechanism (31, 35, 36) between a driving clutch half (25) and a driven clutch half (27, 30, 39), and a spring (32) is arranged to bias and displace a first one of the clutch halves (27, 30, 39) towards the other in an engagement direction, a signal emitting release detecting sensor (46), and an activation element (40) arranged to be thrown off an abutting contact with the spring biassed clutch half (27, 30, 39) to reach an active position beyond its inactive low torque position as the spring biassed clutch half (27, 30, 39) is abruptly returned to its engagement position after an axial release movement.

Abstract: The invention pertains to a hydraulic rotary drive for the rotating rod assembly of a drilling machine which contains at least two hydraulic motors (1-3) with the motor shafts (34-36) that are connected to a common output shaft (11) by means of a gear, with a clutch (4-6) being arranged between the motor shaft (34-36) of each hydraulic motor (1-3) and the gear such that the rotational movement of each hydraulic motor (1-3) can be disengaged from the rotational movement of the output shaft (11). The invention aims to develop a highly variable rotary drive for ground and rock drilling machines.

Abstract: A power tool is provided which includes a motor assembly having a rotatable motor shaft mechanism, and a motor control coupled to the motor assembly and operable between a normal off condition de-energizing the motor and an on condition energizing the motor. The tool includes a rotatable tool shaft mechanism, and a clutch shiftable between a normal disengaged condition decoupling the motor shaft mechanism from the tool shaft mechanism and an engaged condition coupling the motor shaft mechanism to the tool shaft mechanism. A trigger member is engageable with both the motor control and the clutch and is moveable between a first position, wherein the motor control is in its off condition and the clutch is in its disengaged condition, and a second position holding the motor control in its on condition and the clutch in its engaged condition for driving the tool shaft mechanism. The trigger member is designed to prevent premature energization of the motor assembly.

Abstract: A surgical instrument having a locking mechanism for preventing an output shaft of the surgical instrument from rotating and a further locking mechanism for mounting a battery pack to a distal end of a housing of the surgical instrument. The surgical instrument further includes a clutch mechanism for limiting the torque of a drive shaft of the surgical instrument. The locking mechanism for preventing the output shaft from rotating includes a locking switch which mates with a locking cap disposed on the output shaft. The locking mechanism for mounting the battery pack to the housing includes a groove at the distal end of the housing and a retaining ring which engages the groove when the battery pack is mounted on the housing. The clutch mechanism includes a clutch plate that interfaces with both the output shaft and the drive shaft and prevents failure of the motor shaft.

Abstract: An automatic spindle arresting device for hand tools, especially for drills, drill screwdrivers, angle grinders and the like, with a latching part (50; 120), which is connected to the spindle (20) or the housing (10) so that there cannot be any mutual rotation, and which can be coupled in both direction of rotation of the spindle (20) with at least one arresting part (40; 140), which is connected with the housing (10) or the spindle (20) so that there cannot be any mutual rotation, and with a driving part (34; 110), which is disposed equiaxially to the spindle (20) and has unlocking elements, by means of which the latching part (50; 120) and the arresting part (40; 140) can be uncoupled, is characterized in that the unlocking elements are one or more control paths (38; 116), which are disposed at the driving part (34; 110) and at which one or more control cams (54; 124) of the latching part (50; 120) slide due to a rotational motion of the driving part (34; 110) in such a manner, that the latching part (50; 1

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 torque impulse tool for screw joint tightening includes a housing, a pneumatic motor with a rotor, an output shaft, a hydraulic impulse generator coupling the rotor to the output shaft, and an automatic power shut-off device including a pressure air inlet valve communicating with the pneumatic motor and shiftable between a fully open condition, a partially open condition and a closed condition. In addition, an activation mechanism is provided which is co-rotative with the rotor and which includes a connection member engaging the inlet valve for shifting the inlet valve between the fully open condition, the partially open condition and the closed condition.

Abstract: A hand held power tool has a coupling formed for transmission of torques of different values and including at least two coupling parts provided with transmission members for rotary-fixed connection with one another, a coupling spring having an adjustable tensioning force operatable for holding one of the coupling members of one of the coupling parts in a rotary-locked engagement with another of the coupling members of another of the coupling parts, and blocking members with which the coupling parts are rotary-fixed coupled in addition to the transmission members, and which are bringable in engagement with one another in a drilling operation or an impact drilling operation for transmitting a maximum torque.

Abstract: A pneumatic screwdriver incorporates a torque limiter for cutting off the supply of compressed air when the torque reaches a particular threshold. The invention includes a first positive clutch connected to a drive shaft and a second positive clutch connected to the tool. These components have three teeth offset by 120.degree. facing each other with a groove in the teeth in which there is a boss. Balls are inserted between the positive clutches in order to separate them when the torque is reached to shut off the admission of compressed air and then escape from the bosses so that the teeth rub on each other to brake the drive shaft.

Abstract: An automatic shaft lock is incorporated into the transmission or drive components of a power driving tool of the type commonly used to tighten or loosen threaded fasteners, for example. The automatic shaft lock operates to prevent an externally-applied rotational back-force or back-torque, such as results from use of the tool to manually tighten or loosen a fastener, from being transmitted all the way through the drive components to the tool's motor or armature shaft. The shaft lock also effectively reduces the amount of back-torque, functioning automatically in either rotational direction, due to being disposed at an intermediate location in the drive train, between an intermediate gear enmeshed for driving rotation with the tool's armature shaft and an output gear enmeshed in a driving relationship with the tool's output shaft.

Abstract: A power screwdriver has a tool body, a motor, a drive member rotatably driven by the motor, a spindle rotatably mounted on the tool body and a clutch mechanism provided between the drive member and the spindle. The clutch mechanism includes an engaging clutch and a synchronizer device. The synchronizer device is operable to rotate the spindle at a predetermined speed that is substantially equal to or less than the rotational speed of the drive member, prior to connection of the engaging clutch.

Abstract: A rotary impulse tool has a motor-driven drive shaft and an output shaft. The drive shaft is threadedly coupled to a flywheel sleeve, which is spring-biased forwardly and is splined to a rotatable race structure of a wrap spring clutch assembly, which includes a wrap spring disposed in clearance fit coaxially between cylindrical surfaces of the race structure, the wrap spring having a front end fixed to the output shaft and a rear end coupled to a first conical control member. A second conical control member is axially movable between engaged and disengaged positions relative to the first control member for, respectively, shifting the clutch assembly to an engaged condition for transmitting torque between the drive and output shafts and a disengaged condition for decoupling those shafts.

Abstract: A threading attachment for internal or external threading includes a spindle head (1) which is intended to be attached to a spindle on a machine tool and also a tap holder (5) with a holder body (6) in which a tap (13) is arranged during the threading work, the spindle head (1) and the tap holder (5) being extended along a joint axle. The tap holder (5) and the holder body (6) respectively have in threading position a power transmitting connection to the spindle head (1) via driving members (15, 16 and 28, 29, respectively) and have in back out position freely rotatable in relation to the spindle head (1) and arranged to be effected by a compressed medium via a driving member (18). The driving member can be a reaction turbine or an action turbine.

Abstract: A power tool has a drive mechanism with an output shaft which performs an intermittent rotary motion. The output shaft drives, via an overrunning clutch, a tool drive shaft to drive a tool, which thus performs a quasi-continuous rotary motion that, as the load on the machine increases, transitions increasingly into a discontinuous rotary motion. The power tool can advantageously be used as a hand-held power tool for screwing, drilling, sawing, sanding, and the like, a high output torque with a low reaction torque being achievable as a result of the intermittent drive mechanism.

Abstract: A manually operable tool for driving screws has a drive pinion (3) axially fixed with a housing (1). A spindle (5) in the housing (1) is axially displaceable relative to the drive pinion against the force of a first spring (4). A clutch element (6) is located in a passageway in a collar (20) on the drive pinion (3) and is radially displaceable by a actuating member (8) for engaging the spindle (5) to the drive pinion. In the engaged position the clutch element (6) sits against a stop surface (9) in the spindle (5). The actuation member (8) is axially displaceable by stops (10, 11) located on the spindle (5) and can be axially fixed to the drive pinion by a retaining element (14) and a snap-element (15).

Abstract: A power screw driver for tightening self-tapping screws comprises a housing (10), a rotation motor, an output shaft (12), a torque limiting release clutch (11) having torque transferring cam unit (17, 19) and a spring biassed thrust element (20) exerting an engagement force on the cam unit (17, 19) and yielding axially to a release position as a desired output torque is reached. A screw bed (32) engaging contact member (31) coupled is to an activation unit (42) and is arranged to be axially displaced via the activation unit (42) of the activation means (42) a lock means (36, 39) from a thrust element (20) locking position during the thread forming phase of the tightening process to a thrust element (20) unlocking position during the final pretensioning phase.

Abstract: A production assembly tool for securing fasteners to a workpiece such as an automobile body. The production assembly tool of the present invention includes a housing which encases a motor, a transmission, a clutch mechanism and a control module. The control module controls the running and braking of the motor and prevents both over and under securing of a fastener caused by falsely detected tool clutch conditions. An improved clutch sensor switch is operatively associated with the control module for detecting clutch disengagement. The clutch mechanism is designed to drive the fastener until the clutch sensor switch detects clutch disengagement and signals the control circuit to stop drive and start braking. The production assembly tool further includes a system for ensuring accurate placement of the power tool motor in the power tool housing subsequent to motor servicing or repair.

Abstract: A two-speed fastener driving tool includes a reversible rotary motor including means to reverse, having an output shaft connected in axial alignment with a tool driving output shaft by an improved drive assembly comprising a first overrunning clutch axially aligned with the motor output shaft for providing a high speed drive connection with the tool driving output shaft when the motor is rotated in a first direction. A second overrunning clutch surrounds the first overrunning clutch and functions for providing a low speed drive connection with the tool driving output shaft when the motor is rotated in a direction opposite to the first direction.

Abstract: A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck and has associated therewith a degree of looseness which must be taken up before torque from the motor is applied to the tool bit. The control circuit for the power tool increases the effective torque output of the tool after a predetermined torque level is attained, by alternately turning the motor on and off, with the duration of the off-time sufficient to permit the gear train to relax, thus giving the motor a "running start" when power is reapplied. Various alternative schemes for transitioning to this ratcheting mode of operation are disclosed including the sensing of a predetermined threshold current, a predetermined increase in motor current, and a predetermined rate of deceleration in motor speed.

Abstract: A screw driving tool includes a housing (1) containing a motor (2), and an axially fixed drive pinion (3) powered by the motor. An axially extending spindle (5) is mounted in the housing (1) and is axially displaceable against the force of a spring (4) relative to the drive pinion and a ball shaped clutch element (6) positioned between the drive pinion and the spindle and cooperating with stop faces on the drive pinion and spindle. The clutch element (6) can be disengaged from the drive pinion and is axially displaceable and rotatable to a limited extent relative to the spindle (5).

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).

Abstract: An improved structure of an impact screwdriver is provided which achieves a low-noise screw-driving operation. The impact screwdriver includes a clutch assembly for transmitting torque provided by a motor to a tool bit. The clutch assembly includes a toque-transmitting member, a torque-outputting member, and a clutch coil spring. The clutch coil spring is selectively wound around the torque-transmitting member and the torque-outputting member according to a rotational difference therebetween to establish torque transmission for providing the torque to the tool bit intermittently.

Abstract: An impulse tool (20) having a housing (22), a motor (26), drive mechanism (30), impulse mechanism (28), trigger mechanism (67), and sensor (32) for automatic shut-off is disclosed. The sensor (32) uses a spring-biased ball (144) that sits on a ball seat (149) adjacent an entry orifice (108) and a spring-biased piston (112) such that when a predetermined non-transient torque is reached, the strength, duration and frequency of pulses of the working fluid entering the entry orifice (108) will lift the ball (144) sufficiently to impose on the piston (112) and to progressively lift the piston (112) to allow the working fluid to a triggering height which starts the shut-off of the impulse tool (20). A delay mechanism is also disclosed that may include a regulator (172), dashpot (170), spring latch (204), and trigger bar (56) or latch. A method of cooling an impulse tool with cold, dense air throughout is also disclosed.

Abstract: Disclosed herein is an impact absorption mechanism and a power tool including an impact absorption mechanism. When a tool bit binds a high energy impulse of short duration is generated that may damage components of the power tool. The impact absorption mechanism absorbs this high energy impulse and prevents damage to other components of the power tool.

Abstract: Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

Abstract: The invention provides a power tool including an improved slip clutch assembly for transmitting torque from a motor-driven driving member to the rotatably driveable output shaft of the tool. The clutch assembly includes an annular clutch gear around the output shaft. The clutch gear meshes with the driving member and includes circumferentially spaced pockets that correspond to circumferentially spaced, conically-shaped detent depressions in the output shaft. The clutch assembly also includes a plurality of ball members each positioned in one of the pockets in the clutch gear. The ball members are spring-biased toward seated positions in the detent depressions to engage torque transmission between the clutch gear and the output shaft. When subjected to an overload torque, the ball members unseat from the detent depressions with a ratcheting action to disengage torque transmission between the clutch gear and the output shaft.

Abstract: A gear shifting power tool (10) includes a rotatably-driven, torque-responsive, gear shift device (30). Rotatably-driven, torque-responsive, gear shift device (30) may include drive spindle (38), plunger (54) positioned within drive spindle (38). Drive spindle (38) has first hole pair (44) and second hole pair (46) in which first ball pair (48) and second ball pair (50) contact plunger (54). Drive clutch member (32) is drivably engaged to drive spindle (38) through ball screw arrangement (64). Drive clutch member (32) disengages from driven clutch member (34) in response to a resistive torque overcoming torque spring (40). Inertial device (62) forces first ball pair (48) into one end of plunger (54) which forces plunger (54) towards reset spring (60). Plunger (54) forces second ball pair (46) into inner axial groove (36) of drive clutch member (32) and prevents drive clutch member (32) from engaging driven clutch member (34) until all rotation ceases.

Abstract: A torque responsive release clutch mechanism for a pneumatic power nutrunner having a housing (16) with an air inlet passage (11) and an air motor (12). The clutch mechanism includes a driving clutch half (22) with pockets (33) for two or more torque transferring balls (24), a bias spring (38), and an axially displaceable thrust element (34) for transferring the bias spring load to the balls (24), and a driven clutch half (23) having cam surfaces (25) for cooperation with the balls (24), wherein the driving clutch half (22) includes means (36, 44, 45) for feeding pressure air to the cylinder chamber (30), and the thrust element (34) has a cylindrical skirt portion (43) for sealing guidance in the cylinder chamber (30). A valve (44, 45, 48, 49) is arranged to accomplish a bias spring (38) compressing air force on the thrust element (34) as the latter has been initially displaced a certain distance by the balls (24) at release of the clutch.

Abstract: Disclosed herein is a reciprocating saw including a housing, a shaft rotatably mounted in the housing, a motor, a spindle reciprocally supported by the housing, a wobble plate mounted on the shaft and connected to the spindle and converting rotational motion to reciprocal motion, and a clutch drivingly connecting the motor to the shaft and providing slippage between the motor and the shaft if there is binding of the spindle.

Abstract: A pneumatic power nutrunner comprises a housing (10), a rotation motor (19), an air inlet passage (15), a torque limiting release clutch (20) located between the motor (19) and an output shaft (13), which clutch (20) includes overriding cam elements (24, 25) spring biassed via a thrust sleeve (26), and a shut-off valve (30) in the air inlet passage (15) axially supported by an activating rod (32, 36) which by its forward end engages a latch (40) radially displaceable into a recess (42) in the thrust sleeve (26) for releasing the activating rod (32, 36) and the shut-off valve (30) for axial displacement at clutch release. The shut-off valve (30) comprises a pneumatic actuator (31, 34) for accomplishing an extension of the axial displacement of the activating rod (32, 36) at part closure of the shut-off valve (30).

Abstract: A power tool clutch assembly is provided. A first spindle is configured to rotate in a gear case. A drive clutch element is fixed to the first spindle. A second spindle rotates independently of the first spindle. An output clutch element is fixed to the second spindle. An intermediate clutch element is positioned between the drive and output clutch elements, rotatable and slidable relative to the second spindle. A compression spring is provided between the intermediate and output clutch elements. A clutch housing supports the clutch components. The clutch housing and clutch components all can be removed from a power tool gear casing for easy service.

Abstract: A power drill includes a casing, a bit-carrying shaft provided with a front toothed member, a rear toothed member fixed on the casing, a driving unit, and a speed reduction device which interconnects the driving unit and the shaft so as to rotate the shaft at a speed smaller than that of the driving unit. The speed reduction device includes a planetary gear train provided with an internal gear mounted in the casing, and a coiled compression spring which presses the internal gear against an inner wall of the casing so as to fix the internal gear in the casing. An adjustment member is mounted rotatably on the casing and cannot move axially on the casing. The compression spring is located between the internal gear and the stepped portion of the adjustment member.

Abstract: An impulse tool (20) having a housing (22), a motor (26), drive mechanism (30), impulse mechanism (28), trigger mechanism (67), and sensor (32) for automatic shut-off is disclosed. The sensor (32) uses a spring-biased ball (144) that sits on a ball seat (149) adjacent an entry orifice (108) and a spring-biased piston (112) such that when a predetermined non-transient torque is reached, the strength, duration and frequency of pulses of the working fluid entering the entry orifice (108) will lift the ball (144) sufficiently to impose on the piston (112) and to progressively lift the piston (112) to allow the working fluid to a triggering height which starts the shut-off of the impulse tool (20). A delay mechanism is also disclosed that may include a regulator (172), dashpot (170), spring latch (204), and trigger bar (56) or latch. A method of cooling an impulse tool with cold, dense air throughout is also disclosed.

Abstract: A clutch torque control features a plurality of clutch balls disposed between complementary races of input and output cams which are relatively axially displaceable upon the input cam rolling the clutch balls between matching cam peaks responsive to a drive output reaching a predetermined output torque.

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).

Abstract: A chuck spindle device (300) has the following basic components:--a body (310), a bearing (316) mounting a chuck spindle (302) and an end cap (312) through which the spindle projects for connection to a gearbox. An annular space is defined in the body to receive a hammer mechanism in the form of rotary ratchet (378), fixed ratchet (376) and cam ring (308) to press them together. The body has a slot to accept a control knob (360) of the cam ring. The body is threaded (317) to receive a clutch mechanism in the form of control ring (322) and multiple springs (330) pressing balls (334,336) against a torque control ring of the gear box.

Abstract: A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck and has associated therewith a degree of looseness which must be taken up before torque from the motor is applied to the tool bit. The control circuit for the power tool increases the effective torque output of the tool after a predetermined torque level is attained, by alternately turning the motor on and off, with the duration of the off-time sufficient to permit the gear train to relax, thus giving the motor a "running start" when power is reapplied. Various alternative schemes for transitioning to this ratcheting mode of operation are disclosed including the sensing of a predetermined threshold current, a predetermined increase in motor current, and a predetermined rate of deceleration in motor speed.

Abstract: A tightening tool includes a drive member rotatably driven by a motor. An intermediate member is interposed between the drive member and a spindle and rotatable with the drive member. A claw clutch is formed between the spindle and the intermediate member and is engageable when the spindle is moved axially through abutment of a bit on a work. A connecting mechanism is interposed between the intermediate member and the drive member for permitting rotation of the intermediate member relative to the drive member within a predetermined range. A biasing member normally keeps the rotational position of the intermediate member relative to the drive member. The rotation of the drive member is transmitted to the intermediate member after the drive member is rotated relative to the intermediate member by a predetermined angle when the claw clutch is engaged by movement of the spindle through abutment of the bit on the work.

Abstract: The invention directed to a portable handheld drilling apparatus for receiving and driving a drill which can encounter a drilling resistance during a drilling operation thereby causing the drilling apparatus to undergo an unwanted rotational movement.

Abstract: In a power-driven electrical hand tool, especially an electric screwdriver, with a coupling that undoes the drive connection between driving electric motor and tool output shaft when the working process is complete, and with an output shaft mounted so as to be displaced axially with a depth stop, it is proposed that the coupling be configured as a friction coupling which produces the drive connection at least predominantly by frictional engagement on the basis of the applied pressure exerted on the output shaft, which friction coupling separates the drive connection again when the applied pressure is reduced or absent, force deflection elements being provided that transmit the pressure effect received from the applied pressure via the output shaft, with concurrent amplification, to the annular coupling surfaces effecting the nonpositive frictional entrainment.

Abstract: An air impact tool has an air motor driving a rotary impact mechanism which has a drive shaft which is coupled to a coaxial load shaft through a torque-limiting clutch mechanism which includes a rigid torque member coupled to one of the shafts and having a peripheral drive surface with drive surface portions, and a yieldable torque member coupled to the other shaft. A plurality of flexible and resilient arms on the yieldable torque member are equiangularly spaced apart around the axis of rotation parallel thereto and are cantilevered from a support yoke, the distal ends of the arms being respectively engaged with the drive surface portions of the torque receiving member. A retaining cylinder encircles the arms and holds them against the drive surface, the retaining cylinder being threadedly engaged with an adjusting member which is rotatable but axially fixed to effect axial movement of the retaining cylinder to vary the retaining force on the torque transmitting arms.

Abstract: A slipping torque changing mechanism for an impact tool includes a driving source for generating a rotational motion. A motion converting mechanism is connected with this driving source for converting the rotational motion of the driving source into a reciprocating motion. An impact mechanism is connected with this motion converting mechanism for transmitting the reciprocating motion to a tool end. A rotational motion transmitting mechanism is disposed separately from the motion converting mechanism for transmitting the rotational motion of the driving source to the tool end. A plurality of clutches, having different slipping torques, are disposed at different portions on the rotational motion transmitting mechanism.

Abstract: The present invention provides a power-driven rotary tool having an improved power transmission mechanism which has little frictional resistance against a spindle rotatable about and reciprocating along a longitudinal axis. The power-driven rotary tool of the invention includes: a spindle rotatably mounted in a housing for receiving rotation of a transmission shaft; a fixed clutch member idly rotatably mounted on the spindle; a movable clutch member mounted on the spindle to face the fixed clutch cam; a coil spring for pressing the movable clutch member towards the fixed clutch member; and a motor for rotating the fixed clutch member. The spindle has three ball spline grooves and the movable clutch member has three ball grooves. The movable clutch member is coupled with the spindle to be rotatable integrally therewith and reciprocate along a longitudinal axis via three balls.

Abstract: An automatic overload release and power stoppage device consisted of a central control mechanism, a power switching mechanism, a power output mechanism, a torque control mechanism, and a release control mechanism, whereby the central control rod of the central control mechanism is moved upwards to trigger the power switch of the power switching mechanism in turning the main shaft thereof and the output shaft as the output shaft of the power output mechanism; the central control rod is moved downwards by the release control ring of the release control mechanism to cut off power source as the torsional force surpasses the critical level set by a torque control mechanism.

Abstract: A power driven screwdriver includes a clutch mechanism provided between a spindle for mounting a driver bit thereon and a drive member rotatably driven by a motor. The clutch mechanism includes a protrusion formed on one of the spindle and the drive member and a recess formed on the other for engagement with the protrusion. The protrusion includes a conical outer surface having a diameter decreasing toward the protrusion. The recess includes a conical inner surface which corresponds substantially to the conical outer surface of the protrusion and has a diameter increasing toward the recess. The conical outer surface has a second central axis displaced from the first central axis of the spindle or the drive member by a first distance. The conical inner surface has a third central axis displaced from the first central axis by a second distance.

Abstract: A power driven screwdriver includes a device interposed between a spindle and a housing for preventing rotation of the spindle. The device includes a first member and a second member. The first member is disposed on the spindle and is rotatable therewith. The second member is fixed to the housing and axially opposed to the first member. The first and the second members include a first conical surface and a second conical surface, respectively. The first and the second conical surfaces have central axes parallel to a central axis of the spindle, respectively, and are opposed to each other. At least one of the central axes of the first and the second conical surfaces is displaced from the central axis of the spindle. The first conical surface contacts the second surface when the spindle is positioned at a first position where a clutch mechanism disconnects the spindle from a motor.

Abstract: An air impact tool has an air motor driving a rotary impact mechanism which has a drive shaft which is coupled to a coaxial load shaft through a torque-limiting clutch mechanism which includes a rigid torque member coupled to one of the shafts and having a peripheral drive surface with drive surface portions, and a yieldable torque member coupled to the other shaft. A plurality of flexible and resilient arms on the yieldable torque member are equiangularly spaced apart around the axis of rotation parallel thereto and are cantilevered from a support yoke, the distal ends of the arms being respectively engaged with the drive surface portions of the torque receiving member. A retaining cylinder encircles the arms and holds them against the drive surface, the retaining cylinder being threadedly engaged with an adjusting member which is rotatable but axially fixed to effect axial movement of the retaining cylinder to vary the retaining force on the torque transmitting arms.