Abstract: An electric tool system includes an electric tool and an inspection device. The electric tool includes: a tightening unit configured to tighten a workpiece onto an attaching target by driving force of a drive source; and a sensor configured to measure a tightening torque provided by the tightening unit. The inspection device includes a measuring unit configured to measure tightening force applied from the tightening unit. The electric tool system further includes an association processor configured to associate a first torque measured value with a second torque measured value. The first torque measured value corresponds to a measurement result by the sensor. The second torque measured value corresponds to a measurement result by the measuring unit.

Abstract: A torque tool for applying torque to a workpiece is disclosed. A drive shaft is connected to a first component with a rotatable output such that rotation of the drive shaft rotates the rotatable output and a second component is fixedly arranged relative to the first component. A beam transducer extends lengthwise axially and is coupled to the two components. The first component is arranged such that a reaction force experienced by the rotatable output tends to turn the first component relative to the second component. The transducer beam resists which causes it to bend. A bending measurement means or sub-system is then used to measure the degree to which the beam transducer bends.

Abstract: An electrical outlet assembly is mountable in a floor or work surface, and includes an upper bezel and a lower insert that are joined in a non-rigid manner that permits some adjustment to the spacing and/or tilt of the upper bezel relative to the lower insert. The upper bezel and lower insert are joined together by a plurality of fasteners extending between a plurality of fastener receivers coupled to the upper bezel, and to the lower insert. At least one end of each coupling fastener is loosely captured in such a way that when the coupling fasteners are fully secured, they are permitted to move axially relative to the fastener receiver or the lower insert. This allows the lower insert to be repositionable in its axial direction relative to the upper bezel, and also permits the lower insert to be tilted out of alignment with the upper bezel.

Abstract: A method for evaluating a condition of a torque wrench includes connecting the torque wrench to an adapter, detecting a click point, where a click mechanism of the torque wrench is decoupled from a first position into a second position, and measuring a click torque value at the click point, detecting a peak point and measuring a peak torque value at the peak point, detecting a release point, where the click mechanism is moving back from the second position into the first position, and measuring a release torque value at the release point, determining that the evaluation was performed correctly if the click point, the peak point and the release point were detected.

Abstract: A torque connector structure includes a first body, a second body assembled with the first body, a first drive member assembled with the first body, a second drive member received in the first body and having a plurality of first receiving grooves each having a cylindrical shape, a third drive member received in the first body and the second body, a fourth drive member mounted on the third drive member and having a plurality of second receiving grooves, an elastic member biased between the first drive member and the second drive member, and a plurality of pins received between the first receiving grooves and the second receiving grooves. The second drive member and the first drive member are driven simultaneously.

Abstract: An electronic torque wrench with double display screens includes a main body having a shank. A front end of the shank has a working head. The shank is defined with a central vertical face in the longitudinal direction. The electronic torque wrench further includes a display unit having two display screens. The two display screens are respectively disposed on two sides of the central vertical face. The two display screens are disposed by an inclination and directed upward and outward, whereby a user can easily observe the torque value displayed on the display screens.

Abstract: A display protecting device is disposed on an electric wrench which has an opening. The display protecting device includes a printed circuit board, a display, a cover and a protection member. The printed circuit board is disposed in the opening. The display is disposed on the printed circuit board. The cover is located above the printed circuit board and covers on the opening. The protection member is assembled with the cover. The protection member includes a body and two wing portions. The body covers on the display. The two wing portions are connected to two sides of the body and cover on two sides of the display.

Abstract: A torque wrench includes a main body, a holder, an adjusting member, and at least one first washer. The main body has a receiving recess. The holder has a first threaded portion. The adjusting member is provided with a second threaded portion, a head portion, a first abutting face, a second abutting face, and an annular groove. The at least one first washer is mounted in the annular groove of the adjusting member. Thus, when the head portion is moved toward the holder by rotation of the second threaded portion relative to the first threaded portion, the at least one first washer is moved to abut the holder, thereby providing a buffering effect between the head portion and the holder, and thereby preventing the head portion from directly hitting the holder.

Abstract: A torque tool for identifying locking state of torque adjustment mechanism includes: a tubular body; a tool head having a stem body fitted in the tubular body, a torque adjustment mechanism being used to adjust the torque of the torque tool, a handle with at least one display window being fitted around the tubular body; a locking mechanism for selectively locking the torque adjustment mechanism; a push unit positioned behind the locking mechanism; and a first identification area and a second identification area respectively formed on the locking mechanism and the push unit. When the locking mechanism is not pushed by the push unit, the first identification area is displayed through the display window. When the push unit pushes the locking mechanism to lock the torque adjustment mechanism, it is impossible to adjust the torque of the torque tool and the second identification area is displayed through the display window.

Abstract: A power screwdriver may include a main body including a bit drive device configured to rotate a driver bit. A screw may be attached to the driver bit. The power screwdriver may further include a locator attached to the main body and configured to adjust a driving depth of the screw into a workpiece. The locator may include a contact member including a contact surface for contacting with the surface of the workpiece. An orientation adjusting device may adjust the orientation of the contact member relative to the main body or the axial direction of the driver bit.

Abstract: A method of verifying a magnitude of a delivered output torque during a tightening operation of a threaded joint performed by a hand held power wrench including a housing, a motor, an output shaft, and a power transmission connecting the motor to the output shaft. The method includes: tightening the threaded joint; monitoring a magnitude of a direct torque acting along the power transmission during the tightening by at least one direct torque indicating sensor; monitoring a magnitude of a reaction torque transferred via the housing during the tightening by at least one reaction torque sensor; comparing the monitored magnitude of the direct torque with the monitored magnitude of the reaction torque; and determining, based on the comparison, whether the accuracy of the delivered output torque is acceptable.

Abstract: A tool is provided for machining an interface between coplanar first and second layers of a workpiece that defines an orifice extending at least partially through the first and second layers and intersecting the interface. A housing portion includes a first end, a longitudinally-opposed second end, and a peripheral surface extending therebetween. The housing portion is configured to rotate about its longitudinal axis and extend at least partially through the orifice. A contacting element operably engaged with the housing portion between the first and second ends and proximate the peripheral surface is movable between stored and operating positions. The contacting element is configured to extend outwardly from the peripheral surface of the housing portion to operably engage the interface within the orifice when the contacting element is in the operating position. An associated method is also provided.

Abstract: A torque-limiting driver has a handle, a body, a torque-limiting assembly and a work-piece engaging tip. The torque-limiting assembly includes an upper and lower shank that have a plurality of teeth circumferentially spaced. The teeth have a vertical face, an inclined face, and a flat peak. There is a spring for applying pressure across the upper and lower shank with multiple washers interposed between the lower shaft and spring. In some instances, there is a round square drive with arched catches having preselected radii to assure operation over certain cycles at selected torque and to reduced nose cone damage and breakage at a predetermined inch pounds of torque.

Abstract: A twist-on wire connector is releasably engageable with a tool. The connector and the tool are provided with complimentary driving features which allow the tool to be moved independent of and relative to the connector when the tool is moved in one rotational direction and which place the tool and connector into driving engagement when the tool is moved in the opposite rotational direction such that the connector is moved with the tool to apply the connector onto a plurality of electrical conductors. The complimentary driving features are provided to the tool and the connector by providing to each of the tool and the connector one or more engagement surfaces positioned adjacent to a slipping surface.

Abstract: The present application relates to a torque limiter (1) comprising a handle (2) with a mono-block cylindrical handle-body. The cylindrical handle-body includes a central through bore (3) having an axis (B) at a right angle to a longitudinal axis (A) of the cylindrical handle-body as well as a first pocket (4) and a second pocket (5). The first pocket (4) is arranged on a first side and the second pocket (5) is arranged on a second side of said cylindrical handle-body opposite of said first side. The first pocket (4) and the second pocket (5) are arranged along said longitudinal axis (A) and intersect each other in the area of said central through bore (3), each of said first pocket (4) and said second pocket (5) comprising at least one magnet (6a, 6b, 7a, 7b; 35). Further, the torque limiter (1) comprises a mono-block shaft (20) having a central shaft (21) removably arranged in said central through bore (3), said central shaft (21) having a drive (23) arranged at a first end.

Abstract: A torque-limiting device which may include a shaft extending axially through a clutch assembly and a spring to connect to a nut. The upper and lower shanks may be under a force from the spring and further configured to selectively engage within a predetermined torque limit and disengage at above the predetermined torque limit. Accordingly, the shaft may receive torque up to the predetermined limit as provided by a user operating a handle of the torque-limiting device. The torque-limiting device may be disposable, reusable, economical, and have high torque capabilities.

Abstract: A power driven in-line disposable torque-limiting device having a tool shaft extending axially through upper and lower shanks, and a spring to connect to a nut and a drive shaft, the tool shaft extending from the distal end of the device and a drive shaft extending from the proximal end of the device which mates with a power supply to provide rotational force, is disclosed. The face-to-floor gears within the device provide superior heat management capabilities, thereby reducing ablation and melting as compared to traditional gear arrangements. A fortified connector mount supports a power driven shaft.

Abstract: A portable power tool has at least one actuating element and at least one tool holding unit. A center axis of the at least one tool holding unit is configured to extend at least through a vicinity of the at least one actuating element.

Abstract: A tool to screw/unscrew a screwing element, having a module comprising a lever extending radially from and rotatable around a drive axis, a first transmission element rotatable around the drive axis by the lever, a transmission module comprising a second transmission element cooperating with the first element, a third transmission element rotatable around a screwing/unscrewing axis parallel to, and spaced from, the drive axis, a transmission system comprising an element transmitting the second element rotation to the third element, and an adapter with a fourth transmission element cooperating with the third element, and a cavity confirming to the screwing element. The tool includes a wedge with at least one rotatable adapter mounted thereon. The wedge comprises two support surfaces on planes parallel to the drive axis and disposed opposite one another to define a groove receiving an end of the transmission module on the third element side.

Abstract: A disposable ratcheting device and method is disclosed, which may include a shaft extending axially through at least a shank. The shank also provides a cup or chamber wherein a series of drive bodies reside in a movable fashion. The shank is placed in a body having an inner wall with teeth formed radially, The drive bodies have toes protruding beyond the shank and which, in a locked direction, engage the teeth inside the body.

Abstract: A surgical instrument includes a body assembly and a selectively coupleable end effector assembly. The end effector assembly may include a transmission assembly, an end effector, and a rotational knob operable to rotate the transmission assembly and the end effector. The body assembly includes a trigger and a casing having a distal aperture configured to receive a portion of the end effector assembly. First and second coupling assembly portions cooperatively couple the end effector assembly to the body assembly for use. An attachment assembly may be used to rotatably couple the first and second coupling assembly portions.

Abstract: The multi-socket wrench includes a housing, first and second head portions extending from the housing, a plurality of main shafts having an exposed end extending through the second head portion, and a socket removably attached to each exposed end of each of the main shafts for engaging lug nuts on tire. A gearbox is disposed within the housing. The gearbox includes a drive assembly that is connected to the main shafts by a chain. The drive assembly drives the main shafts to rotate in a clockwise or counter clockwise direction. The drive assembly is configured to provide two different levels of torque to drive the main shafts to simultaneously tighten or untighten the lug nuts of a car tire.

Abstract: The present invention relates to a device for adjusting the position of a surgical instrument (1) with respect to a solid (3) tracked by a navigation system (2), wherein the instrument (1) comprises a fixed part (11) that is rigidly fixed to the solid (3) and a mobile part (12) that is attached to the fixed part by screws (13), the device (4) comprising: a stem (41) comprising a tip (42) suited to the head (130) of the screws (13), a motorized system (45) for driving the stem (41) in rotation, a communication device with the navigation system (2), such that the navigation systems (2) transmits to the motorized system (45) the number of turns to apply to the stem (41) to reach the target position of each screw (13).

Abstract: An electronic socket is provided. The electronic socket includes a body, a strain gauge, an electronic control module, and a display unit. The body has a driving groove and a passive groove. The driving groove and the passive groove are connected to each other through a channel, wherein the body includes a containing space located on an outside and a recessed groove located in the containing space corresponding to the channel. The strain gauge is disposed in the recessed groove. The electronic control module and a display unit are disposed in the containing space, and the display unit is for showing a data sensed by the electronic control module which obtains from the strain gauge.

Abstract: A single-shaft yaw electric bolt-tightening machine, comprising a base (1), a bracket (2), an electric tightening shaft assembly (14), a sleeve (15), a reaction force supporting board (16), a dedicated sleeve (17), a reaction force sleeve (18), a servomotor (19), a torque sensor (20), an angle sensor (21) and a connecting shaft (22). The bracket (2) is fixed on the base (1) and is provided with a rotary servomotor (3) and an encoder (4). The rotary servomotor (3) is connected with an output shaft (5) which is provided with a small pulley (6). The small pulley (6) is fitted with a big pulley (8) by a toothed belt (7). The big pulley (8) is connected with a rotating shaft (9). A guide rod (12) is connected with a rotating arm (10) by a shaft sleeve (11) and is fixed on a cover-plate bracket (13) in which the electric tightening shaft assembly (14) is fixed.

Abstract: A torque wrench, a torque wrench contains a hollowing extension, a tool head, a torque adjusting mechanism, a controlling member, and a value adjusting device. The tool head connects with a first end of the hollow extension, the torque adjusting mechanism includes a first end coupling with a second end of the hollow extension, the controlling member connects with a second end of the torque adjusting mechanism. The value displaying device couples with the controlling member and includes a housing, a plurality of digital wheels mounted in the housing, a central shaft, and a plurality of driving gears, wherein the central shaft inserts through the plurality of driving gears, each driving gear meshes with one side of a respective one of the plurality of digital wheels so as to drive the respective one of the plurality of digital wheels.

Abstract: The instant invention is directed to a universal bone screw screwdriver and in particular to a universal screwdriver that permits the removal of screws from bone plates that are manufactured by different manufacturers having distinct characteristics. The universal bone screw screwdriver is adapted to replaceably receive tool bits corresponding to the screw heads of different manufacturers and comprises a torque limiting spring to secure the tool bit to the driver shaft and inhibit over-tightening of the bone screw into the bone or bone plate as the case may be.

Abstract: A torque limiting driver with a belt driven use indicator, having a body with a shaft and tool at one end and a counter or indicator at the other end, is disclosed. The indicator is driven by a drive shaft and belt corresponding to movement of the tool. The indicator provides at least one visual cue which corresponds to a predetermined amount of use, or end of life. Alignment of the at least one visual cue with a sight or mark may be used to estimate or determine usage.

Abstract: Devices, systems, and methods are provided for applying a controlled amount of torque during a surgical procedure. In one exemplary embodiment, after the amount of torque applied reaches a threshold amount, a modular driver tip can be deformed, for instance by breaking into pieces. A containment shield disposed around at least a portion of the tip is configured to receive at least a portion of the tip after it is deformed. In one aspect, multiple modular driver tips can be disposed in a cartridge, with a distal-most tip being held by a driver tip holder that has a holding force that is greater than a threshold torque value of the tip. Exemplary methods for operating surgical drivers and systems that include tips that deform at a threshold torque value, and a multitude of embodiments of tools and systems, are also provided.

Abstract: A torque wrench equipped with a cam-type torque detection mechanism is provided which is capable of detecting a torque with high accuracy, providing a non-unusual-feeling of handle operation after torque has been detected, and enabling tightening of fastened members such as bolts with safety.

Abstract: A torque-exerting device includes a clutch arranged between a handle and an axle. The handle includes a chamber defined therein by a wall. The clutch includes a movable element, a rotatable element, recesses and balls. The movable element is placed in the chamber in an axially movable manner. The rotatable element is placed in the chamber in a rotatable manner and secured to the axle. The rotatable element is in releasable engagement with the movable element. The recesses are defined in the movable element or the wall of the chamber of the handle. Each of the balls is partially placed in a respective one of the recesses and in contact with the wall of the chamber of the handle or the movable element.

Abstract: A torque tool having a visible indicator indicating that a predetermined number of usages of the torque tool has occurred. The indicator is carried on a movable platform which is moved into alignment with a window in the housing of the torque tool by a gearing assembly ultimately driven by a torque shaft for applying torque to a fastener. The gearing assembly includes gears extending along less than the full extent of the gear, so that a point is reached wherein at least one of the gears disengages from another gear, such that further rotation of the last gear does not occur. The indicator is eventually displayed to signal exhaustion of permissible usages, but is not moved further to conceal the indicator by disengagement of at least one gear from another.

Abstract: A torque wrench comprising a hollow housing comprising an outer wall and an inner wall each having a proximal end and a distal end, the inner wall being spaced from the outer wall so as to provide a gap therebetween, the proximal end of the outer wall being connected to the proximal end of the inner wall, and the distal end of the outer wall being configured to engage a workpiece housing; a mechanical multiplier disposed within the inner wall, the mechanical multiplier comprising a torque input shaft and a torque output shaft, the mechanical multiplier being connected to the inner wall, and the torque output shaft being configured to engage a workpiece fastener; and a torque monitoring system comprising at least one strain gauge mounted to the inner wall proximally of the midpoint of the inner wall.

Abstract: A torque wrench with double drive ends includes a handle having at least two hollow tubular bodies coaxially connected with each other, two drive heads respectively disposed at two ends of the handle, and a double torque adjustment mechanism including at least one adjustment member, two slide blocks and two elastic members. The two slide blocks are movable within the two tubular bodies. The adjustment member is positioned between the two slide blocks for driving the two slide blocks. The two elastic members are respectively positioned between the two slide blocks and the tubular bodies. By means of the adjustment member, the elastic force applied by the elastic members to the drive heads the can be adjusted to set the torque values thereof.

Abstract: A filter turning mechanism is attached to an engine in proximity to a filter (such as an oil filter), and may be used to install or remove a filter by turning the filter. The filter turning mechanism contacts a filter, and rotates the filter when the filter turning mechanism is rotated with a tool. One implementation of the filter turning mechanism includes an inner drive gear and a filter drive mechanism. The inner drive gear normally spins freely within the filter drive mechanism, but when pushed into the filter drive mechanism with a suitable tool such as a ratchet extension, the inner drive gear engages the filter drive mechanism, thereby causing rotation of the inner drive gear to rotate the filter drive mechanism as well, which in turn rotates the filter.

Abstract: A torque limiting tool, method for using the same, and set of torque limiting tools according to different loads are arranged for adjusting a device to a predetermined load, and preventing further adjustment once the predetermined load is reached.

Abstract: A torque adjustment device for a screwdriver includes a tube located in the handle of the screwdriver and has an adjusting member connected to the first end thereof, a cap is connected to the second end of the tube. A first block and a second block are connected with each other by engagement of the teeth on the two blocks. A spring is biased between the first block and the adjusting member. A link is connected to the cap which pushes a pushing member to move the second block toward the first block when using an assistance tool to rotate the cap. The first block is able to move toward the second block by rotating the adjusting member so as to change the matching force between the teeth of the blocks. The cap has digits and marks to acknowledge the user the setting value of the torque.

Abstract: A torque wrench, a torque wrench contains a hollowing extension, a tool head, a torque adjusting mechanism, a controlling member, and a value adjusting device. The tool head connects with a first end of the hollow extension, the torque adjusting mechanism includes a first end coupling with a second end of the hollow extension, the controlling member connects with a second end of the torque adjusting mechanism. The value displaying device couples with the controlling member and includes a housing, a plurality of digital wheels mounted in the housing, a central shaft, and a plurality of driving gears, wherein the central shaft inserts through the plurality of driving gears, each driving gear meshes with one side of a respective one of the plurality of digital wheels so as to drive the respective one of the plurality of digital wheels.

Abstract: An electronic torque wrench includes a main body, a display device and at least one pushbutton module. A torque detector is disposed on the main body in adjacency to a working head for outputting a torque value. The display device has an operation unit and a display panel. The pushbutton module is for setting a torque value. The pushbutton module and the torque detector are electrically connected to the operation unit. The operation unit serves to receive and process the torque value to display the torque value on the display panel. The display panel and the pushbutton module are respectively disposed on a top side and a lateral side of the main body.

Abstract: A filter turning mechanism is attached to an engine in proximity to a filter (such as an oil filter), and may be used to install or remove a filter by turning the filter. The filter turning mechanism contacts a filter, and rotates the filter when the filter turning mechanism is rotated with a tool. One implementation of the filter turning mechanism includes an inner drive gear and a filter drive mechanism. The inner drive gear normally spins freely within the filter drive mechanism, but when pushed into the filter drive mechanism with a suitable tool such as a ratchet extension, the inner drive gear engages the filter drive mechanism, thereby causing rotation of the inner drive gear to rotate the filter drive mechanism as well, which in turn rotates the filter.

Abstract: A torsion assembly includes a torsion tool and at least one wireless displayer for simultaneously receiving and displaying the torsion datum from the torsion tool. The torsion tool includes a seat disposed therein and a display module detachably received in the seat. The wireless displayer includes a base and a body rotatably mounted on the base. The base can be put on a desktop or adhered on a machine by a magnet. The body can wirelessly receive and shown the torsion datum from the first wireless transceiver that is disposed in the seat on the torsion tool.

Abstract: An internal adapter for use in torque-limiting handles for interchangeable orthopedic tools contains a slidable collar component, house component, retaining ring, spring, driver component, cover and cam which engages a torque-limiting mechanism. A plurality of securing ball mechanisms releasably secure an orthopedic tool in the adapter, while a configuration of chamfered surfaces centrally stabilize the tool. A plurality of guiding chamfers located in a driver component rotationally secures the orthopedic tool.

Abstract: A top surface of a transmitter on a torque wrench is opposed to a position camera, and bolt holes to fix the transmitter to a wrench main body open on the top surface. The bolt holes are formed to four places so as to define a rectangle and extend in a thickness direction of the transmitter. The marker is attached to the top surface of a head of one of the bolts, which extends through a through bolt hole. When the transmitter is fixed to the main body using a bolt, the depth of a large diameter portion of the through bolt hole is larger than the total thickness of the bolt head portion and the marker. Therefore, the marker is disposed lower than an aperture surface of the bolt hole and the possibility of the marker being damaged during work is reduced.

Abstract: An extendable multi-tool comprising an extendable pole and a head unit selectively detachably coupled together. The head unit comprises a grasping mechanism configured to engage a light bulb, a control switch and a rotation mechanism. The control switch configured to cause the grasping mechanism to become secured to a light bulb, and to cause the rotation mechanism to automatically detect when a light bulb is secured to the grasping mechanism and then rotate the grasping unit and the secured light bulb in a first direction based on the position of the control switch. The tool further comprises an arm unit for positioning the grasping mechanism in a desired configuration to engage the light bulb, wherein the arm member is coupled to the grasping mechanism.

Abstract: An electronic torque wrench is disclosed that instantaneously logs data in real time from a torqueing operation and can later transfer the data to an external device, such as a computer, for further analysis. For example, the computer can create a graph that can be analyzed to determine relevant parameters of the torqueing profile. The parameters of the graph can be analyzed to determine whether the torqueing operation was performed properly for a particular work piece or job task, or to assist users in future torqueing operations.

Abstract: A communication port interface facilitates downloading of torque and/or angle log information from an electronic torque tool to an external device. Torque and/or angle preset job information may be entered in client software and uploaded from the external device to the electronic torque tool via the communication port interface. Additional information including real time clock information and wrench system parameters may be uploaded to the electronic torque tool via the communication port interface.

Abstract: The present disclosure relates to an electronic torque tool, a calibration fixture, and a method for calibrating the electronic torque tool. The calibration includes applying a torque to the torque wrench and releasing the applied torque once the applied torque reaches a full scale calibration torque. The calibration fixture holds and displays a peak value of the applied torque and the torque wrench holds and displays a measured peak value of the applied torque. The measured peak value on the torque wrench may then be adjusted, by incrementing or decrementing the displayed value, to match the peak value displayed on the calibration fixture.

Abstract: The present disclosure relates to electronic torque tools that allow an offset length of an adapter or extension being used in conjunction with the tool to be input into the tools. The tools may also include an input for a head length, when the head of the tool is interchangeable. The tools use the input(s) to calculate a correction factor. The correction factor is used to adjust the torque measurement of the tools so that the tools display the actual torque value without the need for re-calibration or the performance of external calculations.

Abstract: A torque wrench for implantable medical devices is disclosed. The torque wrench comprises a first and a second component. The first component has first and second ends with a bore extending between the first and second ends of the first component. The first component includes a plurality of anti-rotation members extending from an inner surface of the bore at the second end of the first component. A second component includes a middle portion having a first and second ends. A drive shaft extends from the first end and a plurality of fingers extends from an exterior surface of the second end. The second component is received in the bore of the first component such that the fingers are interdigitate with the anti-rotation members.

Abstract: A torque wrench with functional lock includes a hollow main shaft, a tool member, an adjustable grip, a torque-adjustment elastic member, a clutch device, and a functional lock. The locking ring axially moves along the main shaft between a locked position and an unlocked position. When the locking ring is in the locked position, the rotation of the adjustable grip against the hollow main shaft is limited. When the locking ring is in the unlocked position, the rotation of the adjustable grip against the hollow main shaft is allowed, whereby the torque is adjusted. Therein, a percussion sound is produced when the locking ring is switched between the locked position and the unlocked position.