Abstract: A sensor configured to detect a stress wave propagating through a vehicle frame member caused by a vehicle collision is provided. The sensor includes a sensor body configured to be rigidly coupled to the vehicle frame member, a first strain sensing device and a second strain sensing device attached to the sensor body. The sensor body is configured to exhibit stress in response to transverse and torsional stress wave propagating along the vehicle frame member. The first strain sensing device generates a first signal indicative of stress in the sensor body and the second strain sensing device generates a second signal indicative of stress in the sensor body. A first end portion of the sensor body is characterized as trapezoidal prism shaped and a second end portion of the sensor body is characterized as trapezoidal prism shaped.

Abstract: Techniques and devices for measuring the distribution of polarization crosstalk in birefringence optical media including polarization maintaining fiber based on suppressing the number and magnitude of ghost interference peaks.

Abstract: A method for testing the mechanical properties of a specimen having a first contact surface and a second contact surface spaced apart and opposing the first contact surface, the method comprising: applying forces to the contact surfaces of the specimen to deform the specimen over a period of time and determining the response of the specimen to the forces over time; and defining a spatial distance between the contact surfaces such that the equivalent gauge length of the specimen is greater than the distance between the contact surfaces.

Abstract: A reduction in cost and improvement in evaluation accuracy are achieved.

Abstract: An apparatus applies a pull test to a bond of a semi-conductor assembly, the bond including a ball or a bump of solder. The apparatus includes a probe having a longitudinal axis; a heater for heating a tip of the probe; a holder for supporting the probe; an actuation device for moving the holder and the probe up and down; and a pull force applier for applying a pull force on the holder along the longitudinal axis of the probe. A force measuring system measures a force applied to the probe during the pull test to determine the strength of the bond.

Abstract: An apparatus applies a pull test to a bond of a semi-conductor assembly, the bond including a ball or a bump of solder. The apparatus includes a probe including a straight, thermally conductive pin; a heater for heating a tip of the probe; a holder for supporting the probe and including a clamping mechanism that is configured to provide a clamping force on the probe; an actuation device for moving the holder and the probe up and down; and a pull force applier for applying a pull force on the holder. A force measuring system measures a force applied to the probe during the pull test to determine the strength of the bond.

Abstract: The present invention relates to a housing arrangement for an ultrasound flow meter, comprising a unipartite or multipartite housing (2) provided to be connected to a fluid line, comprising an ultrasonic transducer having an ultrasonic transducer body and a housing or covering which at least partially surrounds the ultrasonic transducer body, comprising a housing opening provided in the housing (2) for positioning the ultrasonic transducer at the housing arrangement, comprising a sealing element arranged between the housing (2) and the ultrasonic transducer, wherein a housing insert (5) can be inserted in the housing opening (16) as a module, the housing insert (5) is adapted to receive at least two ultrasonic transducer bodies (4, 7) which are positioned separately, without the ultrasonic transducer body (4, 7) coming into contact with the fluid, and the housing insert (5) is connected to the housing (2) via a sealing element (13) which is common to the ultrasonic transducer bodies (4, 7) which are positione

Abstract: An ultrasound measurement apparatus (10) is set forth for measuring the flow speed of a fluid in a conduit (12) having a plurality of ultrasonic transducers (14) pairs of which span between them a plurality of main measurement paths and at least one diagnosis measurement path, and having an evaluation unit (12) which is made to determine a respective individual measured value for the flow speed from transit times of ultrasound transmitted and received with and against the flow on each measurement path (16, 18), to calculate individual measured values of the main measurement paths as a main measured value for the flow speed, to determine a measured diagnosis value from the at least one individual measured value of the diagnosis measured path and to compare the main measured value and the measured diagnosis value with one another.

Abstract: A Coriolis flow meter that measures a flow rate of a fluid flowing through a vibrating tube based on a Coriolis force acting on the vibrating tube, the Coriolis flow meter may include a driving unit that applies a driving force to vibrate the vibrating tube, a change ratio obtaining apparatus that obtains a change ratio of a vibration of the vibrating tube, which has been given the driving force, a calculating unit that calculates a spring constant and a damping coefficient of the vibrating tube as parameters independent of each other, based on the change ratio obtained by the change ratio obtaining apparatus and on the driving force, and a diagnosing unit that diagnoses a state of the vibrating tube based on the parameters, which has been calculated by the calculating unit.

Abstract: A system for measuring forces applied to a moving vehicle is disclosed. The system includes a sensor plate that is configured to be mounted between a wheel and a hub of the vehicle. The sensor plate is further configured to sense at least one of the set of longitudinal, vertical, and lateral forces as well as longitudinal and vertical moments that are transferred between the wheel and the hub through the sensor plate. The system also includes an electronics package that is coupled to the sensor plate. The electronics package is configured to measure the forces and moments sensed by the sensor plate and provide an output comprising at least one signal representative of at least a portion of the measurements. The system also includes data system coupled to the electronics package, the data system configured to receive the output of the electronics package.

Abstract: A stress test apparatus used for testing torque between a top portion and a bottom portion of an electronic device. The stress test apparatus includes a console, a rotary table, a lifting pole, a traversing arm, a securing fixture and torque sensor. The rotary table is located on the console for retaining the bottom portion. The lifting pole extends from the console. The traversing arm is gearingly engaged to the lifting pole to adjust a height of the traversing arm relative to the console. The securing fixture clasps the top portion of the electronic device. The torque sensor is fixed between the traversing arm and the securing fixture. The bottom portion is rotated relative to the top portion with rotation of the rotary table, and the torque sensor is capable of detecting needed for rotating the top portion relative to the bottom portion.

Abstract: A load transducer for use in an automated control system such as those used in robotic assemblies, and other linkage systems separated by joints. The transducer is capable of measuring force and moments transmitted by the joint of the robotic assembly. This localized sensory data is utilized by a microprocessor to control the motion of the linkages of the system. In addition to being very accurate and reliable, the Load transducer has a low profile and small size. This invention is easily manufactured using strain gage technology.

Abstract: A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agent, chemical attribution signatures and toxic industrial chemicals.

Abstract: A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from the fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agent, chemical attribution signatures and toxic industrial chemicals.

Abstract: A two-part coaxial needle for a pipetting device, in particular for use in microscopy of cell probes, makes it possible both to inject a liquid into a pipetting container and to remove by suction a liquid from the pipetting container. Both the drive for lowering the coaxial needle into the pipetting container, and injection and removal by suction of the liquid take place pneumatically by way of only one pressure source. The design of the coaxial needle and of the drive systems makes possible fast and reliable pipetting with high metering accuracy and a particularly compact pipetting unit which without mutual interference can be used with a multitude of widely-used microscope types.

Abstract: A system and method for an easy-to-open liner for use in connection with soil and sediment samplers, including direct push technology, rotary and coring systems, is disclosed. The liner is pre-scored along its length by one or more score lines formed in the exterior surface or the interior surface of the liner. After removal from the sampler, the liner can easily be opened to expose the contained sample without the need of cutting blades or other sharp objects, in accordance with health and safety requirements.

Abstract: A system for evaluating cutting efficiency of root canal rotary instruments is provided. The system includes a root canal rotary instrument, a driving unit, a cutting object, a prestressing force providing unit and a feeding unit. The root canal rotary instrument is attached on the driving unit, and driven thereby. The cutting object is pressed by the prestressing force providing unit to contact the root canal rotary instrument. The feeding unit feeds the cutting object to the root canal rotary instrument, and the root canal rotary instrument cuts an uncut surface of the cutting object.

Abstract: Semi-finished products for the production of devices containing thermoelastic materials with improved reliability and reproducibility are described. The semi-finished products are based on an alloy of Ni—Ti plus elements X and/or Y. The nickel amount is comprised between 40 and 52 atom %, X is comprised between 0.1 and 1 atom %, Y is comprised between 1 and 10 atom % and the balance is titanium. The one or more additional elements X are chosen from Al, Ta, Hf, Si, Ca, Ce, La, Re, Nb, V, W, Y, Zr, Mo, and B. The one or more additional elements Y are chosen from Al, Ag, Au, Co, Cr, Fe, Mn, Mo, Nb, Pd, Pt, Ta and W.

Abstract: An instrumentation fitting includes a main body. The main body includes a first end configured to be inserted into an aperture of a vessel and a second end including at least one slot configured to accommodate at least one lead of at least one sensor. The instrumentation fitting further includes a gasket assembly supported by the second end of the main body. The gasket assembly includes a first gasket and a second gasket. The second gasket includes an aperture through which the at least one lead may pass. A flange is secured to the main body. The flange includes at least one aperture configured to receive at least one fastener. A cover plate is configured to be removably attached to the main body by the at least one fastener. The cover plate is configured to contact the first gasket and compress the at least one lead between the first and second gaskets when attached to the main body.

Abstract: A sensor element assembly, including: a sensor element; lead frames provided with the sensor element therebetween, the lead frames fixing the sensor element; a first head protection film protecting the sensor element fixed between the lead frames; an insulating film covering the first head protection film and the lead frames to insulate the lead frames; and a second head protection film (resin layer) further covering the head covered with the insulating film. The sensor element assembly is advantageous in that an epoxy resin layer is formed on a film layer covering a sensor element, so that the strength of the sensor element assembly can be maintained by the epoxy resin layer itself, thereby improving the impact resistance and compressive strength thereof.

Abstract: According to the invention, an actuator device comprises rollers positioned and guided by spacer rings, and an assembly consisting of said rollers and said rings is provided between a male part and a female part. The rollers include synchronization pinions arranged at the ends thereof and include, on the threaded portion located between said pinions, annular grooves used as a journal for interfacing with open bearings in the form of notches provided on each spacer ring.

Abstract: A synchronizer hub comprises a one-piece, disk-shaped base body having a longitudinal extent, an external toothing on an outer periphery of the base body, and an internal toothing on an inner periphery of the base body. The external toothing is divided into a plurality of tooth segments which, as viewed in the longitudinal extent, alternately extend from the base body in opposite directions.

Abstract: A method of compensating for load-induced twisting of a gear assembly under load that includes a gear on a gear shaft, bearings on each side of the gear that support the gear shaft and a carrier fastened to a stationary support surface that mounts a proximal one of the bearings near the stationary support surface and mounts a distal one of the bearings away from the stationary support surface. The method includes the steps of determining the twisting deflection of a distal bearing axis of rotation for the distal bearing relative to a proximal bearing axis of rotation for the proximal bearing and offsetting the position of the distal bearing axis of rotation relative to the proximal bearing axis of rotation in the carrier opposite the determined deflection under no gear loading.

Abstract: A connecting apparatus of a vehicle seat includes a member with internal teeth; a member with external teeth that is assembled to the member with internal teeth so as to rotate relative to the member with internal teeth while changing a meshing position; a pair of wedge members that are arranged in a gap between the members, and that prevent the members from relative rotation by being urged in a circumferential direction of the connecting members, while sliding against the connecting members, so as to become jammed between the connecting members; and an operating shaft that moves the wedge members in a direction against the urging force, and rotates the gear with external teeth with respect to the gear with internal teeth. A resin composition in which polyethylene has been added to a binder resin is coated onto sliding surfaces of the wedge members.

Abstract: A model helicopter includes a drive mechanism comprising a battery powered motor comprising a toothed motor shaft; a main rotor comprising a main shaft aligned with the motor shaft and including a main gear; and a reduction gear assembly comprising a lower section including four first gears arranged around the motor shaft, and four second gears smaller than the first gears, each second gear fixed to top of the first gear; an upper section including four third gears and four fourth gears each being smaller than the third gear and fixed to top of the third gear, the fourth gears being meshed with the main gear; and four shafts each axially passing through the fourth gear, the third gear, the second gear, and the first gear so that a revolution of the motor shaft rotates the main shaft via the first gears, the fourth gears, and the main gear.

Abstract: A overload protection mechanism protects a driven load, such as a driven lever. An overload lever is pivotally coupled to a first part of the driven load. The overload lever has a first end that receives an applied force and an opposing second end. A zero length spring mechanism is coupled to a second part of the driven load spaced apart from the first part and to the second end of the overload lever. The zero length spring mechanism urges the second end of the overload lever toward the second part of the driven load with a force that is substantially proportional to the distance between the second end of the overload lever and the second part of the driven load. A stop mechanism is coupled to the zero length spring mechanism to maintain a minimum distance between the second end of the overload lever and the second part of the driven load.

Abstract: A method of managing a transmission ratio with an assisted CVT with a governed engine to emulate a hydrostatic transmission and prevent a drivebelt abuse is provided, the method comprising: providing a reference power source rotational speed, using the assisted CVT to transmit rotatable motion between a power source and a drive mechanism, managing a torque of the power source to maintain a substantially even rotational speed upon a power source load variation and modulating a transmission ratio of the assisted CVT to change the rotational speed of the drive mechanism. A system and a vehicle having such a drivebelt abuse preventing mechanism is also provided.

Abstract: A shifter assembly for a vehicle that includes a shift lever connected to a shifter and in communication with the vehicle and a transmission. A display is positioned on the shift lever indicating data of the vehicle or transmission. A start button is positioned on the shift lever and is linked with an ignition of the vehicle.

Abstract: A cable guide re-orders a plurality of cables. A first guide plate has a plurality of first guide holes that receive a plurality of cables in a first order. A second guide plate has a plurality of second guide holes that receive the plurality of cables in a different second order. An intermediate guide plate is located between the first and second guide plates. The intermediate guide plate has a plurality of intermediate guide holes. Each of the intermediate guide holes receives one of the plurality of cables and causes a change of direction in the cable to facilitate the change from the first to the second order. The intermediate guide plate may further include cable passages to allow some cables to pass through without changing direction. There may be more than one intermediate guide plate. The cables may change from a generally linear to a generally circular arrangement.

Abstract: A force transmission transmits a force received by an input gimbal plate having two degrees of freedom to an output gimbal plate. The input gimbal plate is coupled to a first end of least three lever arms supported by a pivot. The output gimbal plate is coupled to a second end of the lever arms. The output gimbal plate may be coupled to the lever arms by flexible cables. The cables may be substantially contained within a tube. The output gimbal plate may be substantially smaller than the input gimbal plate. The force transmission may include a secondary output gimbal plate coupled to secondary levers that are coupled to the lever arms. The secondary levers may be third class levers. The secondary output gimbal plate may move proportionately to movement of the output gimbal plate. The force transmission may control a surgical end effector in a robotic surgical instrument.

Abstract: Delta robot for increased requirements on dynamics, hygiene and protection against the consequences of collision, comprising a stationary housing, in which at least three drives are installed and on which at least three upper arms are mounted such that they are pivotable about an axle in each case and are in each case connected to a drive, and at their free ends are connected to a pair of elongate and mutually parallel lower arms via one ball joint in each case, and at their other end are connected to a movable parallel plate via a further ball joint in each case, a ball head or a ball socket being fixed at both ends of each underarm as part of a ball joint, the lower arms comprising in each case a stainless steel tube, the inner space of which is sealed in a watertight manner, by means of a ball head or a ball socket at both ends of the stainless steel tube, and which is plastically deformable.

Abstract: A control panel for a communications system of an aircraft has at least one transmitter and at least one receiver, with multiple transmission and reception channels, and multiple operating elements that have an on/off function, in each instance. Each operating element is assigned to one of the transmission and reception channels. Reception on the transmission and reception channel, in each instance, can be released by the on/off function. A selection switch has a selection position for each transmission and reception channel, in which it releases the related transmission and reception channel for the transmission and blocks the other transmission and reception channels for transmission. The selection switch has a further selection position, in which it releases the transmission and reception channels that are released for reception by the operating elements, for transmission, and blocks the other transmission and reception channels for transmission.

Abstract: The electronic pedal assembly includes a housing configured to mount onto a fire wall of a vehicle. The housing includes a pair of spaced apart side walls extending outwardly from an elongated center portion, a first housing portion axially aligned with a second housing portion. A pedal arm is rotatably disposed in the first housing portion. The pedal arm includes an end portion. A rotatable member disposed in the second housing portion and is pivotably mounted to a second pivot rod. The rotatable member is mechanically linked to the end portion of the pedal arm so as to rotate about the second pivot rod upon depression of the pedal arm. A position sensor is connected to the rotatable member. The position sensor is operable to detect the degree of rotation of the rotatable member upon depression of the pedal arm.

Abstract: An accelerator pedal assembly for a vehicle includes a pedal arm having a first end portion pivotally secured to the vehicle, a pedal pivotally mounted to a second end portion of the pedal arm, and a guard plate secured to the pedal arm forwardly of the pedal.

Abstract: A stroke-controlling device includes a first body having a first surface and a second body movably engaged with the first body having a second surface. A dimension between the first surface and the second surface is configured to engage a tool. And at least one dog is in operable communication with the first body and the second body to maintain the dimension at a first value when in a first position and to limit reduction of the dimension to a second value when in to a second position.

Abstract: A handlebar grip comprises a sleeve, a clamping device and a fastening means. The sleeve made of rigid plastic materials includes a cylindrical body, a front opening end, a rear opening end and at least a vacant area near the rear opening end. The clamping device includes a ring-shaped body, a first extending end and a second extending end. A slot is defined by the first and second extending ends. The clamping device further has at least a protruding disposed on the inner surface of the body. The clamping device is fitted around the rear opening end of the sleeve in such a way that the protruding of the clamping device is wedged into the vacant area of the sleeve. The fastening means includes a threaded bore and a screw. The bore extends through the first and second extending ends of the clamping device along a reference axis. The screw has a shaft with a proximal end and a distal end opposite the proximal end, a head disposed on the proximal end and a threaded region.

Abstract: The variable inertia flywheel is a wheel on an axle with a toroidal hollow tubular rim that is completely filled with a fluid. The tubular rim contains one of more one-way valves that allow the fluid to pass in the opposite direction of rotation. When torque is applied to the axle the wheel accelerates but the fluid lags in acceleration. The wheel has two components of inertia, the solid material of wheel and the fluid. The fluid lag lowers the effective moment of inertia of the total system compared to a solid flywheel of the same mass. After a period of time the fluid acquires the same speed as the wheel. The one way valves close on deceleration. The wheel now operates as a solid flywheel of the same total mass to deliver energy to the load.

Abstract: A kickdown assembly for a pedal assembly including a pedal. In one embodiment, the kickdown assembly a leaf spring kickdown element including a base, a first arm which extends from a first end of the base and defines a recess, and a second arm which extends from a second end of the base and includes a distal end seated in the recess of the first arm and adapted to transfer a resistance force to the pedal when the second arm of the kickdown element contacts the pedal. The resistance force is overcome by the application of a kickdown or step force against the pedal which is greater than the resistance force and causes the distal end of the second arm of the kickdown element to spring out of the recess defined in the first arm of the kickdown element.

Abstract: A gear housing for a bevel gear having a surface which is made up of sections and attachment faces. The sections are convexly curved along at least one surface curve.

Abstract: A process for synthesizing metal nanopowders by introducing metal carbonyl into an induction plasma torch. By taking advantage of the much lower dissolution temperature of carbonyl as opposed to the high melting temperature of conventional metal powder feeds less torch power is required. Moreover, in contrast to current powder production techniques utilizing electrode based plasma torches, the induction plasma torch does not introduce contaminants into the nanopowder.

Abstract: A process for the direct reduction of iron ore when the external source of reductants is one or both of coke oven gas (COG) and basic oxygen furnace gas (BOFG). Carbon dioxide (CO2) is removed from a mixture of shaft furnace off gas, obtained from a conventional direct reduction shaft furnace, and BOFG. This CO2 lean gas is mixed with clean COG, humidified, and heated in an indirect heater. Oxygen (O2) is injected into the heated reducing gas. This hot reducing gas flows to the direct reduction shaft furnace for use. The spent hot reducing gas exits the direct reduction shaft furnace as shaft furnace off gas, produces steam in a waste heat boiler, is cleaned in a cooler scrubber, and is compressed and recycled to join fresh BOFG. A portion of the shaft furnace off gas is sent to the heater burners. The BOFG and COG are also employed for a variety of other purposes in the process.

Abstract: A method for separating a lanthanide from a mixture containing at least one other lanthanide is provided. In particular, an HPLC and liquid separation method using a chromatographic column for separating a lanthanide from a mixture containing at least one other lanthanide is provided.

Abstract: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: A knife sharpening device of a circular knife contains a wheel member including a sharpening portion disposed therein, the sharpening portion including an abrasive piece mounted therearound, an annular loop with a hole mounted on a central portion thereof, and a peripheral wheel formed therearound; a retaining member connected with one side of the wheel member and including a first rib disposed thereon, an abutting post with a first limiting block extending therefrom, the first limiting block including an insertion extending therefrom, the abutting post including a biasing projection proximate to the abutting post; a connecting member connected on another side of the wheel member and including a second rib disposed thereon, a second limiting block with an opening and plural locking tabs fixed on a central portion of an inner side thereof, the connecting member including a contacting peg arranged adjacent to an inner side thereof.

Abstract: The invention provides methods for making bunters used to form headstamp indicia into ammunition cases. The invention also provides bunter blanks that are specially configured to yield high quality bunters.

Abstract: The invention includes a tool system for extracting watch bezels, including a holding body arranged for cooperating with an expansion and retraction mechanism for operating a bell-chuck which is arranged to rest on the periphery of a bezel mounted on the middle part of a watch. The tool system includes thrust means, coaxially mounted inside the bell-chuck and arranged to rest on a crystal driven into the middle part, to exert on the crystal a sufficient thrust force to cause a relative displacement of the bell-chuck relative to the crystal.

Abstract: A tool for installing a saddle tee with a piercing cap on a poly pipe includes a housing having a top, a bottom and side portions. The top portion is adapted for receiving a drive device. The bottom portion is adapted with at least one pair of fins shaped to couple to wings on the piercing cap to apply a rotational force to the piercing cap. The side portion of the housing has a slot to accommodate an angular fitting that may be installed in the piercing cap. Such a tool may be a drive socket. The drive device attached to the top may be permanently attached or may be a quick release fitting. The drive device may include an extension bar, a T-handle, a speed handle, or a ratchet. The drive device may connect to a portable power drill to turn the drive socket.

Abstract: An adjustable hex wrench structure, in its basic embodiment, requires only two parts: a main body configured with a socket cavity having special modified hex cross-sectional shape, and a user operable clamping screw, traversing a wall of the main body and preferably captivated against loss, with a special pressure disc surface for securing a hex fastener workpiece in place in the modified hex cavity operationally without defacing the workpiece. The main body is made cylindrical in shape and configured with a square driver opening to engage the square end of a conventional socket wrench driver shaft.

Abstract: An open end wrench includes first and second jaws. The first jaw includes an arcuate sliding groove having an arcuate sliding wall. A slide is received in the sliding groove and includes an arcuate sliding face slideable along the sliding wall. An arcuate guiding slot is formed in the slide. A guide is fixed in the sliding groove and received in the guiding slot. The guiding slot includes an abutting end and a pressing end. The abutting end is in contact with the guide when the slide is in an initial position. A spring seat is mounted in the pressing end of the guiding slot. The spring seat includes a face pressing against the pressing end. An elastic element has two ends respectively abutting the guide and the other face of the spring seat for biasing the slide to the initial position.

Abstract: An open end wrench includes a jaw portion having first and second jaws. The first jaw includes a sliding groove slideably receiving a slide. When the jaw portion is not engaged with a workpiece, the slide is in a free position. When the jaw portion receives the workpiece but does not drive the workpiece, a buffering space is formed between an abutting end of the guiding slot and a guide fixed in the sliding groove. When the jaw portion drives the workpiece and deforms elastically, the body rotates relative to the workpiece, but the slide does not rotate together with the body due to the buffering space such that the end of the slide remains in surface contact with a face of the workpiece. Also, a buffering angle can be formed between a wrenching face on the slide and the face of the workpiece when the jaw portion receives the workpiece but does not drive the workpiece.