Abstract: A motorized chassis dynamometer machine. In one embodiment, the dynamometer machine includes a fixed frame assembly. At least one roller assembly is mounted on the fixed frame assembly. At least one independent motor assembly is connected to each roller assembly. The independent motor assembly is used for driving the roller assembly. At least one independent loading dynamometer assembly capable of measuring the vehicle input power at each roller assembly is coupled to each roller assembly. In a preferred embodiment, the dynamometer assembly is only operable for loading each independent roller assembly, while the motor assembly is operable for driving each independent roller assembly. The machine has at least one motor controller capable of controlling each independent motor assembly and at least one dynamometer controller capable of controlling each independent dynamometer assembly.

Abstract: A system and method for detecting changes in tire status in real time, e.g., changes in tire pressure or changes that might indicate an imminent tread separation or other failure, using magnetic sidewall torsion (SWT) signatures for tires. A measured magnetic signature of a tire is compared to a stored magnetic signature that describes the tire in an undamaged state or otherwise acceptable state. If the measured magnetic signature deviates too much from the stored signature, or if a change in tire pressure is detected, the system and method can further provide an associated warning to the driver and/or provide an input to a vehicle control system, which would automatically take action to correct or at least mitigate the effects of the failing tire, e.g., by decelerating the vehicle.

Abstract: We disclose density measurement methods that are accurate over an extended range of standoff distances. One method embodiment includes: a) obtaining a standoff distance, a near detector count rate, and a far detector count rate; b) determining a formation density measurement using near and far detector count rates when the standoff distance is less than a predetermined value; and c) determining the formation density measurement using just the far detector count rate and the standoff distance measurement when the standoff distance is greater than the predetermined value. The method may further include calculating a calibration parameter when the standoff distance is less than the predetermined value. The calibration parameter serves to calibrate a standoff-based correction to the far detector count rate, enabling accurate formation density measurements at large standoff distances. The measurements are made with a rotating logging tool, causing the standoff distance to cycle between large and small values.

Abstract: According to the invention, to correct the curvature characteristic in output due to individual difference between the frequency output type hot-wire flow meters, a frequency output type hot-wire flow meter comprises a heating resistor disposed in the measurement target fluid and a voltage frequency conversion circuit for converting the air flow rate voltage signal that is proportional to the current flowing through the heating resistor, wherein the voltage frequency conversion circuit converts the air flow rate voltage signal non-linearly to generate the output frequency.

Abstract: A filling level measurement device and a process for its insertion into a tank. The tank has a passage opening leading from the outside of the tank through the tank wall to the inside of the tank, and the filling level measurement device is introduced into the passage opening from the outside of the tank, and a seal is introduced between the wall of the tank and the filling level measurement device. By the nature of the seal, a smooth surface is maintained on the inside of the tank for simplified cleaning. Specifically, an opening wall that protrudes into the passage opening, tapers the passage opening toward the inside of the tank. The filling level measurement device is introduced in the lateral direction from the opening wall, protruding into passage opening, with a clearance area around the opening wall. A dog fashioned on the circumference of the filling level measurement device presses the seal in the direction of the inside of the tank, against the protruding opening wall, and into the clearance area.

Abstract: A level detector for storage tanks for fluids comprises a microprocessor, a network of resistive elements connected in series or parallel, and a plurality of conductive elements between them, connected across a power source. The resistive elements have a high temperature coefficient, and are heated by passing a high electric current through them, after which a low electric current is passed through them and the voltage between them is sampled by the microprocessor. The resistive elements lose heat through conduction, so that a pair of resistive elements can be detected having differential cooling between them as a consequence of being adjacent to the void within the tank or the fluid within the tank. Thus, an approximation of the fluid level within the storage tank can be determined and signalled remotely.

Abstract: A side-mounted float sensor has eight components: a reed switch, two leads, a molded connector, a sensor body, a sealing grommet, a float, and an activation magnet. The two leads are assembled to the molded connector and the reed switch is welded across the leads. The molded connector is inserted into the sensor body. The sensor body has an opening that receives a portion of the float. The float is keyed to the sensor body and a flange extends from the sensor body so that the float can only be installed on one side of the sensor body. The float rests on an upper portion of the sensor body and is completely contained behind a circular disk which terminates the sensor body and guides the sensor body during insertion through the sealing grommet.

Abstract: A high-reliability complex sensor protected against vibration and electromagnetic wave noise from outside. Shield case (38) is provided with power conjunction terminal (39), GND conjunction terminal (40), angular velocity conjunction terminal (41), X axis acceleration conjunction terminal (42) and Y axis acceleration conjunction terminal (43). Both power supply terminal (27) of angular velocity detection means (21) and power supply terminal (32) of acceleration detection means (31) are electrically connected with power connector terminal (47) of protection case (45), via power conjunction terminal (39) of shield case (38). Both GND terminal (29) of angular velocity detection means (21) and GND terminal (29) of acceleration detection means (31) are electrically connected with GND connector terminal (51) of protection case (45), via GND conjunction terminal (40) of shield case (38). Circuit board (35) is contained completely within shield case (38).

Abstract: The present invention discloses a resonator gyroscope comprising a resonator including two bodies, each with a center of mass and transverse inertia symmetry about an axis that are substantially coincident and each supported by one or more elastic elements and wherein the bodies together forming two differential rocking modes of vibration transverse to the axis with substantially equal frequencies and wherein the two bodies transfer substantially no net momentum to the baseplate when the resonator is excited. The gyroscope further includes a baseplate affixed to the resonator by the one or more elastic elements.

Abstract: A miniaturized micromachined (MEMS) accelerometer-based sensor suitable for use in biological applications, such as a middle ear implant, is provided. An encapsulation layer is deposited on top of an accelerometer proof mass and flexure prior to release of the proof mass and flexure. The encapsulation layer protects the proof mass and flexure from subsequent processing steps, such as dicing and packaging, which enables fabrication of finished devices having reduced size. Surfaces within the accelerometer may be passivated after releasing the proof mass and flexure. Remote piezoresistive sensing is performed in order to provide low noise and reduced sensor head size.

Abstract: A method and apparatus for acoustically inspecting a tubular member is presented. In particular a method for inspecting coiled tubing using ultrasound is presented. The method includes contacting a tubular with a coupling material, transmitting an acoustic signal, receiving a returned acoustic signal and then releasing the contact of the coupling material with the tubular. The method has particular application for determining the wall thickness of coiled tubing as it is being unreeled into a borehole or wound on coiled tubing reel.

Abstract: In the method of detecting a sun gear fault, in the operation of an epicyclic gear train having ring, planet and sun gears, and a planet carrier, the steps that include detecting sun gear vibrations transmitted through each planet gear, computing separated averages of such detected vibrations, phase shifting said averages to account for the differences in gear meshing positions, and re-combining said phase shifted averages to produce a modified average value of the sun gear vibration.

Abstract: An improved scanning station and method for a tray-fed scanning acoustic microscope has a vacuum system which at least assists in immobilizing loosely held parts in the trays during insonification by an ultrasonic beam generator.

Abstract: Provided is a device for measuring at least one parameter of an extruded flat conductor cable in a water bath that follows the extruder. The device distinguishes itself in that the flat conductor cable is guided with one of its flat sides essentially perpendicular across an ultrasonic head arranged in a water bath and that the ultrasonic head is a displaceable ultrasonic head that can be displaced crosswise to the longitudinal direction, or the ultrasonic head is a stationary ultrasonic element row that extends crosswise to the longitudinal direction of the flat conductor cable. This device allows measuring the total width of the flat conductor cable, such that different parameters can be determined.

Abstract: A device for measuring pressure, e.g., for measuring high pressure, including a pressure transducer that is arranged in a housing and includes sensor elements and a sensor diaphragm on a first side, and on a second side opposite the first side is provided with a cutout that extends from the second side to the sensor diaphragm. The pressure transducer is formed as a semiconductor pressure transducer and, with an edge area of the second side surrounding the cutout, is directly soldered onto a support part, provided with a first pressure-channel section, with the aid of a solder layer in such a manner that the first pressure-channel section and the cutout are interconnected.

Abstract: A ceramic pressure measurement cell for use in a sensor for static and/or dynamic monitoring of the pressure of a liquid or flowable medium which includes a base body and a membrane connected to the base body such that one side of the membrane is in contact with the medium to be monitored. The pressure measurement cell has high chemical resistance and high temperature resistance for a plurality of chemicals which is achieved by applying at least one plastic film on the side of the membrane in contact with the medium.

Abstract: A dynamic pressure probe for a combustor comprising a holder body having a pressure sensing passage; a pressure sensor and a pressure chamber located in a housing portion arranged substantially perpendicularly to the pressure sensing passage; and wherein the pressure chamber communicates with the pressure sensing passage via a relatively small aperture in a wall separating the pressure chamber from the pressure sensing passage.

Abstract: A pressure instrument with a seal connection connecting a pressure gauge to a process. A pressure sensor located in a base of the seal connection is in data communication with the pressure gauge that is spaced apart from the pressure sensor. Embodiments are particularly applicable on sanitary seal connections or where a low measuring range or high accuracy is required. Embodiments can include, for example, digital pressure gauges, pressure transducers and transmitters with any seal connection.

Abstract: A measuring device (1; 21; 33) for controlling an installation torque of a fastening element (4; 32) and securable to engagement means (3; 35) of the fastening element (4; 32), includes an indicator (5; 24) for a visual display of the installation torque, a plurality of microcapsules filled with a dispersible color die and supported on the indicator (5; 24), and a transparent, at least regionwise, covering (7.1; 7.2; 22) provided on an outer surface of the indicator (5; 24); and an opening (27) through which a fastening element (4; 32) can extend.

Abstract: An exemplary system and method for integrated pressure sensing is disclosed as including inter alia: a sensing cavity having a surface capable of mechanical deformation; a plurality of piezoresistors; a plurality of electrical contact pads; a plurality of conductive pathways connecting the piezoresistors and the contact pads; and a monolithic device package. Disclosed features and specifications may be variously controlled, adapted or otherwise optionally modified to improve sensing in any microfluidic application. Exemplary embodiments of the present invention representatively provide for sensing fluid pressures in a microfluidic channel or reservoir. Representatively disclosed embodiments may be readily integrated with existing portable ceramic technologies for the improvement of device package form factors, weights and other manufacturing and/or device performance metrics.

Abstract: A pressure converter insusceptible to the error of hydraulic pressure introducing position or the interference of installation depth of water and producing a signal corresponding to the effective soil pressure accurately while realizing cost reduction. since filters(34,35) are provided in an air gap(10) defined by two rigid plates(13,14) Receiving the soil pressure, a hydraulic pressure is applied but sand pressure is not applied. A load gauge(41) insensitive to the hydraulic pressure detects only the effective soil pressure. Since a signal cable(51) can be passed through the air gap(10), a plurality of pressure converters(1,2) can be coupled efficiently and since the signal cable(51,52) can be inserted internally, a pressure distributed in the depth direction can also be measured accurately.

Abstract: A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

Abstract: A pedal force sensing apparatus includes a pedal force input shaft, a force action sleeve, a torque output shaft, at least one elastomer, a micro optical pickup head module, a diversion sleeve, a linear sliding bush and a displacement sensor. The pedal force input shaft to which an input torque is applied drives the force action sleeve combined with it to simultaneously rotate. Sequentially, the force action sleeve applies forces to the elastomer to have reaction force acting on the torque output shaft. When a reverse torque from the loading of the electric bicycle is applied to the opposite end of the torque output shaft, the rotations of the torque output shaft and the force action sleeve occur, and relative angular displacement between them simultaneously exists.

Abstract: A sensor for measuring stress corrosion cracking and methods of using the sensor. The sensor is a MEMS device and has a cantilevered beam made from a material of interest. The sensor has on-chip electrical connections for measuring electrical characteristics that indicate cracking of the beam. The sensor may further have on-chip actuators for applying stress to the beam.

Abstract: An automated apparatus for preparing material samples includes a rotatable drum support assembly, a drum rotatably contacting the drum support assembly, a fan, and a powered drive mechanism. The drum includes a hollow main section and first and second hollow end sections attached to the main section. The first hollow end section includes a first end wall tapering to a first outer aperture. The second hollow end section includes a second end wall tapering to a second outer aperture. The fan is mounted approximate to the first outer aperture for establishing forced air flow through the drum toward the second outer aperture. The drive mechanism rotatably communicates with the drum support assembly for rotating the drum. The apparatus is useful for preparing samples such as paving materials for test such as the determination of specific gravity and absorption.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: An actuator is disclosed which can be used in multiple applications, and which provides both linear and rotary outputs. The device comprises a motor driven rotor having clutch plates on both sides thereof. One clutch plate includes a gear driven output, and the other clutch plate drives a linear rack for the linear output. An electromagnet controls the engagement of the first and second clutches.

Abstract: An easily accessible phase adjustment mechanism for a vibratory plate compactor includes an improved seal arrangement to protect against leakage of internal lubricating oil into the hydraulic cylinder providing fluid pressure to the adjustment mechanism. An easily demountable cylinder housing provides ready access to the piston and seal assembly which can then be threadably detached and replaced in its entirety.

Abstract: A bearing system for coaxial input shafts of a twin-clutch transmission mounts the outer input shaft rotatably on the inner input shaft via at least two internal radial roller bearings which are mounted on the inner input shaft. The outer input shaft is secured in an axial direction thereof via two axial roller bearings which are effective in respective opposite directions. The inner input shaft is secured in an axial direction thereof and is rotatably mounted, via a fixed roller bearing, in an external housing wall on the engine-remote side of the transmission housing. The inner input shaft is mounted rotatably and displaceably in the axial direction in an internal housing wall of the transmission on the engine side via an external radial roller bearing which is mounted on the outer input shaft.

Abstract: A shift control system rotates an actuator to allow a wall of a detent plate and a roller of a detent spring to contact each other and then detects the position of contact so as to detect the position of the wall of the detent plate. After the wall position is determined, the actuator is driven in the direction opposite to the wall until the actuator reaches a position located before the wall position and distant therefrom by a predetermined amount, in order to cancel flexure or extension of the detent spring that is caused when the detent spring is pushed against the wall of the detent plate. Accordingly, such a situation where the shift position is moved by the recovery force of the detent spring can be avoided.

Abstract: A device for compensating for the tooth backlash between two toothed gears in engagement with one another, with a toothed disk, which is connected in parallel with one of the toothed gears and provided with the same gear pitch, and which is held such that it can be hydraulically adjusted relative thereto until it bears against the non-force-transmitting tooth flanks of the mating toothed gear. In order to achieve a design that is as simple as possible and requires little mounting space, there must be provided at least one hydraulic adjusting element, which exerts an adjusting force in circumferential direction on the toothed gear and which is equipped with a steel piston held adjustably in a housing and urged by a spring as well as by pressurized fluid supplied via a check valve.

Abstract: A ball screw device comprises a nut having a thread groove in the inner peripheral surface thereof, a screw shaft having a thread groove in the outer peripheral surface thereof and a plurality of balls interposed between the respective thread grooves. In the screw shaft, the thread groove is of at least substantially one turn. In the screw shaft is provided a ball circulation groove for coupling the downstream and upstream sides of the thread groove so that the balls are returned to the upstream side from the downstream side so as to be thereby circulated.

Abstract: A robot arm is provided at a forward end thereof with a rotation shaft member rotatable about a rotation axis thereof, in which a hollow portion is formed along the rotation axis. A laying device for laying a line element includes a relaying means for relaying an arm side section of the line element, extending through the hollow portion out of a lead-out opening formed on a side of the rotation shaft member, to a tool side section of the line element extending from the tool. A direction in which the relaying means connects the line element is substantially parallel to a tool mount surface and forms an angle other than 0° with regard to a radial direction perpendicular to the rotation axis.

Abstract: The present invention relates, in general, to a tilt steering apparatus for a vehicle, and more specifically, to a tilt steering apparatus for a vehicle, capable of adjusting the angle of a steering column by engaging a movable gear with a fixed gear or disengaging the movable gear from the fixed gear, using a lock slider that does a rectilinear motion by an operation lever. If the lock slider is separated from the operation lever, even when the operation lever rotates, the lock slider does a rectilinear motion only. Hence, the lock slider and the movable gear can always make the line contact with each other. Through this line contact, the supporting rigidity and the abrasion resistance of components can be improved.

Abstract: At least one first mounting part (1), which has at least one passage opening (1a) for guiding a connector (3). The connector connects to one another at least two clamping parts (4, 7) that are movable in relation to one another, which clamp the connecting piece (2). The connector (3) and the clamping parts (4, 7) form a first clamping mechanism. Structure is provided for securing the first clamping mechanism, and includes a second clamping mechanism (10, 11), which is located between the clamping parts (4, 7) of the first clamping mechanism and is coupled with same. The second clamping mechanism has at least one second mounting part (1), which has a passage opening (11a) that is at least congruent with the passage opening (1a) of the first mounting part (1), as well as a spindle (10), which is connected with the first clamping mechanism (3, 4, 7) via a clamping part (4) of the first clamping mechanism (3, 4, 7).

Abstract: An apparatus and accompanying method are disclosed for a handgrip based gear-shifting mechanism used to manipulate the front and rear derailleur cables on a vehicle having a multi-sprocket gear system. The gear-shifter comprises a substantially hollow handgrip member that has first and second cam guide paths in the bore of its substantially cylindrical surface. First and second cam followers, preferably located inside the bore of the handgrip member, engage the first and second cam guide paths respectively. The first and second cam followers are coupled to the front and rear derailleur cables, such that a single rotation of the handgrip simultaneously adjusts the positions of the first and second cam followers and the front and rear derailleur cables.

Abstract: An adjustable control pedal includes an upper arm, a lower arm, and a drive assembly operatively connected to the lower arm to selectively move the lower arm relative to the upper arm. The drive assembly includes a drive screw, a drive nut cooperating with the drive screw such that the drive nut travels along the drive screw upon rotation of the drive screw, and an electric motor to selectively rotate the drive screw. A hall-effect sensor is located adjacent the drive screw and cooperates with a ring magnet rotatable with the drive screw to detect motion information, including distance and velocity information, upon rotation of the drive screw. The controller determines stall conditions of the lower pedal arm between the limits of travel based on the velocity information received during movement of the lower pedal arm to reduce injury or damage resulting from engagement with obstructions.

Abstract: An accelerator device includes a bearing portion, an accelerator pedal having a cam with a cam shaft that is supported by the bearing portion to be turned forward and reversely by an action of a treading force, a follower that abuts against a cam surface of the cam when a turning position of the accelerator pedal is in a kickdown region, a bias device that generates a biasing force to press the follower against the cam surface, and a turning position sensor that detects a turning position of the accelerator pedal. Further, the biasing force of the bias device is set to act on the follower substantially toward a center of the cam shaft. Thus, the accelerator device can accurately detects a turning position of an accelerator pedal while giving a kickdown feeling to a driver.

Abstract: A vehicle steering wheel comprises a steering wheel rim having a skeleton, whereon several predetermined deformation zones with predetermined deformation directions are defined. A rigid wood casing surrounds the skeleton. The wood casing has an inner side facing the skeleton, and a deformation space is provided in deformation direction between the inner side of the wood casing facing the skeleton and the skeleton in the predetermined deformation zones. The deformation space is greater than a space of the inner side of the wood casing to the skeleton in radial direction in other zones.

Abstract: In order to increase the grip of a hand wheel (4) which is especially intended for a roller file, said hand wheel consists of a base body (6), an outer shell (9) and a rubber-elastic insert (12) disposed between the base body (6) and the outer shell (9). Said insert is provided with protuberances (11) which jut out in the outer shell (9).

Abstract: A motorcycle footpeg assembly comprising a footpeg mount having a first portion and a second portion. The first portion is adapted to attach to a motorcycle. The footpeg assembly also includes a footpeg coupled to the second portion with a fastener such that the fastener is not visible from the exterior of the footpeg.

Abstract: A torsion-vibration absorber for use with a motor vehicle includes a transmission element at a driving end and a transmission element at a driven end adapted to be rotary deflected around an axis to the transmission element at the driving end. At least one compression spring connects the transmission element at the driven end with the transmission element at the driving end. At least one reinforcing component is encompassed by at least a portion of the at least one compression spring and includes a securing device to substantially limit displacement of the at least one reinforcing component in relation to the at least one compression spring.

Abstract: A hollow bicycle crank arm has a central tubular portion to reduce weight and two mounting-boss portions for mounting a crank spindle and pedal during use. A crank arm base is forged or cast with a relatively thin back and sides, preferably out of aluminum or magnesium. The crank arm base has a generally C-shaped cross section. An arm cover has a top and sides and is made from stamped steel or titanium. The cover is placed over the open crank arm base to enclose a significant hollow section. The stamped arm cover does not require any threading or welding. It can be made using a very inexpensive stamping process. The crank arm can be made using relatively inexpensive traditional manufacturing processes such as die casting or forging.

Abstract: An adjustable timing gear assembly and the method of making same that can readily be adjusted in the field in a manner to permit precise cam timing adjustments without having to remove the engine timing belt from the gear member of the apparatus.

Abstract: The invention relates to a transmission assembly comprising at least one input shaft (1) driven in rotation and in engagement with a toothed wheel (2A).

Abstract: A powder composition for a capacitor comprising a tantalum or niobium and a compound having a silicon-oxygen bond, at least a part of which may be nitrided and which has an average particle size of from 0.1 to 5 &mgr;m; a sintered body using the composition; and a capacitor constituted by the sintered body as one part electrode, and another part electrode. A capacitor favored with high reliability, lower dissipation level of power and smaller deterioration of capacitance than conventional tantalum capacitors using tantalum can be produced by using a sintered body of the powder composition for a capacitor.

Abstract: Provided are a method for preparing metallic nickel powders capable of decreasing the content of an alkaline metal in the metallic nickel powders, metallic nickel powders with the low content of an alkaline metal, a conductive paste including metallic nickel powders with the low content of an alkaline metal, and a multi-layer ceramic capacitor (MLCC) including a nickel inner electrode with the low content of an alkaline metal. The method for preparing the metallic nickel powders includes heating a mixture including an organic base, a nickel precursor compound, and a polyol. Wherein, the nickel precursor compound is converted to the metallic nickel powders through reduction by the organic base and the polyol. In the method, the organic base is used instead of the hydroxide of an alkaline metal such as NaOH and KOH. Therefore, the content of an alkaline metal such as sodium and potassium that can be incorporated as an impurity into the metallic nickel powders can be significantly reduced.

Abstract: Provided are non-magnetic nickel powders and a method for preparing the same. The nickel powders have non-magnetic property and a HCP crystal structure. The method include (a) dispersing nickel powders with a FCC crystal structure in an organic solvent to prepare a starting material dispersion, and (b) heating the starting material dispersion to transform the nickel powders with the FCC crystal structure to the nickel powders with the HCP crystal structure. The nickel powders do not exhibit magnetic agglomeration phenomenon. Therefore, the pastes for inner electrode formation in various electronic devices, which contain the nickel powders of the present invention, can keep the well-dispersed state. Also, inner electrodes made of the nickel powders can have a low impedance value even at high frequency band.

Abstract: A hydraulic torque wrench having a separate ratchet unit and hydraulic cylinder drive unit connectable by an overlapping cylindrical connection at selected angles of rotation providing clearance in use. The hydraulic cylinder actuates the ratchet mechanism by a connecting rod traveling through the overlapping cylindrical connection and engaging a pivotable drive plate. The ratchet may have a male drive shaft for driving a socket, or a female driver such a hex or spline wrench. The ratchet unit case may be integral, or split for removable accesses to the ratchet mechanisms. The cylinder unit hydraulic connections may be separate rotatable connections or a single connection and collar, allowing three-way rotation. Attachments for the hydraulic unit include a pipe flange spreader, a nut splitter, scissor action shears, and a lift/spreader for lifting an object from a flat surface or spreading surfaces apart. A reaction bar affixes to the drive unit body.

Abstract: A wrench structure includes a drive head formed with a receiving chamber and having an end face formed with a direction control recess. The end face of the drive head is formed with a spacing portion. Thus, the spacing portion is continuously extended through the end face of the drive head and is not broken, so that the end face of the drive head is continuously extended through the drive head and is not broken, thereby preventing the stress from being concentrated on the portion between the receiving chamber and the direction control recess of the drive head, such that the structural strength of the drive head can be enhanced.