Abstract: Apparatus for measuring the amount of previously applied torque to a fastener. A transducer is utilized to sense the amount of a subsequently applied torque to the fastener and provides an output signal representative of the applied torque. The torque is applied until further motion or breakaway of the fastener is obtained. Typically, the signal from the transducer increases until breakaway of the fastener is obtained and then the signal decreases momentarily to a valley before it again increases with further applied torque. A positive peak detector senses the maximum positive output of the transducer before the signal begins to decrease. A negative peak detector senses the minimum negative output of the transducer before the signal again increases. The negative peak detector is energized by a switching network upon detection of a negatively sloped signal from the transducer.

Abstract: A load cell for measuring the rolling resistance of a tire as a function of a load placed on the tire. The cell includes a block having major parallel surfaces and a centrally disposed opening through which a shaft coupled to the tire rotates. An inner hub surrounding the opening and an outer hub are connected by a plurality of beams. Each beam is defined by a first pair of bores on the periphery of the inner hub and a second pair of bores in the outer hub. The first pair of bores are connected by a recessed web portion, as is the second pair of bores. The thickness of the first web portion relative to the major surfaces of the block is greater than the thickness of the other web. A first strain gage in one bore of the second pair and a second strain gage in the other bore of the second pair sense the rolling resistance of the tire along one axis and the loading force applied to the tire along another axis, respectively.

Abstract: A battery operated torque wrench having a digital display to give a numerical representation of torque applied to a rotational workpiece, such as a socket head bolt. Applied torque is sensed by variable resistors responsive to mechanical strain in a flexure element in the head of the wrench. The variable resistors are connected in a bridge circuit which yields an electrical analog signal when the bridge is unbalanced due to mechanical strain in the variable resistors. The electrical analog signal is tracked and converted into a digital equivalent by a servo-type feedback circuit. Each iteration of the feedback circuit generates a counting pulse which is registered on a set of binary coded decimal (BCD) counters connected in cascade. The outputs of the BCD counters are displayed on light emitting diode displays on the wrench handle. Overrange, underrange, and low power indicator means and power strobing means are also disclosed.

Abstract: A load cell which may be embodied in an arch beam structure or a shear tension link and comprising a flexure area design which requires the machining of only five parallel holes. The five holes comprise a large central hole and four satellite holes to define two opposite load paths, each including two flexure areas which react to a load in opposite tension-compression sense. Strain gage resistors of the foil type are bonded onto the flexure areas and connected into a Wheatstone bridge circuit.

Abstract: A torque measuring apparatus having a head adapted to rotate about an axis of rotation and a lever arm extending from the head and perpendicular to the axis of rotation designed to react to normal forces applied at a distance from the head. On the lever arm are a plurality of strain transducers spaced apart a certain distance as determined in accordance with predetermined mechanical properties of the lever arm. The transducers are joined electrically to form a bridge circuit, the output of which is directly proportional to the torque on the workpiece. This output is then transmitted to a display for a visual presentation of the torque.

Abstract: A load cell of the shear-link type comprising a solid body of high modulus of elasticity material having a longitudinal axis of sensitivity and longitudinally spaced transverse slots entering the body from opposite directions to define the shear link. The body is bored out in the area of the shear link to create a stress concentration which is monitored using bonded-on strain gage resistors connected in a Wheatstone bridge circuit.

Abstract: A load cell for measuring the torque and/or thrust forces in a driveline having a universal coupling joint, such as the drive shaft of an automobile. The load cell is designed to replace the standard cross element in the U-joint. Due to the operative association of the load cell with the driveline and the particular strain gage arrangement disclosed, the load cell is capable of accurately measuring the axial force and rotational torque transmitted through the driveline.

Abstract: A weigh scale apparatus in which forces caused by the applied load are transformed into moments of opposite sense and applied to opposite ends of a substantially rigid beam. Deflection of the beam is measured by centrally disposed strain gage resistors to produce an electrical signal quantity proportional to the applied load. The conversion of applied load to moments of opposite sense is accomplished by a pair of spaced parallel pivot members which are suspended by straps between the load receiving pan and the base such that the pivots tend to rotate in opposite directions. The beam is mechanically connected between the pivots such that it is subjected to the bending moment over substantially its entire length. A split scale device is provided by a composite pan, one portion of which is connected to the pivots directly and another portion of which is connected to the pivots through long lever arms to provide moment multiplication. A vibrator device for dithering the pivots is provided.