Abstract: Apparatus and a method are presented for determining the torque load applied to a fastening element by a fluid powered wrench, and displaying a digital readout of the torque. The operating pressure of the wrench, after compensation for the temperature of the pressure transducer, is converted to a torque measurement by programmed microprocessor and the torque value is displayed on a digital readout. The system is useable with and adjusts for wrenches of several sizes by an input selector switch connected to the microprocessor.

Abstract: A magnetic disc memory unit is presented wherein a pair of read/write heads are attached to and driven by a continuous belt driven by a stepper motor. The read/write heads move linearly, and they retract to a landing position fully off the disc when the unit is shut down. The heads carriage structure is counterbalanced by a counterbalance assembly to allow operation at all altitudes and minimize vibration and shock problems.

Abstract: A vacuum coupled ultrasonic transducer is presented for coupling a transducer to a bolt for ultrasonic measurement of bolt elongation. A central passageway extends through the transducer body, the piezoelectric crystal and a seal element. A vacuum line extends through the central passageway.

Abstract: A low profile power wrench is provided which is useful both for general application and for easy accesses to bolts and nuts in cramped or hard to reach places. The drive of the wrench and the reaction system are in tension, thereby resulting in important advantages for the wrench. The wrench includes a power cylinder having a piston rod extending therethrough. An anchor or reaction assembly comprising an anchoring ring and attached anchor rod is adjustably (i.e., threadably) attached to the piston rod to permit connection of the anchoring ring to a nut spaced from the nut to be turned. A wrench assembly comprising a preferably arcuate lever arm with a ratchet assembly is pivotably connected to the power cylinder. Operating fluid (hydraulic or pneumatic) is delivered sequentially to the power cylinder through first and second inlet/outlet openings.

Abstract: The external sleeve of a slip brake in a torque wrench with a pair of clutches in series is provided with a spiral groove which houses lubricant. "O" rings at opposite ends of the external sleeve cooperate with an internal sleeve to seal in the lubricant. The slip brake of the present invention incorporates an internal split ring or drum which is adjustable to set the desired bias load of the slip brake. However, the split ring or drum is encased in a very thin steel sleeve which is attached, as by soldering, to the split ring. The outer surface of the thin steel sleeve abutts the inner surface of the outer ring and serves as the brake drum. Although the split ring is encased in a thin steel sleeve, the sleeve is thin enough (from about 0.025" to 0.030" thick) so that this sleeve will stretch when the split ring is expanded to increase the bias load on the slip brake.

Abstract: An improved ratchet construction for a powered wrench of the type which includes an oscillating power unit adapted to provide torque to a socket assembly during each forward stroke, and a ratchet mechanism which permits the drive mechanism to return to its initial position at the completion of each stroke without applying a reverse torque to the select assembly is presented. The improved ratchet construction acts to synchronize the coupling elements (i.e., the pins) so that the correct number of pins will (1) be seated in their recesses at the same time; and (2) the pins will wait until a "throat" is properly opened before dropping into their respective recesses (thus preventing a pin from partially seating and making a "click" sound which might signal the operator to apply the power stroke). In this way the correct number of pins will be completely seated in its recess when the operator attempts the power stroke.

Abstract: A combined torque wrench and geared wrench which includes a ratchet mechanism, so that it can be operated in either a clockwise or a counter-clockwise output direction and so that a nut can be run down by ratcheting if necessary (due to space limitation) or desireable. The body of the wrench is relatively small so it can be operated by hand for quick run down. Provision is made for incorporation of an elongated handle which can be used for quick run down, pre-torquing, and/or a reaction bar. The wrench also incorporates a gear train for torque multiplication, and the gear train can be crank actuated by either of two inputs which are accessible at opposite sides of the body of the wrench, thus making the wrench accessible for crank input even though one side may be in quarters which are too close for use of the crank. The two inputs on opposite sides of the wrench also serves the purpose of allowing drive input on the side opposed to the side which must be supported against a reaction surface.

Abstract: A self-aligning post is presented to direct and/or balance a load being transmitted. The post has a semispherical end section split from the remaining main cylindrical portion of the post whereby misalignment of the main cylindrical portion is compensated by the split end section. The post is further provided with means for retaining the cylindrical portion in contact with the semispherical end section and for preventing the split end section from slipping from a socket. Preferably, the retaining means is an annular skirt disposed along the flat perimeter of the semispherical end section wherein the cylindrical portion of the post will bear against the skirt during misalignment and thereby prevent slippage.

Abstract: A torque producing tool of compact design may have its driven output member displaced from the tool body through use of an easily attachable extension drive. By providing a plurality of different extension drives the maximum output torque of the tool may be varied in stepwise fashion.

Abstract: A tape transport cartridge is presented wherein the rotational kinetic energy of the two reels and tape packs are balanced, constant tension on a drive belt is effected by a counterbalanced idler roller assembly, and a temperature compensated brake acting on the drive belt contributes to achieving a stable tape pack over a wide temperature range.

Abstract: A control for a digital cassette tape drive maintains constant linear tape velocity at the playback head, constant tape tension, provides compensation for inertial imbalances and provides for minimal stop time. Constant linear velocity is obtained by computing actual velocity at the head and using the computed information to control takeup motor speed. Tape tension control is achieved by energizing the payout hub drive motor with a voltage which is a function of hub rotational speed and motor current.

Abstract: A method and apparatus for determining the residual force or tension in a bolt or stud is presented. The bolt or stud in a previously tightened joint is stressed by the imposition of a pulling force, the resulting strain on the bolt is measured to develop a force-strain relationship, and the measured force-strain relationship is compared to previously determined force-strain relationships for the joint to determine the residual force or tension in the bolt or stud.

Abstract: A calibration test stand and method is presented for calibration of hydraulically powered torque wrenches. A hydraulic wrench to be powered by a pump is directly calibrated with the pump so that the pressure level of the pump can be accurately set to obtain the desired output torque level.

Abstract: A calibration apparatus and method is presented for calibrating an ultrasonic extensometer which is used to determine the average level of stress in a bolt or stud. The calibration apparatus uses linear displacement transducers and force measuring apparatus to accurately determine the stress-strain relationship of a bolt or stud. Simultaneously, readings on an ultrasonic extensometer strain measuring apparatus are monitored, and the ultrasonic extensometer is calibrated in accordance with the linear transducer and force measuring readings.

Abstract: A torque wrench is presented having a pair of clutches in series. One clutch is a one way clutch, preferably reversible, which transmits the input force in one direction during torquing operations; and the second clutch provides friction restraint against movement in the opposite direction. When desired, force applied to the wrench in the opposite direction overcomes the friction clutches to release the wrench from the work.

Abstract: A coded safing device is provided which produces a desired output upon receipt of a predetermined dual channel binary code. A stepping drive solenoid provides motion input to dual channel electromechanical binary code sensors to drive the sensors and establish the system output only when the proper code has been delivered to permit the electromechanical sensors to move.

Abstract: Long and short term variations in the speed at which a magnetic tape is moved with respect to a read and/or write head are minimized by maintaining the product of the speed of the tape payout and take-up reels constant. In accordance with a preferred embodiment the rotational speed of the payout reel and the rotational speed of the take-up reel are sensed and effectively multiplied to derive a signal which is compared with a predetermined constant magnitude reference signal. The result of the comparison is an error voltage which is employed to energize and thus control the speed of the drive motor for the take-up reel.

Abstract: A torque wrench is presented having bidirectional operating capability, accurate readout, and preset or load selection capability. The input drives a pair of ring gears, one of which is connected to the output of the wrench and the other of which is part of a reaction arm system which interacts with the readout and preset features.

Abstract: A self-aligning post is presented to direct and/or balance a load being transmitted. The post has a semispherical end section split from the remaining main cylindrical portion of the post whereby misalignment of the main cylindrical portion is compensated by the split end section.