Abstract: A torque-limiting tool which comprises a drive member and a driven member. A plurality of balls extends from one of the members; a corresponding plurality of cylinders extends from the other. The relationship of the drive member and the driven member is such that when a torque is applied to the drive member, the balls and the cylinders engage and drive the driven member until a predetermined torque is applied. Once this torque is attained, the balls and cylinders mutually rotate so as to release the driven member. A calibration screw adjusts the overlap between the balls and cylinders to calibrate the limiting torque.

Abstract: A digital indicating torque wrench comprising a shaft having a high modulus of elasticity and including a handle at one end, and an elongate actuating arm including a free end which moves with respect to the shaft in response to the application of torque to a workpiece. Displacement measuring means comprising an optical encoder measures the relative movement between the actuating arm and the shaft and provides deflection signals which are related to the amount of relative movement. A programmed microcomputer responsive to the deflection signals converts the amount of deflection into signals representing the amount of torque applied to the workpiece, and displays a visual representation of the applied torque.

Abstract: A ratchet reversing mechanism of the shifting pawl type is operated by a reversing apparatus which is confined to a small arcuate segment of the work-turning member, leaving space over the work-turning member for a quick-release mechanism and for attachment of a speeder ring. A switching ring lies over the pawl and includes a spring-receiving recess which positions a compression spring in a radial plane above the pawl, one end of the spring engaging the pawl and the other end of the spring engaging the switching ring at a location radially outwardly of the engagement with the pawl, such that the spring extends only over the segment of the work-turning member defined by the recess in the work-turning member which receives the pawl. A second pawl is provided in another embodiment of the invention.