Abstract: A torque wrench structure comprising a reduction gear train within a case. The gear train includes an input shaft with an end accessible at the exterior of the case and an output shaft, a work engaging part at the exterior of the case concentric with the output shaft and coupling structure drivingly coupling the work engaging part with the output shaft. A reaction part with a body portion having a central opening freely accommodating said coupling structure is positioned adjacent the case. A plurality of circumferentially and radially spaced locking pins project from the body and engage in lock pin receiving structure in a part to be worked upon by the wrench. A plurality of circumferentially spaced elongate deflection beams project from the body and engaging stops on the case. Strain gauges are fixed to the deflection beams between the stops and the body.

Abstract: A torque wrench comprising an elongate, straight tubular lever with open front and rear ends, a work-engaging head at the front end of the lever and having a lever arm projecting into and pivotally connected with the front end portion of the lever, an elongate crank projecting freely rearwardly into the lever, an elongate axially biased compression spring extending longitudinally in the lever rearward of the crank, cam means between the spring and the crank normally releasably holding the crank concentric in the lever and operating to allow the crank to pivot and strike a side of the lever when a predetermined set operating force is exerted between the head and the lever through and about the axis of the lever arm. The wrench next includes adjusting means to vary the bias on said spring to adjust the operating force. Said means includes a plug set in the lever rearward of the spring, an elongate screw is engaged through the plug. The front end of the screw engages the rear end of the spring.