Patent attributes
A torque applying tool such as a nutrunner or torque wrench incorporates torque sensors responsive to strain in a shaft mounting an output square drive head the strain being measured as it exists immediately adjacent the drive head. The shaft is a hollow quill shaft an outer diameter of which is splined to receive a torque drive input at a location axially spaced from the drive head. A central shaft extends from the drive head centrally up the quill shaft and a flexible cantilever beam is mounted between a cranked end of the central shaft as it extends out of the quill shaft and the corresponding end of the quill shaft. One or more strain sensing transducers, preferably S.A.W. devices, are mounted on the cantilever beam to detect flexure of the beam, and the resulting output signal is passed through an inductive or capacitive coupling for transmission to a CPU and display.
