GB990197A - Improvements relating to torque indicating mechanisms - Google Patents

Abstract

990,197. Measuring torque. HOPKINSONS Ltd. July 26, 1963 [July 18, 1962], No. 27568/62. Heading G1W. A final gear reduction stage of a rotary actuator drive of a torque limiting or indicating mechanism includes a single helical spur pinion 2 which is capable of axial movement against the force of a spring 14; and upon a predetermined torque being exceeded, end thrust on the pinion causes axial movement which is communicated to indicating or torque controlling means. The pinion 2 drives a final reduction gear 1 and is fixed on a shaft 3 which is free to move axially in bearings 4, 5. A forked lever 8 links the shaft 3 to and communicates its movement to cylindrical housing 12 enclosing the spring 14. The spring normally holds the shaft 3 in a central position and is compressed if the housing 12 moves in either direction on stationary rod 13. The displacement of the shaft 3 may be used to actuate directly a limit switch 22; or the movement of the housing may operate limit switches 25. Alternatively the lever 8 may communicate the shaft movement, through its spindle 9 to an indicator calibrated in units of torque or it may co-operate with adjustable means to control the torque (Figs. 2, 3 not shown). In a further embodiment (Fig. 4 not shown) the pinion 2 forms part of a sleeve which is slidable but not rotatable on a shaft and the shaft is not movable longitudinally, also the spring is coaxial with the sleeve.