Disposable torque limiting wrench

Abstract

A disposable, limited-use torque limiting wrench is provided having a predetermined maximum number of torque-applying cycles of use for applying a fixed torque to an adaptably connected driven member. This torque limiting wrench includes a rotatable casing including a slotted hub portion and a curved bias spring dimensioned to fit around the slotted hub portion. A dowel pin is also included having a center portion which is dimensioned to fit within and be gripped by a slot formed in the slotted hub portion and to be rotated thereby in response to a torque imparted on the rotatable casing. A torque ring is cooperatively engaged with the above by a predetermined number of pairs of radially extending and substantially equiangularly spaced slots. The respective ends of the dowel pin are uniquely dimensioned to fit within respective ones of the slots which become positioned colinearly therewith as the dowel pin is caused to be circumferentially rotated about the torque ring. The dowel pin ends move from an initial one of the pairs of slots to an adjacent pair of slots during each torque-applying cycle. The curved bias spring operates to bias the dowel pin into engagement with the torque ring. One of the pairs of slots is uniquely dimensioned such when the dowel pin engages therein after a final torque-applying cycle, the dowel pin is disengaged from the slotted hub portion under the urging of the bias spring.