Bending beam torque wrench

Abstract

A torque indicating wrench has a resilient beam with a handle end and a work-engaging end carrying a ratchet mechanism. The resilient beam is generally channel-shaped in transverse cross section and is tapered in thickness from the work-engaging end to the handle end. A reference beam is disposed in the channel and has first and second ends respectively pivotally coupled to the work-engaging and handle ends of the resilient beam. The reference beam has openings adjacent to its first and second ends to facilitate pivotal coupling to the resilient beam while substantially eliminating non-pivotal relative movement in use. A handle housing encloses the beams along substantially their entire lengths and is fixed to the resilient beam only adjacent to its handle end. The reference beam carries a Hall-effect sensor disposed between magnets on the resilient beam and coupled to electronic indicating circuitry including a display viewable through a window in the housing and push-button switches operable through apertures in the housing.