Dental handpiece wrench

Abstract

An improved chuck wrench for contra-angle dental handpieces. The wrench includes a unitary angular C-shaped body, one of the arms of the body being provided with a socket and recess for accurately locating the wrench in position relative to the head of a handpiece when chuck adjustment (or removal) is desired. Between the paired arms is a knurled cylindrical wheel dimensioned to fit comfortably between, and be rotated by, the same fingers that receive the narrower connecting portion of the C-shaped body. A torsion spring shaft extends through the wheel and into the socket and has a non-circular end portion receivable within an opening of a handpiece chuck for locking the two parts (chuck and shaft) against independent relative rotation. A shoulder of the shaft limits the extent that the end portion may be inserted into the chuck opening, and the substantial length of that shaft, and its relationship with the other parts of the wrench, result in a torsional flexure of the shaft upon chuck tightening that signals the user when the torque limit is approached. The shaft, as well as the tangs which engage the burtube of the handpiece during an adjustment operation, are spring-loaded for limited axial movement.