STRUCTURE OF AN ELECTRONIC TORQUE WRENCH

摘要

An electronic torque wrench has a rigid metallic sleeve of generally regular section extending along a tool axis and having a front end and an opposite handle end and a holder integrally formed with a flat rear part, a socket-like front part, and a flat web part interconnecting the rear and front parts. The flat rear part extends generally diametrically of the axis in the front end of the sleeve and has a pair of outer edges radially outwardly engaging the sleeve in surface contact. The front socket part is adapted to receive a wrench fitting engageable with the element to be torqued and is wholly out of contact with the sleeve. The flat intermediate web part interconnecting the front and rear parts extends diametrically of the axis and generally perpendicular to the rear part, has a pair of oppositely directed faces, and is wholly out of contact with the sleeve. This web part is substantially only capable of flexing perpendicular to itself and parallel to the rear part. A strain gauge on at least one face of the web part changes electrical characteristics, normally impedance, on flexing of the web part. Electronic circuitry connected to the strain gauge forms an output corresponding to the flexing of the web part and a display is provided to show this output.