Collet wrench (pinching)

INTRODUCTION
This document describes functionality of the wrench, design data, design units and complete manufacturing drawings.

MAIN SECTION
Pinching wrench works exactly like a collet with the difference that the wrench body applies a rotating torque to the clamping part. The wrench collet is a hardened steel sleeve having slits cut partway along its length and forming flexible jaws whose ends are brought close to each other. The form and size of the hole in pinching wrench opening must correspond to the workpiece profile. The collet is actuated by a hand operated left handed single start trapezoidal screw thread. The drawback of the collet forces its tabs to bend and clamp the part. After clamping the operator simple rotates right handed the wrench with the part in order to screw the second. Because there are no rotating masses there is no need for oversize parts and large safety factors. Our main concern is to provide enough clamping force to transmit the required torque.