Machine vise with clamping force detector

摘要

A machine vise for clamping a workpiece between a stationary jaw fixed to a body, and a movable jaw provided on a movable member which is moved relative to the body by a rotating motion of a feedscrew member which is rotatably supported by a support portion formed on one of the body and the movable member, the feedscrew member having an externally threaded portion engaging an internally threaded member provided fixedly to the other of the body and the movable member. The feedscrew member includes a radially outwardly extending flange portion which prevents the feedscrew member from moving in the axial direction relative to the support portion, due to a reaction force which is produced upon clamping of the workpiece. The machine vise includes a strain detector device disposed between the support portion and the flange portion of the feedscrew member, for detecting an axial force which is exerted on the support portion via the flange portion and the detector device due to the reaction force. The detector device generates an output signal that indicates the axial force and consequently a clamping force of the workpiece.