Workholding apparatus

Abstract

An apparatus for holding a workpiece in a predetermined position in a machine tool. The apparatus has an axis of rotation and comprises an outer body having an outer surface, an inner bore, a first end and a second end with the second end being insertable into a tapered opening of a spindle of the machine tool. The outer body includes means projecting radially from the outer surface for abutment against a face of the spindle for stopping inward movement of the apparatus upon achieving a predetermined final position in the spindle. A portion of the outer surface adjacent the stop means and extending toward the second end is inwardly tapered by an amount whereby the taper of the outer surface is generally equal to the taper of the spindle opening. The workholding apparatus includes a connector attached to the second end of the outer body, the connector having a first end insertable into the second end of the outer body and a second end comprising a plurality of spaced-apart lugs extending radially outward. The inventive apparatus further comprises a collet located at the first end of the inner bore and a contractor located in the inner bore. The contractor is axially movable and comprises a first end having one or more angled surfaces in contact with respective angled surfaces on the collet whereby axial movement of the contractor expands or contracts the collet. The contractor has a second end comprising a plurality of spaced-apart lugs extending radially outward.