Patent ID: 9321109
Filing Date: 2016-04-26
CPC Classification: B23B,Y10T

Claim Text:
1. A power-operated chuck for supporting cylindrically shaped workpieces which are to be machined by means of a machine tool in the areas of their free ends, the chuck comprising: a chuck body having a passage opening extending into its lengthways axis in order to accommodate a workpiece, a driving means for producing an actuation force, wherein the actuation force is absorbed by at least one actuating pin axially movably mounted in the chuck body, a guide hole disposed in said chuck body, the guide hole being angled in a direction of a free end of the workpiece, wherein an actuating pin is inserted in the guide hole, and at least three centring jaws, each mounted in a guide groove provided in the chuck body, and mounted so as to move radially in the direction of the workpiece, wherein each centring jaw interacts in a driving arrangement with one of the actuating pins, wherein an anti-friction bearing comprising a roller or a plain bearing is provided on an end of the driving means facing the actuating pin, a contact surface being provided on on the free end of the actuating pin and extending at a right angle to the lengthways axis of the chuck body, wherein the contact surface and the anti-friction bearing interact such that the actuation force of the driving means is transferred from the anti-friction bearing onto the contact surface of the actuating pin in an axial direction, and simultaneously a relative movement vectored at a right angle to the lengthways axis of the chuck body is released between the contact surface of the actuating pin and the anti-friction bearing; wherein the driving means is formed by at least one advance piston and at least one clamping piston mounted one inside another in a telescopic arrangement, and further wherein the clamping piston is axially moveable relative to the advance piston in order to generate clamping force.