Chuck with angular compensation

The invention relates to a compensating chuck for machine tools which makes it possible to grip a workpiece mounted between centers even on slightly eccentric surfaces without deteriorating the same or exerting undesirable bending moments on the workpiece. This is in particular necessary when the workpiece is mounted between centers, so that these determine its rotation axis during a particularly precise machining step, whilst the workpiece must simultaneously be griped by the collet of a chuck in order to transmit a sizeable moment to it e.g. to perform an eccentric grinding. Because of unavoidable allowances of the surface of the workpiece that is griped by the collet, one must expect that the rotation axis of the collet-simply called chuck axis hereafter-will not coincide exactly with the actual rotation axis of the workpiece, which axis is dictated by the centers. The chuck comprises jaws which, in addition to their radial movement, can each swivel around an axis essentially parallel to the axis of the chuck, and where this axis glides in a radial slideway of the chuck in order to allow said radial movement. This swivelling action ensures that the working surfaces of the jaws or of shoes sitting on them which are adapted to the outer shape of the workpiece will sit evenly on the workpiece even when the latter is mounted between centers and as a consequence its rotation axis does not coincide exactly with that of the chuck.