Chuck

A chuck (1) via which workpieces (2) are supported on a machine tool in a separate and centered manner for machining by the machine tool,

• including a chuck body (3) and at least four radially oriented guide grooves (4) that are incorporated into same,
• including at least four clamping jaws (5, 6, 7, 8) that are situated in each case in pairs in an x or y plane, and separately inserted into one of the guide grooves (4) in a movably supported manner,
• including a drive element (9) that is mounted in the chuck body (3), and which synchronously feeds the four clamping jaws (5, 6, 7, 8) in the direction of the workpiece (2) to be clamped or is moved away by same,
• including a rocker (11) that is provided in each case between the drive element (9) and two adjacent clamping jaws (5, 7 or 6, 8), the rocker having a center of symmetry (12) into which a bolt (13) that is swivelably mounted on the drive element (9) is inserted, the rocker (11) being swivelable about the bolt as a function of the contact of the clamping jaws (5, 6 or 7, 8) with the workpiece (2),
• characterized in that
• a wedge rod (31) is provided between the drive element (9) and the particular chuck jaw (5, 6, 7, 8), the wedge rod in each case being drivingly coupled to the drive element (9) and to one of the clamping jaws (5, 6, 7, 8), a force transmission means (32) being associated with each of the wedge rods (31), the particular force transmission means (32) of the wedge rods (31) being designed as helical teeth, and helical teeth (33) that correspond to the particular chuck jaw (5, 6, 7, 8) being incorporated at the surface of the particular chuck jaw facing the wedge rod (31), the helical teeth being in form-fit engagement with one another during the movement process and during the clamped state of the clamping jaws (5, 6, 7, 8), and the guide grooves (4) of the clamping jaws (5, 6, 7, 8) being open in the region of the outer circumferential surface of the chuck body (3), and the particular chuck jaw (5, 6, 7, 8) being disengageable from the wedge rod by pushing the wedge rod away from the chuck jaw (5, 6, 7, 8) in such a way that the particular chuck jaw is released and is removable from or insertable into the particular guide groove (4).