| 摘要 |
The invention relates to a chuck comprising a chuck body (1), a number of guide points for chuck jaws running radially in relation to the chuck axis, a wedge bar mechanism for actuating the chuck jaws having a number of wedge bars (5) which are guided in wedge bar pockets (6) of the chuck body (1) running transversely in relation to the guide grooves (3), and which can be adjusted by a drive in a working region between an inner working position, corresponding to an inner chuck position of the chuck jaws (4), and an outer working position, corresponding to an outer chuck position of the chuck jaws (4). One safety mechanism is assigned to each wedge bar (5). This comprises a release bolt (9) which is rotatably arranged about its longitudinal axis, in a holding borehole (11) of the chuck body (1) that extends in the longitudinal direction of the corresponding wedge bar (5). An end section (9a) of the release bolt (9) leading into the chuck body (1) rotatably engages in a receiving borehole (13) of the associated wedge bar (5), wherein a control groove is formed in the peripheral surface of the end section (9a), said control groove (14) being engaged with a control pin (15), which is held in the wedge bar (5) and projects into the receiving borehole (13), in such a way that a rotation of the release bolt (9) from its starting position into its release position causes the wedge bar (5) to be pulled away beyond the outer working position into a jaw change position to such an extent that a row of teeth (7) of the wedge bar (5) are positioned outside the region of the guide groove (3), thereby permitting a chuck jaw (4) to be removed from the guide groove (3). The safety mechanism comprises locking means which prevent the wedge bar (5) from being moved from its jaw change position back into its outer working position by rotating the release bolt, without a chuck jaw (4) being inserted into the guide groove (3). |
