Power-operated chuck

In a power-operated chuck having a chuck body that is disposed on a rotatably driven arbor, and also having clamping jaws that are displaceably guided in radial guide means of said chuck body and are adapted to be actuated by at least one drive element, which is displaceably guided in said chuck body and is actuated by a force producer that is operated with pressure medium, with said chuck body being provided with at least one chamber for receiving lubricating grease and lubricating bores establish communication between said at least one chamber and at least some glide surfaces for said chuck, and with at least one chuck component being associated with said at least one chamber and being moved during actuation of said clamping jaws for producing a pump movement for pressing said lubricating grease into said lubricating bores, the improvement wherein:

• said at least one chuck component is one of a plurality of respective centrifugal force counter-weights that are reciprocal in radially extending guides at least one of which being in communication with said at least one chamber;
• and
• for each of said clamping jaws, a respective lever is provided that is supported in said chuck body and connects one of said clamping jaws with one of said centrifugal force counter-weights such that during actuation of said clamping jaws, and hence displacement of said centrifugal force counter-weights, said pump movement is produced and said lubricating grease is pressed from said at least one chamber into said lubricating bores and to said glide surfaces.