Power-operated chuck for turning machines

A power-operated chuck for turning machines, said chuck comprising:

• a chuck body;
• at least one movable jaw which is radially guided in said chuck body;
• a pressure medium cylinder which is provided with a working chamber, and a pressure medium piston which is movably guided in said chuck body;
• said pressure medium piston being operatively associated with said at least one movable jaw for actuating same;
• a source of pressure medium;
• a releasable check valve, with said working chamber of said pressure medium cylinder being connected to said source of pressure medium via said check valve;
• and
• a centrifugal force compensating cylinder having a pressure chamber which communicates with said working chamber of said pressure medium cylinder;
• said centrifugal force compensating cylinder being provided with a compensating piston which is designed as a centrifugal weight, and which is radially movable within said chuck body;
• said compensating piston having a radially outer end which projects into said pressure chamber of said centrifugal force compensating cylinder, said centrifugal force compensating cylinder also having a relief chamber;
• and a short-circuit line for directly connecting said relief chamber with said source of pressure medium;
• said compensating piston having a radially inner end which projects into said relief chamber of said centrifugal force compensating cylinder.