| 摘要 |
A chuck has a chuck body adapted to be rotated about an axis and formed centered on the axis with a forwardly open tool-receiving seat. A holding element is displaceable axially in the body between a rear holding position securing a tool in the seat and a front releasing position permitting the tool to be inserted backwardly into and withdrawn forwardly from the seat, with a holding spring urging the element backwardly into the holding position. A piston axially coupled to the holding element has an axially backwardly directed piston face exposed in a chamber formed between this axially backwardly directed face and the forwardly directed face of an actuating member that is urged axially forwardly by a locking spring. A plurality of locking balls are displaceable radially but not axially in the chuck between radially inner locking positions engaged in a groove in the piston and radially outer positions engaged in a groove in the actuating member. This groove of the actuating member is only aligned with the balls when the actuating member is displaced axially backwardly by pressurization of the chamber to allow the balls to move radially outwardly out of the groove of the piston, thereby freeing the piston and holding element for axial displacement in the chuck. |
