SELF-LOCKING CHUCK

摘要

A tool holding assembly wherein a self-locking chuck or tool holder is releasably secured in a rotary spindle by a draw bar and collet type tool holder gripping means. The self-locking chuck is provided with a spring-biased, ball locking means that functions as a safety retainer means for holding the chuck or tool holder in the spindle in case of a breakage of the collet type tool holder gripping means. The spindle is provided with a tapered seat against which the balls of the ball locking means are normally urged by a spring biased plunger that is movable to a ball unlocking position by the draw bar.