Abstract: A machine tool high speed spindle assembly and draw bar assembly, wherein the spindle assembly includes a hollow, rotary spindle shaft, and the draw bar assembly is nonrotational relative to the spindle shaft. The draw bar assembly is axially movable within the hollow rotary spindle shaft, and it includes a tool holder gripping means. The draw bar assembly rotates with the hollow rotary spindle shaft during a machining operation. The draw bar assembly with its tool holder gripping means is moved by an actuator means between an operative position for retaining a tool holder or the like in the spindle shaft, and an inoperative position to permit a tool holder or the like to be removed from or inserted into the spindle shaft. A spindle shaft holding or gripping means retains the hollow rotary spindle shaft in a stationary position when the draw bar actuator means moves the draw bar assembly between said operative and inoperative positions.

Abstract: A machine tool high speed spindle assembly and draw bar assembly, wherein the spindle assembly includes a hollow, rotary spindle shaft, and the draw bar assembly is nonrotational relative to the spindle shaft. The draw bar assembly is axially movable within the hollow rotary spindle shaft, and it includes a tool holder gripping means. The draw bar assembly rotates with the hollow rotary spindle shaft during a machining operation. The draw bar assembly with its tool holder gripping means is moved by an actuator means between an operative position for retaining a tool holder or the like in the spindle shaft, and an inoperative position to permit a tool holder or the like to be removed from or inserted into the spindle shaft. A spindle shaft holding or gripping means retains the hollow rotary spindle shaft in a stationary position when the draw bar actuator means moves the draw bar assembly between said operative and inoperative positions.

Abstract: 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.