Dispositivo di bloccaggio dell'utensile sul mandrino di una macchina utensile

摘要

Apparatus for locking a shank of a tool to a spindle of a machine tool device comprising first and second sets of balls housed in radial recesses of a bushing which is slidable relative to the spindle and is housed within a fixed sleeve. A rod is provided within the bushing to drive the first set of balls into recesses in the tool shank. The rod includes a tapered conical section which cooperates with a conical section of the sleeve to cam the second balls into position in the bushing so that the bushing moves with the rod but at reduced speed relative to the speed of movement of the rod.