Abstract: A device for mounting a turning or milling tool-holder on the slide of a machine-tool, wherein a sleeve is mounted for sliding inside the slide body, said sleeve receiving internally a rotary spindle, and being designed to occupy one position in which it is moved inwards of the body and in which the turning tool-holder is immobilized on the seat of the slide, by means of notchings or serrations, under the action of an axial force exerted by one of the ends of the spindle on the turning tool-holder, and another position in which said sleeve is moved out of the slide body and brought against a centering seat of said body, for which the milling tool-holder is mounted on the end of the spindle which is rotatable under the action of rotating drive means.

Abstract: A device for clamping together two coaxial members having mutual mating centering means, such as a milling cutter in a rotary tool-carrying spindle, for instance. A plurality of hook shaped dogs are mounted for rocking movement on one of the members between an operative position in which they are engaged in a groove of the other member and an inoperative position in which they are located out of said groove. The dogs are provided with cam portions to be engaged by mating cam elements operatively connected to an annular operating part which is slidably movable axially with respect to the coaxial members for actuating the dogs.