Abstract: A brake mechanism has a brake disk, multiple clutches, and multiple brake assemblies. The brake disk is coaxially connected to a rotatable work table. The multiple clutches are capable of clamping the brake disk. The multiple brake assemblies correspond in position to the multiple clutches. Each one of the multiple brake assemblies has a housing, an abutting shaft inserted in the housing, and multiple elastic units received in the housing and abutting against the abutting shaft. The multiple abutting shafts of the multiple brake assemblies abut against the brake disk for stopping the work table from rotating. A hydraulic system applies hydraulic pressure inside the multiple housings of the multiple brake assemblies and forces the multiple abutting shafts to depart from the corresponding clutch, making the work table rotate again.

Abstract: An assembly for fastening and locating an added head of a numerical machine tool comprises two cylinder mounts located in the periphery of a main shaft of the numerical machine tool. A piston is movably disposed between the two cylinder mounts such that the piston is driven by the hydraulic-pneumatic loops to move up and down so as to control the movement of an engagement block for retaining a retaining block of the added head. The main shaft of the numerical machine tool is provided with a crank-tooth coupler to facilitate the adjusting of the angular position of the added head in accordance with the operational requirement for processing a workpiece.