Abstract: A machine tool includes a carrier supporting a plurality of rotary spindles each carrying a chuck for holding a workpiece and each having an individual drive motor. The carrier can be indexed to move the spindles between different stations, while the drive motors remain stationary. Clutches are provided to couple each drive motor to a spindle to be driven. The carrier includes a central shaft supported at its ends on bearings and spindles are coupled to the shaft by supports. Each spindle may be provided with a friction clutch and a tooth clutch for coupling the spindle to the drive motor. The chuck is actuated by a hydraulic piston and cylinder which may be internal to the spindle. Alternatively, the cylinder may be formed by a stationary housing around the spindle containing an annular piston. A shuttle assemble capable of providing a mechanical advantage may be provided for transmitting motion of the piston to the chuck.

Abstract: A machine tool includes a carrier supporting a plurality of rotary spindles each carrying a chuck for holding a workpiece. The carrier can be indexed to move the spindles between different stations. In one aspect of the invention, individual drive motors are provided. The drive motors remain stationery while the carrier is indexed and clutches are provided to couple each drive motor to a spindle to be driven. In another aspect of the invention, the carrier includes a central shaft supported at its ends on bearings and spindles are coupled to the shaft by supports.