Abstract: A cylindrical tool holder is mounted on a a housing containing a motor, the output shaft of which is coupled through a gear train to a driving ring. One axial face of the driving ring has cam surfaces engageable with cooperating cam surfaces on an axial face of an axially movable locking ring which is spring-urged toward the driving ring. The other axial face of the locking ring has axially facing gear-like teeth which are engageable with mating teeth on a flange formed on the housing and on a ring attached to the tool holder. A lock bolt mounted in the housing and operated by an electromagnet is withdrawn from a ring coupled to the tool holder to permit rotation to a new position and is extended to lock the holder near the new position.

Abstract: A control apparatus for a shaping machine such as a lathe includes a positionable piston and cylinder assembly for driving the cutting tool toward the workpiece to establish cut depth. A feeler rides a pattern to limit cut depth and control cut shape. A plurality of cam-operated switches responsive to piston and cylinder assembly position controls cut depth in successive cycles until control is assumed by the feeler. The feeler operates switches and a control valve to permit close control of the shaping in accordance with the pattern.

Abstract: A cutting tool is mounted on a tool slide which is movable along a workpiece to cut a thread therein or thereon. The tool is shiftable toward and away from the workpiece by a piston and cylinder arrangement having a fixed stroke length. Adjustment of the starting and therefore the ending point of the stroke is accomplished by a differentially threaded assembly which is rotated by a drive motor. Rotation of the threaded assembly produces pulses which are counted and compared with a stored count to start and stop the drive motor. Cycles of operation are also counted and compared with fixed counts, the extent of adjustment in each cycle being related to the number of cycles.