Abstract: For controlling the locking of the rotatable tool holder of a tool turret, the angular position of the tool holder is determined by a rotating transmitter. The rotating transmitter is rotated corresponding to the rotary movement of a control and synchronization device. Digital signals are produced with the aid of the rotating transmitter. Each digital signal is associated with one angular position of those which may be selected. With each of these signals, the indicator is changed in those two angular positions of the control and synchronization device for locking and unlocking of the tool holder at each of its angular positions. The indicator is changed by the rotary movement of the device in one or the other direction out of the associated angular position and into the angular position associated with the locking of the tool holder. These rotary transmission signals are used to control the locking.

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.