DIGITALLY CONTROLLED SCREW THREAD CUTTING DEVICE.

摘要

A digitally controlled screw thread cutting device which can start cutting threads from an arbitrary position of rotation of the spindle. This device comprises thread cutting starting position indexing means for comparing the spindle rotational position detected by spindle rotational position detecting means with a predesignated rotational position to start cutting threads and starts feeding a cutter synchronized with the revolution of the spindle into a workpiece when the two positions of rotation coincide with one another. This device can thus cut special threads such as multiple screw threads and the like simply.