Patent US 6,397,111

A numerically controlled machine tool which allows the automatic generation of a restoring program for carrying out processing required for the resumption of an NC machining program to resume the execution of the NC machining program after the execution of the NC machining program has been stopped and interrupt processing has been performed. Specifically, even for nesting programs, when the machining program is re-executed from where it had stopped after the execution of the machining program has stopped and the operator has performed optional interrupt processing, the stop-time and re-execution-time machine statuses are compared to automatically generate the restoring program so that the machine status may be returned to the stop-time status, whereby the operator can perform the resumption processing of the machining program without any restrictions.