Method of retracting and returning a tool from and to a workpiece during the machining of this workpiece by a numerically controlled machining device, and numerically controlled machining device for performing the method

摘要

The control of a tool during a machining operation on a workpiece by means of a numerically controlled device may be interrupted for various reasons. On the occurrence of an interruption the tool is immediately retracted from the workpiece in order to be moved to a retraction position R to avoid marking the workpiece. When the tool is returned to the workpiece, the invention provides a method of moving it so that it converges tangentially towards the workpiece along a curved path, taking up the original tool machining path without marking the workpiece.