Wire electrode protection system for electrical discharge machining

摘要

A wire feed protection system for an electrical discharge machining apparatus and machine tool. The workpiece is supported for movement along two coordinate axes in the "X" and "Y" direction through electrically controlled stepping motors in a manner which is well known to the art. The electrode is of a wire or band configuration and is so supported, guided, and driven that the cutting portion of the electrode which is aligned with the workpiece before and during cutting remains properly oriented and travels without bend or distortion in its path. When the wire breaks, bows or otherwise is caused to lose tension, a switch is operated to interrupt machining power pulses being supplied to the machining gap. For this purpose, a switch is located at one or more critical and predetermined locations in the wire electrode path, with the switch actuator in each case in engagement with the wire during transversal.