Threading and conveying device for an electrode wire in an EDM apparatus

摘要

A threading mechanism for threading the electrode wire of a travelling wire EDM apparatus, the end of the electrode wire being passed through a starter hole or aperture in the workpiece prior to effecting a cutting operation in the workpiece, wherein the entrance throat to the wire conveying mechanism adapted to take hold of the wire after passage through the starter aperture is offset laterally relative to the axis of the starter hole such as to laterally displace the wire to engage the wire with a guiding surface and a current feeding surface which are also offset relative to the axis of travel of the wire through the starter aperture.