PURPOSE: To prevent the local consumption of a restoring electrode for restoring a machining electrode by making the restoring electrode run successively in the fixed direction.
CONSTITUTION: While the machining electrode 14 being moved to the position where the restoration is performed, a restoring electrode 22 consisting of a linear material such as copper and brass is given electrical discharge power by a feeder plate 42 in the course wherein the electrode 22 is rolled out from a supply reel 24, stretched and supported by guide rollres 26, 28, 30 and 32 for its running and colied by a coiling reel 34, and the consumed part of the machining electrode is restored by the electrical spark generated between the electorde 22 and the plate 42. In this way, the restoring electrode 22 contributes constantly afresh to the restoring action when the action is performed and thereby the deterioration of the roughness of the restoring surface of the restoring electrode 22 due to the local consumption can be prevented.
ITOU TETSUO
YAMADA SHIGEO
