PURPOSE: To reduce substantially working time by constituting an electrode from electrode materials divided into small pieces and interconnected by insulating materials and connecting individually feeder lines to the electrode for working under the conductive condition in the rough working and under the insulated condition in finish working.
CONSTITUTION: An electrode 11 is constituted from electrode materials 16 divided into small pieces and interconnected with insulating materials 18. In the drawing are shown two electrode materials 16 in the electrode for example. When a roll 3 is worked under the condition of rough working, a contactor 22 is automatically closed within a power source 19 to make the electrode materials 16 conductive to each other in the electrode 11 and connect two combined feeder lines to one electrode. When the roll 3 is worked under the condition of finish working, the contactor 22 is opened to insulate the electrode materials 16 in the electrode 11 from each other and connect individually the feeder lines to the respective electrodes 11 so that the electrode is divided into from four to eight electrode materials to reduce working time to about 1/2 of prior one.
KAWANO MITSUGI
AOSHIMA FUJIO
KATOU YUKIO
ASAMOTO TETSUHIRO
MITSUBISHI ELECTRIC CORP