ELECTRODE HOLDER FOR ELECTRIC DISCHARGE MACHINE

PURPOSE:To prevent breakage and deterioration in an O ring from occurring, by installing a hydraulic cylinder which acts on the upper part of a claw plate and gives such force that resists the turning force made by a spring, in this claw plate. CONSTITUTION:When attaching an electrode, a cylinder rod 29 of a hydraulic cylinder 26 is advanced for word, and a claw plate 21 is turned round in a direction where a claw 21a is separated from a body part 20 against a spring 28. Next, a shank 12 of the electrode 11 is inserted into a through hole of the body 20 and, after the upper part is projected out of the body 20, the rod 29 of the hydraulic cylinder 26 is retreated, the claw plate 21 is rotated in the reverse direction by the spring 28, and the claw 21a is engaged with the notch 14 installed in the shank 12. When the electrode 12 is removed, reverse operation to the above-mentioned takes place. Doing like this, forcible pressure from the outside is not added to an O ring being attached to the shank 12 of the electrode 11 so that breakage and deterioration in this O ring will not occur and, what is more, maintenance for the electrode 11 comes easy enough.