Electrode assembly for simultaneously machining parallel holes - uses electrode rods located by hydrostatic pressure in a common gland box

摘要

The electrode mounting is for a spark erosion machine tool which produces several holes in a workpiece in one operation. The object of the proposed electrode mounting is to permit easy adjustment for wear after each operating cycle. The electrodes (24) pass through a common gland box (36). Each electrode passes through an individual hole (40,42) in opposite faces of the box, and is surrounded by gland bushes (48,50) in each hole. An insulating flexible sleeve (32) electrically isolates the electrode from the box. It also acts to transfer hydrostatic pressure from a fluid inside the box (38) to a loose segment (58) in one of the bushes (48). With the pressure high the segment (58) presses against the electrode (24) locking the latter against axial movement. After a machining operation the wear on the electrodes will be uneven. The pressure is then reduced which releases the clamping force on the electrodes which can then be repositioned.