Electrode tube for electrical discharge machining and manufacturing method thereof
AssigneeSumitomo Electric Industries, Ltd.
InventorsShigeo Ezaki, Tsuyoshi Isejima, Kazutoshi Harada
Life of this patent
Estimating the term…
Abstract
An electrode tube for electrical discharge machining includes an outer peripheral portion and a plurality of rails or ribs projecting inwardly from an outer peripheral portion toward the central axis of the tube. The rails or ribs are formed integrally with the outer peripheral portion by drawing, or cold rolling, or hot extrusion. The space inside the tube is substantially divided into a plurality of through holes along the central axis by the plurality of rails or ribs.
Claims6
An electrode tube for electrical discharge machining, comprising an integral single piece tubular member produced by first extruding or cold rolling and then drawing so that said integral single piece tubular member has a substantially circular outer shape in a cross-section taken perpendicularly to a central longitudinal axis, said integral single piece tubular member comprising an outer peripheral portion and a plurality of radially inwardly projecting longitudinal ribs (3) extending integrally from said peripheral portion inwardly toward said central longitudinal axis of said integral single piece member to such an extent that radially inner ends of said ribs (3) contact each other along said central longitudinal axis, whereby a space inside said integral single piece tubular member is substantially divided by said plurality of ribs (3) into a plurality of through holes extending parallel to said central longitudinal axis.
A method of manufacturing an electrode tube for electrical discharge machining, comprising the following steps:
- (a) forming an integral, single piece tubular member by a working process selected from the group consisting of hot extrusion, cold rolling and drawing;
- (b) further drawing said integral, single piece tubular member a plurality of times through dice having a circular hole, thereby forming said electrode tube with a plurality of radially inwardly extending ribs that separate longitudinal through holes from each other, said ribs projecting from an outer peripheral portion of said integral single piece tubular member toward a central longitudinal axis of said single piece integral tubular member;
- and
- (c) repeating said further drawing steps until said ribs contact each other along said central longitudinal axis.
Dependencies are inferred from the claim text.