Patent ID: 6177647
Filing Date: 2001-01-23
Classification: H05H

Abstract:
An electrode for use in plasma arc torches, the electrode comprising:a tip body fabricated from copper or a copper alloy, said tip body having a central axis and a free terminating surface substantially normal to said central axis;a tip cavity having a cavity sidewall, said tip cavity residing in said tip body and extending to said free terminating surface;an emissive insert having an insert sidewall which is textured to provide a textured surface, said insert sidewall being substantially symmetrical about said central axis of said tip body and said emissive insert forming part of said free terminating surface when said emissive insert is positioned in said tip cavity;a foil of a noble metal interposed between said cavity sidewall and said insert sidewall, said foil having an insert-contacting surface, which is in interlocking, engaging contact with said textured surface of said insert sidewall, and a cavity-contacting surface, which is substantially parallel to said insert-contacting surface so as to be in interlocking, engaging contact with said cavity sidewall, said insert-contacting surface and said cavity-contacting surface being separated by a thickness T of less than about 0.01 inches.