The Perkin-elmer Corporation

Robert F Savill, Jr

Richard D Trapani

Martin E Hacker

Thomas J Fox

Lawrence A Saia

Melvyn E Turner

William S Willen

A plasma gun for spraying in a recessed region comprises a cathode member and a tubular anode arranged with the cathode member to generate a plasma stream. An elongated tubular extension including a tubular wall with an axial plasma duct therein extends forwardly from the anode. A transverse plasma duct causes the plasma stream to exit transversely from the tubular extension. Channeling for fluid coolant is in the tubular wall and extends substantially the length of the axial plasma duct. A first external pipe connected to the tubular extension forwardly of the transverse duct directs fluid coolant to the channeling. A powder injector injects spray powder rearwardly into the exiting plasma stream. A second external pipe from a powder source is connected to the powder injector.

Plasma gun extension for coating slots

An arc spray gun has a generally frusto-conical head member of electrically insulating material, with the small end facing forwardly in the direction of spray. Wire is fed through a pair of electrically conductive tubular wire guides containing pressure contact means that extend through the head member and converge to contact the wire ends for arc formation and melting of the metal. A gas jet nozzle provides compressed gas for atomization and spraying of the molten metal. A first gas cap is disposed coaxially on the head with rear and forward gas seals so as to define an annular gas chamber. A secondary gas is supplied to the annular chamber, and the first gas cap has a pair of diametrically opposite orifices therein for directing the secondary gas from the chamber to modify the molten metal spray in a fan shape. The orifice may have elongated cross sections to produce a rough coating surface if desired. A second gas cap is adapted to replace the first gas cap in sealing relationship with only the rear gas seal so as to provide, as an option, an annular flow of the secondary gas about the wire ends. A pair of hose assemblies supply the primary and secondary gases seprately to the gun, as well as wire and arc current. A distribution block on the gun separates the gas flow and metal wire from the hose assembly.

Arc spray system

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Beechhurst, NY, United States of America

Robert F Savill, Jr