Plasma flame powder spray gun

Claim 1

IN A SPRAY GUN FOR SPRAYING DIVIDED, HEAT-FUSIBLE MATERIAL, COMPRISING MEANS DEFINING A SUBSTANTIALLY ENCLOSED CHAMBER HAVING A NOZZLE ELECTRODE DEFINING AN OUTLET FROM SAID CHAMBER, A SECOND ELECTRODE AT LEAST PARTIALLY POSITIONED IN SAID CHAMBER IN SPACED RELATIONSHIP TO SAID NOZZLE ELECTRODE, MEANS FOR PASSING AN ARCFORMING ELECTRIC CURRENT BETWEEN SAID ELECTRODES, MEANS FOR PASSING A PLASMA-FORMING GAS ALONG THE ARC AND OUT THROUGH THE NOZZLE ELECTRODE OUT OF CONTACT WITH THE ARC AS A FREE PLASMA STREAM, CONSTRICTING THE ARC, CAUSING THE SAME TO STRIKE PART WAY DOWN THE INTERIOR OF THE NOZZLE ELECTRODE PRIOR TO ITS OUTLET END, THE IMPROVEMENT WHICH COMPRISES SAID NOZZLE ELECTRODE HAVING A CONTINUOUS TUBULAR BORE OF CIRCULAR CROSS-SECTION AND OF CONSTANT DIAMETER IN THE PORTION IN WHICH THE ARC IS STRUCK AND CONSTRICTED, THE OUTLET END OF SAID NOZZLE ELECTRODE FROM SAID PORTION OF CONSTANT DIAMETER CONTINUOUSLY DIVERGING TO A MAXIMUM DIAMETER AT THE NOZZLE ELECTRODE OUTLET, AND A PASSAGE HAVING AN AXIS WHICH SUBSTANTIALLY INTERSECTS THE AXIS OF THE NOZZLE ELECTRODE DEFINED LATERALLY THROUGH THE WALL OF SAID NOZZLE INTO SAID DIVERGING PORTION PAST THE STRIKING POINT OF THE ARC, AND MEANS FOR PASSING HEAT-FUSIBLE POWDER THROUGH SAID PASSAGE.