Method and apparatus for sweeping electric arcs

Claim 1

A MULTI-ARC WORKING SYSTEM FOR TREATING A WORKPIECE WHICH COMPRISES AT LEAST THREE CLOSELY SPACED ELECTRIC ARC TORCHES FURNISHED WITH AN ELECTRODE AND A NOZZLE WHEREIN AND ARC IS ESTABLISHED FROM SAID ELECTRODE AND PASSES THROUGH SAID NOZZLE; MEANS FOR FLOWING GAS INTO SAID ARC TORCH SUCH THAT AT LEAST SOME OF THE GAS IS PASSED INTO THE RAC; THE INSIDE DIAMETER OF SAID NOZZLE AND SAID GAS FLOW BEING SO CORRELATED AS TO PROVIDE A DIRECTIONALL STABLE ARC EFFLUENT IN THE ABSENCE OF A SUPERIMPOSED MAGNETIC FIELD, SAID TORCHES BEING ARRANGED IN A ROW IN A COMMON PLANE IN A PARALLEL RELATIONSHIP TO ONE ANOTHER TO PROVIDE INDIVIDUAL ARC GAP WITH SAID WORKPIECE; AND POWER SUPPLY MEANS FOR ENERGIZING SAID MULTI-ARCS WITH A VOLTAGE SELECTED SO THAT SUCH ARCS INTERECAT WITH ONE ANOTHER TO CAUSE THEM TO OSCILLATE WITH RESPECT TO ONE ANOTHER WITH A SWEEPING MOTION ON SUCH WORKPIECE, AND WHEREIN EACH ARC IS SHIELDED BY A STREAM OF PROTECTIVE GAS DISCHARGED AROUND THE TIP OF THE CORRESPONDING ELECTRODE FROM A SUITABLE NOZZLE, AND SUCH NOZZLE IS IN TURN SHIELDED BY ANOTHER STREAM OF PROTECTIVE GAS DISCHARGED AROUND IT IN THE DIRECTION OF SUCH SURFACE, SO THAT THE ENTIRE SURFACE AREA THAT IS HEATED BY SUCH ARCS IS ALSO PROTECTED BY SUCH GAS STREAM FROM THE ATMOSPHERE.