Sigma welding controls

Claim 1

SIGMA WELDING APPARATUS COMPRISING THE COMBINATION WITH MEANS FOR FEEDING AN ELECTRODE WIRE TOWARD WORK TO BE WELDED INCLUDING A WIRE FEED MOTOR; MEANS FOR CONDUCTING ARC WELDING CURRENT TO A WELDING CIRCUIT INCLUDING A WELDING CONTACTOR, THE END PORTION OF SUCH ELECTRODE WIRE AND THE WORK; MEANS FOR SUPPLYING ARC SHIELDING GAS AROUND SUCH ELECTRODE WIRE END PORTION INCLUDING A WELDING TORCH AND A GAS SOLENOID VALVE; A WELD INITATING CONTROL CIRCUIT INCLUDING A WELD INITIATING SWITCH AND A WELD START RELAY; AND AN ELECTRODE WIRE INCHING CIRCUIT INCLUDING AN INCHING SWITCH, AN ADJUSTABLE RESISTOR AND SAID WIRE FEED MOTOR; OF A WELD CONTROL SYSTEM THEREFORE COMPRISING AN INPUT CIRCUIT ADAPTED TO BE CONNECTED TO A SOURCE OF ELECTRIC POWER SELECTED FROM THE CLASS CONSISTING OF A.C. AND D.C., A POTENTIOMETER CIRCUIT ENERGIZED BY SUCH POWER SOURCE FOR APPLYING A SUITABLE VOLTAGE DIFFERENT FROM THAT OF SAID SOURCE TO SAID INCHING CIRCUIT AND SAID WIRE FEED MOTOR AND TO SAID WELD INITIATING CIRCUIT; AND MEANS FOR APPLYING A RELATIVELY HIGHER VOLTAGE DERIVED FROM SUCH SOURCE TO SAID WELDING CONTACTOR AND SAID GAS SOLENOID VALVE.