Arc welding apparatus and method

Claim 1

IN WELDING APPARATUS FOR GAS SHIELDED ELECTRIC ARC WELDING INCLUDING A SUPPLY OF CONSUMABLE ELECTRODE, MECHANISM FORMING AN ELECTRIC CONNECTION TO SAID ELECTRODE AND ARRANGED TO FEED THE ELECTRODE TOWARD A WORKPIECE AT A PREDETERMINED RATE, AND MEANS FOR SUPPLYING SHIELDING GAS TO THE AREA SURROUNDING THE WORKPIECE AND THE END OF THE ELECTRODE ACROSS WHICH THE ARC IS STRUCK; THE IMPROVEMENT COMPRISING AN ARC WELDING CIRCUIT INCLUDING ELECTRICAL LEADS ADAPTED FOR CONNECTION TO THE WORKPIECE AND TO THE ELECTRIC CONNECTION TO SAID CONSUMABLE ELECTRODE RESPECTIVELY, AN ELECTRICAL RESISTANCE ELEMENT OF PREDETERMINED RESISTANCE CHARACTERISTICS INCLUDING LACK OF INDUCTIVE REACTANCE EFFECT IN A D.C. CIRCUIT AND HAVING SUFFICIENT RESISTANCE TO ASSURE THAT CURRENT FLOW IN THE WELDING CIRCUIT DURING SHORT CIRCUITING BETWEEN THE CONSUMABLE ELECTRODE AND THE WORKPIECE DOES NOT EXCEED APPROXIMATELY SIX TIMES THE CURRENT NORMALLY FLOWING IN SUCH CIRCUIT WHEN AN ARC EXISTS THEREBETWEEN, SAID RESISTANCE ELEMENT BEING CONNECTED TO ONE OF SAID ELECTRICAL LEADS, AND A D.C. WELDING GENERATOR HAVING OUTPUT TERMINALS CONNECTED TO THE OTHER OF SAID ELECTRICAL LEADS AND TO SAID RESISTANCE ELEMENT RESPECTIVELY FORMING A SERIES CIRCUIT THEREWITH IN WHICH RESISTANCE ELEMENT IS CONNECTED AT ALL TIMES AND IN WHICH THE SOLE EFFECTIVE INDUCTIVE REACTANCE IS PROVIDED BY THE INHERENT INDUCTANCE OF THE WINDINGS OF SAID GENERATOR.