Patent ID: 7495193
Filing Date: 2009-02-24
Classification: B23K

Abstract:
1. A modified series arc welder for depositing weld metal along a groove proximate two edges of a metal workpiece using a plurality of welding cycles having a short-circuit condition and an arc condition, said welder comprising: first and second wire feeders respectively adapted to direct first and second electrodes toward a point proximate said workpiece; a first power source having a first output terminal coupled with said first electrode to provide a first current thereto according to a selected first waveform in a welding cycle; and a second power source having a first output terminal coupled with said second electrode to provide a second current thereto according to a selected second waveform in said welding cycle; said power sources and said electrodes being coupled in a series circuit to provide electrical power to said electrodes as a plurality of said welding cycles for depositing molten metal in the form of a pool along said groove during a welding operation, each of said welding cycles including an arc condition during which said first electrode is spaced from said pool and energy applied to said first electrode causes a first molten metal to form on an end of said first electrode and a short-circuit condition during which said first molten metal on said end of said first electrode contacts said pool and then transfers from said first electrode to said pool by a necking action; wherein said first power source provides said first current having a first polarity during said arc condition and at least a portion of said short-circuit condition, and provides said first current having a second opposite polarity during a reverse boost portion of said welding cycle according to said first waveform to transfer molten metal from said second electrode to said first electrode prior to a short-circuit condition of a subsequent welding cycle.