Patent ID: 7253377

Claim:
A welding system adapted for welding a plurality of overlapping adjacent workpieces to form a lap weld, wherein each workpiece presents an outer edge, said system comprising: a perforating device configured to engage at least a portion of the plurality of workpieces, so as to produce an opening cooperatively defined by each of the workpieces; and a heating combination including a plurality of separate and concurrently functionable welding elements, said elements being oriented relative to the device, and configured to cooperatively and contemporaneously heat a zone adjacent the opening to a minimum temperature, so as to cause the weld to form at least predominately within the opening, said opening being adjacent to and spaced from the outer edge of each of said plurality of workpieces, said combination further including an electrode, wherein said electrode is coaxially aligned with and spaced from a first end of a conductive sleeve, said electrode and sleeve being cooperatively configured to form an electric arc between the first end and electrode, said sleeve being fluidly coupled to a gas source, so that the source, electrode and sleeve are cooperatively configured to direct a gaseous stream through the arc, and produce a plasma column between the electrode and an outermost surface of the plurality of workpieces.