Welding apparatus

In a welding apparatus for utilizing a consumable filler wire to produce a weld on a workpiece, a drive feed roller assembly for advancing the consumable filler wire to a nozzle, comprising:

• a rotatable drive shaft;
• a plurality of individual roller segments mounted axially on said drive shaft in a side-by-side abutting arrangement and generally concentric with the axis of rotation thereof for rotation therewith, each roller segment having a generally concentric peripheral groove for engaging and advancing the consumable filler wire for advancement to said nozzle, and each roller segment being removable from the drive shaft for selectively interchanging the roller segments in different side-by-side arrangements on the drive shaft to permit placement of any one of the roller segments in position for engaging the filler wire;
• an enlarged portion on said drive shaft defining a shoulder against which an end one of said side-by-side roller segments abuts;
• means for holding the roller segments axially on the drive shaft in any side-by-side arrangement;
• and
• back-up roller means for engaging the filler wire on a side thereof opposite said roller segments to maintain the filler wire in engagement with the groove of a properly positioned one of said roller segments.