METHOD TO CONTROL STARTING AND STOPPING A PLASMA ARC WELDING KEYHOLE

摘要

An improved plasma arc welding arm method and apparatus for keyhole welding rotating workpieces has an arcuate gear track (40) supporting a corresponding arcuate geared cart (30) bearing a plasma arc welding torch prevents voids in keyhole weld starts and finishes. The gear track is mounted on a manipulator arm (70) for positioning the welding torch in proximity to a rotating workpiece (10) to be welded. The torch may be rotated on the cart and gear track in the same direction and at the same rotational speed as the workpiece.