Electrode system for spot welding aluminum and other difficult-to-weld materials

摘要

An electrode system for spot welding difficult-to-weld materials, such as aluminum, wherein a pair of spaced apart electrodes, one of which is a roller, clamp the overlapped strips of material to be spot welded. Mechanism moves the roller electrode toward and away from the other electrode, and other means is operated responsively to this movement for indexing the roller electrode incrementally circumferentially to successively present a new surface to the work held between the electrodes. A control circuit applies DC power to the electrodes such that the roller mentioned has the positive polarity and the other electrode the negative polarity.