Welding strip ends together to make continuous metal strip - where light reflected from strip edges is used to switch seam welding roller on and off

摘要

The tail end of one strip is joined to the front end of another strip, esp. by roller seam resistance welding. A welding trolley is driven transversely across the joint to be welded, and the electric welding current is switched on and off by reflection from the side edges of the two strips. In the pref. welding machine, two photocells receiving light reflected from the edges of the strip are located slightly in front of the axis of the welding roller; and two more photocells are used in a similar manner with a roller employed to smooth the welded joint. A similar conventional machine uses light sources in conjunction with photoelectric cells, and therefore requires a lot of appts. which is unreliable. The invention provides a much simpler and reliable machine.