Abstract:
Method and apparatus for joining metal strip in general end-toend relationship involving first aligning the strip lengths both transversely and angularly (to prevent dogleg) whereby the joint will be made so that the centerline of the strips will coincide with the longitudinal centerline of a machine. The control system includes, at each side of the joining means or welder, two sensors along one side of the strip which are interconnected by a sprocket and chain or equivalent means so that as one of the sensors follows the edge of the strip, the other will move correspondingly whereby both sensors will always be equidistant from the longitudinal centerline of the machine and one will control lateral movement of an auxiliary strip clamp to move the strip accordingly. A third sensor on the opposite side of the strip and of one of said sensor, and similarly linked thereto by a sprocket and chain or the like, is effective to control the main clamp to finally move the strip laterally so that its centerline will coincide with that of the machine. Similar controls are provided at the exit (tail end) and the entry (head end) of the machine. A fourth sensor control is optional to prevent the necessity of circuit switching.