DEVICE FOR THE CONTINUOUS LONGITUDINAL SEAM WELDING OF TUBES

摘要

A device for the continuous longitudinal seam welding of tubes particularly by electron beam welding, includes a pair of opposed rollers arranged with their mating groove portions in opposition on a bracket which may be rotated so as to shift the rollers in transverse directions. The arrangement includes means for scanning the strip edges of a sheet material which is fed and formed into the form of a slotted tube and adjusting the edges so that the tube is fed between the rollers with the longitudinal groove or slot centered therebetween. The scanning elements are arranged along the strip edges to be welded and actuate a control for a motor which is employed for shifting the grooved rollers with the tube in order to control the position of the weld seam for the purpose of centering the seam in respect to the electron beam. In a preferred arrangement the workpiece is guided by pressure rolls arranged on respective opposite sides of the workpiece which are advantageously carried on a rocker arm so that they may be jointly pivoted about the axis of the workpiece. A second pressure roll pair for guiding the workpiece is advantageously arranged on the rocker arm at a location between the contactless scanning device and the welding pressure roll pair. The second pressure roll pair forces the two band edges of the sheet to be formed firmly together and firmly grips the workpiece running therebetween in the same manner as the welding pressure roll pair.