Fremgangsmåde og apparat til fremstilling af et spiralviklet falsrör med luftdyser

摘要

In a method of manufacturing a helically-wound lock-seam tube for a ventilation duct system, the tube is provided with a plurality of air nozzles through its wall. The method involves the steps of: feeding a strip of sheet metal from a supply to a punching and pressing unit; punching and pressing the strip in the punching/pressing unit to form two rows of spaced openings through the strip; feeding the punched strip to a roller unit, in which a longitudinal bead is formed in the strip; feeding the punched and beaded strip to a forming head in which the strip is helically-wound to form a tube having a helical lock seam; feeding the helically-wound lock-seam tube out of the forming head; and cutting the tube into desired lengths. The apparatus has components for carrying out the various method steps, and the finished tube is provided with a desired pattern of air nozzles.