Improvements in rain-water pipes, with method and device for their manufacture

摘要

681,337. Making tubes. THIES, A. Jan. 16, 1951 [Dec. 3, 1948], No. 1164/51. Classes 83 (ii) and 83 (iv). Angular bending; coiling; seaming.-In a machine for making helically seamed tubes a winding mandrel 5 is rotated at a higher peripheral speed than the stripfeeding mechanism. A strip 2 is fed from a reel 1 and the edges are shaped as shown in Fig. 12 by rolls 12-16. The strip edges are folded in a helically grooved head 4 containing the milled mandrel 5 rotated at a speed in excess of that of the strip and terminating in a tapered end. The joint is folded by rolls 7, 8, 9 which in conjunction with the mandrel rotates the tube. The tube may be cut to length by a cutter 10.