GB974097A - A method and machine for forming helical lock seam pipe - Google Patents

Abstract

974,097. Making helically seamed tubing. LOCKFORMER CO. Sept. 12, 1962 [Dec. 6, 1961], No. 34814/62. Headings B3E and B3J. A method of making helical lock seam pipe from continuous metal strip comprises moving the strip longitudinally and during such movement forming a flange along one edge and a channel along the other edge, guiding the flange along a helical path and into the channel by means which engage opposite faces of the strip along the juncture between the flange and the remainder of the strip, leaving the said remainder of the strip free and unengaged. Strip 20 from a coil 48 supported on a drum 52 carried by an extension 50 of a main frame 1 passes around flanged wheels 55 through grooves 60 in side guide plates 58, 59 to three pairs 2, 3, 4 of driven rolls. To support a coil 48 of narrow strip a spacer ring, Fig. 14 (not shown) is fitted over the drum 52 and spaced from one flange thereof. The frame 1 is adjustable about a vertical pivot 42 by a gear 45. The rollers 5 and 8 of pair 2, and 6 and 9 of pair 3, are so shaped, Fig. 12, as to form a flange 71 and a channel 72 on the strip edges. The rollers 7 and 10 of the pair 4 have adjustable ring members 83, 89, Fig. 13, which further bend the flange 71 and channel 72 over to compensate for spring- back. Staggered ribs on the rolls allow heavy gauge metal to spring slightly therebetween. As the strip approaches a coiling head 40 on the frame it is engaged, at the junction of the flange 71 with the remainder of the strip, between inner and outer helical rods 93, 92 which force the flange along a helical path. A third rod 95 may be provided to engage the flange 71. From the rods 92, 93 the flange passes under a convex guide shoe 99 which directs it into the channel 72, the seam then passing between rollers 27, 29, Fig. 3, to compress and lock it.