GB1479246A - Helical formed metal pipe - Google Patents

Abstract

1479246 Helically forming pipes HUME INDUSTRIES (NZ) Ltd 25 April 1975 17391/75 Heading B3E Apparatus for helically forming a pipe 17, Fig. 5, from metal strip includes three roller units 13, 14 and 15 between which the strip is fed, one unit 13 being cantilever mounted within the pipe and all units being provided with a series of rollers (generally aligned with the pipe axis) which are angularly adjustable relative to the axis of the unit. The rollers 20 of unit 15, for example, are each carried in a support 23( Fig. 6, in plan) which is pivotable about an axis 23a corresponding to the roller centre. The supports 23 are linked together for common adjustment of all the rollers by a rod 25. The units may also be adjusted so that their axes are slightly out of parallel with each other. To control the pipe diameter, the unit 14, Fig. 5, is carried on a support 22 which is laterally adjustable by a link 27 relative to the unit 15, and the unit 15 may be adjustable to vary the spacing between itself and unit 13. Further guide rollers (Fig. 4, not shown) are positioned around the exterior of the formed pipe 17. The edges of the formed strip can be joined by a welding assembly, with the use of an automatically controlled step roller for aligning adjacent edges. Alternatively, in the case of thin strip, the adjacent edges can be connected mechanically by a lock seam. The rollers of the unit 13 may be staggered relative to those of the other units, to form a corrugated pipe. A strip feed assembly, Fig. 1, feeds strip from a coil 1 through pinch rolls 2, a welding clamp 3 (for joining strip ends), ironing rolls 4, rotary shears 5 (together with a scrap cutter 6 and a conveyer 7), an edge trimmer 8, drive rolls 9, and an edge setter 10. The assembly is mounted on a bed 11 which is angularly adjustable (automatically if required) relative to the framework 16 of the roller units.