GB1394501A - Machine and method for producing an expansible lattice structure in particular for a reinforcement of a pipe having a socket and the lattice structure obtained - Google Patents

Abstract

1394501 Making lattices; corrugating and winding TREFILUNION 22 Jan 1973 [3 Feb 1972 15 Jan 1973] 3105/73 Headings B3A and B3E An expansible cylindrical or conical lattice structure, e.g. a reinforcement for a concrete pipe having an enlarged socket at one end, is formed by winding a helical wire round an assembly of longitudinal wires 1, one end of the helix being corrugated as at 3a so that the end can be enlarged. The apparatus shown comprises a rotary driven plate 6 on a headstock 5 and a rotatable plate 9 on a tailstock 8. The longitudinal wires 1 are attached to plate 9 and are drawn through plate 6 from supply reels 12 mounted on the plate as the tailstock moves along runway 11. Simultaneously the headstock is rotated to wind on the helical wire 2 from a supply reel 15. A fixed welding electrode 17 cooperates with successive electrodes 18 on plate 6 to weld wires 1, 2 at their intersections, welding switch 20 being operated by successive actuators 19. Wire guides (not shown) feed wire 2 between corrugating wheels 26a, 26b, the latter being movable by jack 34 controlled by fixed switch 43 and ramp 44 on tailstock 8, so that only the end portion 3a of the helical wire is corrugated. The wheels 26a, 26b have flat sided teeth, the sides meeting at an angle slightly less than a right angle. The drive to the shaft 24, Fig. 6, of the movable wheel, is through spur gears 29a, 30a, 30b, 29b, gears 30a and 30b being mounted in bearings movable in arcuate slots centred on the axes of gears 29a, 29b and urged as shown by springs 33a, 33b, so that the drive engages as the corrugating wheels come together. The corrugating drive motor is also controlled by switch 43. In an alternative embodiment, the tailstock is stationary, and the supply reel 15 and electrode 17 are moved along together with switch 43 which co-operates with a fixed ramp. To facilitate making the enlarged end of the finished reinforcement exactly concentric with and parallel to the remainder, a ring of wire perpendicular to the longitudinal axis of the reinforcement may be added at the end of the corrugated section, either as a separate item or by halting the relative movement between the longitudinal wires and reel 15 for one revolution of the plate 6.