GB1389633A - Method of and apparatus for continuously manufacturing a pipe - Google Patents

Abstract

1389633 Winding pipes KAKUICHI SEISAKUSHO KK 7 Feb 1973 [29 Feb 1972] 6064/73 Heading B8G [Also in Division F2] In winding a semi-molten strip 15 into a spiral, so that adjacent turns adhere to form a pipe, helical motion is imparted to the developing pipe by three or more (four as shown) rollers 2 rotating at the same speed and in the same direction. The rollers each have four splines 9 each of which slidably engages a groove 10 in an external segment 11. Each segment 11 carries a radially projecting pin 12, which tracks in a stationary groove 13 in a support frame 1. As each roller 2 turns, its segments 11 successively engage the inside of the developing pipe, and those segment 11a in the engaging position are moved axially by their pins 12 so as to produce the axial component of the helical motion. When out of the pipe-engaging position, 11c, 11d, they are returned axially in the opposite direction. The strip 15 which may be of reinforced on unreinforced plastics or of metal passes through a feeding device 14 immediately after it has been extruded. The reinforcement 16, which may be hard synthetic resin may extend to, or project from, one or both surfaces of the strip. The semi-molten material may be a softer synthetic resin, which may be pvc. The reinforcement may impart a corrugated form to the outside of the tube (Fig. 8, not shown).