| 摘要 |
<p>PURPOSE:To exhibit powerful pressure resistance and prevent the generation of corrosion or the like by feeding half-molten belt-shaped synthetic resin materials respectively on the inner peripheral flexed surface of a helically winding tubular body through optional guide rollers disposed by large pitches and onto the outer peripheral surface of the helically winding tubular body moving forward on guide rollers disposed by small pitches. CONSTITUTION:A flexed thin belt-shaped plate p1 is formed by flexing a metal thin belt-shaped plate P with a section of almost V-shape or U-shape by means of a couple of forming rollers 1 and 2, upper and lower. The flexed thin belt-shaped plate P1 is bent into a helical tubular shape with given curvature radius to form a helically winding tubular body P2. Pitches for the inner peripheral diameter of the helically winding tubular body 2 and in the length direction of a revolving shaft 6 are fixed by means of guide rollers with grooves 7, 7....., 7 provided on the revolving shafts 6, 6. Half-molten belt-shaped synthetic resin materials 15 and 16 with thick-wall and fine width from respective nozzles 13 and 14 are wound respectively and helically from the outside between the guide rollers 7, 7 with large pitches and also from the outside of guide rollers 7, 7 with small pitches to the inner peripheral surface of the helically winding tubular body P2 and spaces between ring section p2, p2. Then, half-molten wide half-molten belt-shaped synthetic resin 18 is wound from a nozzle 07 on the outer peripheral surface of the helically winding tubular body P2 while being formed into V-shape or U-shape.</p> |
