GB1325759A - Apparatus and method for the formation of tubular articles - Google Patents

Abstract

1325759 Making tubes; corrugating ETABS BUTIN-GILLET 1 Dec 1970 57120/70 Headings B3A and B3Q A tube T is formed with annular corrugations by simultaneously expanding the tube outwardly by fluid pressure against formers F, Fig. 5, and applying axial pressure to the tube. The fluid pressure is exerted by fluid in a cylinder 15, the fluid having access to the tube through holes in a mandrel 50 which initially supports the tube. The axial pressure is exterted by a fluid-pressure or screw-operated ram 25 which acts on a work support 35. The ram pushes the tube against the end of the cylinder 15. The mandrel is mounted on an axially movable carriage 40, and is pivotal about a vertical axis -X during loading and unloading. To load a tube on the mandrel (which is integral with the work holder), the holder is pivoted about the axis XX so that it extends outwardly of the forming machine. End collars 53, 53<SP>1</SP> and formers F are assembled on the mandrel, and the holder is pivoted back within the machine. An initial low pressure is exerted by the fluid to bulge the tube as shown in Fig. 5. Supports 58 for the formers can then be removed. As a higher pressure is exerted and the ram 25 moves to the left, the final form Fig. 7 of the tube is reached, the shape of the corrugations being determined by the size and spacing of the formers. Each former may be constructed in two halves, and the tube may be formed with annular chambers by suitable choice of formers or blocks surrounding the tube.