process for the production of one end to dialmente calibrated internally reinforced cavity at ra and stable in shape and size on the closure profiles as a platform to bicchiages on tubes of plastic material and device to form for the realization of the same

摘要

1389079 Pipe couplings RIEBER & SON PLASTIC-INDUSTRI AS 27 March 1972 [1 April 1971] 14225/72 Heading F2G The heated end 10 (Fig. 1), of a pipe is shaped by pushing it over the end shaped socket 11 that is left in the pipe (see Fig. 5) as reinforcement. Succeeding zones of the pipe end are heated to different temperatures by propane gas or hot oil, and the pipe comprises rigid PVC, or polyethylene. Cooling is by free air convection. The socket 11 (Fig. 1) includes a rib 17a and sealing rings 18 and 21. Rotation in the pipe is prevented by projections on the socket, which is spray formed from rigid PVC, injection moulded from acrylonitrile-butadiene-styrene copolymer or glass-fibre-filled polyester, or rolled or cast from aluminium.