| 摘要 |
1,134,663. Moulding flanges on thermoplastic liners for pipes. DOW CHEMICAL CO. 25 April, 1966 [26 April, 1965], No. 18057/66. Heading B5A. [Also in Division F2] A flange is moulded on a polypropylene lining of a steel pipe by a method comprising cutting away a portion of the pipe leaving an extending annular portion of the lining, putting a metal flange on the pipe, heating the lining to soften it and then moulding the lining to lie radially of the pipe along the metal flange, the moulding apparatus being withdrawn when the temperature has fallen below the softening temperature. A frame 46 connects the pipe 47 coaxially with the moulding apparatus, which comprises a ram 12 on the end 14 of which is slidingly and resiliently mounted a frusto-conical plug 20. As the ram pushes the plug inside the lining 49, thereby supporting and bending it outwardly, the plug slides against the action of spring 39 into a cavity 33 in an annular mould member 28 which is rigidly attached to the end 14 of the ram. As the ram extends further, a hollow cylindrical body 41 slidingly surrounding the member 28 abuts the flange 50, and then mould ends 29 of the member 28 engage the lining and push it against the flange, thereby forming a radially extending plastic flange. The temperature is then allowed to fall and the moulding apparatus with the frame 46, is removed. The operation is hydraulic, electrical or manual. |
