The manufacture of spigot-and-socket concrete pipe joints

摘要

816,767. Concrete pipes; pipe Joints. HUME PIPE CO. (SOUTH AFRICA) Ltd. Jan. 20, 1958 [July 1, 1957], No. 1900/58. Classes 99(1) and 99(2). In a spigot and socket joint for concrete pipes at least the outer surface of the spigot has a coating 16 of synthetic resin which may be continued around the end face of the pipe and into the pipe bore to form a lining 24. The internal surfaces of the socket may be lined with synthetic resin which may also extend around the end face and into the bore of the pipe. As shown, the pipes are prestressed by helically wound and tensioned wires 12, 40 which are covered by layers of cementitious material 14, 42; the wires are embedded in the coatings of synthetic resin. The joint is made by means of a toroidal rubber ring 46 disposed within the annular space 48; alternatively the joint is made by caulking. The polyesters or epoxy resin employed may be moulded, sprayed or otherwise applied to the pipes and resinforced by fibre glass. The pipe linings may be of fibre glass.