| abstract |
Glass reinforced plastic pipe having preformed threads integrally disposed therein formed by: (1) molding threaded portions wherein the outer surface is preferably corrugated or irregular and which tapers down to the inside diameter of the pipe to which the thread is to be attached; (2) mounting said molded thread on the end of a mandrel; and (3) forming a pipe on said mandrel by providing pretensioned filamentous reinforcements longitudinally and helically disposed thereon and imbedded in a cured resin. The described tapered portion and corrugated portion of the thread is overwound with the above-mentioned helical and longitudinal filamentous material. |