Patent ID: 6033617
Filing Date: 2000-03-07
Classification: B29C,Y10S

Abstract:
A method of installing a gasket in a socket end of a thermoplastic pipe which is used to form a pipe coupling, the method comprising the steps of:providing a mandrel with an inner end and an outer end and having a generally cylindrical outer working surface;installing a gasket at a first circumferential position on the outer working surface;providing a plurality of outwardly biased detents at a second circumferential location on the mandrel nearer the inner end of the mandrel, the outwardly biased detents having exposed lip portions which abut the gasket in a normally extended position, the detents being retractable to a retracted position flush with the outer working surface of the mandrel;heating a socket end of the thermoplastic pipe;forcing the heated socket end of the thermoplastic pipe over the working surface of the mandrel and over the gasket with the detents in the extended position, the gasket being retained in position by abutting the exposed lip portions of the detents, whereby the heated socket end of the thermoplastic pipe flows over the gasket to form a retention groove for retaining the gasket and again contacts the working surface of the mandrel;cooling the heated socket end of the thermoplastic pipe;retracting the cooled socket end of the thermoplastic pipe and the retained gasket from the working surface of the mandrel, the retracting step serving to force the detents to the retracted position to allow travel of the thermoplastic pipe over the working surface of the mandrel; andwherein the heated, socket end of the thermoplastic pipe directly contacts the working surface of the mandrel after passing over the gasket, without contacting any additional apparatus used in the method.