Method of forming a socket end on a plastic pipe and a molding device for use of the method

Abstract From the Canadian patent

For the purpose of making a joint socket comprising at least two portions, namely a portion for receiving a plastic pipe end and another portion into which a rubber ring is fitted, a method of heating and softening a plastic pipe end and enlarging the radius of the softened pipe end to twice its size which includes an inwardly slanted portion between a first outwardly slanted portion and a second outwardly slanted portion, whose radius becomes smaller as it comes nearer to the front end thereof. As the result the, frictional resistance between an improved core and the radius enlarged softened pipe is reduced to a value which enables the method to be carried out, such that wall-thickened …