Abstract: A method of making a composite tube utilizing known equipment and process to form spaced end sections and a central section having an inner corrugated portion and surrounding portion bonded to at least certain crests of the corrugations. A spaced pair of generally cylindrical end couplings are formed by sequentially telescoping the end sections over an internal cylindrically contoured die part and continuing the telescoping until an inner surface of the telescoped end section engages at least three circumferentially spaced fingers to locate the telescoped end section in concentric relationship with the core part. Positioning an external die part in spaced concentric relationship around the telescoped end section, the external die part having an inner surface contoured to the desired external configuration of a coupling being formed. Injecting a heat softened thermoplastic material into the space between the die inner surface and the core to form a coupling.

Abstract: An apparatus is disclosed for making a composite tube with end couplings. The composite tube is made utilizing known equipment and process to form spaced end sections and a central section having an inner corrugated portion and surrounding portion bonded to at least certain crests of the corrugations. A spaced pair of generally cylindrical end couplings are formed by sequentially telescoping the end sections over an internal cylindrically contoured die part and continuing the telescoping until an inner surface of the telescoped end section engages at least three circumferentially spaced fingers to locate the telescoped end section in concentric relationship with the core part. An external die part is positioned in spaced concentric relationship around the telescoped end section, the external die part having an inner surface contoured to the desired external configuration of a coupling being formed.

Abstract: A composite tube for use in such applications as an automobile heater hose has inner and outer tubes. The inner tube has a corrugated central section and cylindrical end portions. The outer tube is bonded to the end portions of the inner tube and to the crests of the corrugations. The composite tube has spaced identical end couplings, each with a portion extending into and bonded to the associated inner tube end portion, an end part overlying and bonded to ends of the tube portions and an external flange surrounding and bonded to the reinforcing tube end portion. The couplings include circumferentially spaced end reliefs for facilitating connection of the coupling to a tube such as a fluid inlet to or outlet from an associated automobile radiator or the like. The composite tube is continuously formed in a known manner while the end couplings are molded with a novel and improved mold and process.