초록 ▼

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

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.

대표청구항 ▼

A composite tube comprising: a) an inner tube of polypropylene having a central section of a crested, corrugated configuration and being of substantially constant cross sectional thickness end to end, the inner tube having spaced generally cylindrical end portions formed at opposite ends of the cent

A composite tube comprising: a) an inner tube of polypropylene having a central section of a crested, corrugated configuration and being of substantially constant cross sectional thickness end to end, the inner tube having spaced generally cylindrical end portions formed at opposite ends of the central section; b) an outer generally cylindrical tube of thermoplastic material including a polypropylene component surrounding the inner tube, the outer tube engaging and being bonded to at least certain of the corrugation crests and being spaced from inner tube wall portions delineating corrugation recesses disposed longitudinally between the crests, the outer tube also surrounding and being bonded to at least parts of the end portions; and, c) tubular end couplings each projecting into an associated one of the end portions, the couplings each having an inner end section within the end portions, an outer section overlying the end portions and parts overlapping and bonded to end parts of the inner and outer tube end portions.