Pipe coupling

Abstract

Two coaxial metal pipes, whose confronting extremities are each provided with a plurality of peripheral ribs of staggered height separated by two or more peripheral grooves, are interconnected by a coupling sleeve of fiber-reinforced thermosetting resin subdivided into several coaxially interleaved and independently deformable cylindrical shells each terminating in a pair of internal beads engaged in a respective peripheral pipe groove. The shells, increasing in axial tensile strength from the innermost to the outermost one, are preferably separated from one another by interposed antibonding layers of thermoplastic resin. A resinous filler can be inserted between the pipe extremities for electrically insulating them from each other. The shells of the coupling sleeve can be formed by coiling resin-coated filaments around the pipe axis, advantageously with application of an antifriction layer on each inner shell before the thermosetting material thereof has been fully hardened.

Dependencies are inferred from the claim text.