Pipe repair coupling

Claim 1

A pipe repair coupling of organic thermoplastic polymeric material for joining aligned, spaced apart first and second pipe ends and comprising: a cylinder formed medially with a barrel defining an interior cylindrical sealing surface and having first and second extremities, said first extremity being formed with a first fitting for being bonded to said first pipe end and said second extremity being formed with a neck; a cylindrical protective sleeve surrounding said barrel to support weight applied to the exterior thereof; a hollow piston telescopically received in said cylinder and including a plurality of seals for cooperating with said sealing surface in forming a dynamic seal, said piston further including a tube projecting telescopically through said neck and formed on its free end with a second fitting for joining with said second pipe end; and, a cylindrical stiffener sleeve in said piston and surrounded by said seals, whereby said piston may be telescoped axially into said cylinder to facilitate joining said first and second fittings with said first and second pipe ends and said protective sleeve will protect said cylinder from exterior forces and when the binding forces are applied to said coupling, said stiffener sleeve will support the walls of said piston from collapsing radially inwardly and consequently, breaking the sealing engagement between said seals and said sealing surface.