Connection for foam insulated pipes

Claim 1

A pipe connection comprising two aligned pipes having opposed ends which are secured together, each pipe including an external layer of foam plastic material thereon, said layer of foam material not extending to the end of the respective pipe so that the layers on the secured pipes define a space therebetween, a finishing cover layer of thermoplastic material on each said foam layer, said finishing layer being of substantially uniform thickness, an elastic sealing ring mounted on the finishing layer on each pipe proximate the end thereof, a sleeve enclosing said space and having ends surrounding the rings, said sleeve being heat shrunk onto the finishing layers to compress the sealing rings, said finishing layer of thermoplastic material tending to creep under the pressure applied to the sealing rings, and a ring of rigid material embedded in each layer of foam plastic material underneath the finishing layer in the region of the associated sealing ring to prevent deformation of the finishing layer and presserve the seal thereat, said ring being cylindrical and having a rectangular cross-section of greater thickness than the finishing layer with opposed parallel side surfaces in abutment with the foam plastic material in which it is embedded, a bottom surface resting on the foam plastic material, and an upper surface flush with the upper surface of the foam layer and in contact with said finishing layer.