Socketing of Pipe
OwnerGeorge Macovaz, Peter Glanville Chapman +1inventors
InventorsGeorge Macovaz, Peter Glanville Chapman, Joshua Stanley Gotham
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Abstract
A method of modifying compressive strains in formation of a pipe ring groove (16), in which a differential temperature profile is established across the pipe wall in a narrow bending locus (l3) corresponding to the ring groove position, and the material is bent to form the ring groove. The temperature differential creates a differential in elastic modulus between the inner and outer surfaces of the pipe material, modifying the strain induced in inner concave and outer convex surfaces of the ring groove during the bending step.
Claims14
A method of modifying localised compression of surfaces of a bend formed in post-forming a jointing formation in plastics material pipe, including the steps of:
- controlling a temperature profile across the material of the pipe wall to create a differential in elastic modulus of the pipe material between opposite surfaces of the pipe material at a bending locus;
- and
- bending of the pipe wall at said bending locus to create concave and convex surfaces of the bend.
A method of forming a circumferential ring groove in plastics material pipe, said ring groove having an enlarged diameter portion with a concave inner surface, including the steps of:
- establishing a localised differential in temperature between inner and outer surfaces of the pipe at a locus substantially corresponding to the enlarged diameter portion of the ring groove such that the modulus of elasticity of the pipe material of said inner surface is higher than the modulus of elasticity of the pipe material of said outer surface at said locus, and
- maintaining said temperature differential while bending said pipe material to create said ring groove, such that said higher elastic modulus inner surface is bent to a concave shape and the lower elastic modulus outer surface is bent to a convex shape.
Apparatus for forming a circumferential ring groove on a pipe, said ring groove having a concave inner surface and a convex outer surface, comprising:
- temperature control means establishing a temperature differential between said inner and outer surfaces of the pipe at a locus corresponding to said ring groove such that the pipe material at said inner surface has a higher elastic modulus than that of the pipe material of the outer surface;
- and
- bending means bending said pipe material at said locus to form said ring groove.
Dependencies are inferred from the claim text.