Abstract A coupling for use in forming a welded tube joint is disclosed along with a method for forming such joint. A thin coupling sleeve is tightly swage-fitted onto the end of a tube to form a male or female tube end assembly suitable for engagement with a tubular mating part assembly which may be a fitting or another coupling sleeve and tube assembly. The male-female interlocking arrangement provides radial and axial alignment of the joined assemblies. The structure is arranged to provide a space between the tube end face and the interior end face of the tubular mating part assembly. During the welding operation, external fusion heat is applied to form a single weld bead extending from the interior of the tube to the exterior surfaces of the assemblies. The width of the weld at its inner radial extremities is longer than the axial width of the space between the interior end faces and its width at its outer radial extremities is at least equal to twice the axial length of the male-female telescoped portion so that all the members are fused into a single unitary structure.
Inventors
👤 H Patel
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-04 15:10
CPC Classifications
B; B23; B23K; B23K33/00; B23K33/004; B23K33/006
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
291 words
A method of forming a welded joint between a tube and a tubular mating part assembly, comprising forming a tube end assembly including a tube extending to an end face, positioning a sleeve having an end surface around said tube tightly engaging the outer surface thereof along an interface therebetween and adjacent to one end of said tube so that said tube end assembly includes said end face extending radially outward from the inner surface of the tube and an end surface extending radially inward from the outermost surface of said tube end assembly at a location axially spaced from said end face and a cylindrical surface extending between the associated end face and end surface, placing said tube end assembly in abutting engagement with said tubular mating part assembly also having an interfitting similar end face, end surface and cylindrical surface proportioned to telescope with said cylindrical surface of said tube end assembly so as to axially and radially align said assemblies, providing a greater axial spacing between said end face and end surface of one of said assemblies than that of the other assembly so that said end faces are spaced when said end surfaces are in abutting engagement, and applying fusion heat along the joint between said abutting end surfaces to form a single weld bead extending the entire radial distance from the inner surface of said tube to the outer surface of said assemblies and having a width at said inner surface at least equal to the spacing between said end faces and a width at the outer surface at least equal to twice said axial spacing between said end face and end surface so that the weld encompasses both the end faces and the end surfaces.
Claim 2
Independent Claim
291 words
A method of forming a welded joint between a tube and a tubular mating part assembly, comprising forming a tube end assembly including a tube extending to an end face, positioning a sleeve having an end surface around said tube tightly engaging the outer surface thereof along an interface therebetween and adjacent to one end of said tube so that said tube end assembly includes said end face extending radially outward from the inner surface of the tube and an end surface extending radially inward from the outermost surface of said tube end assembly at a location axially spaced from said end face and a cylindrical surface extending between the associated end face and end surface, placing said tube end assembly in abutting engagement with said tubular mating part assembly also having an interfitting similar end face, end surface and cylindrical surface proportioned to telescope with said cylindrical surface of said tube end assembly so as to axially and radially align said assemblies, providing a greater axial spacing between said end face and end surface of one of said assemblies than that of the other assembly so that said end faces are spaced when said end surfaces are in abutting engagement, and applying fusion heat along the joint between said abutting end surfaces to form a single weld bead extending the entire radial distance from the inner surface of said tube to the outer surface of said assemblies and having a width at said inner surface at least equal to the spacing between said end faces and a width at the outer surface at least equal to twice said axial spacing between said end face and end surface so that the weld encompasses both the end faces and the end surfaces.
Claim 3
Dependent Claim
36 words
A method of forming a welded joint as set forth in claim 1 wherein said mating part assembly is formed by a second tube and a second sleeve positioned around said tube in tight engagement therewith.
Claim 4
Dependent Claim
54 words
A method of forming a welded joint as set forth in claim 1 wherein said sleeve is initially formed to freely fit over said tube and is secured to said tube by swaging said tube from its inside to increase the diameter of said tube and cause tight engagement between said sleeve and tube.
Claim 5
Dependent Claim
49 words
A method of forming a welded joint as set forth in claim 3 wherein said sleeve projects beyond said end face to provide a projecting portion, said projecting portion before swaging is flared outward and said swaging increases the diameter of said sleeve until said projecting portion is cylindrical.
Claim 6
Dependent Claim
59 words
A method of forming a welded joint as set forth in claim 1 wherein a lubricating film is applied along a substantial axial portion of said interface, said lubricating film extending from the end of said sleeve remote from said end surface along such interface toward said end surface and terminating at a location spaced from said end surface.
Claim 7
Dependent Claim
26 words
A method of forming a welded joint as set forth in claim 5 wherein said lubricating film is a dry film coating applied to said sleeve.
Claim 8
Dependent Claim
26 words
A method of forming a welded joint as set forth in claim 5 wherein said lubricating film is a dry film coating applied to said tube.