Ductile iron pipe joint employing a coupling and coupling therefor
AssigneeAmerican Cast Iron Pipe Company
InventorWilliam T. Adams, Jr.
Life of this patent
Estimating the term…
Abstract
A pipe joint capable of transmitting high axial compressive loads includes a reduced wall thickness section at the ends of the pipe to be joined and a coupling sleeve supported in telescoping relation with the reduced wall thickness section. Shoulders formed at the ends of the reduced sections bear against the ends of the sleeve, and the ends of the reduced thickness sections bear against each other so that a portion of the axial compressive load is transmitted through the coupling sleeve and a portion through the reduced thickness sections and a substantially uniform unit stress is maintained. O-rings carried by the coupling sleeve provide a fluid-tight seal between the sleeve and the adjacent surface of the reduced thickness section of the pipe.
Claims22
A method of forming a high axial compression strength joint between two ductile iron pipes of equal diameter for trenchless installation, comprising
- providing a substantially planar end face on one end of each of the two pipes to be joined, the planar end faces being perpendicular to the longitudinal axis of the respective pipes,
- providing a section of reduced substantially uniform wall thickness on the end of each said pipe, said sections each extending a predetermined distance from said planar end face and having a cylindrical surface terminating in a substantially radial shoulder,
- providing a high strength axial compressive load carrying coupling sleeve having a cylindrical wall in telescoping relation with and substantially complementary to said cylindrical surfaces on said pipes to be joined, said coupling sleeve having planar end faces which are perpendicular to said cylindrical wall,
- providing a plurality of O-ring grooves formed in said cylindrical wall, and
- providing an O-ring supported in each said O-ring groove, said O-rings forming a fluid-tight seal between said coupling sleeve and each said cylindrical surface,
- the length of said coupling sleeve being equal to the sum of the lengths of said sections of reduced wall thickness whereby, when said cylindrical wall and said cylindrical surfaces are in said telescoping relation, the end faces of said pipe are in abutting relation and the end faces of said coupling sleeve are in abutting relation one with each said radial shoulder whereby all axial compressive loads applied between the two pipes are transmitted therebetween partially through said coupling sleeve and partially through said reduced wall thickness sections of each said pipe.
A pipe joint coupling for transmitting high axial compressive loads between two ductile iron pipes of equal diameter for a trenchless installation, the joint comprising,
- a substantially planar end face on one end of each pipe to be joined, the planar end faces being perpendicular to the longitudinal axis of the respective pipes,
- a section of reduced, substantially uniform wall thickness on said one end of each said pipe, said reduced wall thickness section providing a cylindrical surface extending a predetermined distance from said planar end face and terminating in a radial shoulder,
- a high strength compressive load carrying coupling sleeve having a cylindrical wall portion in telescoping relation with and substantially complementary to each said cylindrical surface, said sleeve having a plane end face at each end perpendicular to said cylindrical wall portion,
- a plurality of O-ring grooves formed in said cylindrical wall portion and an O-ring supported in each said O-ring groove with at least one O-ring contacting and forming a fluid-tight seal between the cylindrical wall portion and each said cylindrical surface,
- said coupling sleeve having its planar end faces in abutting relationship one with each said radial shoulder and said planar end faces on said one end of each said pipe being in abutting relationship whereby all axial compressive loads applied between said two pipes are transmitted partially through said coupling sleeve and partially through said reduced wall thickness sections.
A method of forming a high axial compression strength joint between two ductile iron pipes of equal diameter for trenchless installation, comprising
- providing a substantially planar end face on one end of each of the two pipes to be joined, the planar end faces being perpendicular to the longitudinal axis of the respective pipes,
- providing a section of reduced substantially uniform wall thickness on the end of each said pipe, said reduced wall thickness sections each extending a predetermined distance from said planar end face and having a cylindrical surface terminating in a substantially radial shoulder,
- providing a single load bearing coupling member in the form of a high strength coupling sleeve between said one end of said pipes, said coupling sleeve having a pair of axially spaced cylindrical wall portions adapted to be received one in telescoping relation with and substantially complementary to said cylindrical surface on each of said pipes to be joined, said coupling sleeve having planar end faces which are perpendicular to said cylindrical wall surfaces,
- providing an annular radially extending ring around said coupling sleeve at a location equally spaced from each end thereof, said annular ring having parallel end faces perpendicular to said cylindrical wall portion,
- providing at least one O-ring groove in each said cylindrical wall portion,
- providing an O-ring supported in each said O-ring groove, said O-rings forming a fluid-tight seal between said coupling sleeve and each said cylindrical surface, and
- mounting said coupling sleeve on said pipes to be joined with said cylindrical wall portions in telescoping relation one with each said cylindrical surface with the end faces of said coupling sleeve in abutting relationship with said shoulders and the end face of said pipes in abutting relationship one with each said end face on said annular ring whereby all axial compressive load applied between the two pipes will be transmitted partially through said coupling sleeve to said shoulders and partially through said annular ring and said reduced wall thickness sections of each said pipe.
A pipe joint coupling for transmitting high axial compressive loads between two ductile iron pipes of equal diameter for trenchless installation, the joint comprising,
- a substantially planar end face on one end of each pipe to be joined, the planar end faces being perpendicular to the longitudinal axis of the respective pipes,
- a section of reduced substantially uniform wall thickness on said one end of each said pipe, said reduced wall thickness section providing a cylindrical surface extending a predetermined distance from said planar end face and terminating in a radial shoulder,
- a high strength coupling sleeve having a cylindrical wall in telescoping relation with and substantially complementary to each said cylindrical surface, said sleeve having end faces perpendicular to said cylindrical wall,
- an annular flange on said coupling sleeve projecting radially from said cylindrical wall at a location equally spaced from the end faces thereof,
- at least one O-ring groove formed in said cylindrical wall between said annular flange and each said planar end of said coupling sleeve, and an O-ring supported in each said O-ring groove with at least one O-ring contacting and forming a fluid-tight seal between the cylindrical wall and each said cylindrical surface,
- said coupling sleeve having its planar end faces in abutting relationship one with each said radial shoulder and said planar end faces on said one end of each said pipe being in abutting relationship with said annular flange whereby all compressive loads applied between the two pipes are transmitted therebetween partially through said coupling sleeve and partially through said reduced wall thickness sections of each said pipe.
Dependencies are inferred from the claim text.