Flexible pressure-type joint for rigid tubing

Claim 2

A pressure-type joint for the internally threaded end of a first tubular element and the externally threaded end of a second tubular element, one of said threaded elements being composed of a substantially non-flexible plastics material soFter than that of the other threaded element, one of said threaded elements being provided with a radial shoulder at the inner extremity of its threaded area, said external threads and said second threaded element being of sufficiently reduced dimensions with respect to said first threaded element and the internal threads thereof to provide an annular clearance to permit substantial transverse angular movement of said elements relative to each other, an annular compressible seal engaging said shoulder, which, when the joint is assembled and tightened, is of sufficient thickness to provide a longitudinal spacing between said shoulder and the end of said other element, said seal being sufficiently compressible when assembled to accommodate the relative angular movement of said elements while still maintaining a seal, an elongated third element slidably insertable longitudinally through said engaging threaded elements, and an annular compressible sealing ring means engaging the periphery of said insertable third element between the latter and a surrounding threaded element, said third element having sufficient clearance relative to said threaded elements to accommodate said angular movement.

Claim 3

A pressure-type joint for the internally threaded end of a first tubular element and the externally threaded end of a second tubular element, one of said threaded elements being composed of a substantially non-flexible plastics material softer than that of the other threaded element, said threaded elements being provided with radial shoulders at the inner extremities of their threaded areas, said external threads and said second threaded element being of sufficiently reduced dimensions with respect to said first threaded element and the internal threads thereof to provide an annular clearance to permit substantial transverse angular movement of said elements relative to each other, annular compressible seals interposed between and engaging the shoulders of said elements and the adjacent ends of the opposite elements, respectively, which, when the joint is assembled and tightened, are of sufficient thickness to provide a longitudinal spacing between each shoulder and the adjacent end of the opposite element, said seals being sufficiently compressible when assembled to accommodate the relative angular movement of said elements while still maintaining a seal, an elongated third element slidably insertable longitudinally through said engaging threaded elements, and an annular compressible sealing ring means engaging the periphery of said insertable third element between the latter and a surrounding threaded element.

Claim 4

A pressure-type joint for the internally threaded end of a first tubular element and the externally threaded end of a second tubular element, one of said threaded elements being composed of a substantially non-flexible plastics material softer than that of the other threaded element, said threaded elements being provided with radial shoulders at the inner extremities of their threaded areas, said external threads and said second threaded element being of sufficiently reduced dimensions with respect to said first threaded element and the internal threads thereof to provide an annular clearance to permit substantial transverse angular movement of said elements relative to each other, annular compressible seals interposed between and engaging the shoulders of said elements and the adjacent ends of the opposite elements, respectively, which, when the joint is assembled and tightened, are of sufficient thickness to provide a longitudinal spacing between each shoulder and the adjacent end of the opposite element, said seals being sufficiently compressible when assembled to accommodate the relative angular movement of said elements while still maintaining a seal, an elongated third element slidably insertable longitudinally through said engaging threaded elements, and an annular compressible sealing ring means engaging the periphery of said insertable third element between the latter and a surrounding threaded element.

Claim 5

A joint as claimed in claim 2, wherein the internally threaded element is provided with an internally directed, radial shoulder and one of said seals is interposed between said last-named shoulder and the end of the externally threaded element.

Claim 6

A joint as claimed in claim 3, wherein said last-named seal additionally engages the periphery of said third element and serves the dual purpose of sealing the joint and sealing the third element within the externally threaded element.

Claim 7

A joint as claimed in claim 4, wherein the seal engaging surface of said internally directed radial shoulder is arcuate in cross-section, with its open area directed axially of said joint.

Claim 8

A pressure-type joint for the internally threaded end of a first tubular element and the externally threaded end of a second tubular element, one of said elements being composed of substantially non-flexible plastics material softer than that of the other threaded element, the internally threaded element being provided with an inwardly directed radial shoulder adjacent the inner extremity of its threaded area, said external threads and said second threaded element being of sufficiently reduced dimensions with respect to said first threaded element and the internal threads thereof to provide an annular clearance to permit substantial angular transverse movement of said elements relative to each other, an annular, compressible seal engaging the shoulder of said internally threaded element, which, when the joint is assembled and tightened, is of sufficient thickness to provide a longitudinal spacing between said shoulder and the end of said externally threaded element, said seal being sufficiently compressible when assembled to accommodate the relative angular movement of said elements while still maintaining a seal, said internally threaded element having an end which surrounds said externally threaded element, said externally threaded element having an outer cylindrical surface adjacent to said end of said internally threaded element, substantially uniformly smaller in diameter than said end of said internally threaded element, and free of a seal thereto.

Claim 9

A pressure-type joint for the internally threaded end of a first tubular element and the externally threaded end of a second tubular element, one of said elements being composed of substantially non-flexible plastics material softer than that of the other threaded element, the internally threaded element being provided with an inwardly directed radial shoulder adjacent the inner extremity of its threaded area, said external threads and said second threaded element being of sufficiently reduced dimensions with respect to said first threaded element and the internal threads thereof to provide an annular clearance to permit substantial angular transverse movement of said elements relative to each other, an annular, compressible seal engaging the shoulder of said internally threaded element, which, when the joint is assembled and tightened, is of sufficient thickness to provide a longitudinal spacing between said shoulder and the end of said externally threaded element, said seal being sufficiently compressible when assembled to accommodate the relative angular movement of said elements while still maintaining a seal, said internally threaded element having an end which surrounds said externally threaded element, said externally threaded element having an outer cylindrical surface adjacent to said end of said internally threaded element, substantially uniformly smaller in diameter than said end of said internally threaded element, and free of a seal thereto.