Tube coupling

Claim 1

A TUBE COUPLING COMPRISING A TUBULAR FITTING PROVIDED WITH A CYLINDRICAL EXTERIOR SURFACE DISPOSED CONCENTRIC WITH THE AXIS OF SAID TUBULAR FITTING, PROVIDED INTERIORLY THEREOF SUBSTANTIALLY MIDWAY ITS ENDS WITH AN INWARDLY PROJECTING ANNULAR PORTION HAVING A CYLINDRICAL INNER SURFACE CONCENTRIC WITH SAID CYLINDRICAL EXTERIOR SURFACE, PROVIDED AT OPPOSITE SIDES OF SAID ANNULAR PORTION WITH ANNULAR INWARDLY OPENING GROOVES, EACH OF SAID GROOVES HAVING THREE LATERALLY CONNECTING PLANAR SIDES, THE INTERMEDIATE OF SAID THREE SIDES BEING CYLINDRICAL AND CONCENTRIC WITH SAID CYLINDRICAL EXTERIOR SURFACE, THE OTHER OF SAID SIDES FORMING EQUAL OBTUSE ANGLES WITH SAID INTERMEDIATE SIDE, SAID FITTING BEING PROVIDED AT THE OUTER SIDES OF SAID GROOVES WITH INWARDLY PROJECTING ANNULAR PORTIONS RESPECTIVELY HAVING CYLINDRICAL INNER SURFACES CONCENTRIC WITH SAID CYLINDRICAL EXTERIOR SURFACE AND DISPOSED SUBSTANTIALLY IN ALIGNMENT WITH THE CYLINDRICAL INNER SURFACE OF SAID FIRST MENTIONED ANNULAR PORTION, TWO ALIGNED TUBULAR MEMBERS OF SUBSTANTIALLY EQUAL DIAMETER EXTENDING AXIALLY OF SAID FITTING AND HAVING SUBSTANTIALLY VERTICAL ENDS DISPOSED IN OPPOSED RELATION TO EACH OTHER, SAID TUBULAR MEMBERS BEING PROVIDED AT SAID ENDS WITH OUTWARDLY PROJECTING LATERAL FLANGES HAVING CYLINDRICAL OUTER EDGES CONCENTRIC WITH SAID CYLINDRICAL EXTERIOR SURFACE AND IN SURFACE-TO-SURFACE ENGAGEMENT WITH THE CYLINDRICAL INNER SURFACE OF SAID FIRST MENTIONED ANNULAR PORTION, THE OPPOSED FACES OF SAID FLANGES BEING SUBSTANTIALLY VERTICAL AND BEING SUBSTANTIALLY FLUSH WITH THE VERTICAL ENDS OF SAID TUBULAR MEMBERS, THE OUTER FACES RESPECTIVELY OF SAID FLANGES BEING UPWARDLY AND INWARDLY INCLINED PLANAR SURFACES OPPOSED TO AND SUBSTANTIALLY PARALLEL WITH THE OUTERMOST OF THE OTHER OF SAID PLANAR SIDES OF SAID GROOVES, OF SAID FLANGES AND THE THREE LATERALLY PLANAR SURFACES OF SAID FLANGES AND THE THREE LATERALLY CONNECTING PLANAR SIDES OF SAID GROOVES FOR RETAINING THE FLANGES OF SAID TUBULAR MEMBERS IN COUPLED RELATION WITH SAID FITTING AND FOR PROVIDING FLUID-TIGHT JOINTS BETWEEN SAID FLANGES AND SAID FITTING, SAID MEANS COMPRISING TWO SEALING RINGS, EACH HAVING A UNIFORM HEXAGONAL CROSS SECTION THROUGHOUT ITS CIRCUMFERENCE, AND EACH OF SAID SEALING RINGS INCLUDING MEANS TO EXERT A CONTINUOUS RADIALLY OUTWARDLY ACTING FORCE ON AT LEAST TWO OF SAID PLANAR SIDES, WHEREBY FOUR LATERALLY CONNECTING PLANAR SURFACES RESPECTIVELY OF SAID RINGS HAVING SURFACE-TO-SURFACE SEALING ENGAGEMENT WITH THE ENTIRE PERIPHERY OF THE INCLINED PLANAR SURFACES RESPECTIVELY OF SAID FLANGES AND WITH THE THREE LATERALLY CONNECTING PLANAR SIDES OF THE GROOVES IN SAID FITTING.