Flareless tube coupling for plastic or metal tubing

Claim 1

IN A FLARELESS TUBE COUPLING, THE COMBINATION OF A PAIR OF THREADEDLY ENGAGED MEMBERS DEFINING THEREBETWEEN AN ANNULAR CHAMBER THAT INCLUDES AXIALLY SPACED END WALLS CONSTITUTED BY THE RESPECTIVE MEMBERS AND OF WHICH AT LEAST ONE IS A FRUSTO-CONICAL WEDGE SURFACE; AND A TUBULAR FERRULE IN SUCH CHAMBER, THE ONE END OF SAID TUBULAR FERRULE ADJACENT SAID WEDGE SURFACE HAVING AN OUTER DIAMETER GREATER THAN THE DIAMETER OF THE RADIAL INNER END OF SAID WEDGE SURFACE AND LESS THAN THE DIAMETER OF THE RADIAL OUTER END OF SAID WEDGE SURFCE, WHEREBY SAID ONE END OF SAID FERRULE WILL CONFRONT SAID WEDGE SURFACE SO AS TO BE RADIALLY CONTRACTED THEREBY INTO SEALING ENGAGEMENT WITH A TUBE ADAPTED TO BE POSITIONED WITHIN SAID FERRULE WHEN SAID FERRULE IS MOVED AXIALLY AGAINST SAID WEDGE SURFACE, SAID FERRULE BEING FORMED WITH A RADIALLY THICKENED PORTION AXIALLY SPACED FROM SUCH ONE END OF SAID FERRULE AND SAID WEDGE SURFACE, SAID OTHER END WALL OF SAID THREADEDLY ENGAGED MEMBERS HAVING AN INNER DIAMETER GREATER THAN SAID OUTER DIAMETER OF SAID ONE END OF SAID FERRULE AND LESS THAN THE OUTER DIAMETER OF SAID RADIALLY THICKENED PORTION, WHEREBY ONE END OF SAID RADIALLY THICKENED PORTION WILL CONTACT SAID OTHER END WALL ON A DIAMETER GREATER THAN THE DIAMETER OF CONTACT BETWEEN SAID ONE END OF SAID FERRULE AND SAID WEDGE SURFACE, SAID FERRULE THUS BEING MOVED AXIALLY UPON SCREWING TOGETHER OF SAID MEMBERS, THE END OF SAID RADIALLY THICKENED PORTION BEING EXTERIORLY BEVELED AND INTERIORLY UNDERCUT TO PROVIDE DEFROMABLE PORTIONS WHICH ARE AT LEAST PARTIALLY FLATTENED, AND THUS RADIALLY CONTRACTED INTO TUBE GRIPPING ENGAGEMENT UPON APPLICATION OF AXIAL FORCES ON SAID FERRULE, SAID UNDERCUTTING CONSTITUTING A PAIR OF AXIALLY SPACED INTERNAL ANNULAR GROOVE MEANS HAVING A DEPTH SUFFICIENT TO PROVIDE SUCH DEFORMABLE PORTIONS AS AFORSAID, SAID RADIALLY THICKENED PORTION HAVING A THICK UNRELIEVED PORTION BETWEEN SUCH ANNULAR GROOVE MEANS TO RESIST OUTWARD BOWING UPON APPLICATION OF OPPOSED AXIAL FORCES ON SAID FERRULE.