Tubular coupling having a metallic sealing ring

Claim 1

A FLUID PRESSURE COUPLING FOR USE WITH A MEMBER PROVIDED WITH A PORT HAVING AN INNER THREADED PORTION AND AN OUTER UNTHREADED OUTWARDLY BEVELLED ENTRANCE SURFACE ENCIRCLING THE ENTRANCE TO THE THREADED PORTION COMPRISING: A TUBULAR FITTING HAVING A THREADED LENGTH ADJACENT ONE END AND HAVING A CIRCUMFERENTIAL RADIALLY OUTWARDLY EXTENDING SEALING SURFACE SPACED AXIALLY FROM SAID THREADED LENGTH BY AN UNTHREADED LENGTH OF LESS DIAMETER THAN THE THREADED LENGTH; A RESILIENT AND RESISTINGLY DEFORMABLE CONTINUOUS SEALING RING OF SOLID GENERALLY TRAPEZOIDAL SHAPE IN CROSS SECTION ENCIRCLING SAID UNTHREADED LENGTH AND PRESWAGED RADIALLY INWARDLY THEREABOUT THROUGHOUT THE AXIAL DIMENSION OF THE RING FROM AN INITIAL INTERNAL DIAMETER SUFFICIENT TO BE PASSED OVER THE THREADED LENGTH TO A CAPTIVE INTERNAL DIAMETER LESS THAN THE CREST DIAMETER OF SUCH THREADED LENGTH BUT SUFFICIENTLY GREATER THAN THE DIAMETER OF THE UNTHREADED LENGTH TO ALLOW RELATIVE ROTATION THEREBETWEEN; SUCH RING HAVING AN INNER END FACE OPPOSED TO SAID RADIALLY OUTWARDLY EXTENDING SEALING SURFACE OF THE FITTING TO ABUT THE SAME, AND HAVING AN OUTER END FACE DISPOSED AT THE OPPOSITE END OF THE RING FROM THE INNER END FACE AND EXTENDING RADIALLY OUTWARDLY FROM SAID INTERNAL CAPTIVE DIAMETER OF THE RING, AND A RADIALLY DISPOSED EXTERNAL BEVELLED FACE EXTENDING SUBSTANTIALLY FROM SAID OUTER TO SAID INNER END FACE AND BEVELLED TO CONFORM SUBSTANTIALLY TO THE BEVELLED ENTRANCE OF THE PORT TO ABUT THE SAME, AND SAID RING HAVING A RADIALLY DISPOSED SMOOTH INTERNAL CYLINDRICAL FACE EXTENDING AXIALLY OF THE RING FROM THE INNER END TO THE OUTER END FACES THEREOF AND OPPOSED TO AND ADAPTED TO ABUT THE UNTHREADED LENGTH WHEN THE FITTING IS TIGHTENED INTO THE PORT, SAID RING BEING RESISTINGLY RESILIENTLY CONTRACTABLE AND DEFORMABLE TO HAVE ITS INTERNAL CYLINDRICAL FACE THROUGHOUT SUBSTANTIALLY ITS ENTIRE AXIAL DIMENSION DIAMETRICALLY CONTRACTED FROM SAID CAPTIVE INTERNAL DIAMETER INTO FLUSH CIRCUMFERENTIAL SEALING ENGAGEMENT ABOUT THE UNTHREADED LENGTH AND TO HAVE ITS BEVELLED EXTERNAL FACE CIRCUMFERENTIALLY WEDGED FLUSH AGAINST THE BEVELLED SURFACE OF THE ENTRANCE OF THE PORT WHEN THE INNER END FACE OF THE RING IS ENGAGED WITH THE CIRCUMFERENTIAL SEALING SURFACE OF THE FITTING AND THE FITTING IS THREADED INTO THE PORT COMPRESSING THE RING CIRCUMFERENTIALLY AGAINST THE BEVELLED SURFACE OF THE PORT ENTRANCE, SAID RING BEING SUFFICIENTLY RESILIENT WHEN RELEASED FROM SAID COMPRESSION TO SPRING BACK AWAY FROM THE UNTHREADED LENGTH OF THE FITTING DIAMETRICALLY EXPANDING ITS INTERNAL CYLINDRIC SMOOTH FACE TO ITS CAPTIVE INTERNAL DIAMETER SUFFICIENT TO ALLOW RELATIVE ROTATION BETWEEN THE FITTING AND THE RING, AND AT LEAST ONE OF SAID RADIALLY DISPOSED FACES OF THE RING WHICH IS OPPOSED TO AND ADAPTED TO ABUT AN OPPOSED SURFACE TO ESTABLISH A SEAL THEREBETWEEN LYING ON AN ANGLE WITH RESPECT TO SUCH OPPOSED SURFACE WHEREBY TIGHTENING OF THE FITTING INTO THE PORT AS AFORESAID TO BRING SUCH ANGULARLY RELATED SURFACES INTO FLUSH SEALING RELATIONSHIP WILL IMPOSE A TWISTING TENSION ON THE RING ABOUT ITS CIRCUMFERENTIAL AXIS OF MASS.