Coupling

Claim 1

IN COMBINATION, A CYLINDRICAL SLEEVE HAVING A THREADED PORTION ON ITS OUTER PERIPHERY ADJACENT ONE END THEREOF, THE INNER PERIPHERAL EDGE OF THE SLEEVE AT SAID END BEING BEVELED TO FORM AN INWARDLY DIRECTED SEATING SURFACE; A PIPE EXTENDING INTO THE SLEEVE FROM THE END HAVING THE SEATING SURFACE, THE PIPE BEING SLIDABLE WITHIN THE SLEEVE; A COMPRESSION RING OF RESILIENT MATERIAL EXTENDING AROUND THE PIPE AND LOCATED OUTSIDE THE SLEEVE ADJACENT THE SEATING SURFACE, THE MATERIAL IN THE RING HAVING LOW COMPRESSION SET CHARACTERISTICS; A COMPRESSION NUT ENCIRCLING THE PIPE AND THE COMPRESSION RING AND CARRYING A THREADED PORTION AT ONE END OF WHICH MATES WITH THE THREADED PORTION ON THE SLEEVE; A SHOULDER FORMED ON THE INSIDE OF THE NUT AT THE END OPPOSITE THE THREADED PORTION; A TRUNCATED CONICAL SURFACE FORMED ON THE INNER PERIPHERY OF THE NUT AND ARRANGED TO ENGAGE THE COMPRESSION RING WHEN THE NUT IS THREADED ONTO THE CYLINDRI CAL SLEEVE AND FORCE IT RADIALLY INTO CONTACT WITH THE PIPE AND LONGITUDINALLY INTO CONTACT WITH THE SEATING SURFACE, THE COMPRESSION NUT, THE PIPE, AND THE COMPRESSION RING DEFINING AN ANNULAR SPACE AT THE END OF THE COMPRESSION RING OPPOSITE THE SEATING SURFACE WHEN THE COMPRESSION NUT IS IN THE POSITION IN WHICH THE TRUNCATED CONICAL SURFACE FIRST CONTACTS THE COMPRESSION RING, THE TRUNCATED CONICAL SURFACE CAUSING THE COMPRESSION RING TO EXTRUDE INTO SAID SPACE AS IT IS FORCED IN THE RADIAL AND LONGITUDINAL DIRECTIONS DURING CONTINUED ADVANCEMENT OF THE COMPRESSION NUT; A SPLIT ANTI-EXTRUSION RING ENCIRCLING THE PIPE AND LOCATED WITHIN THE NUT BETWEEN THE SHOULDER AND THE COMPRESSION RING; AND A THIN, ADHERENT, LUBRICATING COATING ON THE OUTER PERIPHERY OF THE COMPRESSION RING.