Closure

Claim 1

IN COMBINATION WITH AN EXTERNALLY COARSE THREADED CONDUIT FITTING END PORTION HAVING AN INTERNAL SHOULDER SPACED FROM THE OPEN END THEREOF AND FACING OUTWARDLY, AN ANNULAR RESILIENT SEALING MEMBER RESTING ON THE SHOULDER WITH THE OUTER SURFACE THEREOF SPACED A PREDETERMINED DISTANCE FROM THE OPEN END OF SAID FITTING PORTION, A CLOSURE COMPRISING AN INTEGRALLY FORMED PLASTIC BODY OF SEMI-RIGID RESILIENT MATERIAL HAVING A TOP WALL, AN INTERNALLY THREADED OUTER SKIRT DEPENDING FROM THE PERIPHERY OF THE TOP WALL HAVING A HEAVY THREAD ON THE INNER SURFACE THEREOF EXTENDING SUBSTANTIALLY THE FULL DEPTH THEREOF ENGAGEABLE WITH THE HEAVY THREAD ON THE FITTING PORTION AND EXTERNAL HAND GRIP RIB MEMBERS EXTENDING LONGITUDINALLY ALONG THE OUTER SURFACE OF THE OUTER SKIRT OVER THE LENGTH OF SAID THREAD REINFORCING SAID OUTER SKIRT, SAID RIBS EXTENDING LONGITUDINALLY OVER SAID SKIRT A DISTANCE LESS THAN THE LENGTH OF THE SKIRT AND TERMINATING IN RADIALLY TAPERED ENDS ADJACENT TO SAID TOP WALL, AN INNER SKIRT FORMED BY CONVERGING WALLS DEPENDING FROM THE TOP WALL CONCENTRIC TO AND SPACED INWARDLY FROM SAID OUTER SKIRT AND TELESCOPING FREELY INTO SAID FITTING PORTION THROUGH SAID OPEN END IN ALIGNMENT WITH SAID SEALING MEMBER, SAID INNER SKIRT EXTENDING A MAJOR PORTION OF THE LENGTH OF THE OUTER SKIRT BUT FROM SAID TOP WALL DISTANCE GREATER THAN SAID PREDETERMINED DISTANCE TO PROVIDE CLEARANCE AT ALL TIMES BETWEEN SAID TOP WALL AND THE UPPER END OF SAID CONDUIT FITTING PORTION AND TERMINATING IN AN AXIALLY DIRECTED ROUNDED SEALING SURFACE TO ENGAGE SAID SEALING MEMBER IN SEALED RELATIONSHIP UNDER TORQUE INDUCED COMPRESSION, SAID TOP WALL BETWEEN SAID SKIRTS RESILIENTLY TRANSMITTING THE AXIAL PRESSURE BETWEEN SAID SHOULDER AND SAID FITTING PORTION THAT IS EXERTED THROUGH SAID RESILIENT SEALING MEMBER, SAID SKIRTS AND A TIGHTENED THREADED ENGAGEMENT BETWEEN THE HEAVY THREADS ON THE OUTER SKIRT AND ON SAID FITTING PORTION.