Plastic cap

Claim 1

A L CLOSURE FOR USE ON A THREADED NECK CONTAINER INCLUDING A THREADED OUTER WALL, AN INNER WALL AND AN INTERCONNECTING RIM, SAID CLOSURE COMPRISING A TOP WALL, A TAPPED CYLINDRICAL SKIRT DEPENDING FROM THE TOP WALL FOR THREADED ENGAGEMENT WITH THE OUTER WALL OF THE NECK, AN ANNULAR RESILIENT BEAD POSITIONED ON THE UNDER SIDE OF THE TOP WALL TAPERING OUTWARDLY FROM ITS INNER PERIPHERAL EDGE TO ITS OUTER PERIPHERAL EDGE WITH ITS INNER SURFACE AT AN ANGLE WITH RESPECT TO THE TOP WALL SURFACE OF 75* TO 85* AND ITS OUTER SURFACE AT AN ANGLE WITH RESPECT TO THE TOP WALL OF 80* TO 90*, THE ANNULAR RESILIENT BEAD BEING DISPOSED CONCENTRICALLY WITH THE SKIRT AND HAVING A MEDIAN DIAMETER GREATER THAN THE DIAMETER OF THE INNER WALL OF THE NECK BUT LESS THAN THE DIAMETER OF THE OUTER WALL OF THE NECK, AN ANNULAR RESILIENT SLEEVE POSITIONED ON THE UNDER SIDE OF THE TOP WALL AND DISPOSED CONCENTRICALLY WITHIN THE ANNULAR RESILIENT BEAD, THE ANNULAR RESILIENT SLEEVE BEING JOINED AT ITS INNER PERIPHERAL EDGE TO THE TOP WALL, DEPENDING ANGULARLY DOWNWARDLY FROM THE TOP WALL OUTWARDLY TOWARD THE SKIRT SUCH THAT ITS INNER SURFACE IS AT AN ANGLE WITH RESPECT TO THE TOP WALL SURFACE OF 40* TO 50* AND ITS OUTER SURFACE IS AT AN ANGLE WITH RESPECT TO THE TOP WALL SURFACE OF 55* TO 65*, AND HAVING A SLANT HEIGHT FROM ITS INNER PERIPHERAL EDGE TO ITS OUTER PERIPHERAL EDGE GREATER THAN THE RADIAL DISTANCE BETWEEN THE INNER PERIPHERAL EDGE AND THE MEDIAN DIAMETER OF THE ANNULAR RESILIENT BEAD; WHEREBY AS THE CLOSURE ENGAGES THE THREADED NECK, THE RESILIENT SLEVE IS DEFLECTED UPWARDLY AND OUTWARDLY BY THE RIM SO AT TO BEAR AGAINST THE ANNULAR RESILIENT BEAD ON ONE SIDE WHEREBY THE OUTER PERIPHERAL EDGE OF THE ANNULAR RESILIENT BEAD IS DEFLECTED UPWARDLY AND DOWNWARDLY BY THE DEFLECTED RESILIENT SLEEVE AND AGAINST THE RRIM ON THE OTHER SIDE THEREBY FORMING A SEALING RELATIONSHIP.