Closure for sealing container outlet

Claim 1

IN A CLOSURE STRUCTURE OF THE CLASS WHEREIN A CYLINDRICAL HUB IS ATTACHED TO A CONTAINER AND THE CYLINDRICAL HUB HAS A SIDE WALL AND A TOP WALL WITH AN OPENING THEREIN, AND A CAP FITS OVER THE HUB AND HAS A SIDE WALL AND A TOP WALL ADJACENT TO THE CORRESPONDING WALLS OF THE HUB, AND THE CAP OSCILLATAES ON THE HUB TO BRING AN OPENING THROUGH THE CAP INTO REGISTER WITH THE OPENING THROUGH THE TOP WALLS OF THE HUB, AND THERE ARE CAM MEANS ON THE CONFRONTING SIDE WALLS OF THE HUB AND CAP INCLUDING A CAM TRACK ON ONE OF THE WALLS AND A CAM FOLLOWER ON THE OTHER OF SAID WALLS WITH THE CAM TRACK SHAPED TO PULL THE TOP WALLS TOGETHER WHEN THE OPENINGS THROUGH THE TOP WALLS ARE IN REGISTER AND WHEN THEY ARE SHIFTED OUT OF OVERLAPPING RELATION WITH ONE ANOTHER, THE INTERMEDIATE PORTION OF THE CAM TRACK RISING PROGRESSIVELY AND THEN RUNNING DOWN AGAIN BETWEEN THE PORTIONS OF THE TRACK THAT PULL THE TOP WALLS TOGETHER, THE IMPROVEMENT WHICH COMPRISES A RESILIENT TOP WALL ON THE HUB HAVING AN ORIGINAL DOMED CONTOUR ACROSS THE CENTER PORTION OF THE TOP WALL WHEN SAID TOP WALL OF THE HUB IS NOT DISTORTED BY PRESSURE OF THE CAP, THE TOP WALL OF THE CAP BEING FLATTER THAN SAID CONTOUR, AND THE CAM TRACK AND FOLLOWER BEING CORRELATED WITH THE HEIGHTS OF THE HUB AND CAP TO HOLD THE CAP DOWN ON THE HUB WITH PRESSURE ON THE PORTION HAVING THE DOME-SHAPED CONTOUR AND TO HOLD THE TOP WALL OF THE HUB DISTORTED TO A FLATTER CONTOUR FOR ALL POSITIONS OF THE FOLLOWER ALONG THE CAM TRACK.