Container and closure therefor

Claim 1

AN IMPROVED THREE PIECE CLOSURE FOR USE IN PACKAGING CARBONATED BEVERAGES, BEVERAGES UNDER PRESSURE, AND BEER COMPRISING: AN ALUMINUM SHELL STRUCTURE HAVING A TOP WALL AND A CYLINDRICAL SIDE WALL DEPENDING DOWNWARDLY THEREFROM AND CONNECTED THERETO BY A CURVED EDGE PORTION, SAID CYLINDRICAL SIDE WALL HAVING A LOWER FREE EDGE PORTION CAPABLE OF BEING ROLLED ABOUT A BEAD ON A CONTAINER MOUTH, SAID TOP WALL HAVING AN ARCUATE INCISION THERETHROUGH LARGER THAN A SEMICIRCLE AND A PAIR OF PARALLEL INCISIONS THERETHROUGH EXTENDING TOWARD AND TERMINATING SHORT OF THE SIDE WALL, SAID PARALLEL INCISIONS PROVIDING EXTENSIONS OF THE ENDS OF SAID ARCUATE INCISION AND TOGETHER WITH SAID ARCUATE INCISION DEFINING A PULL TAB LYING NORMALLY IN THE PLANE OF AND FORMING A PART OF THE TOP WALL; A METALLIC DISC INSERTED WITHIN SAID SHELL AND HAVING A CURVED PERIPHERAL EDGE WITH A RADIUS OF CURVATURE GREATER THAN THE RADIUS OF CURVATURE OF THE CURVED EDGE PORTION OF SAID SHELL STRUCTURE, SAID METALLIC DISC HAVING A DIAMETER SUBSTANTIALLY EQUAL TO THE INSIDE DIAMETER OF THE CYLINDRICAL SIDE WALL; AND A DISC SHAPED PLASTISOL SEALING LINER INSERTED WITHIN SAID SHELL STRUCTURE AND COVERING THE METALLIC DISC, SAID LINER HAVING A CURVED PERIPHERAL EDGE PORTION AND A CIRCULAR BOSS SPACED INWARDLY THEREFROM AND EXTENDING IN THE SAME DIRECTION FOR MAKING SEALING ENGAGEMENT WITH THE LIP OF A CONTAINER.