Background of the Invention

The invention relates to closures for containers such as metal or plastic or composite containers, or cans, used for packaging various and sundry products including food, non-food, beverages and other conventional commodities. Summary of the Invention In one preferred form of the invention, an easy-open end closure, or lid, is provided for closing the end of a container through the use of existing double seam machinery. A metal ring is double seamed to a container body using known equipment, the metal ring having a central opening for passing product into and out of the container. The central opening is to be closed following introduction of product, closure being accomplished through the use of an end panel which may be in the form of foil, such as aluminum and the like, or a plastic end panel which may be of a single layer or laminated, or a metal end panel, all of which have sufficient area for closing the central opening. The various types of end panels may be suitably adhered to the metal ring through the use of adhesives or, in one form of the invention, through the use of a molded plastic ring for securing one of the types of end panels to the container ring. In one preferred form of the invention, the metal ring has its inner marginal edge reversely turned and folded back upon the ring to present a treated surface for promoting adhesion between the metal ring and at least a portion of the underside area of the end panel. It is possible in this form of the invention to allow the outermost marginal portion of the end panel to extend outwardly of the folded back and treated portion of the ring for presenting a gripping edge portion to aid in peeling the end panel from the metal ring. In a still further form of the invention it is desirable to bend or tilt the inner portion of the metal ring upwardly between 3 to 87 degrees, preferably about 30 degrees, for precluding internally initiated peeling of the bonded interface between the metal ring and the central end panel because such geometry will place the tensile load on the end panel, such as during a retort operation, in shear rather than in peel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, sectional view of a container body having a ring member double-seamed thereto and having a molded ring and end panel secured thereto for closing the container. FIG. 2 is a fragmentary, sectional view of the container body of FIG. 1 showing a cross-section through a pull tab integrally formed as part of the molded ring. FIG. 3 is a fragmentary, sectional view of a container body having a metal ring double-seamed thereto, the ring having a radially inward flange portion thereof including an upwardly and outwardly reversely folded portion and having a marginal portion of an end panel adhered thereto, and the innermost portion of the ring extending upwardly at an angle. FIG. 4 is a view similar to FIG. 3 wherein the inner ring portion has its raw edge buried and shows the end panel as slightly overlapping the reversely folded portion of the flange. DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a fragmentary section of a container body, generally indicated by the numeral 10, including a side wall 12 of the usually cylindrical or oval container 10. A conventional double seam 14 is used to secure a metal ring or flange 16 to the side wall 12, the flange 16 having an open-center portion terminating in a radially inward portion thereof including an upwardly and outwardly reversely folded portion 18 and having a marginal portion of an end panel 20 adhered thereto. As is shown in FIG. 1, the end panel 20 has an outer peripheral edge 21 of a marginal portion 22 enclosed within a molded ring member 24, and the folded portion 18 of the flange 16 has a raw edge 19 buried within the ring member 24. In one form of the invention, the end panel 20 is to be severed from ring 16 along peripheral edge 21, thereby producing a raw edge 19. In this form of the invention, ring 16 and end panel 20 are made of the same metal, and the end panel 20 is saved from becoming wasted. Ring member 24 is shown in FIG. 2 as including an integral pull tab 26 for assisting in the removal of end panel 20 from the folded portion 18 of the flange 16. FIG. 3 is similar to FIGS. 1 and 2 differing therefrom by- having an innermost portion 28 of flange 16 bent upwardly at an angle that can vary from 3 degrees to about 87 degrees so that an end panel 30 that is bonded to portion 28 will resist separation that would otherwise be caused by internal pressure from retorting, and the like. If the end panel 30 is bowed upwardly during retorting, the portion thereof bonded to the folded portion 28 will be placed in shear rather than in peel and thereby avoid undesired opening of the container 10. FIG. 4 is similar to the showing in FIG. 3 but shows the folded portion 28 as having an additional fold for burying the raw edge 32. It is also to be noted that an outermost marginal edge portion 34 of end panel 30 extends out past folded portion 28 and is not adhered thereto or to the flange 16. This feature provides a gripping portion for initiating peeling of the end panel 30 for gaining access to the product within the container 10. It is to be understood that various features are changeable without departing from the scope of the invention. The end panels 20 and 30 may be formed of foil, such as aluminum and the like, or may be of steel or other metal, or a composite or laminated plastic which can contain oxygen barrier layers and also be formed of, for example/ polypropylene to aid in being heat bonded to the metal flange 16. It is to be understood that the bonding can include a maliated polypropylene coating applied to the portion 28 of flange 16 to provide a bond that will fail cohesively during opening of and removal of the end panel from the container 10. Another example of possible variations is that oxygen scavenging material 40 can be applied to the underside of the end panels to reduce oxygen content in the closed container 10 and also to reduce oxygen ingress thereby extending the shelf life for the container and its contents. The end panels may be formed of extruded, or co-extruded, or laminated nylon with barrier coatings of SiO2 or Al2O3 thus allowing a heated sealing tool to bond the end panel to the folded portion 28 or ring 16. Various other modifications may be obvious to those skilled in the container art without departing from the spirit and scope of the invention, as disclosed above.