Abstract: A container with an integrally molded flap for covering an opening has a top that is deflected during cooling to provide a self-closing capability. This capability is provided by causing the top to cool to room temperature when the flaps are closed into a warped shape, either concave or convex in which the hinge formed integral with the flap and the rest of the cover is curved with the flaps closed. This could be done by careful design of the cap such that it warps this way during cooling naturally, or by pressing on the cap during cooling to “set” the cap and hinge in a curved shape. When the flap is opened, the arrangement of the flap and hinge reduce the chance that the flap will return to its as-molded position and jam.

Abstract: A plastic cap has one or more hinged flaps that cover openings in the cap, as well as a stepped sealing ring against which the top of a plastic bottle seals. The sealing ring is stepped, much like the rows of seats in a circular stadium. This stepped arrangement permits the cap to be used with many different bottle rim diameters and automatically corrects any ovality of the bottle rim by forcing it to flex into a more circular shape as it engages the steps of the stepped ring.

Abstract: A container with an integrally molded flap for covering an opening has a top that is deflected during cooling to provide a self-closing capability. This capability is provided by causing the top to cool to room temperature when the flaps are closed into a warped shape, either concave or convex in which the hinge formed integral with the flap and the rest of the cover is curved with the flaps closed. This could be done by careful design of the cap such that it warps this way during cooling naturally, or by pressing on the cap during cooling to “set” the cap and hinge in a curved shape. When the flap is opened, the arrangement of the flap and hinge reduce the chance that the flap will return to its as-molded position and jam.

Abstract: A plastic cap has one or more hinged flaps that cover openings in the cap, as well as a stepped sealing ring against which the top of a plastic bottle seals. The sealing ring is stepped, much like the rows of seats in a circular stadium. This stepped arrangement permits the cap to be used with many different bottle rim diameters and automatically corrects any ovality of the bottle rim by forcing it to flex into a more circular shape as it engages the steps of the stepped ring.