US Patent 6874647 Plastic closure, closure and container package, and method of manufacture

A plastic closure includes a plastic closure shell having a base wall with a central opening and a skirt with at least one internal thread or bead for securing the closure to a container finish. A plastic disk is retained within the shell parallel to but spaced from the base wall. The disk includes a plurality of axially extending spacer elements around the disk to engage the undersurface of the base wall and space the disk from the base wall of the shell, and angularly spaced fingers extending from the disk through the central opening of the base wall to retain the disk within the shell. A resilient liner is disposed on an underside of the disk for sealing engagement with the container finish.