Energy storage device with multi-function protective seal

Claim 1

A sealed electric cell comprising a cylindrical container with an open end, anode and cathode elements in the container, the anode and cathode elements separated from each other, an organic electrolyte in the container, a cover comprising a disc with a peripheral flange in the open end of the container, sealing means between the container and the cover to seal the container, the sealing means including an elastomeric element molded on the flange of said cover and said elastomeric element being prone to attack by the organic electrolyte in the container which attack harmfully affects the sealing characteristic of the elastomeric element, and a compressible plastic element outwardly adjacent to the elastomeric element and fitted against the side wall of the container at about the open end of the container, the plastic of the plastic element being prone to cold-flow movement when subjected to pressure, which flow harmfully affects the sealing characteristic of the plastic element, the plastic element having formed therein a cavity to seat and substantially enfold the elastomeric element thereby isolating said elastomeric element from the organic electrolyte contained within the container and from the inner wall of said container, the portion of the container adjacent the open end thereof causing pressure to be exerted against the plastic element and the elastomeric element resulting in cold-flow movement by the plastic of the plastic element and outwardly directed pressure by the elastomeric element counter to the cold-flow movement of plastic in the plastic element to maintain said compressible plastic element in its position fitted against the side wall of the container to thereby prevent electrolyte flow between said compressible plastic element and said wall.