US Patent 7442467 Sealed battery

A sealed battery in which an opening of a battery case is sealed with any one of a sealing member via an insulating gasket, and a sealing unit in which a sealing member is crimped inside a filter via an inner gasket. The sealed battery includes a sheet-like gasket placed upon the sealing member so that the battery case is tightly sealed with any one of a combination of the insulating gasket and the sheet-like gasket, and a combination of the insulating gasket, the sheet-like gasket, and the inner gasket, by crimping the opening of the battery case inwards. This secures sufficient space for the compressing while the crimp-sealing is achieved.