Safety valve means for battery

Abstract

The present application discloses a safety valve means for battery comprising a lid plate having therein a valve hole, a thin plate overlapped on the lid plate for closing the valve hole, a terminal plate in the reverse dish shape overlapped on the thin plate and having a gas removing hole and a downwardly projected cutter means and forming a valve chamber together with the thin plate, a holding means for holding the periphery of the thin plate between the lid plate and the terminal plate by caulking the turning edge of the lid plate or the terminal plate and an annular resilient member disposed between the thin plate and the terminal plate and pressed by the terminal plate to press the thin plate. According to safety valve means for battery of the present invention, when the periphery of the thin plate is held by and between the lid plate and the terminal plate, holding pressure is adapted to be adsorbed by the annular resilient member, thereby to restrain the occurrence of bent of the thin plate which is otherwise resulted from the holding pressure above-mentioned. Therefore, the thin plate may be located at a predetermined position, whereby a highly reliable safety valve having high precision may be obtained. Furthermore, it is possible to maintain strong sticking of the lid plate to the thin plate. Moreover, in the valve chamber the annular resilient member is disposed between the thin plate and terminal plate in a compressed manner, thereby to prevent the electrolyte from leaking along the abutment surfaces of the annular resilient member and the terminal plate.