Patent ID: 6120931
Filing Date: 2000-09-19
Classification: H01M,Y02E

Abstract:
A lead-acid accumulator comprising a container having at least one hole in an upper surface thereof, a tubular plug disposed in said hole and having a vent duct for discharging gasses developed in said accumulator to the atmosphere, a filtering element disposed in an annular bearing seat formed in an outer end portion of the tubular plug and an open pressure element secured to an internal wall of the tubular plug in engagement with said filtering element to hold said filtering element in position on said seat, wherein said filtering element is comprised of a porous substrate covered by a polytetra-fluoroethylene membrane and wherein said pressure element is provided with a plurality of vent holes for discharging gasses in normal operative conditions and at least one peripheral notch and at least one blind notch in a surface of the pressure element disposed in engagement with said filtering element which allows displacement of said filtering element adjacent said blind notch to permit gasses to escape through said blind notch and said peripheral notch under excessive pressure conditions in said accumulator.