Patent ID: 6224640
Filing Date: 2001-05-01
Classification: H01M,Y10T

Abstract:
A method for making a galvanic dry cell having a pressure vent closure with a safety feature that prevents premature venting of cell which comprises the steps:(a) placing within a conductive container a separator, an anode, a cathode, and an electrolyte;(b) preparing a gasket comprising a base member having an upstanding peripheral wall and a centrally located upstanding wall forming a hub defining an opening, said base member having a first segment extending radially inwardly from the peripheral upstanding wall to an inclined second segment, facing the open end of the container, which terminates at a third segment disposed substantially parallel to the upstanding wall of the hub, said third segment extending to a fourth segment disposed substantially perpendicular to the upstanding wall of the hub and terminating at the upstanding wall of the hub, and wherein the inclined second segment and third segment form an angle of between 10.degree. to 90.degree.;(c) assembling a cover member on the gasket and having the cover-gasket assembly and a current collector placed into the container; and(d) reducing the top edge portion of the container over the peripheral wall of the gasket onto the cover member to provide a sealed cell.