Hermetic seal closure

Claim 1

In a battery having a sealed case containing corrosive liquid, said case including an end wall with an aperture in it, the improvement comprising an axially out turned lip in said end wall, said lip having an outer side wall, an inner side wall and a free radial surface between said side walls, said inner side wall defining said aperture in said end wall; a washer of material substantially impervious and resistant to said corrosive liquid, said washer having a wall part with an under surface projecting radially beyond the perimeter of said lip and covering the free radial surface of said lip and positioning means for locating said washer with respect to said lip, said washer having an opening extending axially through it; a terminal cap of electrically conductive material having a cavity defined by an inner side wall and a central web spanning the boundry defined by said inner side wall, said inner side wall embracing said washer and projecting axially beyond said washer toward said case end wall but spaced axially from said case end wall, and bonding material bonded to and extending hermetically uninterruptedly through space between the said outer side wall of the said lip and the inner side wall of said terminal cap and between those said walls and said under surface of the said washer, whereby the said cap, washer and case are bonded to one another, and the case is hermetically sealed at said terminal cap.