V-shaped gasket for galvanic cells

DETAILED DESCRIPTION The invention relates to an electrochemical cell comprising an anode electrode, a cathode electrode and an electrolyte contained in a container, said container having an open end and a closed end and wherein the open end of the container is sealed with a V-shaped gasket, said 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 upstanding peripheral 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 incline second segment and third segment form an angle of between 10.
degree.
to 90.
degree.
which defines the V-shaped portion of the gasket.
Preferably, at least a portion of the area in the base adjacent to the upstanding wall of the hub, preferably between 10.
degree.
to 360.
degree.
, has a thickness less than the thickness of the remaining fourth segment.
The gasket is provided with a compressive preload force at the reduced area on the base that will delay the onset of tensile stresses at the reduced area caused by any pressure buildup of gases produced in the cell, so that premature venting of the cell can be prevented.
The angle defined by the inclined second segment and the third segment is preferably between 30.
degree.
to 60.
degree.
and more preferably between 40.
degree.
to 50.
degree.
.
The gasket of this invention is constructed with several segments that cooperate during the sealing of the cell to place a compressive preload in a segment of the gasket that will delay the onset of tensile stresses in the vent area of the gasket and therefore prevent premature venting of the cell.
It has been found that using the novel gasket of this invention, the onset of tensile stresses can be delayed, if desired, up to about 70 psi internal pressure for C-size cells