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AssigneesTexas Instruments Incorporated, Duracell Inc.
InventorsViet H. Vu, Lucien P. Fontaine, William T. McHugh, Robert J. Pinault, Jane A. Blasi, Steven K. Sullivan, Geoffrey J. Paquin, Stephen S. Johnson, Gary K. Maus, Lance E. Cambra
Estimating the term…
A current interrupt mechanism for electrochemical cells is disclosed. A thermally activated current interrupt mechanism is integrated into an end cap assembly for an electrochemical cell. The thermally responsive mechanism preferably includes a free floating bimetallic disk which deforms when exposed to elevated temperature causing a break in an electrical pathway within the end cap assembly. This prevents current from flowing through the cell and effectively shuts down an operating cell. Alternatively, the thermally responsive mechanism may include a meltable mass of material which melts when exposed to elevated temperature to break an electrical pathway within the end cap assembly. The end cap assembly may also include integrated therein a pressure responsive current interrupt mechanism. If the internal gas pressure within an operating cell exceeds a predetermined value, the pressure responsive mechanism activates to sever an electrical pathway within the end cap assembly to prevent current from passing through the cell. The pressure responsive mechanism may include a diaphragm which ruptures when there is extreme gas pressure buildup. Gas is allowed to escape from the cell interior to the external environment through a series of vent apertures within the end cap assembly.
An end cap assembly for application to an electrochemical cell having a positive and a negative terminal and a pair of internal electrodes (anode and cathode), said end cap assembly comprising a housing and an end cap plate, said plate functional as a cell terminal, said end cap assembly having an electrically conductive pathway therethrough permitting the end cap plate to be electrically connected to a cell electrode when said end cap assembly is applied to a cell, said end cap assembly further comprising a) thermally responsive means for preventing current from flowing through said electrical pathway, wherein said thermally responsive means is activatable when the temperature within said end cap assembly reaches a predetermined level causing a break in said electrical pathway and b) pressure responsive means for preventing current from flowing through said electrical pathway, wherein said pressure responsive means is activatable when gas pressure applied to at least a portion of said electrical pathway reaches a predetermined level causing a break therein.
In an electrochemical cell of the type formed by an end cap assembly inserted into an open ended cylindrical case for the cell, said cell further having a positive and a negative terminal and a pair of internal electrodes (anode and cathode), wherein said end cap assembly has a housing and an exposed end cap plate, said end cap plate functional as a cell terminal, the improvement comprising said end cap plate being electrically connected to one of said electrodes through an electrically conductive pathway within said end cap assembly, said end cap assembly further comprising a) thermally responsive means for preventing current from flowing through the cell, wherein said thermally responsive means is activatable when the temperature within the cell reaches a predetermined level causing a break in said electrical pathway between said end cap plate and said electrode thereby preventing current from flowing through the cell and b) pressure responsive means for causing a break in said electrical pathway between said end cap plate and said electrode when the internal gas pressure within the cell reaches a predetermined level thereby preventing current from-flowing through the cell.
A current interrupter for providing protection to a device being supplied with electrical current comprising a housing member having an electrically conductive pathway therethrough in electrical connection with said device, a thermally responsive means contained within said housing member for preventing current from flowing through said electrical pathway, wherein said thermally responsive means is activated when the temperature within said housing reaches a predetermined level causing a break in said electrical pathway, and a pressure responsive means contained within said housing separate from said thermally responsive means for preventing current from flowing through said electrical pathway, wherein said pressure responsive means is activated when fluid pressure reaches a predetermined level causing a break in said electrical pathway.
Dependencies are inferred from the claim text.