Patent ID: 6083639
Filing Date: 2000-07-04
Classification: H01H,H01M,Y02E

Abstract:
In an electrochemical cell formed by a current interrupter assembly inserted into an open ended case for the cell, said cell further having a positive and a negative terminal and a pair of internal positive and negative electrodes, wherein said assembly has a housing, a chamber within said 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 assembly, wherein said assembly comprises therein a flexible electrically conductive member forming a portion of said electrical pathway within said assembly, said assembly further comprising a thermally responsive means for causing current to cease flowing through the cell when a predetermined temperature level is reached, wherein said thermally responsive means comprises a member of shape memory alloy having a curved surface, wherein said assembly further comprises physical means for causing movement of said flexible conductive member responsive to change in surface curvature of said shape memory member, wherein when the cell temperature reaches a predetermined temperature said shape memory member deflects altering the curvature on at least a portion of its surface causing movement of said flexible conductive member to break said electrical pathway between said end cap plate and said electrode thereby preventing current from flowing through the cell, wherein said cell further comprises a second current interrupter assembly, said second assembly comprising a housing, a chamber within the housing, and an end cap sealed from said housing, said second assembly having an electrically conductive pathway therethrough between said housing and said second assembly end cap, wherein said second assembly comprises a thermally responsive means within said chamber for preventing current from flowing through said electrical pathway within said assembly, said thermally responsive means comprising a shape memory alloy member activatable when the temperature within said assembly reaches a predetermined level causing a break in said electrically conductive pathway through said second assembly thereby causing the cell to cease operating.