Abstract:
End cap apparatus (2) is received in the open end of an electrochemical cell casing (6) and is particularly adapted to be crimped thereto electrically separated from the casing by a gasket (4). The end cap apparatus incorporates current interrupt safety protection features including high rate overcharge protection through an over-temperature and/or low pressure switch (22, 12d-18, 18', 18", 118a), low rate overcharge and overdischarge protection through a low pressure switch (12d-18, 18', 18", 118a), extended short circuit protection through an over-temperature switch driven by l. sup. 2 r heating of internal components (20, 22, 16, 12, 12', 16', 16", 16'", 12. sup. v, 102, 122, 120), and pressure venting through a frangible portion (12e) of a diaphragm. The diaphragm can be integrally formed with a header (12, 12", 12'", 12. sup. iv) or can be a separate element (32, 82, 92, 108, 112, 112' 112", 112'").