Abstract: A movable operating member 5 is swingably borne by the base 1, and its distal end is moved upward by allowing its proximal end 5b to be pressed downward. The movable contact 3 is separated from the stationary contact 2 upward by moving the distal end of the movable operating member 5 upward. The proximal end of the movable operating member 5 is pressed downward by a guide pin 6 in response to a reverse action of a bimetal 7. When a reset shaft 8 is pushed upward, the movable contact 3 is pressed upward, and the guide pin 6 is pressed upward so that the bimetal 7 can be returned to an initial state.

Abstract: By using a rivet which serves also as a terminal member, and a sealing member which serves also as an insulating member, the terminal member and the insulating member can be omitted, thereby forming the lid of the secondary battery from only three parts, i.e. the body, rivet and sealing member. The sealing member includes a cylindrical portion and a flange portion which are separate members. The cylindrical portion is formed by cutting a fluororesin tube. The flange portion is formed by punching a polypropylene resin sheet. Thus, the number of parts can be reduced to four, so that it is possible to reduce the parts cost and manufacturing cost as compared to conventional lids.

Abstract: An extremely safe non-aqueous electrolyte secondary cell free of explosions and which can promptly release the internal pressure in case of rise in the internal pressure. The non-aqueous electrolyte secondary cell has in its opening a cleavage valve obtained on bonding a metal foil to the opening. In case of rise in the internal pressure, the cleavage valve is cleft to release the pressure. In this cell, a value K corresponding to the internal volume in the cell in cm3 divided by the area of the opening in cm2 is set so that 40≦K≦350. By selecting the value K to a suitable value, the cleavage valve is in operation when the internal pressure reaches a predetermined value to release the pressure. The metal foil is produced by, for example, a electro-forming method or a cladding method. Preferably, a fluorine-based water-proofing agent is coated on the foil surface.

Abstract: A safety device for a battery which can prevent explosion of the battery due to overcharging or shortcircuiting. In the safety device, a current flows through generating unit, lead, terminal of a conductor case, PTC plate, annular terminal, contact to electrode lid. A disk spring, generally called a bimetal, is adapted to bend backward when it is heated to a predetermined temperature. If the generating unit heats up by producing gas due to overcharging or shortcircuiting, the disk spring is heated. When heated to a predetermined temperature, it will bend backward, while pushing up a moving piece, which in turn pushing up the contact, thus separating the contact from the annular terminal. The current-flow path in the battery is thus cut, so that the generating unit will not heat up any further.

Abstract: A safety device for use in a secondary battery having a battery case formed with a hole open to outside of the battery case, and a generating unit airtightly housed in the battery case. The safety device includes a disk spring mounted on the battery case to close the hole and having one side thereof convexed toward the inside of the battery case. A switch is provided on the backside of the disk spring. It is adapted to change over under a stress applied from the disk spring when the disk spring bends backward so that the other side thereof is convexed toward the outside of the battery case. The switch is provided in a current flow path of the secondary battery.