Rechargeable battery power source with gas-pressure switch

Claim 1

A rechargeable battery power source comprising a battery of a type adapted to produce an increased gaseous pressure when the battery is fully charged; said battery including a cylindrical jacket having top and bottom walls; control means adapted to be connected to a battery charging device for controlling the operation of said device to prevent overcharging of said battery; sealing means for sealingly connecting said control means to said top wall of said battery jacket; said control means comprising a housing having a movable pressure-responsive flexible and resilient insulating diaphragm therein, a switch operable between a closed position for energizing the charging device and an open position for deenergizing the charging device, connecting means for connecting said switch with said diaphragm for moving said switch to the open position in response to movement of said diaphragm in a first direction, and a passage extending through said battery jacket and said housing connecting the interior of said battery with said diaphragm so that increased gaseous pressure within said jacket moves said diaphragm in said first direction to cause deenergization of the charging device; said diaphragm normally residing in a second position corresponding to the closed position of said switch, and being adapted to be moved in said first direction to a first position by said increased gaseous pressure to cause said switch to move to the open position, said diaphragm including a cup-shaped member connected with said switch, a seat in said housing, a spring in said housing abutting said seat at one end and said cup-shaped member at the other end to normally bias said diaphragm to the second position whereby said switch is moved to the closed position, said diaphragm further including an outer peripheral portion, said housing further comprising a support member having a support wall for supporting said outer peripheral portion of said diaphragm, said passage comprising a vent opening in said top wall of said battery and a bore in said support member to provide for the communication of said increased gaseous pressure with said diaphragm, said sealing means comprising a disc threadedly engaged with said support member, and a compressible O-ring compressed between said disc and said battery top wall and surrounding said vent and said bore.