Automatic shut-off safety device for gas stove

Claim 1

An automatic shut-off safety device for a gas stove that has a gas intake pipe connected to a manifold of a gas valve and a control knob for operating the gas valve, the safety device comprising a gas safety valve device located between the stove intake pipe and the stove gas valve manifold, the gas safety valve device comprising a housing base having an intake orifice connectable to the stove gas intake pipe and an exhaust orifice connectable to the stove gas valve manifold, an intake valve device comprising a function shaft having a first groove therein and being axially positionable by the stove control knob, a piston mounted on said function shaft and configured so as to be able to prevent the flow of gas between said housing intake and exhaust orifices when said function shaft is in a first axial position and to permit the gas flow when said function shaft is in a second axial position, a piston spring means for urging said piston in a first axial direction toward said first axial position, an electromagnet actuator mounted on said base and comprising an electromagnet coil, a magnetizable control rod extending in a radial direction with respect to said function shaft for engagement with said function shaft groove to prevent the withdrawal of said function shaft when so engaged, said control rod being positionable by said coil to disengage from said function shaft groove when said coil is energized, and a spring for resiliently urging said control rod in a position to engage said function shaft; and an electronic circuit comprising switch means controllable by the stove gas valve for supplying power to said circuit when the stove gas valve is operated, means for sensing the operation of the stove's gas fire when burning and providing a signal to actuate said electromagnetic actuator when said fire is out; and timing means to send a signal to actuate said electromagnetic actuator when a predetermined time has expired.