US Patent 7152615 Earthquake actuated horizontal valve with micro switch

An earthquake actuated device includes a flapper-valve adapted to block a gas flow and a micro switch for closing or opening a circuit. A seismic sensor responds to accelerations characteristic of an earthquake. The sensor cooperates with a magnet in a flapper arm to hold the flapper-valve open. When the sensor experiences sufficient motion, the flapper arm is released and the flapper-valve falls onto a seat, thereby closing and blocking the gas flow. The closing of the flapper-valve is further coupled into an actuation of the micro switch, thereby opening or closing the circuit.