Abstract: An automatic valve motor for shutting off utilities, such as gas, in the event of an earthquake. The valve motor is self-contained and can be mounted by unskilled persons on a conventional residential gas installation adjacent the main valve without modifying the valve or interfering with the operation of the gas line. An omnidirectionally movable pendulum acting on a pivotal latch is used to release for rotation a wheel whose hub has a key slot which engages the actuator bar of the gas valve. The wheel is driven by a linear spring arrangement which exerts a generally tangential turning force on the wheel for maximum leverage throughout an arc of rotation of about 90.degree..