Abstract: The invention contemplates the shutting down of such fields of endeavor which otherwise would likely be injurious to life or property on occasions of earthquakes and the like, and comprises a system wherein disuse in the said fields of endeavor occurs automatically upon the major vibration of one or more essential parts or components of a device causing the said components or parts to be disengaged from the remainder of the system and the shut-off operation thereof. As will appear from the disclosure hereinafter set forth in this application of a light duty and a heavy duty embodiment of the device, the systems set forth rely upon a spring loaded wheel which has a specially shaped under-section so to engage a valve or the like in the supply line of the field of endeavor, and being a part of a system which is very sensitive to vibration, and through slippage the parts of the system are released and the valve is shut off. The system, it is clear, is applicable to numerous fields of use.