Flat tire indicating device

摘要

An air-operated switch device is provided in a housing having an internally threaded part threadedly coupled to the valve stem of a tire. The switch device is in operative proximity with the valve stem and has an open condition when the tire pressure is above a predetermined air pressure and a closed condition when the tire pressure is reduced to one below a predetermined air pressure. The switch device has a movable electrical contact device controlled in position by the pressure of air in the tire. A circuit electrically connects a battery, an audible alarm device and a radio transmitter in the housing with the switch device in circuit whereby when the switch device is moved to its closed condition the battery actuates the alarm device and the transmitter. A radio receiver receives a signal transmitted by the transmitter thereby indicating that the tire is flat.