Patent attributes
A valve device includes a metal tube fixed to a tire rim of a vehicle. A valve is mounted in an end of an air passageway of the metal tube. A transmitter includes two switches respectively connected to two contact members fixed on the metal tube. A Bourdon tube includes a fixed end in communication with the air passageway of the metal tube and a movable end. When a tire pressure of the tire is in a normal range, the movable end of the Bourdon tube is between the contact members, leading to an open circuit. When the tire pressure is too high or too low, the movable end of the Bourdon tube is in contact with one of the contact members. One of the switches is turned on to activate the transmitter to send a signal for reminding the driver of the abnormal tire pressure.
