Patent ID: 7327244

Claim:
A valve device with pressure alarm for a vehicle, the valve device comprising: a metal tube comprising an air passageway, a valve being mounted in an end of the air passageway, the metal tube being adapted to be fixed to a rim of a tire of a vehicle, with another end of the air passageway in communication with an air inlet of the rim; a ring projecting outward from an outer circumference of the metal tube; an insulating casing enclosing the ring; a shield coupled to the casing by a cap; a conductive first contact member fixed on the metal tube; a conductive second contact member fixed on the metal tube; a transmitter comprising a first switch electrically connected to the first contact member and a second switch electrically connected to the second contact member; a power source comprising a positive pole electrically connected to the transmitter and a negative pole electrically connected by a conductive member to the metal tube; a conductive Bourdon tube mounted to the metal tube, the Bourdon tube comprising a fixed end in communication with the air passageway of the metal tube and a movable end; wherein when a tire pressure of the tire is in a normal range, the movable end of the Bourdon tube is between the first contact member and the second contact member, leading to an open circuit; wherein when the tire pressure of the tire is too high, the movable end of the Bourdon tube is in contact with the first contact member, the first switch is turned on to activate the transmitter to send a signal; and wherein when the tire pressure of the tire is too low, the movable end of the Bourdon tube is in contact with the second contact member, the second switch is turned on to activate the transmitter to send a signal.