Tire pressure detecting system for a vehicle

• US 6,252,498 B1
• Filed: 03/01/1999
• Issued: 06/26/2001
• Est. Priority Date: 03/03/1998
• Status: Expired due to Term

• Current Assignee: Charles Pashayan Jr
• Original Assignee: Charles Pashayan Jr
• Inventors: Pashayan, Charles Jr.
• Primary Examiner(s): Wu, Daniel J.
• Application Number:
  US09/259,304
• Time in Patent Office: 848 Days
• Field of Search: 340/442, 340/445, 340/447, 340/448, 340/539, 340/693.5, 731/465, 731/468
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/0494 Valve stem attachments positioned inside the tyre chamber

Abstract

A pressure detector system for vehicle tires, within each tire, a pressure detector/transducer for sending a signal reflecting a under-inflation condition in the tire, receiving antennas, placed adjacent to each tire, a visual display of the under-inflated tire, each tire valve having an enlarged pedestal, the pressure detector/transducer mounted within pedestal, a main air passage bore communicating with the air chamber and with the reference chamber, an outer valve core and a inner valve core having a sealing valve stem extending the length of the valve core, biased upwardly, the reference chamber having a deformable wall which moves outwardly when the air pressure within the air chamber falls below the air pressure in the reference chamber, the deformable wall having an electrical contact mounted on the exterior side, a rigid wall spaced apart from the deformable wall, having an electrical contact facing the electrical contact on the deformable wall, when the air pressure in the air chamber falls, the two electrical contacts coming into contact, thereby closing a switch of the pressure detector/transducer, a microprocessor activated when the switch of the pressure detector/transducer is closed, the microprocessor sending a brief signal to the transmitter, the display unit having four wire leads, one going to a position on the body of the vehicle adjacent each tire, each wire lead terminating in a receiving antennas, each receiving antennas picking up only a signal generated by the pressure detector/transducer adjacent it, and sending the signal to the display unit.

Claims

1. In a pressure detector system for a tires on vehicle, each tire having a tire valve, the combination comprising:

a) a pressure detector/transducer, within each tire, for sending a signal reflecting a under-inflation condition in the tire;

b) receiving antennas, on the frame of the vehicle, placed adjacent to each tire, to receive the signal from the tire to which it is adjacent;

c) a visual display of the tire which has an under-inflation condition, on the dashboard of the vehicle;

d) each tire valve having a pedestal, a stem, and a central bore and an outer valve core and an inner valve core;

e) each pedestal being an enlarged pedestal, each having a pressure detector/transducer being mounted within the enlarged pedestal;

f) the central bore leading to a main air passage bore which communicates with the air chamber formed by the tire and the threaded metal sheath, and also communicating with a secondary air passage bore, which communicates with a post-sealed reference chamber;

g) both the outer valve core and the inner valve core having a apertured bridge at the top and a rim at the bottom, and further having a sealing valve stem extending the length of the valve core, each sealing valve stem terminating in a valve seat, each sealing valve stem further being biased upwardly away from the air chamber of the tire;

h) the sealing valve stem of the outer valve core being depressed by the hose of an air pump, and when so depressed, allowing air from the pump to enter the air chamber of the tire;

i) the sealing valve stem, when depressed, also depressing the sealing valve stem of the inner valve core, and the sealing valve stem of the inner valve core, when depressed, allowing air to enter the reference chamber from the air pump;

j) the sealing valve stem of the outer valve core, when not depressed but biased upwardly sealing the air inside the air chamber of the tire, and the sealing valve stem of the inner valve core, when not depressed but biased upwardly sealing the air inside the reference chamber;

k) the reference chamber having a deformable wall which moves outwardly when the air pressure within the air chamber formed by the tire and the metal wheel falls below the air pressure in the post-sealed reference chamber;

l) the deformable wall of the reference chamber having an electrical contact mounted on the exterior side, and in the center of the deformable wall;

m) a rigid wall of the enlarged pedestal spaced apart from the deformable wall, having an electrical contact facing the electrical contact on the deformable wall;

n) when the air pressure in the air chamber of the tire falls below the air pressure in the reference chamber, the electrical contact on the deformable wall touching the electrical contact on the rigid wall, thereby closing a switch in the electrical circuit of the pressure detector/transducer;

o) the electrical circuit powered by a long-life battery;

p) an inertial switch which is normally biased open and closes under centrifugal force when the inertial switch is rotated by the rotation of the tire;

q) a microprocessor in the electrical circuit which is activated when the inertial switch and the switch of the pressure detector/transducer are both closed;

r) the microprocessor, when activated, sending a brief signal to the transmitter, and then going into a sleep mode for a selected time when no further signal goes to the transmitter;

s) the microprocessor, after the selected time has expired, and if both the inertial switch and the switch of the pressure detector/transducer are still closed, again sending a brief signal to the transmitter, and then going into a sleep mode for a selected time when no further signal goes to the transmitter; and

,

t) the display unit on the dashboard of the vehicle having four wire leads, one going to a position on the body of the vehicle adjacent each tire, each wire lead terminating in one of said receiving antennas, each receiving antennas picking up only a signal generated by the pressure detector/transducer adjacent it, and sending the signal to the display unit;

WHEREBY, the pressure detector/transducer of each tire isolates its long-life battery before installation of the tire valve containing the pressure detector/transducer, further isolates the long-life battery during the time the vehicle is parked, and lastly isolates the long-life battery during the period that adequate pressure is maintained in the air chamber of the tire, and the pressure detector/transducer transmits an under-inflation signal, which is picked up by a receiving antennas associated with that tire, and the signal is sent to the dashboard display unit, which displays the tire which is under-inflated.

2. The combination of claim 1 further including a pre-sealed reference chamber replacing the post-sealed reference chamber.

3. The combination of claim 1 further including four directional antennas within the display unit replacing the four wire leads and the receiving antennas.

4. The combination of claim 1 further including the microprocessor detecting a low voltage condition in the long-life battery and causing the transmitter to send the low voltage signal to the display unit.

5. The combination of claim 1 further including the microprocessor detecting a small low pressure condition and a severe low pressure condition and causing the transmitter to send the either the small low pressure signal or the severe low pressure signal to the display unit.