Remote tire pressure monitoring system employing coded tire identification and radio frequency transmission and enabling recalibration upon tire rotation or replacement
First Claim
1. In a vehicle having a plurality of wheels, each of said wheels having at least one tire mounted thereon, a tire pressure monitoring system including a display interface inside said vehicle for providing an indication of abnormal tire pressure, said system further comprising, for each of said tires, sensing transmitting means which comprise;
- means for sensing pressure;
means for producing signals indicative of temperature-compensated pressure of a respective one of said tires;
means for encoding said signals so as to provide encoded signals, identifying said each of said tires, and location thereof on said vehicle uniquely; and
means for transmitting said encoded signals;
said system further comprising;
means for receiving said encoded signals;
means for decoding said encoded signals, and providing display signals accordingly; and
means for providing a display indicative of low pressure and location of said each of said tires in accordance with said display signals;
characterized in that the sensing/transmitting means are mounted internally of the tire, and in that the system comprises means for recalibrating said system such that, in the event of rotation of tires on said vehicle, said system reacquires information on said location of each of said tires, said means for recalibrating said system comprising a magnetically-activated switch, responsive to a magnetic field in a vicinity thereof, wherein activation of said switch causes transmission of a location of a respective one of said tires on said vehicle.
12 Assignments
0 Petitions
Accused Products
Abstract
A system for indicating low tire pressure in vehicles, in which each vehicle wheel has a transmitter (100) with a unique code. A central receiver (200) in the vehicle is taught, at manufacture, to recognize the codes for the respective transmitters (100) for the vehicle, and also a common transmitter code, in the event one of the transmitters (102) needs to be replaced. During vehicle operation and maintenance, when the tires are rotated, the system can be recalibrated to relearn the locations of the transmitters. The transmitters (100) employ surface acoustic wave (SAW) devices (110). An application specific integrated circuit (ASIC) encoder (130) in each transmitter (100) is programmed at manufacture, in accordance with its unique code, to send its information at different intervals, to avoid clash between two or more transmitters (100) on the vehicle. The transmitters (100) are powered by long-life batteries.
244 Citations
53 Claims
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1. In a vehicle having a plurality of wheels, each of said wheels having at least one tire mounted thereon, a tire pressure monitoring system including a display interface inside said vehicle for providing an indication of abnormal tire pressure, said system further comprising, for each of said tires, sensing transmitting means which comprise;
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means for sensing pressure; means for producing signals indicative of temperature-compensated pressure of a respective one of said tires; means for encoding said signals so as to provide encoded signals, identifying said each of said tires, and location thereof on said vehicle uniquely; and means for transmitting said encoded signals; said system further comprising; means for receiving said encoded signals; means for decoding said encoded signals, and providing display signals accordingly; and means for providing a display indicative of low pressure and location of said each of said tires in accordance with said display signals; characterized in that the sensing/transmitting means are mounted internally of the tire, and in that the system comprises means for recalibrating said system such that, in the event of rotation of tires on said vehicle, said system reacquires information on said location of each of said tires, said means for recalibrating said system comprising a magnetically-activated switch, responsive to a magnetic field in a vicinity thereof, wherein activation of said switch causes transmission of a location of a respective one of said tires on said vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A tire pressure sending unit comprising:
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a pressure sensor; a signal processor, responsive to the pressure sensor, and operative to produce a tire pressure signal indicative of a tire pressure; a transmitter, responsive to the signal processor and operative to generate a radio signal indicative of said tire pressure; and a magnetically-activated switch, responsive to a magnetic field in a vicinity thereof, and coupled to said transmitter to activate said transmitter; wherein said pressure sensor, said signal processor, said transmitter, and said magnetically activated switch are mounted internally of a tire; and wherein, for a plurality of tire pressure sending units, sequential activation of said magnetically-activated switch on each respective one of said tire pressure sending units in a predetermined order in response to said magnetic field causes said transmitter to transmit a code which will indicate a location of said tire on a vehicle. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. In a vehicle having a plurality of wheels, each of said wheels having at least one tire mounted thereon a tire pressure monitoring system including a display interface inside said vehicle for providing am indication of abnormal tire pressure, said system further comprising, for each of said tires, sensing/transmitting means which comprise:
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means for sensing pressure; means for producing signals indicative of temperature-compensated pressure of a respective one of said tires; means for encoding said signals so as to provide encoded signals, identifying said each of said tires, and location thereof on said vehicle uniquely; means for transmitting said encoded signals; and means for recalibrating said system such that, in the event of rotation of tires on said vehicle, said system reacquires information on said location of each of said tires, said means for recalibrating said system comprising a magnetically-activated switch, responsive to a magnetic field in a vicinity thereof, wherein activation of said switch causes transmission of a location of a respective one of said tires on said vehicle; wherein the sensing/transmitting means are mounted internally of the tire. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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Specification