Tire pressure monitor and self check system therefore
First Claim
1. A tire pressure monitoring system comprising:
- radio transmitter means operative to monitor fluid pressure within a pneumatic tire and to generate a uniformly timed succession of tire inflation condition signals when said pressure falls within a predetermined operating range; and
means operative to receive and count said tire condition signals and to generate an operator alerting signal when less than a predetermined number of said tire condition signals are received during a preestablished increment of time.
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Accused Products
Abstract
Tire pressure monitors are incorporated in vehicles having penumatic tires (14) to continuously or periodically measure the air pressure within the tires and to alert the driver should the pressure in one of the tires fall below a predetermined value. A self-contained battery powered rf transmitter unit (10) is affixed within the drop center (22) of each wheel (12) and includes a pressure sensing switch (84). The battery is contained within a housing (20) mounted to the external surface of the wheel adjacent a fill valve (30) through which electrical wires (50) are routed to the transmitter (11). The transmitter emits a pulse every 33 seconds when the air pressure within the tire is above a prescribed value. A receiver (13), located in the passenger compartment of the vehicle, receives the signal(s) from the transmitters and counts the number of signals received over a given time period established by an internal pulse generator. If fewer than a predetermined number of pulses are received during any given time period, a fault condition is indicated and the driver is appropriately warned. The system also has self-check features wherein upon start-up of the associated vehicle, a warning light (320) and buzzer (322) are turned on until the first correct sequence of signals are received from the transmitters.
59 Citations
29 Claims
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1. A tire pressure monitoring system comprising:
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radio transmitter means operative to monitor fluid pressure within a pneumatic tire and to generate a uniformly timed succession of tire inflation condition signals when said pressure falls within a predetermined operating range; and means operative to receive and count said tire condition signals and to generate an operator alerting signal when less than a predetermined number of said tire condition signals are received during a preestablished increment of time. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A tire pressure monitoring system comprising:
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radio transmitter means operative to monitor fluid pressure within a pneumatic tire and to generate a uniformly timed succession of tire inflation condition signals when said pressure substantially equals a predetermined set point level; and means operative to receive and count said tire condition signals, establish a succession of timing pulses and generate an operator alerting signal when less than a predetermined number of said tire condition signals are received between two consecutive timing pulses. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A tire pressure monitoring system for use with a vehicle having a plurality of pneumatic tires and associated mating wheels, said system comprising:
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a plurality of radio transmitter means, one associated with each tire, each said transmitter means having a characteristic far field and operative to monitor fluid pressure within its associated tire and to generate a uniformly timed succession of tire inflation condition signals when said pressure falls within a predetermined operating range; and means operative to receive and cumulatively count said tire condition signals, establish a succession of timing pulses and generate an operator alerting signal when less than a predetermined number of said tire condition signals are received from each transmitter means between two consecutive timing pulses. - View Dependent Claims (21, 22, 23, 24)
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25. A tire pressure monitoring system for use with a vehicle having a plurality of pneumatic tires and associated mating wheels, said system comprising:
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a radio transmitter associated with each tire, each said transmitter having an associated far field and comprising;
a battery mounted for rotation with its associated wheel on the external surface thereof;
an RF transmitter mounted within the cavity defined by the associated tire and wheel for rotation therewith; and
a pressure switch operative to electrically interconnect said battery and transmitter when the fluid pressure within the associated tire substantially equals a predetermined set point level, said transmitter operating during said interconnection to generate a constant rate continuing succession of RF tire inflation condition signals; andan RF receiver disposed within the chassis of said vehicle and operative to receive and cumulatively count the tire condition signals received from all of said transmitters, establish a succession of internal timing pulses and generate an operator alerting signal when less than a predetermined number of said tire condition signals are received between two consecutive timing pulses. - View Dependent Claims (26, 27, 28, 29)
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Specification