Air pressure alert system

• US 4,970,491 A
• Filed: 04/03/1989
• Issued: 11/13/1990
• Est. Priority Date: 04/03/1989
• Status: Expired due to Fees

• Current Assignee: Tyre TRAC Systems Incorporated
• Original Assignee: Trams Enterprises, Inc.
• Inventors: Berger, Robert L., Saint, August
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): TUMM, BRIAN
• Application Number:
  US07/331,875
• Time in Patent Office: 589 Days
• Field of Search: 340/447, 340/442, 340/431, 340/438, 340/457, 340/459, 73/146.5, 73/146.8
• US Class Current: 340/447
• CPC Class Codes: B60C 23/007 having multiple wheels arranged side by side
• CPC Class Codes: B60C 23/0401 characterised by the type of alarm
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A convenient, reliable, and economical low tire pressure alert system (10) for a vehicle provides a graphic display (14) of low tire conditions to a vehicle occupant. The preferred alert system includes a transmitter (12) coupled with a valve stem of each vehicle tire for sensing a respective low pressure condition of the tire and for producing and transmitting digitally encoded amplitude modulated wireless signals in response. The preferred alert system (10) also includes a plurality of indicators (16) as part of a graphic display (14) representative of the vehicle tires, and a receiver (18) coupled with the indicators (16) for selective actuation thereof in response to reception of the low tire pressure signals.

Claims

1. A tire pressure alert system for alerting the occupant of a vehicle to respective low tire pressure conditions of the vehicle'"'"'s pneumatic tires, the vehicle'"'"'s having a passenger compartment, the tires having respective valve stems and presenting respective rotational axes, the vehicle being included in a fleet of vehicles, said alert system comprising:

a plurality of transmitter assemblies for coupling with a plurality of associated vehicle tires, each transmitter assembly including;

pneumatic pressure sensing means operable for sensing pneumatic tire pressure and for producing a low pressure signal representative of a low tire pressure condition,

coupling means for operably coupling said pressure sensing means with and adjacent to the valve stem of an associated tire and offset from the rotational axis thereof,

battery powered transmitter means including means for operably coupling with said pressure sensing means for receiving said pressure signal and responsive thereto for discontinuous, periodic transmission independent of vehicle operation of digital encoded, amplitude modulated, wireless signals representative of said low tire pressure condition of the associated tire and representative of the identity of the fleet to which the vehicle belongs,

mounting means for mounting said transmitter means in substantially co-axial alignment with the rotational axis of the associated tire;

local indicator means actuatable in response to said low tire pressure condition for providing a perceptible indication thereof proximal to the associated tire, and

means coupling at least two of said transmitter means in a juxtaposed relationship in order to form at least one duplex transmitter means;

display means for mounting within the passenger compartment and including a plurality of selectively actuatable indicators corresponding to said plurality of vehicle tires; and

receiver means coupled with said display means for receiving and responding to said wireless signals for selective actuation of said indicators in respective correspondence with said low pressure conditions and the identity of the fleet,

said display means including means for configuring said indicators to provide a graphic display indicative of said low pressure conditions; and

said mounting means being operable for mounting said duplex transmitter means adjacent an outboard tire and substantially aligned with the rotational axis thereof in order to allow coupling of the respective pneumatic pressure sensing means with the respective valve stems of the outboard and inboard tires,

said indicators being coupled with means graphically representing the vehicle for cooperatively presenting a graphic representative of the location of a tire having said low tire condition upon actuation of the corresponding one of said indicators,

the vehicle including at least one compartment door shiftable between closed and unclosed positions associated with a freight storage compartment, said alert system further including door status transmission means for coupling with the vehicle for sensing the unclosed position of the door and for producing and transmitting a door status signal representative thereof, said indicators including a door status indicator, said receiving means being operable for receiving and responding to said door status signal while actuating door status indicator upon occurrence of said door unclosed position.

2. The alert system as set forth in claim 1, said pressure sensing means including

electrical switch means, said coupling means including means for coupling said switch means with the valve stem of the respective tire for activation when the pneumatic pressure of the associated tire falls below a predetermined level in order to produce said low pressure signal.

3. The alert system as set forth in claim 1, said receiver means including means for decoding said digitally encoded signals and for activating a corresponding one of said indicators in response thereto.

4. The alert system as set forth in claim 1, said indicators including light-emitting diodes.

5. The alert system as set forth in claim 1, said receiver means including a superregenerative receiver.