Tire pressure characterization method and key fob

• US 20060055522A1
• Filed: 09/13/2004
• Published: 03/16/2006
• Est. Priority Date: 09/13/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Walenty, Allen J., Rimkus, Robert A.
• Granted Patent: US 7,215,243 B2
• Time in Patent Office: Days
• US Class Current: 340/442
• 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
• CPC Class Codes: B60C 23/0479 Communicating with external units being not part of the vehicle, e.g. tools for diagnostic, mobile phones, electronic keys or service stations
• CPC Class Codes: G07C 2009/00984 fob
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: Y10T 137/36 With pressure-responsive pressure-control means

Abstract

The present invention provides an apparatus and method for characterizing tire pressure on the four tires of a conventional passenger automobile. The method uses an apparatus disposed on a key fob. The key fob includes a tire valve stem interface that is capable of taking manual measurements of tire pressure. The fob further includes a pressure transducer that translates tire pressure into electronic form where it can be displayed on an LCD screen and transmitted by RF to an automobile computer. The automobile computer further includes a program that provides for the measurement of tire pressure in a sequential method thereby assuring that the tires are at placarded pressure or more. The method includes steps of using the key fob to measure the tire pressure and transmitting the tire pressure to the computer for processing.

Claims

1. A method for characterizing tire pressure comprising the steps of:

measuring the pressure of a first tire with a tire valve stem interface disposed on a key fob;

sending tire pressure information by radio frequency from a key fob to a remote function actuator;

allowing a time period to add air pressure to the first tire;

approving the first tire when its pressure meets or exceeds placard pressure;

repeating the above steps for a second tire, a third tire, and a fourth tire; and

characterizing tire pressure when all four tires are approved.

2. The method according to claim 1 further comprising the step of activating a secondary functionality on a set of key fob buttons corresponding to four tires.

3. The method according to claim 1 wherein the time period allowed for adding air pressure is approximately two minutes.

4. The method according to claim 1 further comprising the step of:

setting an electronic flag marker corresponding to a tire to indicate that the tire pressure meets or exceeds placard pressure.

5. The method according to claim 1 further comprising the step of chirping the horn when tire pressure exceeds placard pressure.

6. The method according to claim 1 further comprising the step of providing a series of horn chirps when the pressure of each tire meets or exceeds placard pressure.

7. The method according to claim 1 further comprising providing a series of horn chirps to signal that a tire pressure verification mode has been cancelled.

8. The method according to claim 1 further comprising authorizing tire characterization only when the pressure of each of four tires meets or exceeds placard pressure.

9. A method for authorizing a tire pressure characterization comprising the steps of:

measuring the air pressure in a left front tire;

setting a flag marker approval corresponding to the left front tire when the air pressure in the left front tire meets or exceeds placard pressure;

measuring the air pressure in a right front tire;

setting a flag marker approval corresponding to the right front tire when the air pressure in the right front tire meets or exceeds placard pressure;

measuring the air pressure in a left rear tire;

setting a flag marker approval corresponding to the left rear tire when the air pressure in the left rear tire meets or exceeds placard pressure;

measuring the air pressure in a right rear tire;

setting a flag marker approval corresponding to the right rear tire when the air pressure in the right rear tire meets or exceeds placard pressure; and

testing whether flag marker approvals exist for all four tires;

authorizing a characterization when all four tires have approved 20 flag markers.

10. The method according to claim 9 further comprising the step of determining engine status.

11. The method according to claim 9 further comprising the step of initiating a tire pressure verification mode by simultaneously depressing two keys on a key fob.

12. The method according to claim 9 further comprising the step of providing an audible feedback once the tire pressure verification mode is selected.

13. The method according to claim 9 further comprising the step of initiating a tire pressure characterization sequence by placing the ignition in position 2 and simultaneously depressing the odometer reset button.

14. The method according to claim 9 further comprising transmitting tire pressure to a remote function actuator by radio signal and resetting a timer to two minutes when a transmit on change of pressure greater than 1 PSI occurs.

15. A key fob for use in measuring a tire pressure comprising:

a key fob body having a top and side orientation;

a valve stem interface disposed on said key fob body;

a pressure transducer disposed on said key fob body such that said transducer creates electronic signals corresponding to pressure data received from the valve stem interface; and

an LCD display screen that visually displays pressure information received from the pressure transducer.

16. The key fob according to claim 15 wherein the valve stem interface and pressure transducer are disposed on a side of the key fob.

17. The key fob according to claim 15 wherein the valve stem interface and pressure transducer are disposed on the top of the key fob.

18. The key fob according to claim 15 wherein said pressure transducer generates a signal corresponding to the air pressure measured by the valve stem interface.

19. A key fob with functionality for activating a tire pressure characterization sequence comprising:

a key fob body wherein said key fob body has a front and rear orientation;

a first button disposed on said key fob body corresponding to a left front tire position;

a second button disposed on said key fob body corresponding to a right front tire position;

a third button disposed on said key fob body corresponding to a left rear tire position;

a fourth button disposed on said key fob body corresponding to a right rear tire position;

a means for transmitting radio frequencies carrying tire pressure information corresponding to left front, right front, left rear, and right rear tires to a remote function actuator.

20. The key fob according to claim 19 wherein the first button is disposed on the left front of the key fob body, the second button is disposed on the right front of the key fob body, the third button is disposed on the left rear of the key fob body, and the fourth button is disposed on the right rear of the key fob body.