Tire pressure monitoring devices

• US 20040112129A1
• Filed: 08/18/2003
• Published: 06/17/2004
• Est. Priority Date: 02/20/2002
• Status: Abandoned Application

• Current Assignee: Torbjorn B. Lundqvist
• Original Assignee: Torbjorn B. Lundqvist
• Inventors: Grondahl, Claes Goran, Lundqvist, Torbjorn Boson
• Application Number:
  US10/468,502
• Publication Number:
  US 20040112129A1
• Time in Patent Office: Days
• US Class Current: 73/146
• 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 23/0494 Valve stem attachments positioned inside the tyre chamber
• CPC Class Codes: B60C 23/0496 Valve stem attachments positioned outside of the tyre chamber
• CPC Class Codes: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Abstract

A low tire pressure monitoring device (20) that is provided within a tire valve wire stem (210) and methods of using the same. The monitoring device comprises a counter-pressure chamber (21), a flexible membrane (36), a contact member, counter-pressure chamber pin (230), a PC board (29), and a means for emitting a signal. The monitoring device is calibrated by trapping the tire'"'"'s initial air pressure in the counter-pressure chamber. The monitoring device (20) monitors the pressure differential between the counter-pressure chamber (21) and the tire. When the pressure differential between the pressure in the counter-pressure chamber and the pressure within the tire exceeds a predetermined maximum pressure differential, the flexible membrane (36) is deflected so that an electrical circuit is completed and a warning signal is emitted.

Claims

1. A tire pressure monitoring device for monitoring the air pressure of a tire, said monitoring device comprising:

a tire valve stem having a generally cylindrical body and a bore provided therein, wherein said bore is in communication with said tire;

a counter-pressure chamber located within said tire valve stem;

a flexible membrane disposed over said counter-pressure chamber;

a contact plate positioned over said flexible membrane;

a conduit in communication with said counter-pressure chamber and said bore of said tire valve stem;

a plug capable of sealing said conduit, wherein said plug is biased in a closed position;

a counter-pressure pin extending from an outside wall of said tire valve to said plug, said counter pressure pin capable of displacing said plug from said closed position to an open position; and

a signaling means positioned on the periphery of said tire valve stem, wherein said signaling means emits a warning signal when a pressure within the counter-pressure chamber is greater than a pressure within the tire.

2. The tire pressure monitoring device of claim 1 further comprising a power supply.

3. The tire pressure monitoring device of claim 2 wherein said power supply is at least one battery.

4. The tire pressure monitoring device of claim 1 wherein said flexible membrane and said contact plate are conductive substances.

5. The tire pressure monitoring device of claim 4 wherein said conductive substance is a conductive metal or a conductive rubber.

6. The tire pressure monitoring device of claim 1 wherein said signaling means is coupled to a printed circuit board.

7. The tire pressure monitoring device of claim 1 wherein said signaling means is selected from the group consisting of a light emitting diode (LED), a speaker, a radio frequency (RF) transmitter, and a infrared (IR) transmitter.

13. A method of monitoring air pressure within a tire, said method comprising:

providing a tire pressure monitoring device as defined in claim 1;

calibrating said tire pressure monitoring device;

monitoring a pressure differential between said tire pressure monitoring device and an air pressure of said tire; and

emitting a warning signal when said pressure differential exceeds a predetermined pressure differential.

14. The method of claim 13 wherein said pressure differential is a difference between the pressure of said counter-pressure chamber and said air pressure of said tire.

15. The method of claim 14 wherein said warning signal may be a signal selected from the group consisting of a light, a sound, a radio frequency (RF) wave, and an infrared (IR) light.

16. The method of claim 13 further comprising:

decreasing the air pressure within the tire to periodically to ensure that said device is properly working.

17. The method of claim 13 further comprising:

adding air pressure to said tire; and

recalibrating said tire pressure monitoring device.

8. A tire pressure monitoring device for monitoring the air pressure of a tire, said monitoring device comprising:

a tire valve stem having a generally cylindrical body and a bore provided therein, wherein said bore is in communication with said tire;

a counter-pressure chamber located within said tire valve stem;

a flexible membrane disposed over said counter-pressure chamber;

a contact member positioned over said flexible membrane;

a conduit in communication with said counter-pressure chamber and said bore of said tire valve stem;

a plug capable of sealing said conduit, wherein said plug is biased in a closed position by a resilient member provided in said;

a counter-pressure pin extending from an outside wall of said tire valve to said plug, said counter pressure pin capable of displacing said plug from said closed position to an open position;

a signaling device positioned on the periphery of said tire valve stem, wherein said signaling device emits a warning signal when a pressure within the counter-pressure chamber is different by a predetermined differential from a pressure within the tire; and

a power supply and a printed circuit board positioned below said counter-pressure chamber, wherein said signaling device is in electrical communication with said printed circuit board.

9. The tire pressure monitoring device of claim 8 wherein said power supply is at least one battery.

10. The tire pressure monitoring device of claim 8 wherein said flexible membrane and said contact member comprise a conductive substance.

11. The tire pressure monitoring device of claim 10 wherein said conductive substance is a conductive metal or a conductive rubber.

12. The tire pressure monitoring device of claim 8 wherein said signaling device is selected from the group consisting of a light, a light emitting diode (LED), a speaker, a radio frequency (RF) transmitter, and a infrared (IR) transmitter.