Portable apparatus for measurement and display of internal pressure of tires

• US 5,335,541 A
• Filed: 02/22/1993
• Issued: 08/09/1994
• Est. Priority Date: 02/20/1992
• Status: Expired due to Term

• Current Assignee: GKN Aerospace Services Limited (Melrose Industries Plc)
• Original Assignee: GKN Aerospace Services Limited (Melrose Industries Plc)
• Inventors: Sharpe, Brian A. J.
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): Oen, William L.
• Application Number:
  US08/020,774
• Time in Patent Office: 533 Days
• Field of Search: 73/146.5, 73/706, 364/571.01, 364/558, 340/445, 340/448, 374/143
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/02 Signalling devices actuated by tyre pressure hand-held tyre pressure gauges G01L17/00
• CPC Class Codes: B60C 23/041 Means for supplying power to the signal- transmitting means on the wheel
• CPC Class Codes: B60C 23/0413 Wireless charging of active radio frequency circuits
• CPC Class Codes: B60C 23/0447 Wheel or tyre mounted circuits
• 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: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Abstract

Inflation pressure of an inflated article, e.g. a wheel tire 12, is measured by pressure sensing apparatus 10 located on the inflated article. Portable apparatus 20 is brought into proximity with the sensing apparatus 10 and a power signal is transmitted for the portable apparatus to energise the sensing apparatus. The portable apparatus acquires pressure data signals output by the sensing apparatus, processes these data signals and displays an inflation pressure value. The power signal and pressure data signals are transmitted by engaging a probe 24 provided as part of the portable apparatus with a cylindrical body member 13 of the sensing apparatus. A particular advantage of the portable apparatus is in acquiring and displaying inflation pressure values of aircraft undercarriage wheel tires because the aircraft power does not have to be switched on and the cockpit entered to obtain inflation pressure readings.

Claims

1. Portable hand held apparatus for energizing discrete pressure sensing apparatus located on an inflated article, receiving a pressure signal output by the pressure sensing apparatus when energized and displaying an inflation pressure value;

the portable hand held apparatus comprising an electrical power source, power signal generator means connected with the electrical power source, power signal transmission means connected with the power signal generator means and adapted for transmitting a power signal to energize the discrete pressure sensing apparatus when the hand held portable apparatus is brought into proximity with the pressure sensing apparatus, pressure signal receiver means for receiving a pressure signal output by the pressure sensing apparatus when energized, pressure signal processor means connected with the receiver means and adapted for processing the pressure data signals, and display means connected with the pressure signal processor means and adapted for displaying an inflation pressure value.

2. Apparatus according to claim 1, wherein the power signal generator means comprises an oscillator.

3. Apparatus according to claim 2, wherein the oscillator comprises a sine wave generator.

4. Apparatus according to claim 1, wherein the power signal transmission means comprises a power transmit coil provided with the portable apparatus.

5. Apparatus according to claim 4, wherein the pressure data signal receiver means comprises a capacitive electrode.

6. Apparatus according to claim 1, wherein the power signal transmission means and the pressure data signal receiver means comprises a common coil adapted when placed in proximity with a coil provided with the pressure sensing apparatus to transmit the power signal to said apparatus and to receive pressure data signals modulated onto the power signal.

7. Apparatus according to claim 1, wherein the pressure data signal processor means comprises a modem adapted for converting frequency shift key signal frequencies to a stream of serial data bits.

8. Apparatus according to claim 7, wherein the processor means further comprises a universal asynchronous receiver/transmitter connected for receiving the stream of serial data bits from the modem and adapted for converting the stream of serial data bits to parallel form.

9. Apparatus according to claim 8, wherein the processor means further comprises an 8-bit latch connected for receiving the data bits in parallel form and adapted for passing the parallel form data bits to a binary decoder for decoding and subsequent display by display means as a three digit inflation pressure number.

10. Apparatus for the measurement and display of pressure internal of an inflated article, including pressure sensing apparatus located on the inflated article and portable hand held apparatus for energizing the sensing apparatus, receiving signals output by the pressure sensing apparatus when energized, and displaying inflation pressure values received therefrom;

the pressure sensing apparatus comprising pressure cell means located on the inflated article for sensing pressure internal thereof, power signal receiver means for receiving a power signal transmitted by the portable hand held apparatus, power signal conditioning means connected with the receiver means for conditioning the received power signal and for outputting a signal suitable for energizing the pressure cell means, pressure signal processing means connected with the pressure cell means for receiving and processing signals output by the pressure cell means and for outputting pressure signals corrected for non-linearity and temperature effects, conversion means connected with the processing means for converting corrected pressure signals to binary coded data, frequency shift-key (FSK) signal generator means connected with the conversion means for generating FSK signals representative of the binary coded data, and transmission means connected with the FSK signal generator means for transmitting FSK modulated signals to the portable hand held apparatus;

the portable hand held apparatus comprising an electrical power source, electrical power signal generator means connected with the electrical power source, means connected with the generator means for transmitting an electrical power signal to the pressure sensing apparatus, signal receiver means for receiving FSK modulated signals output by the pressure sensing apparatus when energized, decoder means for decoding the FSK modulated signals, and display means connected with the decoder means for displaying an inflation pressure value.

11. Apparatus according to claim 10, wherein the electrical power signal transmitting means comprises a power transmit coil located on a probe which is adapted for engagement with a body portion of the pressure sensing apparatus so as to bring the power transmit coil into proximity with a power receive coil comprising the power signal receiving means of the pressure sensing apparatus.

12. Apparatus according to claim 11, wherein the signal receiving means comprises a signal receive capacitive electrode located on the probe so as to be brought into proximity with a signal transmit capacitive electrode comprising the signal transmitting means of the pressure sensing apparatus, when the probe is engaged with the body portion of the pressure sensing apparatus.