WO1997038870A1

WO1997038870A1 - Practical apparatus reporting tyre status

Info

Publication number: WO1997038870A1
Application number: PCT/GB1997/001002
Authority: WO
Inventors: Robert Merlyn Farwell; Hubert Colin Smith
Original assignee: Robert Merlyn Farwell; Hubert Colin Smith
Priority date: 1996-04-12
Filing date: 1997-04-11
Publication date: 1997-10-23
Also published as: AU2515997A; GB9607597D0

Abstract

Practical apparatus that reports tyre status simplistically comprises a magnet (1) inside a wheel that will (proportional to proximity at the bottom) induce differing magnetic polarisation patterns into the steel bracing (7) in a tyre (5). When tyre profile is wrong due to under inflation the magnet will be closer and polarisation will differ. As wheel rotates the moving magnet filed will make a non rotating sensor generate signals that are processed by suitable electronics to deduce the tyre status and if differing from a pre-determined reports unsafe tyre conditions. Polarisation is then erased by another magnet housed with the sensor and the system is automatically reset to monitor the tyre status each revolution. Effectively the apparatus acts as an endless loop recorder to record play and erase status of and on revolving tyre. This invention enables the apparatus to be simple and cheap to make and maintain while being efficient in operation.

Description

PRACTICAL APPARATUS REPORTING TYRE STATUS

BACKGROUND TO THIS INVENTION

MANY DEVICES HAVE BEEN PROPOSED TO MONITOR AND REPORT THE

STATUS OF OR IN A WORKING PNEUMATIC TYRE BECAUSE IT IS THE MEANS USED TO SUPPORT A VEHICLE AND DRAMATICALLY AFFECTS EFFICIENCY AND SAFETY BUT NONE HAVE BEEN COMMERCIALLY SUCCESSFUL BECAUSE THEY HAVE NOT BEEN SIMPLE AND CHEAP TO MAKE AND MAINTAIN. IT IS THE INTENTION OF THIS INVENTION TO SUPPLY A METHOD TO MONITOR AND USE AND / OR DEDUCE AND / OR REPORT THE WORKING PRESSURE AND / OR LOADING AND / OR ROLLING CIRCUMFERENCE AND / OR PROFILE AND / OR FOOTPRINT AND / OR SPEED AND / OR TURNING AND / OR TEMPERATURE AND / OR CENTRIFUGAL FORCES OF / OR IN A TYRE OR TYRES. THE PRIMARY AIM IS TO MONITOR AND USE AND / OR GIVE ADVANCED WARNING IF THE STATUS OF A WORKING TYRE IS OR BECOMES NOT ACCEPTABLE OR FIT TO CONTINUE WORKING. IT IS A FURTHER INTENTION OF THIS INVENTION TO SUPPLY A METHOD TO MONITOR AND USE AND / OR DEDUCE AND / OR REPORT THE BRAKING AND / OR ACCELERATION AND / OR MOVEMENT AND / OR DISTANCE COVERED AND / OR THE SURFACES TRAVELLED OVER BY OR OF A VEHICLE.

ACCORDING TO THE PRESENT INVENTION PRACTICAL APPARATUS REPORTS TYRE STATUS COMPRISES MAGNETIC STORAGE MEANS EXTENDING AT LEAST PART WAY AROUND OR IN THE TYRE AND ROTATABLE WITH IT. A MAGNETIC FIELD PRODUCING MEANS ROTATABLE WITH AND FIXED TO THE WHEEL TO INDUCE MAGNETIC POLARISATION PATTERNS INTO THE MAGNETIC STORAGE MEANS. A NON-ROTATABLE MAGNETIC-FIELD PRODUCING MEANS TO ERASE AND / OR SMOOTH OUT UNWANTED AND / OR RESET MAGNETIC FLUX ON THE MAGNETIC STORAGE MEANS. A MAGNETIC SENSOR MEANS WHICH PRODUCES A VOLTAGE AND / OR VARYING VOLTAGES AND / OR PATTERNS AND / OR SIGNALS IN RESPONSE TO THE MOVEMENT OF THE MAGNETIC-FIELD PRODUCING MEANS AND / OR THE RESIDUAL MAGNETIC FLUX AND / OR FLUX PATTERNS CONTAINED IN THE MAGNETIC STORAGE MEANS AND FIXED SO AS TO MAINTAIN ITS RELATIONSHIP WITH THE WHEEL. AND ELECTRONIC MEANS TO WHICH VOLTAGES AND / OR PATTERNS AND / OR SIGNALS PRODUCED BY THE SENSOR MEANS ARE PASSED FOR PROCESSING TO ENABLE STATUS REPORTS . PREFERABLY THE MAGNETIC STORAGE MEANS COMPRISES THE

STEEL REINFORCING COMMONLY FOUND IN TYRES. THE STEEL USED GENERALLY HAS APPROPRIATE MAGNETIC PROPERTIES. ALTERNATIVELY, THE MAGNETIC STORAGE MEANS MAY BE A STRIP OR PATCH OF MAGNETISEABLE TAPE OR THE LIKE (OR IN PLURALITY) FIXED TO THE TYRE OR MANUFACTURED INTO OR ONTO THE TYRE AND MAY EXTEND AROUND ALL OR PART OF THE TYRE.

PREFERABLY THE MAGNETIC-FIELD PRODUCING MEANS WOULD BE A SUITABLE PERMANENT MAGNET OR MAGNETS. MAGNETS DO NOT NEED A

POWER SOURCE OR MAINTENANCE. ALTERNATIVELY, THE MAGNETIC-FIELD

PRODUCING MEANS MAY BE A SUITABLE PERMANENT MAGNET

ARRANGEMENT OR ARRANGEMENTS.

IN A SLIGHTLY LESS ADVANTAGEOUS VERSION, THE MAGNETIC-FIELD

PRODUCING MEANS MAY COMPRISE OR INCLUDE ELECTROMAGNETS AND MAY BE ENERGISED BY ALTERNATING OR DIRECT CURRENT. THE OTHER ADVANTAGES WOULD STILL APPLY.

PREFERABLY THE SENSOR MEANS AND ERASE MAGNET MEANS ARE

SPACED BUT HOUSED TOGETHER AND FIXED NON ROTATABLY SO AS TO MAINTAIN THEIR RELATIONSHIP WITH THE WHEEL.

CONVENIENTLY THE SENSOR WOULD COMPRISE A MAGNETIC PICKUP COIL THAT WOULD IN RESPONSE TO MOVING MAGNETIC FIELD AND / OR

FIELDS PRODUCE PROPORTIONAL VOLTAGES AND / OR PATTERNS AND / OR

SIGNALS THAT WOULD BE PASSED TO THE ELECTRONIC MEANS, ANY NUMBER

OF SUITABLE ELECTRONIC MEANS EXIST IN PRIOR ART FOR THIS PURPOSE.

THE ELECTRONIC MEANS MAY USE AND / OR INTFRPRET AND / OR

COMPARE VARIATIONS IN VOLTAGES AND / OR PATTERNS A D / OR SIGNALS PRODUCED AND USE AND / OR REPORT ON DEVIATION FROM A PRE¬ DETERMINED. FOR EXAMPLE THE ELECTRONIC MEANS MAY COMPARE VOLTAGES AND OR PATTERNS OF DIFFERENT TYRES OR THE LIKE. AS A FURTHER FEATURE THE ELECTRONICS MAY ALSO MONITOR THE

FUNCTIONING OF THE APPARATUS. TO CHECK THAT IT IS WORKING PROPERLY AND REPORT.

AS A FURTHER FEATURE, THE MAGNET OR MAGNETS IN THE WHEEL

MAY BE MOUNTED IN A KNOWN MANNER, SO THAT A PRESSURE CHANGE CAUSES IT OR THEM TO ROTATE OR MOVE AND SUCH MOVEMENT WILL CAUSE A DIFFERENCE IN MAGNETIC FIELD PATTERN AND / OR FLUX DENSITY PRODUCED IN THE MAGNETIC STORAGE MEANS AND WILL INDICATE THE ACTUAL PRESSURE IN THE TYRE

AS A FURTHER FEATURE, THE MAGNET OR MAGNETS IN THE WHEEL MAY BE MOUNTED IN A KNOWN MANNER, SO THAT A TEMPERATURE CHANGE CAUSES IT OR THEM TO ROTATE OR MOVE AND SUCH MOVEMENT WILL CAUSE A DIFFERENCE IN MAGNETIC FIELD PATTERN AND / OR FLUX DENSITY PRODUCED IN THE MAGNETIC STORAGE MEANS AND WILL INDICATE THE ACTUAL TEMPERATURE OF OR IN THE TYRE

AS A FURTHER FEATURE, THE MAGNET OR MAGNETS IN THE WHEEL MAY BE MOUNTED IN A KNOWN MANNER, SO THAT CENTRIFUGAL FORCES CAUSES IT OR THEM TO ROTATE OR MOVE AND SUCH MOVEMENT WILL CAUSE A DIFFERENCE IN MAGNETIC FIELD AND / OR FLUX DENSITY AND / OR PATTERN PRODUCED IN THE MAGNETIC STORAGE MEANS AND WILL INDICATE THE ACTUAL FORCES

AS A FURTHER FEATURE, THE MAGNET OR MAGNETS IN THE WHEEL MAY BE MAGNETS THAT ARE TEMPERATURE DEPENDENT AND CHANGE MAGNETIC FIELD PATTERN WITH TEMPERATURE SUCH CHANGE WILL CAUSE A DIFFERENCE IN MAGNETIC FIELD PATTERN AND / OR FLUX DENSITY PRODUCED IN THE MAGNETIC STORAGE MEANS AND WILL INDICATE THE ACTUAL TEMPERATURE OF OR IN TYRE. A PREFERRED EMBODIMENT OF THE PRESENT INVENTION IS

ILLUSTRATED BY WAY OF EXAMPLE ONLY WITH REFERENCE TO THE ACCOMPANYING DRAWINGS IN WHICH:-

FIGURE 1

IS A PART SCHEMATIC OF A WHEEL AND TYRE WHERE IT WOULD CONTACT THE ROAD AND DEPICTING THE TYRE PROFILE AS BEING WITHIN NORMAL WORKING PARAMETERS AND INCORPORATING PART OF THE APPARATUS ACCORDING TO THE INVENTION

FIGURE 2

IS SIMILAR TO FIGURE 1 BUT DEPICTING AN ABNORMAL WORKING PROFILE POSSIBLY DUE TO UNDER-INFLATION

FIGURE 3 IS

SIMILAR TO FIGURE 1 BUT DEPICTING AN ABNORMAL WORKING PROFILE POSSIBLY DUE TO OVER-INFLATION

FIGURE 4 5 AND 6 ARE SCHEMATIC VIEWS OF A WHEEL AND TYRE INCORPORATING

APPARATUS ACCORDING TO THE INVENTION AND SHOWING DIFFERENT PART ROTATIONS

REFERRING TO FIGURE 1 A MAGNET 1 OF SUFFICIENT FLUX DENSITY IS SHOWN FIXED TO A WHEEL HUB 4 (OF A VEHICLE WHEEL NOT SHOWN) AND INDUCING A PRE-DETERMINED AMOUNT OF RESIDUAL MAGNETIC FLUX 8. (FIGURES 1 TO 6 INCLUSIVE CONTAIN REPRESENTATIONS OF FLUX AND DENSITY IN THE FORM OF THE LETTER X) INTO THE MAGNETIC RECORDING MEDIUM 7 (COMPRISES THE STEEL BRACING INHERENT IN MOST TYRES) DUE DIRECTLY IN THIS INSTANCE TO THE DISTANCE BETWEEN MAGNET 1 AND RECORDING MEDIUM 7. THIS HAPPENS AT LEAST ONCE EACH REVOLUTION WHEN THE MAGNET 1 IS AT ITS CLOSEST TO THE BOTTOM AS IN FIGURE 4. IN FIGURE 5 THE CONTINUED ROTATION 6 ALLOWS THE TYRE TO RESUME ITS UN¬ COMPRESSED POSITION BY THE FREE NATURAL MECHANICAL ACTION OF THE TREAD ROTATING AWAY FROM THE ROAD. THE PERIPHERY CARRYING THE RESIDUAL MAGNETIC FLUX 8 IS CLOSER TO, WHILST MOVING PAST MAGNETIC SENSING DEVICE 3 TOGETHER WITH MAGNET 1 ON WHEEL HUB 4 AND DEPENDING ON THE STRENGTH OF THE COMBINED MOVING MAGNETIC FIELD 8 AND MAGNET 1 A PROPORTIONAL VOLTAGE OR PATTERN IS PRODUCED BY MAGNETIC SENSING DEVICE 3 THIS VOLTAGE OR PATTERN IS PASSED ON TO ANY NUMBER OF KNOWN ELECTRONIC MEANS (NOT SHOWN) TO BE INTERPRETED AND / OR USED. CONTINUED ROTATION 6 IN FIGURE 6 THEN BRINGS MAGNET 1 AND RESIDUAL FLUX 8 TO AN ERASE MAGNET 2 WHICH ERASES, WIPES OFF OR SMOOTHES OUT UNWANTED OR RESIDUAL FLUX 8 AND THE MONITORING CYCLE IS AUTOMATICALLY RESET TO START AGAIN.

NOW FIGURE 2 DEPICTS AN ABNORMAL WORKING PROFILE POSSIBLY DUE TO UNDER-INFLATION AND MAGNET 1 NOW COMES MUCH CLOSER TO RECORDING MEDIUM 7 WHEN MAGNET 1 HAS ROTATED TO THE BOTTOM OF THE WHEEL AND A LARGE AMOUNT OF RESIDUAL MAGNETIC FLUX 8 IS NOW INDUCED INTO RECORDING MEDIUM 7 AND THUS A GREATER VOLTAGE WILL BE PRODUCED BY MAGNETIC SENSING DEVICE 3 IN ITS ROTATION AS IN FIGURES 4 TO 6 .

NOW FIGURE 3 DEPICTS AN ABNORMAL WORKING PROFILE POSSIBLY

DUE TO OVER-INFLATION AND MAGNET 1 IS NOW FARTHER AWAY FROM RECORDING MEDIUM 7 WHEN MAGNET 1 HAS ROTATED TO THE BOTTOM OF THE WHEEL AND A SMALLER AMOUNT (IN COMPARISON WITH FIGURE 1) (PERHAPS EVEN NONE) OF RESIDUAL MAGNETIC FLUX 8 IS NOW INDUCED INTO RECORDING MEDIUM 7 AND THUS A SMALLER VOLTAGE WILL BE PRODUCED BY MAGNETIC SENSING DEVICE 3 IN ITS ROTATION AS IN FIGURES 4 TO 6.

Claims

WHAT IS CLAIMED IS;

1. PRACTICAL APPARATUS REPORTS TYRE STATUS COMPRISES

A MAGNETIC STORAGE MEANS EXTENDING AT LEAST PART WAY

AROUND OR IN THE TYRE AND ROTATABLE WITH IT. A MAGNETIC FIELD PRODUCING MEANS ROTATABLE WITH THE WHEEL

TO INDUCE MAGNETIC POLARISATION PATTERNS INTO THE MAGNETIC

STORAGE MEANS.

A NON-ROTATABLE MAGNETIC-FIELD PRODUCING MEANS TO ERASE

AND / OR SMOOTH OUT UNWANTED AND / OR RESET MAGNETIC FLUX ON THE MAGNETIC STORAGE MEANS

A MAGNETIC SENSOR MEANS WHICH PRODUCES SIGNALS IN

RESPONSE TO THE MOVEMENT OF THE MAGNETIC-FIELD PRODUCING MEANS

AND / OR THE RESIDUAL MAGNETIC FLUX AND / OR FLUX PATTERNS

CONTAINED IN THE MAGNETIC STORAGE MEANS, FIXED SO AS TO MAINTAIN ITS RELATIONSHIP WITH THE WHEEL.

AND ELECTRONIC MEANS TO WHICH SIGNALS PRODUCED BY THE

SENSOR MEANS ARE PASSED FOR PROCESSING AND / OR REPORTING THE

STATUS OF OR IN THE TYRE.

2 APPARATUS AS CLAIMED IN 1. WHEREIN THE MAGNETIC STORAGE

MEANS COMPRISES THE STEEL BRACING FOUND IN MOST TYRES

3 APPARATUS AS IN CLAIM 1. WHEREIN THE MAGNETIC STORAGE

MEANS COMPRISES AT LEAST ONE BAND OR PATCH OF STORAGE MATERIAL

MANUFACTURED IN THE TYRE OR SUBSEQUENTLY INTRODUCED. 4 APPARATUS AS IN CLAIM 3. IN WHICH THE STORAGE MATERIAL

EXTENDS AROUND PART OF THE TYRE

5 APPARATUS AS CLAIMED IN ANY PRECEDING CLAIM WHERE IN

EITHER MAGNETIC-FIELD PRODUCING MEANS COMPRISES AT LEAST ONE

MAGNET OR MAGNET ARRANGEMENT. 6 APPARATUS AS CLAIMED IN ANY OF THE CLAIMS 1 TO 4 IN WHICH

EITHER MAGNETIC-FIELD PRODUCING MEANS COMPRISES ELECTROMAGNETS

ENERGISED BY ALTERNATING AND / OR DIRECT CURRENT.

7 APPARATUS AS CLAIMED IN ANY PRECEDING CLAIM WHEREIN THE SENSOR MEANS AND ERASE MAGNET ARE SPACED BUT HOUSED TOGETHER AND FIXED NON ROTATABLEY SO AS TO MAINTAIN THEIR RELATIONSHIP WITH THE WHEEL.

8 APPARATUS AS CLAIMED IN ANY PRECEDING CLAIM WHEREIN THE SENSOR COMPRISES A PICKUP COIL THAT WOULD IN RESPONSE TO MOVING MAGNETIC FIELDS PRODUCE SIGNAL OR SIGNALS.