WO1996008384A1

WO1996008384A1 - A device for continuously monitoring and signalling the condition of a spare tire in an automotive vehicle

Info

Publication number: WO1996008384A1
Application number: PCT/BR1995/000036
Authority: WO
Inventors: Luis Carlos Caubi Moraes De Souza Rocha
Original assignee: Rocha Luis Carlos Caubi Moraes
Priority date: 1994-09-15
Filing date: 1995-08-25
Publication date: 1996-03-21
Also published as: AU3559095A; UY24037A1

Abstract

A device for continuously monitoring and signalling the condition of a spare tire in an automotive vehicle, comprises a pressure chamber (10) connected by conducts (12, 13) to a valve for filling the spare tire (T), a diaphragm (18) being located within said chamber, said diaphragm being provided with a contact (16) which closes or opens a circuit with a secondary contact (20), in case there is a pressure drop appearing in conducts (12, 13), this circuit opening or closing action activating or deactivating a light indicator (3) situated on the vehicle board. In an alternative, the diaphragm is provided with a nose (23) in one of the sides thereof and with a spring (25) in the other side which, in the extended or rest (zero pressure) position activates a secondary contact (26) situated within the pressure chamber (10) which closes or opens a circuit with a primary contact (27) also situated within the pressure chamber (10). In a further alternative, the diaphragm is eliminated and a piston (24) is located within said chamber, said piston being provided with an adjusting screw (33) in one of the sides thereof and with a spring (35) in the other side.

Description

A DEVICE FOR CONTINUOUSLY MONITORING AND SIGNALLING THE CONDITION OF A SPARE TIRE IN AN AUTOMOTIVE VEHICLE

The present invention relates to a device for continuously monitoring and signalling the condition of a spare tire in automotive vehicles. In a normal situation, when a driver goes to a trip or even during the daily use of his vehicle, he gauges the tires within the pressure ranges of use. However, polls indicate that most of the drivers fails to gauge de spare tire which is housed within the vehicle.

Thus, the present invention relates to a simple and economic device which allows to monitor the condition of said tire by means of a light indicator in the vehicle board. That is, if inadvertently the spare tire which is in a stationary state undergoes a drop in the pressure of use, such a light indicator will warn the driver that his situation occurs so that he promotes the due gauging. In this way, the device monitoring the condition of the spare tire or more simply the empty spare tire detector of the present invention is intended to inform through a display signalling, said condition in both load vehicle and passenger vehicles and said information is absolutely reliable. The device of this invention works utilizing the tension of the vehicle battery and the procedure of confined air within a pressure chamber and it does not interfere in some way with any other control or part of the vehicle. In addition, the device of this invention is of easy installation by virtue of the small size thereof and it is fully feasible in industrial terms, besides being a low cost and highly reliable device which can be installed in vehicles during mounting thereof or in traffic and therefore it provides for secureness for the user.

The electromechanical portion of the device of the invention is naturally located in the same compartment as the spare tire and the indicator will be located in the vehicle's board, the connections being made by usual electrical lines.

Monitoring in accordance with the present invention by means of the pressure exerted on a diaphragm located in a pressure chamber, the "empty" condition being indicated by a light emitting diode (LED) actuated by an element such as a electromechanical or solid state relay, through the voltage of the vehicle battery itself. The operation of device relies on that, with the pressure of the spare tire precalibrated at is normal level, the diaphragm is expanded and a metallic contact situated at the center thereof closes the positive supply circuit via another contact positioned on a secondary plate, the relay being kept in an energized condition and with said contact of the secondary plate in a zero voltage position and then in a non-activating position of the indicator light emitting diode.

As the pressure in the spare tire diminishes, the diaphragm is retracted to the extent that there is no more physical and accordingly electrical contact between the center thereof and the metallic contact of secondary plate. This will then break the circuit, de-energizing the coil of said relay and connecting the battery voltage to a contact position of secondary plate. This will activate the signalling LED via a current limiting resistor, and this condition will be maintained until the spare tire is again inflated by means of the filling valve thereof.

In a second embodiment of the device of the present invention, monitoring is made by means of the pressure exerted on a diaphragm located in a pressure chamber, the "empty" condition being indicated by a light emitting diode (LED) through the voltage of the vehicle battery itself. In this embodiment, the relay is eliminated and the contact of the secondary plate is within the pressure chamber (in the previous embodiment, this contact was located naturally outside said chamber). Thus, the operation of the second embodiment of the device relies on that with the pressure of the spare tire precalibrated at is normal level, the diaphragm is expanded and a metallic contact situated at the center thereof, is open in relation to another secondary contact, which is located within said pressure chamber.

As the pressure in the spare tire diminishes, the diaphragm is retracted to the extent that there is no more physical and accordingly electrical contact between the center thereof and the secondary metallic contact activating with the attendant energization via a current limiting resistor, the indicator LED located on the vehicle's board and this condition will be maintained until the spare tire is again inflated by means of the filling valve thereof.

In a third embodiment of the device of the present invention, even the diaphragm contact can be eliminated, by making up said diaphragm of a conductive elastomeric material. In this case, the circuit will be closed by physical and/or electrical contact between any site in the diaphragm and the secondary contact.

In a fourth embodiment of the device of the present invention, monitoring is made by means of the pressure exerted on a diaphragm located in a pressure chamber, the "empty" condition being indicated by a light emitting diode (LED) through the voltage of the vehicle battery itself. The operation of the fourth embodiment of the device relies on that with the pressure of the spare tire precalibrated at is normal level, the diaphragm is expanded and there is not physical between a nose situated on the diaphragm and metallic contacts disposed within the pressure chamber. Thus, indicator LED is kept off by virtue of the battery-indicator LED electrical circuit being open. As the spare tire does deflated, the nose of the diaphragm gets closer the primary and secondary contacts until in the precalibrated pressure, the contacts are closed by virtue of the action exerted thereon by the diaphragm nose. When the normal pressure is restored by means of the filling/gauging valve, the contacts return to the normal position, that is open, thus turning indicator LED off.

At the side of the diaphragm opposed to the nose, there is a spring the function of which is to ensure that even after being a long period extended, the diaphragm will actuate the contacts closing the circuit in case of a low pressure (deflated spare tire).

In a fifth embodiment of the device of the present invention, monitoring is made by means of releasing the pressure exerted on a piston located in a pressure chamber, the "empty" condition being indicated by a light emitting diode (LED) through the voltage of the vehicle battery itself. The operation of the fourth embodiment of the device relies on that with the

pressure of the spare tire precalibrated at is normal level, the piston is retracted by virtue of the pressure exerted by the confined and compressed air of the pressure chamber and two metallic contacts disposed within the pressure chamber are open. As the spare tire goes deflated, an adjustment screw

integral with the piston approaches the metallic contacts by action of the resultant force generated by a pressure differential of the pressure chamber and of a pre-chamber and of the force component generated by action of a spring coupled to the piston, said spring being extended as a consequence of movement of the piston until the contacts are closed, energizing the indicator LED located on the vehicle's board.

When the normal pressure is restored by means of the filling/gauging valve, the contacts return to the normal position, that is open by piston retraction, thus breaking the circuit and accordingly turning indicator LED

off.

The function of the spring is to ensure that the piston will close the metallic contacts even with the spare tire in a completely deflated condition (zero pressure), thus avoiding the tendency to slight retraction of the piston by action of the contrary force exerted by the spring of the movable contact breaking the circuit and turning LED off unduly. Piston stroke is limited by a limiting stop so that, in the above condition of zero pressure and maximum spring strength, said movable contact is not excessively pressed by the adjustment screw but rather only enough to keep the circuit closed, thus ensuring high reliability to the system. Brief Description of the Drawings Figure 1 is an overall schematic view of the circuit on which the detector of the invention is installed in a vehicle.

Figure 2 is a schematic view of the circuit connecting a first embodiment of the device of the present invention to a spare tire.

Figure 3 is an exploded perspective of the first embodiment of the device of the present invention.

Figure 4 is a plan view of the first embodiment of the device of the present invention.

Figure 5 is a side view of the first embodiment of the device of the present invention. Figure 6 is a front view of the first embodiment of the device of the present invention.

Figure 7 is a sectional view of the first embodiment of the

device of the present invention. Figure 8 is a schematic view of the circuit connecting a second embodiment of the device of the present invention to a spare tire.

Figure 9 is an exploded perspective of the second embodiment of the device of the present invention. Figure 10 is a plan view of the second embodiment of the device of the present invention.

Figure 11 is a side view of the second embodiment of the device of the present invention.

Figure 12 is a front view of the second embodiment of the device of the present invention.

Figure 13 is a sectional view of the second embodiment of the device of the present invention.

Figure 14 is an exploded perspective of a further embodiment of the device of the present invention. Figure 15 is a plan view of the embodiment of the device of the present invention, shown in figure 14.

Figure 16 is a side view of the embodiment of the device of the present invention, shown in figure 14.

Figure 17 is a front view of the embodiment of the device of the present invention, shown in figure 14.

Figure 18 is a sectional view of the embodiment of the device of the present invention, shown in figure 14.

Figure 19 is an exploded perspective of another embodiment of the device of the present invention.

Figure 20 is a plan view of the embodiment of the device of the present invention, shown in figure 19.

Figure 21 is a side view of the embodiment of the device of the present invention, shown in figure 19.

Figure 22 is a front view of the embodiment of the device of the present invention, shown in figure 19.

Figure 23 is a sectional view of the embodiment of the device

of the present invention, shown in figure 19. Description of the Best Modes for Carrying out the Invention

Figure 1 is an overall scheme showing how the detector device of the present invention is installed in a circuit including the spare tire and the vehicle battery. To the filling valve of the spare tire T it is connected a flexible hose H directed coupled to the detector D on which there is disposed a filling/calibrating vaive V. Detector D is connected through a flexible cable C to the vehicle battery B, on which there are serially connected a connector K and visual indicator VI located at the vehicle board and/or an audible indicator Al located inside the vehicle. This scheme stands for all embodiments described hereinafter. A first embodiment of the invention is shown in figures 2-7. The spare tire T includes a valve (not illustrated) which is connected to an end of a hose 13 into the other end of which a duct 12 for conducting air from the spare tire is inserted. This duct 12 is the element which makes connection with the device disclosed by the present invention.

Said device comprises a body 11. This body can, for example, be made of an injected plastic and it has a generally cylindrical shape. Body 11 comprises a pressure chamber 10 and a valve 9 which is intended to fill the spare tire. Also within body 11 , there is a diaphragm 18 made of rubber or of a compatible elastomeric material, integral with a support ring 19. Diaphragm 18 has at the face thereof opposed to the pressure chamber, a primary metallic contact 14 located at the center thereof which is connected to the positive terminal of the vehicle battery through a conductor cable 15. Facing the diaphragm 18 face containing contact 16, there is a secondary metallic contact 20, integral with an insulating ring 14, the secondary contact being interconnected with the pin of a relay 2. In figure 2, this relay 2 is shown on a energized condition and it may be a reversing contact 12 VDC relay. A flexible cable 4 connects the relay circuit with the negative circuit of a light emitting diode LED 3 to be installed with the aid of a small holder to the board of the vehicle and which is indicative of the empty condition of the spare tire. Another flexible cable 5 interconnects the relay circuit to the positive circuit of LED 3.

Completing the overall circuit, the battery B is fed by means of a main positive cable 6 and a main negative cable 7, and in this latter circuit there is a fuse 8. A cable 17 connects contact 16 with the positive terminal of the relay coil.

The assembly is closed by a back cover 22, as indicated in the

drawings. Figures 8-13 depict a second embodiment of the invention which is, in essence, very similar to that one of the first embodiment.

In this version, the same reference numerals have been maintained for the parts identical to those of the first embodiment. Relay 2 and insulating ring 14 and cable 17 are omitted.

Secondary contact 16 is extended so as to be within the pressure chamber 10. Diaphragm 18 of course is inverted so that now it is the concave face thereof that bears secondary contact 16, unlike the previous embodiment, wherein contact 16 is born by on the convex face of diaphragm 18.

The operation of this second embodiment of is very similar to that of the first embodiment of the device of the present invention, with the exception that the spare tire is calibrated, contacts 14 and 16 form an open circuit and where there is a pressure drop, retraction of diaphragm 18 causes contacts 14 and 16 to be connected thus lightning on LED which exists on the vehicle board.

A third embodiment of the present invention (not illustrated in the drawings) is an alternative to the first and/or second embodiments and it would consist in eliminating metallic contact 16 of diaphragm 18 and making up' the latter of a conductive elastomeric material, such as conductive rubber, so that the diaphragm itself would be the electric contact element to open or close the circuit which drives the light emitting diode.

A fourth embodiment of the present invention is depicted in figures 14-18. Identical reference numerals will be maintained for parts identical to those of the previous embodiments.

In these figures, the spare tire and the pressure hose have not been shown, but it will be appreciated that the pressure transmitting procedure is the same as in the previous embodiments. Body 11 has a coupling 12 for attachment to the hose and is further comprises a valve which is intended to fill and calibrating the spare tire. The body 11 also comprises in its interior, a diaphragm 18 made of rubber or of other compatible elastomeric material which is integral with a nose 23 which is an extension of diaphragm 18. Diaphragm 18 has, at the face thereof opposed to a pressure chamber 10, a spring 25 whose function is to ensure that even after a long time in an extended position, diaphragm 18 will displace nose 23. Spring 25 is situated within body 11 and it is surrounded without any physical contact by a movable sleeve 24 acting like a piston the stroke of which is limited by a stop (not illustrated) being a step formed in the inner wall of body 11.

Nose 23 can be made of rubber or other elastomeric material and it has internally thereof a minimum pressure adjustment screw (not shown) coaxially therewith in order to permit length regulation. The function of the nose 23 is to act on a secondary metallic contact 26 disposed on the pressure chamber 10 and situated parallel to a primary metallic contact 27 also situated within the pressure chamber. Secondary contact 25 is connected to the positive terminal of the vehicle battery through a conducting cable 28 and the primary contact 27 is connected by a cable 29 through a current limiting resistor (not shown) to the positive circuit of an indicative LED or light emitting diode, (not shown).

The assembly is closed by a back cover 22, as indicated in the drawings. A fifth embodiment of the invention is illustrate in figures 19-23.

In this embodiment, body 11 comprises a pressure chamber 10 and a coupling 12 for attachment to the hose and is further comprises a valve which is intended to fill and calibrating the spare tire. The body 11 also comprises in its interior a pressure pre-chamber 34 in which it is located a piston 24 on the end of which it is located an adjusting screw 33. At the other end of the piston, it is integral with a spring 35, and this face of the pre-chamber closed by a back cover 22 and between cover 22 and spring 35 there is a sealing ring 31. Spring 35 is situated within body 11 and it is surrounded by piston 24 of which the stroke is limited by a stop (not shown) which is a step formed on the inner wall

of body 1. Between piston 24 and the end of body 11 there is a sealing ring 32.

Screw 33 is a minimum pressure adjusting screw situated coaxially therewith to permit length adjustment thereof. The function of piston is to act on a movable metallic contact 26 disposed within the pressure chamber 10 and situated parallel to a fixed metallic contact 27 also situated within the pressure chamber 10. Movable contact 26 is connected to the vehicles's battery positive terminal through a conductor cable 29 and fixed contact 27 is connected by a cable 30 and through a current limiting resistor (not shown) to the positive circuit of an indicating light emitting diode LED (not shown).

Although the present invention has been described and illustrated in terms of the preferred embodiments thereof, it should be understood that modifications and variations are possible within the limits of the appended claims.

Claims

1. A device for continuously monitoring and signalling the condition of a spare tire in an automotive vehicle, characterized in that it comprises a pressure chamber (10) connected by conducts (12, 13) to a valve for filling the spare tire (T), a diaphragm (18) being located within said chamber, said diaphragm being provided with a contact (16) which closes or opens a circuit with a secondary contact (20), in case there is a pressure drop appearing in conducts (12, 13), this circuit opening or closing action activating or deactivating a light indicator (3) situated on the vehicle board.

2. Device according to claim 1, characterized in that it is enclosed within a cylindrical body (11) made of injected plastic.

3. A device according to claim 1 , characterized in that the light indicator (3) is a light emitting diode.

4. A device according to claim 1 , characterized in that the contact (16) of the diaphragm (18) and the secondary contact (20) are normally connected to each other and are disconnected upon retraction of the diaphragm, so as to de-energize a relay (2) which is connected to the circuit of the light indicator (3) activating said light indicator (3).

5. A device according to claim 1 , characterized in that the contact (16) of the diaphragm and the secondary contact (20) are normally disconnected and are connected to each other upon retracting the diaphragm, activating said light indicator.

6. A device according to the claims 1 to 5, characterized in that contact (16) is metallic.

7. A device according to claim 1 , characterized in that contact

(16) is built in the diaphragm (18) itself when this diaphragm is made of an electrically conductive elastomeric material.

8. A device according to the previous claims, characterized in that the voltage source for the device is the battery of the automotive vehicle.

9. A device for continuously monitoring and signalling the condition of a spare tire in an automotive vehicle, characterized in that it comprises a pressure chamber (10) connected by conducts (12) to a valve for filling the spare tire (T), a diaphragm (18) being located within said chamber, said diaphragm being provided with a nose (23) in one of the sides thereof and with a spring (25) in the other side which, in the extended or rest (zero pressure) position activates a secondary contact (26) situated within the pressure chamber (10) which closes or opens a circuit with a primary contact (27) also situated within the pressure chamber (10), in case there is a pressure drop appearing in conducts (12), this circuit opening or closing action activating or deactivating a light indicator situated on the vehicle board.

10. Device according to claim 9, characterized in that it is enclosed within a cylindrical body (11 ) made of injected plastic.

11. A device according to claim 9, characterized in that the light

indicator is a light emitting diode.

12. A device according to claim 9, characterized in that the primary and secondary contacts (27, 26)) of the diaphragm (18) are normally disconnected and are connected to each other upon extension of the diaphragm (18), through physical contact of the nose (8), the extension of which is regulated by a screw.

13. A device according to claim 9, characterized in that the spring (25) is located within body (11) of the device and it is enclosed without physical contact by a piston (24) the stroke of which is limited by a stop being a step formed in the inner wall of body (11 ).

14. Device according to claim 9, characterized in that secondary contact (26) is connected to the positive terminal of the vehicle battery by a conductor cable (29).

15. Device according to claim 9, characterized in that said primary contact (27) is connected by a cable (30) through a current-limiting resistor to the positive circuit of the light indicator.

16. Device according to any of previous claims 8-15, characterized in that the voltage source for the device is the battery of the

automotive vehicle.

17. A device for continuously monitoring and signalling the condition of a spare tire in an automotive vehicle, characterized in that it comprises a pressure chamber (10) connected by conducts (12) to a valve for filling the spare tire (T), a piston (24) being located within said chamber, said piston being provided with an adjusting screw (33) in one of the sides thereof and with a spring (35) in the other side which, in the extended or rest (zero pressure) position activates a movable contact (26) situated within the pressure chamber (10) which closes or opens a circuit with a fixed contact (27) also situated within the pressure chamber (10), in case there is a pressure drop appearing in conducts (12), this circuit opening or closing action activating or deactivating a light indicator situated on the vehicle board.

18. Device according to claim 17, characterized in that it is enclosed within a cylindrical body (11) made of injected plastic.

19. A device according to claim 17, characterized in that the light indicator is a light emitting diode.

20. A device according to claim 9, characterized in that the primary and secondary contacts (27, 26)) are normally disconnected and are connected to each other upon extension of the piston (24), through physical contact of the screw (33).

21. A device according to claim 17, characterized in that the spring (35) is located within body (11) of the device and it is enclosed without physical contact by said piston (24) the stroke of which is limited by a stop being a step formed in the inner wall of body (11 ).

22. Device according to claim 17, characterized in that movable contact (26) is connected to the positive terminal of the vehicle battery by a conductor cable (29).

23. Device according to claim 17, characterized in that said fixed contact (27) is connected by a cable (30) through a current-limiting resistor to the positive circuit of the light indicator.

24. Device according to any of previous claims 16-23, characterized in that the voltage source for the device is the battery of the automotive vehicle.