DESC:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“ELECTRONIC FUEL LEVEL SENSING SYSTEM FOR A MOTOR VEHICLE”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Aurangabad – 431136, Maharashtra, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of Invention

[001] The present invention relates to systems that are provided for sensing the fuel level and rollover/extreme tilting in two wheeled motor vehicles. It more particularly relates to a comprehensive system comprising fuel level sensing and indicating unit and a tilt responsive fuel cut-off unit for vehicles.

Background of the Invention

[002] The fuel level sensing system provided in motor vehicles ordinarily utilize a combination of a float, a connecting arm, a contact needle and a resistive material track to measure the level of fuel inside a fuel tank. As floats have to stay in contact with the fuel to correctly measure its level, it is necessary to fit the fuel level sensing system either on the outer surface of the fuel tank or within the fuel tank itself depending upon attachment points that can be made available without compromising upon the integrity of the fuel tank. In a conventional system, the float is linked with the contact needle via the connecting arm. Therefore, any change in fuel level inside the tank is reflected in movement of the contact needle. It has been observed that the contact needle, which is in contact with the resistive material track, tends to wear out the resistive material track over a period of time when the fuel tank undergoes multiple filling and emptying cycles. As there are very few other options that can be cheaply and efficiently utilized to perform the same function as that of the contact needle, this wearing out of resistive material from the track is considered as ordinary wear and tear that is to be dealt with by replacing the sensing system if the sensing system ever stops functioning. Even though other systems for sensing fuel level form part of the state of the art, this setup for sensing fuel level is still widely utilized as it is much easier to measure change in fuel level in terms of change of resistance in an electric circuit, than it is by any other existing means.

[003] In addition to the fuel level sensing system, for enhancing safety, rollover/extreme tilt sensing system is also provided on motor vehicles. Most effective conventional rollover/tilt sensing system use a combination of semicircular magnet(s) mounted on a shaft, a sensor for sensing change in polarity and an ECU. The semicircular magnet(s) mounted on the shaft are capable of moving in response to tilting of the vehicle and it is this movement that can be sensed by a sensor capable of sensing change in polarity. The sensor output, processed by the ECU is transmitted to safety mechanisms which terminate fuel flow, disconnect the battery and execute any other protective actions when the sensed rollover/extreme tilt indicates the possibility of an accident having occurred. As correct sensing of rollover/extreme tilt is dependent on correct sensing of change in magnetic polarity, this assembly has to be manufactured very accurately for it to work correctly in all circumstances. As accurate manufacturing is hard to achieve in all instances, there exists a finite possibility that this system may not sense all instances of rollover/extreme tilt accurately. This technical necessity of manufacturing it accurately for it to be functional at all makes it a relatively costly protective system to provide in a motor vehicle.

[004] As providing both of these systems can enhance vehicle user’s convenience and safety, providing both of them in a single package that performs each of its functions properly and without suffering from any of the described limitations, has been felt necessary for a long period of time.

Objectives of the Present Invention

[005] The main object of the present invention is to provide an electronic fuel level sensing, indicating and tilt responsive fuel cut-off system for vehicles.

[006] Another objective of the present invention is to provide a fuel level indicating and tilt responsive fuel cut-off system for vehicles that is quite compact, durable and has an extremely long life that eliminates the need of repairing or changing it during lifetime of the vehicle.

[007] Yet another objective of the present invention is to provide an integrated unit of fuel level sensing, indicating and tilt responsive fuel cut-off system for vehicles that can be depended upon to predictably perform its function when there is an accident.

Brief Description of Drawings

[008] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[009] Figure 1 discloses a cut view of the electronic fuel level sensing system for a motor vehicle in accordance with the present invention.

[0010] Figure 2 illustrates an isometric view of the electronic fuel level sensing and tilt responsive fuel cut-off system of the present invention.
[0011] Figure 3 shows a back view of the electronic fuel level sensing and tilt responsive fuel cut-off system of the present invention.

[0012] Figure 4 discloses a cut view of the electronic fuel level sensing assembly of the present invention.

[0013] Figure 5 presents a magnified cut view of the magnetic housing of the electronic fuel level sensing assembly of the present invention.

[0014] Figure 6 depicts a cut-sectional view of the electronic fuel level sensing assembly of the present invention.

[0015] Figure 6a discloses a magnified cut view of the sleeve of the electronic fuel level sensing assembly of the present invention.

[0016] Figure 7 shows a cut view of the tilt responsive fuel cut-off unit of the electronic fuel level sensing system of the present invention.

Detailed Description of the Present Invention

[0017] Referring to Figs. 1 to 3, the preferred embodiment of the electronic fuel level sensing system (500) in accordance with the present invention, which overcomes the discussed limitations of existing systems, comprises of a fuel level indicating assembly (100) and a tilt responsive fuel cut-off assembly (200). The fuel level indicating assembly (100) comprises of an upper housing (10), a first set of connector points (15), a set of wiring harness (20), a float (F), and a float attachment arm (40). The tilt responsive fuel cut-off assembly (200) has a lower housing (50), a metallic pendulum (60), a set of metallic contact plates (65) and a base plate (90).

[0018] In fuel level indicating and tilt responsive fuel cut-off system (500) (refer Figs. 1 to 3), the upper housing (10) of the fuel level indicating assembly (100) is mounted on the lower housing (50) of the tilt responsive fuel cut-off assembly (200) with the help of suitable fastening means in such a way that the housings (10 and 50) are in electric communication with each other with the help of connector points (75). Thus, the fuel level indicating assembly (100) is in continuous electric communication with the tilt responsive fuel cut-off assembly (200) through the connector points (75). The lower housing (50) is mounted on a base plate (90) and said base plate (90) is fitted at the lower inner surface of the fuel tank of the vehicle with the help of a set of fastening means (95) such as rivets, bolts, screw etc.

[0019] As shown in Figs. 1-4, the upper housing (10) of the fuel level indicating assembly (100) is configured to have a base member (10A) and a vertical member (10B) wherein the base member (10A) and the vertical member (10B) are integral to each other and forms an L-shaped structure. The vertical member (10B) is configured to have a trapezoidal profiled structure having a front face (10FS) and a rear face (10BS). A hollow sleeve (10S) protrudes out from the front face (10FS) of the vertical member (10B) of the upper housing (10) in an overhanging manner. The hollow sleeve (10S) may be formed as an integral part of the vertical member (10B) or it may be press fitted in a groove formed on the front face (10FS) of the vertical member (10B). Further, the rear face (10BS) of the vertical member (10B) of the upper housing (10) is configured to have a resting bracket (10BR). The said resting bracket (BR) is formed in a manner such that the lower face of the bracket (BR) and the lower face of the sleeve (10S) lies in a coincident plane.

[0020] The base member (10A) is a hollow rectangular body having a cavity (10AC) formed in the interior of the base member (10A) and a hollow cylindrical projection (45) projecting from the geometrical center of the base member (10A). The cavity (10AC) houses an integrated chip (70). The cylindrical projection (45) has a cavity (45C) wherein a magnet housing (20) is telescopically disposed within the said cavity (45C) of the cylindrical projection (45) (refer Fig. 5). The said cylindrical projection (45) is configured to have an annular recess (45AS) formed over the outer peripheral surface at its top end.

[0021] As shown in Fig. 5, the magnet housing (20) is a hollow cylindrical body configured to have an annular upper lip (20UL) and an annular lower lip (20LL). The said upper lip (20UL) is formed around a flat resting surface (20RS) in a manner such that the upper lip (20UL) forms a vertical wall extending peripherally around the resting surface (20RS). The magnet housing (20) is closed at its top end by the resting surface (20RS) while it is open at the bottom end by the virtue of the annular lower lip (20LL). The magnet housing (20) is configured to have an annular recess (20R) formed over the outer peripheral surface at it top end. Further, the rectangular shaped boss (35) with chamfered corners protrudes out from the resting surface (20RS). The said protruding boss (35) has with a pivot pin (PP) fixedly mounted to the protruding boss (35) in a manner such that the pivot pin (PP) extends up to some length after being completely passing from the protruding boss (35) so as to get connected with a segment (26C) of a connecting pin (26).
[0022] Referring to Figs. 4 and 5, the magnet housing (20) houses a cylindrical magnet (25) fixedly positioned in between the bottom face of the resting surface (20RS) and the lower lip (20LL) constituting an integral assembly of said housing (20) and the magnet (25) in such a way that the said magnet (25) is configured to travel along with the magnet housing (20). The lower surface of the magnet (25) is being hold on the lower lip (20LL) in such a way that the majority of the surface area of the lower face of the magnet (25) is exposed so that is being sensed by the IC (70) for its magnetic flux. The cylindrical projection (45) and the magnet housing (20) are sealed off by a bellow (30). The said bellow is configured to have an annular upper lip (30UL) and an annular lower lip (30LL) wherein the upper lip (30UL) is snuggly fitted in the annular recess (20R) of the magnetic housing (20) and the lower lip (30LL) of the bellow (30) is snuggly fitted in the annular recess (45AS) of the cylindrical projection (45).

[0023] As shown in Figs. 4 and 6, the float arm (40) is configured to have at least three arm segments namely (40A, 40B and 40C). The arm segment 40B freely suspends over the resting bracket (10BR). The said arm segment (40B) is configured to have a sub segment 40B’ provided in a manner such that the arm segment 40B’ maintains an obtuse angle ? with respect to the arm segment 40B. The angle ? may vary from 100° to 120°. The said arm segment 40C extends orthogonally to the arm segment 40B’ in Y-Y plane while the arm segment 40A extends orthogonally to 40B in X-X plane. The arm segment 40C is connected to the float (F), while the arm segment 40A is connected to a connecting pin (26).

[0024] The said connecting pin (26) is configured to have at least three segments namely 26A, 26B and 26C. The geometric axis of the arm segment (26A) maintains an obtuse angle a with the geometric axis of the arm segment 26B and the geometric axis of the arm segment (26B) maintains an acute angle ? with the geometric axis of the arm segment (26C). The arm segment (26C) is pivotally mounted over the pivoting pin (PP). The arm segment (40A) and the connecting portion between the arm segment (40A) and segment (26A) of the connecting pin (26) is housed in the sleeve (10S). Thus, the joint of the segment (26A) of the connecting pin (26) and the arm segment (40A) of the float arm (40) is housed in the sleeve (10S).

[0025] Referring to Fig. 7, the lower housing (50) of the tilt responsive fuel cut-off assembly (200) houses a metallic pendulum (60) positioned on a projection (80) wherein the projection (80) projects out from a support wall (50BSW). A set of metallic contact plates (65) are fixedly mounted on the support wall (50BSW) projecting out from the said wall (50BSW) and at the same horizontal level as that of the projection (80). The metallic contact plates (65) are symmetrically placed in respect of the projection (80) so as to permit a base section (60B) of the metallic pendulum (60) to have contact with the set of metallic contact plates (65) when the metallic pendulum (60) swings by an angle (ß) along the projection (80). The set of metallic contact plates (65) and the projection (80) are so positioned on the support wall (50BSW) of the lower housing (50) that the contact plates permit the metallic pendulum (60) to swing by an angle (ß), wherein the angle (ß) being in the range of -60 to +60 degree from the vertical line passing through the projection (80) with 5° tolerance. The base section (60B) of the metallic pendulum (60) is configured to have at least two flat surfaces (60BA and 60BB) on its opposite ends to facilitate the positive contact along a wide surface with the set of metallic contact plates (65). The metallic pendulum (60) and the set of metallic contact plates (65) are in communication with a processing unit (63) provided within the support wall (10BSW). The processing unit (63) is positioned on the connector points (not shown in figures) given at the base of the lower housing (50B) and said connector points in turn are in communication with the wiring harness sub set (20A) through the connector point (15).

[0026] When the fuel is filled in the fuel tank of a vehicle, the float (F) rises due to buoyancy effect, this thereby rotates the arm segment (40A) of the float arm (40) in an anti-clockwise direction. The rotation of the arm segment (40A) leads to the rotation of the arm segment (26A) of the connecting pin (26) in anti-clockwise direction, which leads to the downward movement of the arm segment (26C) of the connecting pin (26) finally leading to the downward movement of the magnet housing (20) along with the magnet (25). As the fuel level in the fuel tank is lowered gradually during the operation of a vehicle, the float (F) lowers down and the magnet (20) moves in upward direction along with the magnet housing (20). The upward/downward movement of the magnet (25) from the IC (70) placed in the base member (10B) causes a change in magnetic flux in accordance with the Hall-Effect. The change in magnetic flux sensed by the IC (70) is translated into the voltage readings in order to determine the fuel measurements.

[0027] In the event of an accident, when the vehicle has over turned or is gets tilted on either of its side, the pendulum (60) swings along the axis of the projection (80), moving by an angle (ß) in either clockwise or anticlockwise depending upon the direction (left or right) in which the vehicle is tilting, and establishes contact with the metallic contact plate (65). Hence the disclosed limit for angle (ß) is significant because it decides the condition in which an accident could be stated to have happened. This change is sensed by the processing unit (63), which then through the connector points (15) given at the base of the lower housing (50B), sends a signal through the connector point (15) and the wiring harness sub set (20) to cause, fuel supply cut-off to the engine, disconnection of the battery power and execute any other protective actions as the devices attached with the vehicle permit. As the lower housing (50) is positioned and fixed at the center of the base plate (90) in a manner that base plate (90) is at an inclination (?) with respect to a vertical plane (X-X) passing through the centers of both upper and lower housings (10 and 50), the fuel level indicating and tilt responsive fuel cut-off system (500) can hence be attached at any surface at a commensurate inclination (?). Care is taken to install the fuel level indicating and tilt responsive fuel cut-off system (500) in such a manner that the axis of the projection (80) remains coaxial or parallel to the possible direction of rolling/tilting of the vehicle.

[0028] The fuel level sensing, indicating and tilt responsive fuel cut-off system (500) in accordance with the disclosed embodiment provides the following technical advantages that contributes to the advancement of technology:
- It provides a reliable fuel level indicating and tilt responsive fuel cut-off system for vehicles.
- It provides system that is very durable and has an extremely long life that eliminates the need of repairing or changing it during lifetime of the vehicle.
- It provides a system that can be depended upon to predictably perform its function when there is an accident.
- It provides a system that is capable of differentiating between any two closely resembling operating conditions indicating the level of fuel present inside the fuel tank.
- Ease of assembly as two distinct units are now provided in a single module in the same time which originally was required for the one unit only, leading to reduced cycle time and improvement in production output.
- Conducting copper wire is common till PCB solder point, thus reduction in cost and at the same time effective space management within the fuel tank of a vehicle.
- Single wiring harness is required for connecting the two units in a single module which reduces complexity of wiring harness, reduction in the wiring harness requirement and cost of overall harness design leading the design of invention very simple and easy to handle.
- The cleverly packaged module of fuel level indicating and tilt responsive fuel cut-off system placed inside the fuel tank, isolates it from external intended or unintended damage leading to enhancement in the life of a system.

[0029] The disclosed invention hence overcomes the limitation of the systems forming state of the art. As would be clear to a person skilled in the art, the contact points, the connector points, the fastening means, and the wiring harness can be easily changed in the described invention without changing the overall construction and working of the invention. Therefore, any change pertaining to them must not be construed to be taking a resulting system out of the scope of the claimed invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiment/s herein have been described in terms of preferred embodiment, those skilled in the art will recognize that the embodiment herein can be practiced with modification within the spirit and scope of the embodiments as described herein. ,CLAIMS:We Claim

1. An electronic fuel level sensing system (500) for a motor vehicle comprising of a fuel level indicating assembly (100), a tilt responsive fuel cut-off assembly (200), a connector point (75), and fastening means;
wherein,
- the fuel level indicating assembly (100) is configured to comprise of an upper housing (10), a first set of connector points (15), a set of wiring harness (20), a float (F), and a float attachment arm (40);
- the tilt responsive fuel cut-off assembly (200) is configured to comprise of a lower housing (50), a metallic pendulum (60), a set of metallic contact plates (65) and a base plate (90); and
- the upper housing (10) of the fuel level indicating assembly (100) is mounted on the lower housing (50) of the tilt responsive fuel cut-off assembly (200) with the help of fastening means in such a way that said fuel level indicating assembly (100) is in electric communication with said tilt responsive fuel cut-off assembly (200) through the connector points (75).

2. The electronic fuel level sensing system (500) as claimed in claim 1, wherein
- the upper housing (10) of the fuel level indicating assembly (100) is configured to have a base member (10A) and a vertical member (10B) wherein the base member (10A) and the vertical member (10B) are integral to each other forming an L-shaped structure; and
- the lower housing (50) of the tilt responsive fuel cut-off assembly (200) is mounted at the center of a base plate (90), and said base plate (90) is at an inclination (?) with respect to a vertical plane (X-X) passing through the centers of both upper and lower housings (10 and 50) and is fitted at the lower inner surface of the fuel tank of the vehicle with the help of a set of fastening means (95) selected from rivets, bolts, screws and adhesives.

3. The electronic fuel level sensing system (500) as claimed in claim 2, wherein
- the vertical member (10B) of the upper housing (10) is configured to have a trapezoidal profiled structure having a front face (10FS) and a rear face (10BS);
- the front face (10FS) of the vertical member (10B) is configured to have a hollow sleeve (10S) protruding out from it in an overhanging position as an integral part of the vertical member (10B);
- the rear face (10BS) of the vertical member (10B) of the upper housing (10) is configured to have a resting bracket (10BR), and said resting bracket (BR) is formed in such a way that the lower face of the bracket (BR) and the lower face of the sleeve (10S) lies in a coincident plane.

4. The electronic fuel level sensing system (500) as claimed in claim 2, wherein
- the base member (10A) is configured to have a hollow rectangular body having a cavity (10AC) formed in the interior of said base member (10A) and a hollow cylindrical projection (45) projecting from the geometrical center of said base member (10A);
- said cavity (10AC) is configured to house an integrated chip (70);

- the cylindrical projection (45) has a cavity (45C) wherein a magnet housing (20) is telescopically disposed within the said cavity (45C) of the cylindrical projection (45); and
- said cylindrical projection (45) is configured to have an annular recess (45AS) formed over the outer peripheral surface at its top end.

5. The electronic fuel level sensing system (500) as claimed in claim 4, wherein
- the magnet housing (20) is a hollow cylindrical body and configured to have an annular upper lip (20UL) and an annular lower lip (20LL);
- said upper lip (20UL) is formed around a flat resting surface (20RS) forming a vertical wall extending peripherally around said resting surface (20RS);
- said magnet housing (20) is closed at its top end by the resting surface (20RS) and it is open at the bottom end by the virtue of the annular lower lip (20LL);
- the magnet housing (20) is configured to have an annular recess (20R) formed over the outer peripheral surface at it top end;
- the resting surface (20RS) of the magnet housing (20) is configured to have a rectangular shaped boss (35) with chamfered corners protruding out from the resting surface (20RS); and
- said protruding boss (35) has a pivot pin (PP) fixedly mounted and completely passing through the protruding boss (35) extends to get connected with a segment (26C) of a connecting pin (26).

6. The electronic fuel level sensing system (500) as claimed in claim 5, wherein
- the magnet housing (20) is configured to house a cylindrical magnet (25) fixedly positioned in between the bottom face of the resting surface (20RS) and the lower lip (20LL) constituting an integral assembly of said housing (20) and the magnet (25) in such a way that the said magnet (25) is configured to travel along with the magnet housing (20);
- the lower surface of said magnet (25) is being hold on the lower lip (20LL) in such a way that the majority of the surface area of the lower face of the magnet (25) is exposed to be sensed by a IC (70) positioned in the base member (10B);
- the cylindrical projection (45) and the magnet housing (20) are sealed off by a bellow (30); and
- said bellow is configured to have an annular upper lip (30UL) and an annular lower lip (30LL), wherein the upper lip (30UL) is snuggly fitted in the annular recess (20R) of the magnetic housing (20) and the lower lip (30LL) of the bellow (30) is snuggly fitted in the annular recess (45AS) of the cylindrical projection (45).

7. The electronic fuel level sensing system (500) as claimed in claim 5, wherein
- the connecting pin (26) is configured to have three segments (26A, 26B and 26C);
- the geometric axis of the arm segment (26A) maintains an obtuse angle a with the geometric axis of the arm segment 26B;
- the geometric axis of the arm segment (26B) maintains an acute angle ? with the geometric axis of the arm segment (26C), and said arm segment (26C) is pivotally mounted over the pivoting pin (PP); and
- the joint of the segment (26A) of the connecting pin (26) and the arm segment (40A) of the float arm (40) is housed in the sleeve (10S).

8. The electronic fuel level sensing system (500) as claimed in claim 7, wherein
- the float arm (40) is configured to have three arm segments (40A, 40B and 40C);
- the arm segment (40B) freely suspends over the resting bracket (10BR) and is configured to have a sub segment 40B’ forming an obtuse angle ? with the arm segment 40B, and said angle ? varies from 100° to 120°;
- the arm segment (40C) extends orthogonally to the arm segment (40B’) in Y-Y plane and the arm segment (40A) extends orthogonally to (40B) in X-X plane; and
- said arm segment (40C) is connected with the float (F), and said arm segment (40A) is connected to a connecting pin (26).

9. The electronic fuel level sensing system (500) as claimed in claim 2, wherein
- the lower housing (50) of the tilt responsive fuel cut-off assembly (200) is configured to house a metallic pendulum (60) pivoted on a projection (80) projecting out from a support wall (50BSW);
- a set of metallic contact plates (65) are fixedly mounted on the support wall (50BSW) projecting out from the said wall (50BSW) and at the same horizontal level as that of the projection (80);
- said metallic contact plates (65) are symmetrically placed in respect of the projection (80) so as to permit a base section (60B) of the metallic pendulum (60) to have contact with the set of metallic contact plates (65) when the metallic pendulum (60) swings by an angle (ß) along the projection (80); and
- said swing angle (ß) is in the range of -60 to +60 degrees from the vertical line passing through the projection (80) with 5° tolerances.

10. The electronic fuel level sensing system (500) as claimed in claim 9, wherein
- The base section (60B) of the metallic pendulum (60) is configured to have at two flat surfaces (60BA and 60BB) on its opposite ends to facilitate the positive contact along a wide surface with the set of metallic contact plates (65);
- the metallic pendulum (60) and the set of metallic contact plates (65) are in communication with a processing unit (63); and
- said processing unit (63) is positioned and mounted at the base of the lower housing (50B) and is in communication with the wiring harness sub set (20A) through the connector point (15).

Dated this 28th day of Mar. 2024

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai