FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
ARRANGEMENT UTILIZING MEMS BASED PRESSURE SENSOR FOR MEASURING LIQUID LEVEL IN A TANK
MAHINDRA TWO WHEELERS LTD.
an Indian Company,
of Dl Block, Plot No. 18/2 (Part),
MIDC, Chinchwad,
Pune-411 019 Maharashtra, India.
INVENTORS:
1 PALAYAD SREENIVASAN ASHOK
2. SUNDARAM SUDHARASAN
3. KIRANKUMAR JASTI
4. JOSHUA DORAICKAN SAMUEL
5 RAGUPATHIGOVINDARAJAN
6. NERKAR HARSHALA RATILAL
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF DISCLOSURE
The present disclosure relates to measurement of liquid level in a tank.
Particularly, the present disclosure relates to a pressure sensor based arrangement for measuring and indicating level of liquid in a tank.
DEFINITIONS
The expression "tank" used hereinafter in this disclosure refers to but is not limited to containers, vessels, reservoirs, fuel tank of an automobile including two wheelers and the like.
The expression "liquid" used hereinafter in this disclosure refers to but is not limited to water, fuel including petrol, diesel, oil, kerosene and the like.
BACKGROUND
A typical fuel level measurement system of a fuel tank of an automobile includes measuring means which measures the level of fuel in the tank, and a gauge or a fuel level display device which displays fuel level to an occupant of the automobile. Generally, the measuring means is located inside the fuel tank of the automobile. The measuring means typically includes a float, usually made of non-metallic materials, connected to a thin metal rod. The end of the rod is connected to an electrical resistor based mechanism. As the fuel level inside the fuel tank increases, the float on the surface of the fuel changes its position corresponding to the level of fuel inside the fuel tank thereby causing electrical resistance to change. Specifically, there is a change in electrical resistance corresponding to each

level of fuel in the fuel tank. The change in electrical resistance is measured by the measuring means and the fuel level is displayed by the fuel level display device.
However, the aforementioned prior art arrangement of using float mechanism for measuring fuel levels in the fuel tanks is inaccurate since the float mechanism induces errors during regular use. Further, the aforementioned prior art arrangement is ineffective when used in a dynamic environment and in complex shaped fuel tanks. In case of complex shaped fuel tanks, the aforementioned prior art arrangement cannot be easily fitted, and is difficult to assemble and dissemble. Further, the aforementioned prior art arrangement involves a large number of components, thereby leading to frequent failures and regular maintenance. Thus, the aforementioned prior art arrangement used for measuring the level of fuel in a fuel tank is ineffective, inaccurate, requires regular maintenance and is less reliable and expensive.
Hence, there is a need for an arrangement for measuring the level of fuel in a fuel tank that eliminates use of floats and disadvantages associated with use thereof. There is a need for an arrangement for measuring the level of fuel in a fuel tank that is simple in construction, easy to assemble and dissemble and can be effectively used in dynamic environments and in complex shaped fuel tanks. There is a need for an arrangement for measuring the level of fuel in a fuel tank that uses lesser number of components, is accurate, reliable,, inexpensive and requires less maintenance.

OBJECTS
Some of the objects of the present disclosure aimed to ameliorate one or more problems of the prior art or to at least provide a useful alternative are listed herein below:
An object of the present disclosure is to provide an effective arrangement for measuring the level of fuel in a fuel tank of automobiles including two wheelers.
Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank of complex shapes.
Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank that can be used particularly in dynamic environments.
Another object of the present disclosure is to provide a precise and reliable arrangement for measuring the level of fuel in a fuel tank of automobiles including two wheelers.
Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank that uses lesser number of components.
Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank of a two wheeler that requires less maintenance.

Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank of a two wheeler that is simple in construction, and easy to assemble/disassemble.
Another object of the present disclosure is to provide an arrangement for measuring the level of fuel in a fuel tank, wherein components of the arrangement are resistant to wear and tear.
Another object of the arrangement of the present disclosure is to eliminate the use of floats and disadvantages associated with use thereof, for measuring the level of fuel in a fuel tank.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present disclosure, there is provided an arrangement for measuring liquid level in a tank, the arrangement adapted to be disposed within the tank, the arrangement comprising a MEMS based pressure sensor adapted to generate an output signal in response to the pressure corresponding to liquid level in the tank; an electronic module operatively connected to the pressure sensor; the electronic module adapted to receive and process the output signal; and electrical connection means adapted to receive processed output signal and transmit measured liquid level for display.

In accordance with an embodiment, the arrangement as described herein above further comprises a tubular member defining a through hole between an operative top end and a bottom end, the tubular member being immersed in the liquid contained in the tank, the operative top end being sealingly secured to the pressure sensor; and a flange secured within an opening in the tank, the flange operatively coupled to the tubular member, the flange further adapted to support the pressure sensor and the electronic module.
Typically, the arrangement further comprises a display device adapted to receive and display the measured liquid level.
Preferably, the arrangement further comprises a first gasket operatively disposed between the operative top end and the pressure sensor; and a second gasket operatively disposed between the flange and a peripheral portion of the opening in the tank.
Optionally, the tubular member is a monolithic structure.
Typically, the tubular member is plastic molded.
Preferably, the flange comprises an internal threaded hole centrally configured in an operative bottom portion; the hole receiving the operative top end of the tubular member configured with threads on an external surface thereon.
Typically, the flange comprises a plurality of internal stepped cavities adapted to mate with corresponding external surfaces of the pressure sensor and the electronic module.

In accordance with the present disclosure, there is provided a method for measuring liquid level in a tank, the method comprising the following steps, sensing the pressure imposed on a MEMS based pressure sensor; generating an output signal in response to the liquid level in the tank; processing the output signal to determine the liquid level; and transmitting determined liquid level for display.
In accordance with an embodiment, the step of sensing the pressure includes at least one of: sensing the pressure imposed on the pressure sensor by an air column in response to the liquid level in the tank; and sensing the pressure imposed on the pressure sensor by the liquid level in the tank.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The arrangement of the present disclosure will now be described with the help of the accompanying drawings, in which:
Figure 1 illustrates a schematic representation of an arrangement for measuring the level of fuel in a fuel tank in accordance with the present disclosure; and
Figure 2 illustrates a a schematic representation of an arrangement for measuring the level of fuel in a fuel tank in accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION
The arrangement of the present disclosure will now be described with reference to the embodiments shown in the accompanying drawings. The embodiments do not limit the scope and ambit of the disclosure. The description relates purely to the examples and preferred embodiments of the disclosed arrangement and its suggested applications.
The arrangement herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known parameters and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The arrangement for measuring the level of fuel in a fuel tank of an automobile (hereinafter referred to as the arrangement), particularly, a two-wheeler along with various elements thereof are illustrated in Figure 1 of the accompanying drawings. Referring to Figure 1, in accordance with one embodiment, the arrangement 100 for measuring the level of fuel in a fuel tank of an automobile, particularly, a two-wheeler comprises an open ended tubular member 10 including an operative top end and a bottom end, a first gasket 20, a pressure sensor 30, an electronic module 40 and electrical connection means 50. In accordance with a preferred embodiment, the pressure sensor 30 is a Micro-Electro Mechanical System (MEMS) based pressure sensor. The arrangement 100 for measuring the

level of fuel in a fuel tank of an automobile is specifically suited for use in a dynamic environment. The arrangement 100 is used for measuring level of fuel stored in a complex shaped fuel tank of the two-wheeler. Additionally, the arrangement 100 of the present disclosure is also suitable for measuring fuel levels in fuel tanks of automobiles, particularly where front fueling system is incorporated.
The fuel tank for an automobile, particularly, for a two wheeler includes an opening configured there-on, the opening configured on the fuel tank further includes a flange 60 provided with a plurality of internal stepped cavities for supporting the gasket 20, the pressure sensor 30 and the electronic module 40 of the arrangement 100 thereon. The flange 60 further includes an internal threaded 90 hole centrally configured on an operative bottom portion thereof, the internal threaded 90 hole receives an operative top portion of the tubular member 10 of the arrangement 100. The operative top portion of the tubular member 10 includes external threads 90 for facilitating connection thereof with the internal threaded 90 hole of the flange 60. Although, in accordance with the present disclosure threaded fastening connection is used for connecting the tubular member 10 to the flange 60, the present disclosure is not limited to any particular method for connecting the tubular member 10 to the flange 60. The tubular member 10 is connected to the flange, and the flange is secured to the opening configured on the fuel tank such that the tubular member 10 extends inside the tank with the open bottom end thereof immersed in the fuel contained in the tank. A second gasket 70 is disposed between the flange 60 and the peripheral portion of the opening configured on the fuel tank in order to maintain an air tight configuration. Preferably, the tubular member 10 has a monolithic structure. In accordance with one embodiment, the tubular member 10 is a straight hollow tube. The tubular

member 10 is typically a plastic molded component made from Polyvinyl Cholride (PVC). However, the present disclosure is not limited to any particular material or method for configuring the tubular member 10.
The pressure sensor 30 is secured to the operative top end of the tubular member 10. More specifically, the operative top end of the tubular member 10 receives an elongated portion of the pressure sensor 30 is supported on the step portion of the flange 60. The gasket 20 is disposed between the operative top end of the tubular member 10 and the pressure sensor 30 to prevent any leakage. The tubular member 10 is so configured that the bottom end of the tubular member 10 remains immersed in the fuel held in the fuel tank and an air column is created between the operative top end of the tubular member 10 sealingly closed by the pressure sensor 30 and the bottom end of the tubular member 10 is immersed in the fuel held inside the fuel tank. The air column inside the tubular member 10 is in fluid communication with the pressure sensor 30 disposed on the operative top end of the tubular member 10. As the fuel level inside the fuel tank rises, due to capillary action the fuel enters the tubular member 10 from the bottom end thereof and compresses the air column inside the tubular member 10. As the air column inside the tubular member 10 gets compressed, the pressure of the air column rises, the pressure sensor 30 senses the change in pressure corresponding to the level of fuel in the fuel tank. The fuel in the fuel tank exerts pressure on the air column maintained inside the tubular member 10 depending on the level of the fuel in the fuel tank and the air column in turn exerts pressure on the pressure sensor 30. The output of the pressure sensor 30 is transmitted to and processed by the electronic module 40, and the output from the electronic module 40 is transmitted to a fuel level display device 80 on the vehicle via electrical connection means 50. The electronic module 40 comprises calibration

means, voltage regulators and other signal conditioning circuits. The calibration means, voltage regulators and other signal conditioning circuits are connected to the pressure sensor 30 for providing a calibrated and stable signal output corresponding to the level of fuel in the tank. The display device 80 is typically at least one of digital (LCD, TFT, LED display devices) or analog (needle movement) type of fuel level indicator. Optionally, the display device 80 (analog or digital) is provided with an appropriate damping mechanism for nullifying the signal noises in the output from the pressure sensor 30.
Figure 2 of the accompanying drawings illustrates an alternative embodiment wherein an open ended tube member 110 is secured to a flange 160 of an arrangement 200 for measuring the level of fuel in a fuel tank of an automobile. The open ended tube member 110 is a conical tube of gradually increasing diameter towards the bottom of the tank.
In accordance with another embodiment, the pressure sensor 30 is mounted on an inner surface at the bottom of the tank in direct contact with the fuel, thereby enabling the total pressure of the fuel in the tank to be exerted on the sensor.
Although, the arrangement 100 of the present disclosure for measuring the level of fuel in a fuel tank is explained with respect to a fuel tank of an automobile, particularly, a two-wheeler, the arrangement 100 can also be used for a variety of other applications, where there is a need for regularly checking the level of a liquid stored in a reservoir.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNFICANCE
The technical advancements offered by the arrangement of the present disclosure include the realization of:
• an arrangement, for measuring the level of fuel in a fuel tank of a two wheeler;
• an arrangement for measuring the level of fuel in a fuel tank that can be used in dynamic environments;
• an arrangement for measuring the level of fuel in a fuel tank of complex configuration;
• an arrangement for precise and reliable measurement of the level of fuel in a fuel tank of a two wheeler;
• an arrangement for measuring the level of fuel in a fuel tank that uses lesser number of components;
• an arrangement for measuring the level of fuel in a fuel tank of a two wheeler that requires less maintenance;
• an arrangement for measuring the level of fuel in a fuel tank of a two wheeler that is simple in construction, and easy to assemble/disassemble;
• an arrangement for measuring the level of fuel in a fuel tank, wherein components of the arrangement are resistant to wear and tear; and
• eliminating the use of floats and disadvantages associated with use thereof, for measuring the level of fuel in a fuel tank.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not

the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements, as the use may be in one of the embodiments to achieve one or more of the desired objects or results.
Any discussion of materials, devices, or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The foregoing description of the specific embodiment will so fully reveal the general nature of the embodiment herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiment without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiment. 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 herein has 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 embodiment as described herein.

We claim:
1) An arrangement for measuring liquid level in a tank, said arrangement adapted to be disposed within the tank, said arrangement comprising:
• a MEMS based pressure sensor adapted to generate an output signal in response to pressure corresponding to the liquid level in the tank;
• an electronic module operatively connected to said pressure sensor; said electronic module adapted to receive and process said output signal; and
• electrical connection means adapted to receive processed output signal and transmit measured liquid level for display.
2) The arrangement as claimed in claim 1 further comprising:
• a tubular member defining a through hole between an operative top end and a bottom end, said tubular member being immersed in the liquid contained in the tank, said operative top end being sealingly secured to said pressure sensor; and
• a flange secured within an opening in the tank, said flange operatively coupled to said tubular member, said flange further adapted to support said pressure sensor and said electronic module.

3) The arrangement as claimed in claim 1 further comprising a display device adapted to receive and display said measured liquid level.
4) The arrangement as claimed in claim 2 further comprising
• a first gasket operatively disposed between said operative top end
and said pressure sensor; and

• a second gasket operatively disposed between said flange and a
peripheral portion of the opening in the tank.
5) The arrangement as claimed in claim 2, wherein said tubular member is a monolithic structure.
6) The arrangement as claimed in claim 2, wherein said tubular member is plastic molded.
7) The arrangement as claimed in claim 2, wherein said flange comprises an internal threaded hole centrally configured in an operative bottom portion; said hole receiving said operative top end of said tubular member configured with threads on an external surface thereon.
8) The arrangement as claimed in claim 2, wherein said flange comprises a plurality of internal stepped cavities adapted to mate with corresponding external surfaces of said pressure sensor and said electronic module.
9) A method for measuring liquid level in a tank, said method comprising the following steps:

• sensing the pressure imposed on a MEMS based pressure sensor;
• generating an output signal in response to the liquid level in the tank;
• processing said output signal to determine the liquid level; and
• transmitting determined liquid level for display.

10) The method as claimed in claim 1 further, wherein the step of sensing the pressure includes at least one of:
• sensing the pressure imposed on said pressure sensor by an air column in response to the liquid level in the tank; and
• sensing the pressure imposed on said pressure sensor by the liquid level in the tank.