Claims:I/We Claim:
1. A fuel sender unit assembly (425) of a vehicle (100)extending from a front side to a rear side along a central longitudinal axis (Y-Y’), said fuel sender unit assembly (425) comprising:
a fuel sender unit (500);
a float arm (510) attached to said fuel sender unit (500) to at least one end;
a float (505)attached to said float arm (510)to at least one end;
wherein,
said float (505) along with said float arm (510) is configured to move inclinedly with respect to said central longitudinal axis ( Y-Y’) of said vehicle (100) between a maximum position (520) and a minimum position (525) of said float arm (510).
2. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 2, wherein said float arm (510) sweeps between said maximum position (520) and said minimum position (525) of said float (505) to make a sweep angle (?1).
3. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said fuel sender unit (500) is mounted on a mounting portion (430), wherein said mounting portion (430) is a rearwardly downward sloping region of a fuel tank assembly (120) disposed towards an end of a inverted (U) shaped tunnel, wherein said (U) shaped tunnel is formed at the mid portion of said fuel tank inner (445) of said fuel tank assembly (120).
4. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said float arm (510) extends away from of said fuel sending unit (500).
5. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said float (505) is a small barrel shaped structure attached to at least one end of said float arm (510) and configured to swivel in a direction away from said fuel sending unit (500) thereby tracing one of a 2-dimensional or a 3-dimensional curve.
6. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said float arm (510) is mounted on said fuel sending unit (500) by means of a float arm mounting provision (515) with a swivel axis (C) formed at the mounting end region.
7. A fuel sender unit assembly (425) of a fuel tank assembly (120),
wherein,
said fuel tank assembly (120) comprises of an outer portion (440) and an inner portion (445); said inner portion (445) of said fuel tank assembly (120) is configured with a rearwardly downward sloping portion (430) constituting a plane P,
wherein,
said sloping portion (430) is disposed substantially along a lateral mid-plane of said fuel tank assembly (120) and said sloping portion (430) so formed enables mounting of said fuel sender unit assembly (425);
wherein,
a float arm (510) of said fuel sender unit assembly (425) is configured to trace at least one of a 2-dimensional or a 3-dimensonal curve from a fuel empty condition to a fuel full condition of the said fuel tank assembly (120).
8. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said fuel sending unit assembly (425) makes a second angle (?2) with respect to a horizontal axis (X-X’), wherein said axis (X-X)’ is disposed in a plane S which is substantially orthogonal to a direction of gravity force (G) and parallel to a length direction (L) of said fuel tank assembly (120)..
9. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein the distance between said maximum position (520) and said minimum position (525) when projected on a plane (S), is a predetermined distance (D1).
10. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 9, wherein said predetermined distance (D1) is in a range of 50 mm to 150 mm.
11. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein the angular distance between said maximum position (520) and said minimum position (525), when projected in a plane P, is a predetermined distance (D2).
12. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 11, wherein said predetermined distance (D2) is in range of 150 mm to 200 mm.
13. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1 , wherein the vertical distance between said maximum position (520) and said minimum position (525) when projected on an imaginary plane which is substantially parallel to a direction of gravity force (G), is a predetermined distance (D3).
14. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 13, wherein said predetermined distance (D3) is in a range of 100 to 170 mm.
15. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said fuel sender unit assembly (425) is placed in close proximity of a vapor trap unit (600), and said fuel sender unit assembly (425) is disposed towards a rear side of said fuel tank assembly (120) to achieve a compact fuel tank assembly (120) layout.
16. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 11, wherein said fuel sender unit assembly (425) is placed in close proximity of a fuel pump module (415), and wherein said fuel pump module (415) is disposed on said plane (P) to achieve a compact fuel tank assembly (120) layout.
17. The fuel sender unit assembly (425) of a vehicle (100) as claimed in claim 1, wherein said fuel sender unit assembly (425) is upwardly placed on a rear portion of a sloping region a fuel tank inner (420) just below a vapor trap unit (600) and in proximity to a fuel pump module (415).
18. A vehicle (100) comprising:
a fuel tank assembly (120), said fuel tank assembly (120) is mounted on a frame assembly (200) of said vehicle (100), said fuel tank assembly (120) includes a fuel tank outer portion (440); and a fuel inner profile portion (445), said fuel tank inner portion (445) includes a fuel sender unit assembly (425), said fuel sender unit assembly (425) of said vehicle (100) extends from a front side to a rear side along a central longitudinal axis (Y-Y’), said fuel sender unit assembly (425) comprising:
a fuel sender unit (500);
a float arm (510) attached to said fuel sender unit (500) to at least one end;
a float (505) attached to said float arm (510) to at least one end;
wherein,
said float (505) along with said float arm (510) moves inclinedly with respect said a fuel tank assembly (120) axis ( Y-Y’) of said vehicle (100), between a maximum position (520)and a minimum position (525) of said float (505),
wherein,
said float arm (510) sweeps a sweep angle (?1) between said maximum position (520) and said minimum position (525)of said float (505).
19. The vehicle (100) as claimed in claim 18, wherein maximum range of said sweep angle (?1) is up to 80°.
20. The vehicle (100) as claimed in claim 18, wherein placement of said fuel sender unit assembly (425) in said fuel tank assembly (120) makes a second angle (?2) with respect to a horizontal axis (X-X’). , Description:TECHNICAL FIELD
[0001] The present subject matter described herein generally relates to a vehicle, and particularly but not exclusively relates to a fuel sender unit assembly of a vehicle.

BACKGROUND
[0002] A fuel tank is a part of a fuel system of a vehicle which stores fuel. The fuel is then propelled through a fuel pump into an engine of the vehicle. The fuel tank of a vehicle is either made of metal (steel or aluminum) or of plastic such as high-density polyethylene (HDPE).
[0003] Generally, the fuel tank of the motorcycle type saddle vehicle is mounted on a frame assembly of the vehicle, while being mostly placed ahead of a seat. As the outer part of the fuel tank is visible, it is designed, considering the style elements to give aesthetic appeal to the rider. The inner part of the fuel tank is usually shaped in a complex manner, mostly to accommodate many essential internal or surrounding parts and in accordance with the volume of the fuel it has to store. Along with it, an evaporative emission control system for accommodating the fuel vapors is placed within the fuel tank inner space, disposed between a frame tube and an inner side wall of the inner part of the fuel tank.
[0004] In most of the vehicles, the fuel tank of a vehicle is designed such that the front portion of the fuel tank is broader and the rear portion of the fuel tank is narrower, when viewed from front of the vehicle when a rider is in riding position. The inner portion of the fuel tank is usually shaped as an inverted U shape, with variable width in longitudinal section.
[0005] With increasing demand for addition of features to reduce vehicular emission, many systems such as fuel injection system, evaporative emission control system, fuel gauge system etc. are also housed within the fuel tank and its surrounding areas. Since, systems such as, the fuel pump and the fuel gauge system are to be fitted on inner part of the fuel tank along with the evaporative emission control system; an efficient and compact design of such parts becomes essential.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The detailed description is described with reference to a saddle type two wheeled scooter along with the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0007] Fig. 1 illustrates a side view of a vehicle in accordance with an embodiment of the present invention.
[0008] Fig. 2 illustrates a perspective view of a fuel tank assembly mounted on a frame assembly of a vehicle in accordance with an embodiment of the present invention.
[0009] Fig. 3 illustrates an exploded sub assembly of a fuel tank assembly mounted on a frame assembly of a vehicle in accordance with an embodiment of the present invention.
[00010] Fig. 4 illustrates an exploded sub assembly of the fuel tank assembly with essential components of the fuel tank assembly in accordance with an embodiment of the present invention.
[00011] Fig. 5 illustrates a fuel sender unit assembly of a fuel tank assembly with essential components in accordance with an embodiment of the present invention.
[00012] Fig. 6 illustrates a fuel tank inner profile of the fuel tank assembly (shown in Fig 3) with essential components in accordance with an embodiment of the present invention.
[00013] Fig. 7 illustrates a perspective view of the fuel tank inner profile of the fuel tank assembly (shown in Fig 3) with essential components in accordance with an embodiment of the present invention.
[00014] Fig. 8 illustrates a perspective view of the fuel tank inner profile of the fuel tank assembly (shown in Fig 3)in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION
[00015] A fuel gauge system is a measuring instrument that determines and indicates the amount of fuel present in the vehicle's fuel tank. Typically, the fuel gauge system is of analog type or digital type. Digital fuel gauge system has many advantages over the analog fuel gauge system. These advantages include giving measure of exact quantity of fuel left in the tank, aiding in exterminating fuel theft cases while refueling, and in some cases also aiding in precise determination of fuel efficiency of the vehicles. Along with these advantages there are certain disadvantages associated with the digital fuel gauge systems which include relatively high cost than the analog fuel gauge systems, requirement of high maintenance, and need of a robust construction. Mainly because of the high cost and maintenance factor associated with the digital fuel gauge systems, analog fuel gauge systems are more popularly used in vehicles, for example, two wheeled vehicles.
[00016] Conventionally in vehicles, an analog fuel gauge system, herein referred as a fuel gauge system, comprises of two parts, such as a fuel sending unit assembly and a fuel indicator unit. The fuel sending unit assembly is placed in the fuel tank of the vehicle. The fuel indicator unit is usually placed in front of the vehicle, on a dashboard or an instrument cluster which is easily visible to a rider while riding the vehicle. The fuel sending unit assembly usually uses a float connected to a fuel sender unit by a float arm. As the level of the fuel in the fuel tank decreases, the float drops and slides a moving contact along a resistor, increasing its resistance. Similarly, the float rises with increase in fuel level of the fuel tank, while decreasing its resistance. The resistance is calibrated to indicate the volume of fuel inside the fuel storage unit.
[00017] The fuel indicator unit measures and displays the amount of electric current flowing through the fuel sending unit. Thus, when the fuel tank is full, resistance values decreases, current value increases and when the fuel tank is empty, resistance values increases and current value decreases. Therefore, when the fuel tank level is high and a maximum current is flowing, the fuel indicator unit indicates a full tank. The full tank on the fuel indicator unit is indicated in many vehicles with help of a needle that points towards a symbol "F" or “1” present on the fuel indicator unit. Likewise, when the fuel tank is empty and a minimum current is flowing, the fuel indicator unit indicates an empty tank with help of the needle pointing towards a symbol "E" or “0” or “R” present on the fuel indicator unit. In few vehicles, a special low fuel light is present which turns on automatically to attract the attention of the rider towards the low level of the fuel.
[00018] Fuel level indication is very critical in vehicles, as it helps the rider in estimating the distance that can be covered with the available fuel and avoid getting stranded. Inaccurate fuel level indications can lead to wrong estimations and cause inconvenience to the rider e.g. getting stranded. Further, such inaccurate fuel level indication tends to have an overall adverse impact in the entire fuel system of the vehicle. For instance, accumulation of fuel at the bottom of the fuel tank over a period of time, which typically happens when the fuel level indication is inaccurate, causes formation of debris like material. Such a formation when drawn in while running the vehicle at low fuel levels, could negatively impact the functioning of fuel system components such as fuel pump and fuel filter. Further, this could also negatively impact the evaporative emission control device. Further, inaccurate indication of fuel level can also cause the vehicle to cease running due to empty fuel. In case of engines with fuel injection systems, which typically uses fuel pumps, such a condition of empty fuel will damage the fuel pump and fuel injector.
[00019] Moreover, since the fuel sender unit of the fuel gauge systems of most of the vehicles are primarily variable resistance based; in these fuel gauge systems, resistance changes with the amount of fuel in the fuel tank. In this type of fuel gauge systems, there is always a possibility of inaccurate or inconsistent indication of the fuel level measured because the fuel sending unit of these fuel gauge systems, only measure the height of the fuel level from a reference plane. This problem of inaccurate or inconsistent indication arises when the level of fuel inside the fuel tank is not settled on a particular level owing the phenomenon of frequent slosh of the fuel inside the storage area during the usage of the vehicle especially on uneven roads. Additionally, the non-linear calibration required for the height of the fuel level, to compensate for the complex inner contours of the fuel tank as well as piece to piece variation in production, undermines the accuracy of measurement as the conventional fuel gauge systems are calibrated to only measure the height of the fuel level from a reference plane.
[00020] Conventionally in many vehicles, the fuel gauge of the fuel tank has a float present at the top of the fuel pump, and an arm. One end of the arm is pivotally attached to the body of the gauge and the other end of the arm is disposed such that it acts as a free end of the arm which is freely movable in a predefined plane. The free end of the arm has a float pivotally attached to it. The pivot range of the float at the free end of the arm does not reach the bottom of the main chamber, making it impossible to accurately measure the amount of leftover fuel in the fuel tank. Thus, the float of the fuel sender unit of conventional vehicles has limited angular movement and limited access to the lowest and highest level of the fuel volumes present in the fuel tank, which critically compromises with the accuracy of fuel estimation done by the fuel sender unit assembly.
[00021] This limitation is also caused because of the space constraint of the location at which the fuel sender unit assembly is usually placed, as the location determines the amount of contact of the float with the maximum and minimum volumes of the fuel present in the fuel tank. Thus, even the location of the fuel sender unit assembly of the fuel gauge system determines the accuracy of the results indicated by the indicator unit. Therefore, the fuel sender unit assembly needs to be placed at an optimum location such that, it should be able to accurately measure the lowest and highest level of fuel volumes present in the fuel tank. Often, known arts end up making a tradeoff on either of the lowest or highest level or both in order to achieve a reasonable accuracy in measurement over predominant range of the capacity of the fuel tank. This implies, the readings towards the full capacity of fuel tank or towards the empty condition can be undesirably poor in accuracy. Achieving a consistent measurement method throughout the range appears counterintuitive.
[00022] Also, for a given quantity of fuel, the fuel level height varies when the fuel tank is tilted. Conventional fuel gauge system neither account for the fuel tank tilt nor the vehicle tilt angle. This consequently produces wrong fuel indications when the vehicle is tilted during riding. When the vehicle is tilted, all the fuel gets accumulated on one side of the tank due to gravity. As a result, the fuel level increases on the side to which, the vehicle is tilted and reduces on the opposite side. The fuel sender unit of the fuel gauge system gives output corresponding to the increased or decreased fuel level when the vehicle is tilted. The fuel indicator unit of the fuel gauge in turn estimates and indicates incorrect fuel level based on the output from the fuel sending unit assembly. Due to this incorrect indication, the rider ends up with incorrect estimation of the coverable distance with the available fuel, which further causes inconvenience to the rider.
[00023] In many vehicles, the float of the sender unit is placed in the front portion or the rear portion of the inner fuel tank of the vehicle. In such vehicles, when the vehicle is in motion, during acceleration, deceleration, braking, speed braking, while encountering with pot holes and road bumps, undesired jerks are experienced. These jerks tend to cause erratic movement of the fuel level present in the fuel tank also termed as fuel sloshing. The fuel sloshing results in producing wrong fuel indication, as conventionally the access of the float to maximum and minimum level of fuel in the fuel tank is limited. Limited access of the float to the fuel volumes results into incorrect fuel estimation, which further causes inconvenience to the rider.
[00024] Hence, there is a need for an improved design of a low cost and low maintenance fuel sender unit assembly of a fuel gauge system, overcoming all the above problems and other problems of known arts. There is a need of a non-compromised solution, which provides instantaneously accurate fuel level measurement, irrespective of the factors like tilting of the vehicle, and high magnitude of the fuel sloshes when the vehicle is in dynamic condition etc.
[00025] The present subject matter has been devised in view of the above circumstances as well as solving other problems of known art.
[00026] In an embodiment of the present subject matter, the present subject matter relates to a fuel sender unit assembly of a fuel tank assembly.
[00027] In an aspect of the present embodiment the fuel tank assembly is disposed such that the uppermost part of the upper surface of the fuel tank assembly is configured at a position higher than the front and the rear part of the fuel tank assembly. The fuel sender unit is mounted on a mounting profile of a fuel tank assembly, such that the float rises and falls in an inclined angular direction tracing a 3-dimensional coupler curve.

[00028] In another aspect of the present embodiment the fuel sender unit assembly includes a fuel sender unit, a float arm, and a float. The float arm is an extended arm like structure which is attached to at least one end of the fuel sending unit, in a direction away from of the fuel sending unit. The float arm is mounted on the fuel sending unit by means of a float arm mounting provision. The float is a small barrel shaped structure which is attached to at least one end of the float arm.

.

[00029] In another aspect of the present embodiment, the float arm along with the float is capable of an inclined angular rotation substantially orthogonal to the longitudinal direction of the fuel tank from a maximum to a minimum position of the float.
[00030] In yet another aspect of the present embodiment the range between the maximum and the minimum position of the float is such that the angle between the float arm when at maximum position to a minimum position, is an angle ?1.
[00031] In another aspect of the present embodiment, the placement of the fuel sending unit assembly is such that the mounting plane of the fuel sending unit makes an angle ?2 with respect to an plane P, wherein the plane P is substantially orthogonal to the direction of gravity force G .
[00032] In another aspect of the present embodiment, a distance between the float upper limit position and the float lower limit position is a distance D1 when projected in a plane S which is orthogonal to the direction of gravity force G.
[00033] In another aspect of the present embodiment, an angular distance between the float upper limit position and the float lower limit position is a distance D2 when projected on the plane P.
[00034] In another aspect of the present embodiment, a distance between the float upper limit position and the float lower limit position is a distance D3 when projected in a plane orthogonal to the plane S and parallel to length direction L.
[00035] In another embodiment of the present subject matter, a fuel sender unit assembly is placed near a vapor trap unit.
[00036] In yet another embodiment of the present subject matter, a fuel sender unit assembly is placed near a fuel pump module.
[00037] In an efficacy of the present subject matter, the fuel sender unit assembly described in the present subject matter ensures a low cost fuel sender unit assembly.
[00038] In another efficacy of the present subject matter, the fuel sender unit assembly described in the present subject matter ensures a low maintenance fuel sender unit assembly.
[00039] Exemplary embodiments detailing features regarding the aforesaid and other advantages of the present subject matter will be described hereunder with reference an embodiment in a two wheeled motorcycle type saddle vehicle along with the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled vehicle with a driver riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow R denotes rear side, and an arrow F denotes front side. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[00040] The nature and further characteristic features of the present invention will be made clearer from the following descriptions made with reference to the accompanying drawings.
[00041] Fig. 1 illustrates a side view of a vehicle 100 in accordance with an embodiment of the present invention. The vehicle 100 includes a frame assembly 200 (shown in Fig. 2) to support different parts of the vehicle 100. In an upper portion of the frame assembly 200 (shown in Fig. 3), a handlebar assembly 115 is rotatably integrally connected to the steering shaft (not shown). The handlebar assembly 115 is used to steer the vehicle 100 and is connected to a front wheel 185 through the steering shaft (not shown) and a front fork assembly (not shown). An upper portion of the front wheel 185 is covered by a front fender 190 which prevents mud and water from getting deflected towards the steering shaft (not shown). Further, the front fork assembly (not labelled) is supported on the front fender 190 by means of a brace fender (not shown).
[00042] In a front portion of the frame assembly 200 (shown in Fig. 2) a fuel tank assembly 120 is arranged immediately behind the handlebar assembly 115 and is disposed over a first power source, for example an engine assembly 180. A seat assembly 125is placed behind the fuel tank assembly 120. The seat assembly 125 includes a front rider seating portion and a pillion rider seating portion. The pillion rider seating portion is placed on the rear part of the frame assembly 200 (shown in Fig. 2), where the rear part of the frame assembly 200 (shown in Fig. 2) is covered by the tail cover assembly (not labelled).
[00043] For the safety of the rider and in conformance with the traffic rules, a headlamp assembly 105 that includes a headlamp 110 and front indicator lights 140a are provided in the front portion of the vehicle 100. On the rear portion of the two wheeled vehicle 100 a tail lamp (not labelled) and rear indicator light 140b are provided on the rear portion of the tail cover assembly (not shown). Above the tail cover assembly 130 and behind the seat assembly 125 a pillion handle 135 is provided for the pillion rider to grab.
[00044] Suspension systems are provided for comfortable steering of the two wheeled vehicle 100 on the road. A front suspension assembly 195 serves as rigidity component for the front portion of the vehicle 100 just like the frame assembly 200. The front suspension assembly 195 clamped to the head tube (not shown) through an upper bracket (not shown) and a lower bracket (not shown) is capable of being moved to the left and right. Further, a rear suspension system 160, which is a hydraulic damped arrangement, is connected to the frame assembly 200 (shown in Fig. 2). The rear suspension system 160 comprises of at least one rear suspension 160 preferably disposed centrally in the longitudinal mid plane of the vehicle 100. However, in a vehicle 100 with two rear suspensions, the same may be disposed on the left side and the right side respectively of the vehicle 100.
[00045] The first power source, for example the engine assembly 180 is mounted to a front lower portion of the frame assembly 200 (shown in Fig. 2) by means of an engine mounting bracket (not shown). The engine assembly 180is partially covered on the lower side of the engine assembly 180 by an engine cover 175. The engine assembly 180 is equipped with an exhaust system that includes an exhaust pipe (not labelled) connected to the engine assembly 180 and a muffler assembly 155 connected to the exhaust pipe. The muffler assembly 155 extends rearwards along the right side of the rear wheel 150.
[00046] Further, a swing arm (not shown) extending rearwards is swingably connected to a lower rear portion of the vehicle100. The rear wheel 150 is rotatably supported at a rear end of the swing arm (not labelled). Power from the engine assembly 180 is transmitted to the rear wheel 150 through a power drive mechanism, such as a drive chain, so as to drive and rotate the rear wheel 150. A center stand 165 is provided in between the front wheel 185 and the rear wheel 150 for parking the vehicle 100.
[00047] A rear fender 145 for covering an upper side of the rear wheel 150 is mounted to a rear portion of the vehicle 100 to prevent mud and water splashed by the rotating rear wheel 150 from entering the muffler assembly 155, the engine assembly 180 and other parts disposed close by. To enhance the overall aesthetics of the vehicle 100 and to prevent undesired foreign particles from entering parts of the vehicle 100, a plurality of rear covers (not labelled) is attached to a rear portion of the frame assembly 200 (shown in Fig. 2).
[00048] Area below the seat assembly 125 and the fuel tank assembly 120 of the vehicle 100 is covered on both sides by a cover frame assembly 170. The cover frame assembly 170 includes the one or more side covers.
[00049] Fig. 2 illustrates a perspective view of a fuel tank assembly 120 mounted on a frame assembly 200 of a vehicle 100 in accordance with an embodiment of the present invention. A downward portion (120a) of the fuel tank assembly 120 is mounted on the front portion of the frame assembly 200. The rear portion (120d) of the fuel tank assembly 120 is fastened to the frame assembly 200 with help of a plurality of visible fasteners 205, herein called as fastener fuel tank rear mounting 205. The said front portion (120c) of the fuel tank assembly 120 is disposed just behind a head tube 300 (shown in Fig. 3), on a main tube 305 (shown in Fig. 3) of the frame assembly 200. The upper portion (120b) of the fuel tank assembly 120 has an opening which acts as an inlet for inserting the fuel dispenser for filling the fuel tank assembly 120with fuel. The opening is covered by a cap herein called as a fuel cap assembly 210. The fuel cap assembly 210 is so designed that it can be locked by a locking mechanism to avoid theft of fuel or fuel spillage when the vehicle is titled.
[00050] Fig. 3 illustrates an exploded perspective sub assembly of a fuel tank assembly 120 mounted on a frame assembly 200 of a vehicle 100 in accordance with an embodiment of the present invention. The frame assembly 200 of the vehicle 100 includes the head tube 300, the main tube 305, a pair of mid tubes 310 extending in a rear portion of the vehicle 100 as a pair of rear tubes 315. The main tube 305 extends rearwardly downward from the head tube 300. The pair of mid tubes 310 extends rearward, along a longitudinal axis of the vehicle 100, from a rear portion of the main tube 305. The pair of rear tubes 315 extends inclinedly rearward towards a rear portion of the vehicle 100 from the pair of the mid tube 310.
[00051] The fuel tank assembly 120 of the vehicle 100 is mounted on the frame assembly 200 such that said front portion 120c (shown in Fig. 2) of the fuel tank assembly 120 is mounted on the main tube 305 just behind the head tube 300 of the frame assembly 200. The said rear portion 120d (shown in Fig. 2) of the fuel tank assembly 120 is fastened to a front portion of the pair of the mid tubes 310 of the frame assembly 200 with help of a plurality of visible fasteners 205, herein called as fastener fuel tank rear mounting 205. The upper portion of the fuel tank assembly 120 has an opening covered by a fuel cap assembly 210 which acts as an inlet for inserting the fuel dispenser for filling the fuel tank assembly 120 with fuel.
[00052] Fig. 4 illustrates an exploded sub assembly of the fuel tank assembly 200 with essential components of the fuel tank assembly 120 in accordance with an embodiment of the present invention. The fuel tank assembly 120 can be broadly sub divided into an outer unit 440 herein called as, a fuel tank outer portion 440 and an inner unit 445 herein called as, a fuel inner portion 445. The fuel tank outer portion 440 covers the fuel tank inner portion 445 from outside.
[00053] The fuel tank outer profile portion 440 includes a fuel tank outer cover 410, which acts as an outer covering for the entire fuel tank assembly 120 and protects the internal systems from contaminants and damage due to external factors. The upper portion of the fuel tank outer cover 410 has a fuel cap provision 405, on which a fuel cap assembly 210 is attached. The fuel cap assembly210 is fastened to the fuel cap provision 405 by means of a plurality of fasteners, herein called as a fuel cap fastener 400.
[00054] The fuel tank inner portion 445 includes a fuel tank inner 420 which further includes essential components of the fuel tank assembly 200, for example a fuel pump module 415 and a fuel sender unit assembly 425 herein called as a FSA assembly 425. The fuel pump module 415 aids in supplying fuel from fuel tank to the engine assembly 180 (shown in Fig. 1) by creating a positive pressure. The fuel pump module 415 is placed downwardly towards a front portion of the fuel tank inner 420. The FSA assembly 425 aids in estimating the fuel level available in the fuel tank assembly 120. The FSA assembly 25 is disposed at an upper rear portion of the fuel tank inner 420 of the fuel tank assembly 120. The fuel tank inner 420 has a profile which in a length direction L (shown in Fig 6) forms a substantially inverted U-shaped cross section (shown in Fig 6) in the lateral mid region of the fuel tank inner 420. The rear portion of the fuel tank inner 420 comprises of a downward sloping profile in a plane P (shown in Fig 6) followed by a substantially horizontal profile in a plane S (shown in Fig 6) which is orthogonal to the gravity force G (shown in Fig 6) as well as orthogonal to the length direction L (shown in Fig 6) of the fuel tank inner 420. An FSA mounting portion 430 is disposed in said plane P. The FSA assembly 425 is mounted on the fuel tank inner 420 on a FSA mounting portion 430 of the fuel tank inner portion 445.
[00055] The fuel tank outer profile portion 440 is coupled to the fuel tank inner profile portion 445 by means of a suitable attachment means like welding etc. and the fuel tanks assembly 120 is attached to the frame of the vehicle with suitable attachment means e.g. plurality of fasteners at a fuel tank rear mounting 205. As per an embodiment, the fasteners are inserted on dedicated provisions herein called as a provision rear mounting 435, present on the rear end of the fuel tank inner profile portion 445.
[00056] Fig. 5 illustrates a fuel sender unit assembly 425 of a fuel tank assembly 120 with essential components in accordance with an embodiment of the present invention. The fuel sender unit assembly 425 of the fuel tank assembly 120 (shown in Fig 3), herein called as the FSA assembly 425, includes a fuel sender unit 500, a float arm 510, and a float 505. The fuel sender unit, herein called as the FSU 500 is mounted on a FSA mounting portion 430. An extended arm like structure herein called as a float arm 510, is attached to at least one end of the FSU 500, extending away from the FSU 500.
[00057] A small barrel shaped structure herein called as a float 505 is attached to at least one end of the float arm 510 in a direction away from the FSU 500. The float arm 510 is mounted on the FSU 500 by means of a float arm mounting provision 515 having axis C orthogonal to the mounting provision 515. Further the FSU 500is mounted on the FSA mounting portion 430. The float arm 510 along with the float 505, as per the present configuration and layout, is capable of an inclined angular rotation to trace a 3-dimensional coupler curve path. The swivel arc movement of the float arm is about axis C, and follows a 3-dimensional contour CC (shown in Fig 6 and Fig, 7) from a maximum upward position 520 to a minimum downward position 525.
[00058] The angle between the maximum position 520 to a minimum position 525 is a predetermined angle ?1. The ?1 herein called as a 3-dimensional sweep angle ?1. The position of the float 505 present at a maximum position herein is called as a float upper limit position 520. The position of the float present at a minimum position herein is called as afloat lower limit position 525.
[00059] As the level of the fuel in the fuel tank assembly 120 decreases, the float 505 moves in an inclined downward direction. As a result, the float 505 slides a moving electric contact away from the FSU 500 along a resistor (not shown) present on the float arm 510, thus increasing its resistance. Similarly, the float 505 moves in an inclined upward direction with the increase in the fuel level of the fuel tank assembly 120. As a result, the float 505 slides a moving electrical contact towards the FSU 500 along a resistor (not shown) present on the float arm 510, thus decreasing its resistance.
[00060] Therefore, when the fuel in the fuel tank assembly 120 is at its maximum level, the resistance decreases, and the current flow increases. When the fuel in the fuel tank assembly 120 is at its minimum level or the fuel tank assembly 120 is empty, the resistance increases and the current decreases.
[00061] The fuel level information is processed and indicated to the user through a fuel indicator unit (not shown) which is calibrated to display the fuel amount based on the magnitude of electric current flowing through the FSU assembly 425. Therefore, when the fuel level is high and the float 505 is at the float upper limit position 520, the fuel indicator unit (not shown) indicates a full tank. When the fuel level is low and the float 505 is at the float lower limit position 520, the fuel indicator unit (not shown) indicates an empty tank.
[00062] In the present embodiment, the sweep angle ?1 between the maximum position 520 and minimum position 525 of the float 505 denotes the maximum inclined angular rotation of the float505. This configuration of the float to perform a 3-dimensional couple curve enables increasing the overall range of rotation of the float within a compact space. Thus, by increasing the range i.e. sweep angle ?1 the sensitivity and accuracy of measurement of the float is significantly enhanced. Maximum possible sweep angle ?1 ensures maximum possible contact of the float 505 with the upper and lower limit of the fuel in the fuel tank assembly 120. The maximum sweep angle ?1 for the present embodiment for example, is up to 80 °.The maximum access to the lowest and highest level of the fuel volumes present in the fuel tank assembly 120 within the compact vertical as well as lateral dimension of the fuel tank helps in measurement of the lowest and highest level of fuel volumes more accurately by the FSU assembly 425. In situations, particularly when the vehicle is tilted or when fuel sloshing occurs, the maximum possible sweep angle ?1 helps in maximum surface contact of the float 505 with the fuel present in the tank. Thus the FSU assembly 425 achieves an accurate estimation of the fuel present in the fuel tank within a compact fuel tank and a compact vehicle layout.
[00063] Fig. 6 illustrates a perspective view of the fuel tank inner profile portion 445 of the fuel tank assembly 120 (shown in Fig 3)with essential components in accordance with an embodiment of the present invention. The fuel tank inner profile portion 445 includes a fuel tank inner 420 which further includes some essential components of the fuel tank assembly 120, for example a fuel pump module 415, a vapor trap unit 600, and a FSU 500. The fuel pump module 415 which is disposed downwardly laterally at a front portion of the fuel tank inner 420 at either of the left or right-side vertical walls of the inverted U-shaped profile. As per an embodiment, a vapor trap unit 600 is disposed at an upper portion of the fuel tank inner 420 on the bridge wall of the inverted U profile. The fuel sender unit assembly 425 is disposed at an upper rear portion of the fuel tank inner 420 below and rearward of the vapor trap unit 600. The FSU 500 of the fuel sender unit assembly 425is mounted on the fuel tank inner 420 on a FSA mounting portion 430 of the fuel tank inner profile portion 445 such that the FSA mounting portion is disposed in said plane P.
[00064] The float 505 attached to the FSA 425 by means of a float arm 510,which is capable of an inclined angular rotation from its minimum position 525 to a maximum position 520. The minimum position 525 of the float 505 is a float lower limit position 525 and the maximum position 520 of the float 505 is a float upper limit position 520. The float upper limit position 520 ensures maximum surface contact with the upper limit of the fuel present in the fuel tank assembly 120. The float lower limit position 525 ensures maximum surface contact with the lower limit of the fuel present in the fuel tank assembly 120 thereby enhancing the buoyancy forces acting on the float which thereby enhances the accuracy of measurement.
[00065] Fig. 7 illustrates a side view of the fuel tank inner profile portion 445 of the fuel tank assembly 120 (shown in Fig 3) with essential components in accordance with an embodiment of the present invention. The FSA assembly 425 of the vehicle 100 extends in a inclined rearwardly manner from a front side to a rear side along a central longitudinal axis Y-Y’ disposed in plane P (shown in Fig 6). The FSA assembly 425 is upwardly placed on a rear portion of the sloping region of the fuel tank inner 420 just below a vapor trap unit 600 and in proximity to a fuel pump module 415. The placement of the FSA assembly 425 is such that it makes an angle ?2, herein called as a second angle ?2with respect to a horizontal axis X-X’ which is disposed in said plane P (shown in Fig 6).The second angle ?2 for example, is in range of 0° to130 °.The second angle ?2also enables more accurate fuel indication even when the vehicle is tilted or when vehicle 100 encounters fuel sloshing during acceleration, deceleration, braking, speed braking, encountering with pot holes and road bumps.
[00066] Fig. 8 illustrates a side view of the fuel tank assembly 120 (shown in Fig 3) in accordance with an embodiment of the present invention. The fuel tank inner profile portion 445includes a float 505 of the fuel sender unit assembly (not shown). The illustrated figure in the present embodiment shows the distance covered by the float 505 from its maximum position to the minimum position in the fuel tank inner profile 445 of the fuel tank assembly 120 (shown in Fig 3).
[00067] The placement of the FSA assembly 425 is such that it makes a second angle ?2 with respect to a horizontal axis X-X’. The distance between the float upper limit position 520 and the float lower limit position 525 is D1 when projected in said plane S. The distance D1 as per an embodiment is in the range of 50 mm to 150 mm. The angular distance between the float upper limit position 520 and the float lower limit position 525 is D2 when projected in plane P. The distance D2 for example, as per an embodiment is in the range of 150 mm to 200 mm. The distance between the float upper limit position 520 and the float lower limit position 525 is D3 when project in a plane orthogonal to said plane S .The distance D3 as per an embodiment is in the range of 100 to 170 mm.
[00068] The sweep angle ?1, the second angle ?2and the distances D1, D2 and D3 between the float upper limit position 520 and the float lower limit position 525 enables to achieve higher precision and accuracy in fuel level estimation by the fuel sender unit. As per an alternate embodiment, the sweep movement of the float may be configured to be a 2-dimensional curve to enhance the range and accuracy of fuel level measurement.
[00069] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

LIST OF REFERENCE NUMERALS

100 – Vehicle
105- Head lamp assembly
110- Head lamp
115- Handle bar assembly
120- Fuel tank assembly
120a: Down portion of fuel tank assembly
120b: Upper portion of fuel tank assembly
120c: Front portion of fuel tank assembly
120d: Rear portion of fuel tank assembly
125- Seat assembly
130- Tail cover assembly
135- Pillion handle
140a- Front indicator light
140b- Rear Indicator light
145- Rear fender
150- Rear wheel
155- Muffler assembly
160- Rear suspension system
165- Center stand
170- Cover frame assembly
175- Engine cover
180- Engine assembly
185- Front wheel
190- Front fender
195- Front suspension assembly
200- Frame assembly
205- Fastener fuel tank rear mounting
210- Fuel cap assembly
300-Head tube
305- Main tube
310- Down tube
315- Rear tube
400- Fuel cap fastener
405- Fuel cap provision
410- Fuel tank outer cover
415- Fuel pump module
420- Fuel tank inner
425- Fuel sender unit assembly
430- FSU mounting profile
435- Provision rear mounting
440- Fuel tank outer
445- Fuel tank inner
500- Fuel sender unit
505- Float
510- Float arm
515- Float arm mounting provision
520- Float upper limit position
525- Float lower limit position
600- Vapor trap unit
?1- Sweep angle
?2- Second angle
D1- Horizontal distance
D2- Angular distance
D3- Vertical distance