FIELD OF INVENTION
The present invention relates to a fuel tank assembly for vehicles and more particularly to a hermetic fuel tank assembly for vehicles such as motor cycles, scooters, moped, scooty, and the like.
BACKGROUND OF THE INVENTION
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art(s).
Generally, the automotive vehicles are equipped with a fuel level sensor in a fuel tank to sense or indicate the level of the fuel remaining in the fuel tank. Examples of such fuel level sensors include the subject matters disclosed in 250933, 262944, 256778, and the like. Typically, the fuel level sensors are known for sensing/detecting the level of stored fuel in a fuel tank of a vehicle. The fuel level sensors typically comprise of a float and its arm in a fuel tank which includes a variable impedance element whose impedance varies in proportion to the fuel level in the fuel tank. This impedance is read by a coil-type fuel gauge mounted in a vehicle information display instrument positioned in front of a rider's/driver's seat of the vehicle. Thus, a signal corresponding to the level of the fuel as sensed by the fuel level sensor can be transmitted to the gauge to inform the level of the fuel remaining in the fuel tank. Further, the purely mechanical fuel level sensor includes the float, a spiral strip of metal, and the fuel gauge. During operation, the float moves according to the fuel level in a vertical direction along the spiral strip of metal, which is attached to an indication needle of the fuel gauge. As the fuel level rises and lowers, the float causes the strip of metal to turn, thus moving the indication needle of the fuel gauge and informing the rider about the current fuel level, preferably by indicating the same in the information display instrument device of the vehicles. Conventionally, the fuel level sensors are provided with an arm having a buoyant member i.e. the float at the end of the arm. The arm is pivotally mounted to a fine assembly via a hermetic housing that accommodates a carrier that carry plurality of

movable contact members on a ceramic resistor card. The ceramic resistor card includes multiple traces that typically extend out like the spokes of a wheel in an arc that is approximately of 85 degrees. Thus, as the level of the fuel changes, the float moves up and down and causes the arm to which it is attached to change its angle and therefore move the contact along the arc shaped conductive traces of the ceramic resistor card, which subsequently sends a signal to the fuel level indicator. These ceramic based fuel level sensors are open and exposed to the fuel in the fuel tank. Further, these types of sensors are costly as well. The Indian patent application number 3990/DEL/2014, from the same applicant, claims a non-contact & compact type fluid level sensor for sensing the level of remaining fluid in a tank. However, the fuel level sensor discussed in the Indian patent application number 3990/DEL/2014 functions on a linear movement within the tank. Also, the said fluid level sensor demands terminals to be soldered subsequent to which epoxy also needs to be applied to finalize the assembly. This whole process requires optimum skills as well as ample amount of time required for cooling the epoxy and the assembly too:
Usually, these fuel level sensors employ silver (Ag based conductive inks (Ag, Pd, Pt) and high contents silver contacts (Paliney, Ag/Ni). These materials function in fuels that contain moderate sulfur level or may be in a bio fuel such as ethanol based, fuel (mainly used in automobiles in US and Brazil) which subsequently results in thin lacquer contamination or a complete deterioration of the fuel level sensors. In other words, these silver based fuel level sensors produce opens or a shift in resistance when exposed to such extremely reactive fuel.,These existing fuel level sensors, when subjected to such ethanol based fuel, demands a regular servicing, maintenance and thus replacement resulting in enhanced overall, cost of the fuel level sensors. Moreover, considering the advantages of the bio fuel on the individual and the environment, there must be an improved fuel unit assembly suitable to the requirements of the modern vehicles in India and abroad as well. The Indian patent application number IN 201611010084, from the same applicant^ claims an ultrasonically sealed fuel unit assembly to protect the fuel unit assembly from the contaminated fuel present in the fuel tank of the vehicles. However, the said fuel unit explains the fact that a thin film resistor provided with a compartment.of the fuel unit

assembly is pushed along the base of an U-shaped hermetic housing. This process requires a lot of precision lack of which may result in the deterioration of the thin film resistor. Moreover, a holder provided with the assembly is die-casted to get finally fitted on the assembly wherein the pins are carved as an integral part of the holder. This kind of construction invites the risk of broken pins during the fitting of the the holder onto the assembly. Further, the float arm as described in the hermetic fuel unit assembly of IN 201611010084 is not easily adapted in all the fuel tank units as the design is suitably designed with straight arms, and thus cannot be fitted in the existing fuel unit assemblies as well. Furthermore, the hermetic fuel unit assembly lacked the option of testing the leakage in the fuel unit assembly also.
Various attempts have been made to replace the conventional fuel unit assembly to meet the necessities of the present fuel unit assembly in all kinds of vehicles. However, the concepts could not be commercially accepted due to some drawbacks such as absence of non-degradable components, failure in achieving a shielded structure for the fuel unit assembly, extensive cost with respect to the manufacturing of a suitable fuel unit assembly, and the like. Therefore, it is an object of the present invention to provide an improved hermetic fuel unit assembly which does not suffer from the foregoing drawbacks and also without losing the basic requirements of user-friendly, reliability, safety, less extra cost, and the like.
BRIEF SUMMARY AND OBJECTIVES OF THE INVENTION
^. The present subject matter relates to a fuel unit assembly for vehicles which
preferably includes a stay-arm attached to one end of a hermetic housing and a float
arm assembly connected to another end of the hermetic housing assembly. The
hermetic housing is structured of a lower case encompassing a thin film resistor fitted
within a space en-carved on the lower case. Further, a wiper is fitted above the thin
film resistor in the lower case for movement along an arc shaped conductive trace
carved on the thin film resistor. The present subject matter explains the fact that the
lower case is hermetically shielded by an upper case with ultrasonic welding. Also,
the upper case is provided with an aperture extending there through the upper case in
which a carrier is movably hinged to the upper case to receive and provide the path

for guiding the movement of the float arm assembly in a fuel tank. The uniqueness of the present subject matter is the way the thin film resistor is pushed along the guiding slot designed integrally with the lower case. Additionally, the assembly is provided with a leakage testing valve to diminishes the chance of any possible leakage from the shielded fuel unit assembly. Also, the lower case is designed with a poka-yoke pin protruded through the stay arm to guide the assembly of the stay arm.
BRIEF DESCRIPTION OF DRAWINGS
The summary narrated above and the following detailed description of the invention can be understood with the drawings appended to this claim. The illustrations provide the details of the invention. However, it should be understood that the invention is not limited to the arrangements shown. In the drawings:
FIG. 1 show a perspective view of a vehicles in an embodiment of the present subject matter.
FIG. 2 shows a perspective view of a fuel tank of the vehicles in an embodiment of •' the present subject matter.
FIG. 3 shows an assembled perspective view of a fuel tank assembly of the vehicles in an embodiment of the present subject matter.
FIG. 3A to 31 show perspective views of various parts of the fuel tank assembly of the vehicles in an embodiment of the present subject matter.
FIG. 4 shows a perspective view of a stay arm in an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION
The embodiments of the present subject matter are described in detail with
reference to the accompanying drawings. However, the present subject matter is not
limited to these embodiments which are only provided to explain more clearly the
present subject matter to the ordinarily skilled in the art of the present disclosure. In
the accompanying drawings, like reference alphabets and numerals are used to
indicate like components. .
The present subject matter relates to a fuel unit assembly for vehicles which preferably includes a stay-arm attached to one end of a hermetic housing and a float arm assembly connected to another end of the hermetic housing assembly. The hermetic housing is structured of a lower case encompassing a thin film resistor fitted within a space en-carved on the lower case. Further, a wiper is fitted above the thin film resistor in the lower case for movement along an arc shaped conductive trace carved on the thin film resistor. The present subject matter explains the fact that the lower case is hermetically shielded by an upper case with ultrasonic welding! Also, the upper case is provided with an aperture extending there through the upper case in which a carrier is movably hinged to the upper case to receive and provide the path for guiding the movement of the float arm assembly in a fuel tank. The uniqueness of the present subject matter is the way the thin film resistor is pushed along the guiding slot designed integrally with the lower case. Additionally, the assembly is provided with a leakage testing valve to diminishes the chance of any possible leakage from the shielded fuel unit assembly. Also, the lower case is designed with a poka-yoke pin protruded through the stay arm to guide the assembly of the stay arm.
The present invention relates to a fuel tank assembly for vehicles and more particularly to a hermetic fuel tank assembly for vehicles such as motor cycles, scooters, moped, scooty, and the like. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. The present invention will hereinafter be described in detail below as applied to a motorcycle 100! However, the principles of the present invention are also applicable

to other vehicles 100 such as three wheelers, four wheelers, and the like. Upward, lower, front and rear directions (see the directions indicated by the arrows in FIG. 1) will be described with respect to directions as seated by the rider on the motorcycle 100.
FIG. 1 illustrates a two wheeler that may include a fuel tank 102 and an engine mounted ahead of a rider's seat 104, si frame 106 and two relatively large sized wheels 108 on which the frame 106 rides. The structure is necessarily provided with a pair of left and right front fork members rotatably supported by a head pipe Bon the front end of the vehicle frame. The steering of the two wheelers 100 is possible via a front wheel which is mounted on the front fork member whereas the rear wheel (drive wheel) is at the rear end. FIG. 1 shows a handlebar 112 secured to an upper portion of the front fork member, and the front and rear portion of the handle bar 112 is covered with a handle cover which is further divided into forward and backward portions. The two wheeler 100 is also provided with various lights mounted externally on the vehicle to indicate certain information about the vehicle to other drivers and pedestrians. These lights mainly include brake lights and tail lights besides indicator light bulbs which are provided to indicate the driving direction of the two wheelers. The two wheeler 100 is further provided with the intelligent vehicle information display instrument 114 (as shown in FIG. 2 later) (also known as a speedometer) located between the handle bars 112 of the two wheeler 100. The vehicle information display instrument 114 may be viewable by the rider of the motor cycle 100 when the rider is seated on the seat 104 and operating the vehicle 100. The vehicle information display instrument 114 may be disposed generally in front of the rider so that the rider can inspect or view a variety of information that form part of the vehicle information display instrument 114, which information may indicate an operating condition or conditions of the vehicle. The vehicle information display instrument 114 may be provided with audio/visual warning indicators comprising information such as speed, the fuel level, telephone, bluetooth, rpm of the engine, telltale symbols, turn signal indicator, hazard warning indicator and / or other indicators. FIG. 1 further shows a headlight 116 provided, as an attachment to the top middle of the handlebar of the motor cycle, to light the road ahead.

In an embodiment of the present subject matter, FIG. 2 discloses a perspective view of the fuel tank 102 provided with a fuel supply port 118 formed on the upper surface of the fuel tank 102. The fuel supply port 118 may be closed by a cap unit (not shown) which is basically a cap to seal the fuel tank 102. The cap unit can arbitrarily be opened and closed because its hinge portion is rotatably supported through a hinge pin. In an embodiment of the present subject matter, the locking unit incorporates a lock bar which is capable of moving/retracting sideward by means of an ignition key. The fuel tank 102 is further provided with a fuel pump (not shown) mounted either externally to the fuel tank 102 or in the lowest portion of the inner bottom surface of the fuel tank. The fuel pump and its function is not within the scope of the present subject matter. In an embodiment of the present subject matter, the fuel tank 102 is also provided with a filel unit assembly for sensing/detecting the level of stored fuel in a fuel tank of a vehicle. The fuel unit assembly may vary in configuration, as discussed later, depending on the configuration of the fuel tank 102 and also on the basis of inserting the fuel level sensors into the fuel tank 102. The present subject matter will hereinafter be described in detail below as applied to one of the types of fuel unit assembly i.e. an adjustable lever type fuel unit assembly. However, the principles of the present invention are also applicable to a second type of fuel unit assembly i.e. a simple lever type fuel unit assembly.
In ah embodiment of the present subject matter, FIG- 3 illustrates a perspective view of the fuel unit assembly 200 for vehicles. The fuel unit assembly 200 according to the present subject matter is structured of three major components i.e. a float arm assembly A, a hermetic housing B, and a stay-arm C. In an embodiment of the present subject matter, the hermetic housing B is structured of an upper case 302 and a lower case 304 as-shown in FIG. 3A. The lower case 304 is mainly an U-shaped compartment (shown in FIG. 3B) that accommodates a thin film resistor 306 (also known as TFR as shown in FIG. 3C) along a guiding slot 308 provided integrally with the lower case 304, Further, the lower case 304 is also designed to anchor a contact device 310 which electrically contacts a wiper 312 (as discussed later) and conduct the current out of the wiper 312 by way of plurality of terminal lugs 314 provided with the contact device 310. In an embodiment of the

present subject matter, the wiper is rotatable in an angular range of 50 to 82 degrees. The U-shaped hermetic housing B further holds the wiper 312 placed above the thin film resistor 306 in the U-shaped compartment 312 for movement along an arc shaped conductive trace carved on the thin film resistor 306, in an exemplary embodiment of the present subject matter shown in FIG- 3D. The wiper 312 is riveted with metallic contacts to move on the thin film resistor 306 for sensing the resistance value corresponding to the instant fuel level in the fuel tank 102, as discussed later. In a preferred embodiment of the present subject matter, the U-shaped compartment is hermetically concealed by the upper case 302 to completely enclose the U-shaped compartment as shown in FIG. 3E. In an embodiment of the present subject matter, the upper case 302 and the lower case 304 are made of fuel resistant plastic, such as but not restricted to, acetyl polymer. In an embodiment of the present subject matter, the upper case 302 and the lower case 304 are hermetically sealed to each other by ultrasonic welding. However, various other processes such as laser welding, spin welding, heat plate joining, vibration welding, and the like may be utilized to connect the two cases. In an exemplary embodiment, the upper case 302 is provided with an aperture 316 extending there-through the upper case 302. The said aperture 316 guides a carrier 318 (also refer to FIG. 3G) and there-into a float arm 322 to move along the metallic strip to subsequently indicate the level of fuel inside the water tank in an embodiment of the present subject matter shown in FIG. 3H. FIG. 3F further illustrates an elastomeric rubber gasket 320 disposed around the aperture 316 provided on the upper case 302 of the assembly as shown in FIG. 3E. The elastomeric rubber gasket 320 are formed of material such as, but restricted to, silicone rubber or ethylene propylene rubber. The said elastomeric rubber gasket 320, thus, advantageously hermetically seals the aperture 316 and prohibits any leakage or flow of fluid through the aperture 316 in an embodiment of the present subject matter.In another embodiment, the aperture 316 is covered by the carrier 318 designed to receive the float arm 322 (shown in FIG. 3H) with a float 328 floating in the fuel tank 102. FIG. 3H further shows plurality of wire cables 334 inserted into the lower case to get electrically connected inside the hermetic housing B. Further, the carrier is additionally supported with a carrier holder 324 to hold and thus support

the upper case 302 and lower case 304 together as shown in FIG. 31 in a unique embodiment of the present subject matter. In particular, the carrier holder 324 is screwed to the lower case 304 at one end and to the carrier 318 on the other end. In an embodiment of the present subject matter, the stay C is further attached to the lower case 304 by at least two screws 326 guided by a poka-yoke pin 330 provided with the lower case 304 of the hermetic housing B, as is evident from the FIG. 4. The said poka yoke pin 330 is protruded as an integral part of the lower case 304. Hence, the upper case 302 is connected to the lower case 304 in a manner that the housing B containing the thin film resistor 306, wiper 312, and the like are completely shielded from the liquid environment. In other words, the upper case 302 and the lower case 304 are permanently connected to each other assuring a throughout life of the fuel unit assembly 200. In an exemplary embodiment of the present subject matter, the upper case is provided with a leakage testing valve 332 (as shown in FIG. 3E and FIG. 3F) though which pressurized liquid is pumped into the assembly to check the leakage wherein the outlet flow is controlled by an outlet valve, the scope of which is beyond the scope of the present subject matter.
During operation, the fuel unit assembly 200 is operationally connected to the fuel tank 102, as discussed above. The fuel in the fuel tank 102 cause the float 328 to rise to the top thereof once the fuel tank 102 is filled with the fuel. As the fuel level increases or decreases in the fuel tank 102, the float 328 is raised or lowered to rotate the wiper 312 relative to the thin film resistor 306 via the float arm 322 floating in the fuel. The rotation of wiper 312, and thus terminal lugs 314 move to different positions thereof to vary or provide a different predetermined resistance to indicate the level of the fuel remaining in the fuel tank 102 and thus informing the rider about the current fuel level, preferably by indicating the same in the information display instrument device 114 in the vehicles. In an embodiment of the present subject matter, the thin film resistor 306 is pushed along the guiding slot 308 provided integrally with the lower case 304 as discussed above. Thus, the float arm 322 moving with the level of the fuel inside the fuel tank 102 reads the TFR 306 and transmits the corresponding signals to the vehicle which are evident in the vehicle information display instrument 114 as well. The exemplary embodiment of the present subject

matter facilitates a sealed fuel level assembly 200 that prohibits any contamination or impurity to the fuel present in the fuel tank 112 of the vehicles 100.
The fuel tank assembly for vehicles according to the present subject matter . advantageously facilitates a completely shielded fuel unit assembly that can be implemented in fuel or any specific fuel such as gasoline and ethanol fuel (wherein the percentage of ethanol ranges from 25% to 100%). The arrangement according to the present subject matter discloses a liquid free environment resulting in a secured surrounding conditions, esp for silver (Ag) based conductive inks (Ag, Pd, Pt) 'and high contents silver contacts (Paliney6, Agmi) required for thin film resistors. Further, the presence of elastomeric seal and the upper case guarantees a robust construction of the shielded fuel unit assembly that can be implemented in any kind,of fuels such as gasoline fuel or bio-fuel as mentioned above. Furthermore, such fuel unit assembly remarkably exhibits a dimensional stability when exposed to harsh chemicals present in the ethanol fiiel or any other variety of fuels. Additionally, since each part of the said shielded fuel unit assembly is made of plastic, hence the drawback of corrosion has reduced outstandingly. Further, the quantity of snap-fit arrangements have also reduced to a great level, hence this would further reduces the cost of the structure. Also, since the carrier holder is extended to hold and support the carrier, hence the possibility of failure in load test, vibration test and other similar tests. Thus, the present subject matter ensures least requirement of servicing and maintenance that subsequently lowers the overall cost of any field level measuring apparatus. In a unique embodiment of the present subject matter, the thin film resistor is pushed along the guiding slot provided integrally with the lower case, which consequently reduces the chance of damage of the contact pins while assembling the components inside the lower case of the fuel unit assembly. Further, the presence of leakage testing valve helps in reducing the probability of fuel leakage in and out of the fuel tank assembly. Furthermore, the lower case is designed with the poka-yoke pin protruded through the stay arm that guide the assembly of the stay arm in an effective way, especially for. new skilled workers. Moreover, the present subject matter discloses an improved, advanced, reliable, and customers' friendly fuel tank assembly for every type of fiiel vehicles.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

WE CLAIM:
1. A fuel unit assembly 200 for vehicles comprising:
a stay-arm C attached to one end of a hermetic housing B;
a float arm assembly A connected to another end of the hermetic housing assembly B; the hermetic housing B comprising;
a lower case 304 encompassing a thin film resistor 306 fitted within a space en-carved on the lower case 304;
a wiper 312 fitted above the thin film resistor 306 in the lower case 304 for movement along an arc shaped conductive trace carved on the thin film resistor 306;
the lower case 304 is hermetically shielded by an upper case 302 with ultrasonic welding;
the upper case 302 is provided with an aperture 316 extending there through the upper case 302;
a carrier 318 movably hinged to the upper case 302 to receive and provide the
path for guiding the movement of the float arm assembly A in a fuel tank 102;
* . ■ -
wherein,
a leakage testing valve 332 provided on the upper case 302 to verify the possibility of leakage from the fuel unit assembly 200;
the thin film resistor 306 is pushed along the guiding slot designed integrally with the lower case 304.
2. The fuel unit assembly 200 as claimed in claim 1, wherein the lower case 304 is attached to the upper case 302 by ultrasonic welding.
3. The fuel unit assembly 200 as claimed in claim 1, wherein a carrier holder 324 is fastened to hold the carrier 318 at its one end and the upper case 302 at its other end.

41 The fuel unit assembly 200 as claimed in claim 1, wherein the lower case 304, the upper case 302, the carriers (318,324), and the fasteners are made of plastic.
5. The fuel unit assembly 200 as claimed in claim 1, wherein the top surface of the upper case is provided with^a knife-edge surface that cover a flat rubber gasket 320 to securely seal the opening provided on the upper case 302 of the fuel unit assembly 200.
6. The fuel unit assembly 200 as claimed in claim 1, wherein the wiper 312 is riveted with metallic contacts to move on the thin film resistor 306 for sensing the resistance value corresponding to the instant fliel level in the fuel tank 102.
7. The fuel unit assembly 200 as claimed in claim 1, wherein the aperture 316 is provided with an elastomeric rubber seal 320 tightly gripped on the carrier 318.
8. The fuel unit assembly 200 for vehicles as claimed in claim 1, wherein the wiper is rotatable in an angular range of 50 to 82 degrees.
9. The fuel unit assembly 200 for vehicles as claimed in claim 1, wherein the fasteners may include screws, snaps, rivets, buttons, zippers, mushroom fasteners, and the like.
10. The fuel unit assembly 200 for vehicles as claimed in claim 1, wherein the lower case 304 is designed with a poka-yoke pin 330 protruded through the stay arm C to guide the assembly of the stay arm C.