FORM 2
THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENTES RULES, 2005
COMPLETE SPECIFICATION (See section 10, rule 13)
1. TITLE OF THE INVENTION
"Mechanism For Restricting Fuel Flow From An Auxiliary Chamber To The
Fuel Tank"
2. APPLICANT(S)
(a) Name : MAHINDRA & MAHINDRA LIMITED
(b) Nationality : Indian Company registered under the provisions
of the Companies Act, 1956
(c) Address : R&D Center, Automotive Sector,
89, M.I.D.C, Satpur, NASHIK - 422 007 Maharashtra State, India
3. PREAMBLE OF THE DESCRIPTION
COMPLETE
The following specification
particularly describes the invention and the manner in which it is to be
performed.

Mechanism For Restricting Fuel Flow From An Auxiliary Chamber To The
Fuel Tank
Field of the invention
The present invention relates to a fuel tank of an automobile, and more particularly, the present invention relates to a mechanism that restricts the fuel flow from an auxiliary chamber to the fuel tank body of an automobile.
Background of the invention
Fuel tank of an automotive vehicle is, generally, provided with an auxiliary chamber mounted interior of the fuel tank body to hold the fuel. In the automotive vehicles, more particularly, in non gravity fuel feed vehicles, fuel is required to be supplied from the fuel tank to the combustion engine through fuel lines by means of fuel pump, and these fuel pumps generally extract fuel from the auxiliary chamber mounted interior of the fuel tank body.
When automobile is standing or running on the slant surface, fuel inside the auxiliary chamber flows out to the fuel tank body exposing the suction side of the fuel pump to the air / vapor forcing to the situation that may lead to stalling of the combustion engine due to non supply of fuel to the combustion engine.
Hence, to obviate the abovementioned problems, it is preferred to provide a valve member, particularly, an one way valve to the communication port that would allow the fuel to enter from the fuel tank body to auxiliary chamber but restricts the flow of fuel from auxiliary chamber to the fuel tank body so that, even if the vehicle is moving on slant surface and fuel tank is tilted, then the fuel would not come out of the auxiliary chamber and the suction side of the fuel pump is not get exposed to air and vehicle does not stall. When the vehicle and thereby the fuel

tank again become horizontal, fuel get filled into the auxiliary chamber, thus smooth running of the automotive vehicle is ensured.
Art is known of providing different one way valves to prevent the fluid motion in one direction only, such as solenoid valve, check valve, use of float body, spring loaded one way valve, etc.
US Patent Application No. 10/857,144 discloses a fuel tank system for the automotive vehicle which has first and second fuel tank for storing fuel. The tanks are interconnected by a connecting pipe with a one-way valve disposed in the connecting pipe such that fuel can flow from a filling tank to an engine supply tank but not in the reverse direction.
However, such systems are difficult to mount to the communication port of the auxiliary chamber, and also they are comparatively costly. Secondly, if such valve goes faulty or becomes inoperative, it may stop fuel flow from fuel tank body to auxiliary chamber and vehicle may not run for long, once the fuel level in the fuel tank body goes below the height of the auxiliary chamber.
Accordingly, there exist a need to negate the abovementioned shortcomings and inconveniences, and to provide a system that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body and which is responsive to the tilt of the fuel tank structure, is simple, easy to mount and less costly.
Objects of the invention
An object of the present invention is to ensure that vehicle is running with less quantity of fuel at gradient.

Another object of the present invention is to ensure the fuel supply to fuel pump / fuel feed system even when the fuel tank body is tilted.
Yet another object of the present invention is to provide an arrangement that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body which is tilt responsive.
One more object of the present invention is to provide an arrangement that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body which is less costly.
Further object of the present invention is to provide an arrangement that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body which is easy to mount.
Further one object of the present invention is to provide an arrangement that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body which is simple and does not go inoperative.
Yet another object of the present invention is to reduce dead volume of the fuel tank body.
Summary of the invention
Accordingly, the present invention provides a mechanism for restricting fuel flow from an auxiliary chamber disposed in the fuel tank back to the fuel tank of an automobile when standing or running on the slant surface, characterized in that the auxiliary chamber comprising:
a horizontal base plate;
a vertical cylindrical wall extending from the horizontal base plate;

a communication port extending from inside of the auxiliary chamber to the exterior thereof allowing fuel to flow between the fuel tank and the auxiliary chamber;
a flexible member attached to the vertical cylindrical wall for closing the communication port on tilting of the automobile;
at least one rubber bolt for securing the flexible member to the vertical cylindrical wall; and
a taper step like structure configured along with the rubber bolt for holding the flexible member securely to the vertical cylindrical wall;
wherein , upon flowing of the fuel in the fuel tank body towards one of the corner of the fuel tank when the automobile is standing or running on the slant surface, pressure of the fuel inside the auxiliary chamber forces the flexible member to remain abut against vertical cylindrical wall and the base plate of auxiliary chamber thereby covering the communication port until the fuel tank assembly is tilted so as to prevent the fuel in the auxiliary chamber to go back in to the fuel tank.
Brief description of the accompanying drawings
Figure 1 illustrates a side view of an automotive vehicle with a fuel tank assembly in a preferred embodiment of the present invention;
Figure 2 illustrates top view of the fuel tank assembly of figure 1;
Figure 3 illustrates a sectional view of fuel tank assembly of a preferred embodiment along A-A as shown in Figure 2;
Figure 4 illustrates an enlarged view of the portion as marked by the circle 'C as shown in Figure 3;

Figure 5 illustrates sectional view of the fuel tank assembly along B-B as shown in Figure 2;
Figure 6 illustrates sectional view of fuel tank assembly at the time when automotive vehicle and fuel tank structure is tilted front side down;
Figure 7 illustrates sectional view of fuel tank assembly at the time when automotive vehicle and fuel tank structure is tilted front side upward; and
Figure 8 illustrates the fuel tank assembly with communication port of an embodiment of the invention.
Detailed description of the invention
In accordance with the present invention the drawbacks as- stated hereinabove have been overcome by providing a system that allows fuel flow from fuel tank body to auxiliary chamber and restricts the fuel flow from auxiliary chamber to fuel tank body; which is responsive to the tilt of the fuel tank structure; which is simple, easy to mount and less costly.
For the better understanding of this invention, reference would now be made to the embodiment illustrated in greater depth in the accompanying figures and description here below, further, in the following figures, the same reference numerals are used to identify the same components in various views.
The terms "front", "rear", "left", "right", "up", "down" used therein represents the directions as seen from an automobile driver and these directions are referred by arrows Fr, Rr, L, R, U, D in the drawings.
The present invention provides a mechanism (100) for restricting fuel flow from an auxiliary chamber to a fuel tank when automotive vehicle is standing or

running on the slant surface. The mechanism (100) includes improvement in the auxiliary chamber (15).
Referring now to figure 1, a side view an automotive vehicle (01) employing a fuel tank assembly (06) in a preferred embodiment of the present invention is illustrated. For example, the automotive vehicle (01) is a SUV as illustrated in figure 1. The figure 1 shows inter-alia, an engine unit (02) as power generating unit which runs on the fuel stored in the fuel tank assembly (06) situated on the chassis member (not shown) of the automotive vehicle (01). Generally, fuel is extracted from the fuel tank assembly (06) by negative pressure of the running engine unit (02) or, by fuel pump unit (not shown) along with fuel line is also employed for smooth running of the engine unit (02). The fuel from the fuel tank assembly (06) is supplied to the engine unit (02) through a fuel line (20) and excess fuel from the engine is returned back to the fuel tank assembly (06) though a return fuel line (21). Specifically, lower ends of both the fuel lines (20) and the return fuel lines (21) open inside and at the lower end of the auxiliary chamber (15). Thus, fuel in the fuel tank body (06) once stored in the auxiliary chamber (15) is supplied to the engine unit (02) through the fuel line (20) and after that the fuel which is not used with the engine unit (02) is returned to the auxiliary chamber (15) through the return fuel line (21).
Referring now to figure 2-3, a top view of the fuel tank assembly (06) in accordance with the present invention is illustrated. The fuel tank assembly (06) is approximately rectangular in shape tank in which fuel is stored. The fuel tank assembly (06) is confined by the four vertical side walls as front wall (07), rear wall (08), left side wall (09) and right side wall (10), a top cover (11), an undersurface (12), an inlet neck opening (13).
The undersurface (12) providing a base that rests over the chassis member. The top cover (11) covers the fuel tank assembly (06). The inlet neck opening (13) to receive the spout of fuel dispenser [not shown] is configured in the upper part

thereof of the fuel tank assembly (06), more particularly, on the top cover (11) as shown in the preferred embodiment illustrated in the Figure 2 and Figure 3. The inlet neck opening (13) projects out of the side body (14) of the automotive vehicle (01) enabling easy entry of spout of fuel dispenser and filling of the fuel in the fuel tank assembly (06).
The improvement in the mechanism (100) comprises the auxiliary chamber (15) disposed in the fuel tank assembly (06) with the fuel line (20) suspended therein for supplying fuel from the fuel tank assembly (06) to the engine unit (02) and (shown in figures 1 and 3). In an embodiment, the auxiliary chamber (15) is cylindrical in shape with open top portion and disposed over the undersurface (12) of the fuel tank assembly (06).
Referring now to figures 3, 5, 6 7 & 8, various views of the auxiliary chamber (15) in accordance with the present invention are illustrated. In a preferred embodiment, the auxiliary chamber (15) includes a horizontal base plate (16), a vertical cylindrical wall (17), a communication port (18)), a flexible member (19) and at least one rubber bolt (23) and a taper step like structure (27).
The communication port (18) is an opening, which opens inside and the exterior of the auxiliary chamber (15) for free communication or flow of the fuel between auxiliary chamber (15) and fuel tank assembly (06).
The flexible member (19) opens and closes the communication port (18) on tilting the automotive vehicle (01). The flexible member (19) is attached to the vertical cylindrical wall (17) of the auxiliary chamber (15). Specifically, the inflow of the fuel into the auxiliary chamber (15) is permitted, the flexible member (19) is arranged such that outflow of the fuel from the auxiliary chamber (15) to the fuel tank body (06) is prevented in tilted position.

The flexible member (19) includes opening (not shown) in an upper portion thereof which is fixedly attached to the vertical cylindrical wall (17) from interior side of the auxiliary chamber (15) as illustrated in the figure 4 and figure 5 in the preferred embodiment of the present invention. The flexible member (19) is made of material which is selected such that it remains substantially impassive to the fuel in the fuel tank assembly (06)/ the auxiliary chamber (15) and also to the effect of temperature rise of the fuel in the auxiliary chamber (15) that may caused due to hot fuel from the return fuel line (21). In preferred embodiment, the flexible member (19) is made of nitrile rubber (NBR)/poIyvinyl chloride (PVC) grade material. The flexible member (19) is attached to the vertical cylindrical wall (17) of the auxiliary chamber (15) by means of the rubber bolt (23), as shown in figure 4.
The rubber bolt (23) includes a head member (24) at one end and a stem member (25) extending from the head member (24) in one direction having diameter substantially same as that of a opening (17a) on the vertical cylindrical wall (17) of the auxiliary chamber (15). Along the length of the stem member (25) is provided with taper step like structure (27) comprising a vertical edge (not numbered) and a slant edge ((not numbered) sloping towards free end of the stem member (25), which then merge into diameter of the stem member (25). The distance between the head member (24) and the vertical edge of the taper step like structure (27) is such that, once fixed to the vertical cylindrical wall (17) of the auxiliary chamber (15) holding flexible member (19) therebetween, does not exhibit substantial movement along axial direction of the hole opening (17a).
In an embodiment, the flexible member (19) is mounted on the vertical cylindrical wall (17) using more than one rubber bolts (23). In another embodiment, the flexible member (19) is glued to the vertical cylindrical wall (17) of the auxiliary chamber (15) such that, the flexible member (23) remains unaffected by the surrounding fuel.

Referring again to figure 4, the communication port (18) is provided partially on vertical cylindrical wall (17) and partially on the base plate (16) of the auxiliary chamber (15) so that there is no dead volume of the fuel in the fuel tank body (06), in accordance with the preferred embodiment of the present invention. In this case, the length of the flexible member (19) is maintained such that once fixed to the vertical cylindrical wall (17) of the auxiliary chamber (15) using rubber bolt (23), the other end of the flexible member (19) is essentially lay horizontally on the base plate (16) covering entire opening of the communication port (18).
While fixing the flexible member (19) to the auxiliary chamber (15), initially the rubber bolt (23) is inserted through the opening provided to the flexible member (19) and then the stem member (25) is passed through inside-out in the opening (17a) in the vertical cylindrical wall (17) and pressed so that the taper step like structure (27) get compressed and moves outward of the auxiliary chamber (15). Once vertical edge (27a) of the taper step like structure (27) comes out of vertical cylindrical wall (17), the flexible member (19) get fixedly attached to the auxiliary chamber (15) by head member (24) and taper step like structure (27) on opposite sides.
In an operation, when fuel is filled into the fuel tank assembly (06) through inlet neck opening (13), the fuel level increases in the fuel tank body (06) and the fuel get stored inside the auxiliary chamber (15). When the fuel level in the fuel tank body (06) is below the upper end of the auxiliary chamber (15) and front end of the vehicle and the fuel tank assembly (06) is sloped upward as shown in figure 7, for example, when vehicle is moving upslope, fuel in the fuel tank body (06) tends to flow towards rear lower corner (lc) of the fuel tank body (06). At this time, the flexible member (19) abuts against the vertical cylindrical wall (17) of the auxiliary chamber (15) and covers the communication port (18). Specifically, the pressure of the fuel inside the auxiliary chamber (15) forces the flexible member (19) to remain abut against vertical cylindrical wall (17) and base plate (16) of

auxiliary chamber (15) thereby covering up the communication port (18) until the fuel tank assembly (06) is tilted. Also as some portion of the flexible member (19) is laying on the base plate (16) of the auxiliary chamber (15), the flexible member does not slip and wedge into the communication port (18) thus ensuring shut-off action of the communication port (18) and thereby smooth running of the engine unit (02).
Once, automotive vehicle (01) again starts running on horizontal surface, the communication port (18) allows fuel to enter from the fuel tank body (06) to the auxiliary chamber (15) as there is suction pressure acting inside the auxiliary chamber (15) created due to fuel pump.
Further, when front end of the vehicle and the fuel tank assembly (06) is sloped downward, for example, when the vehicle is moving down-slope, fuel in the fuel tank assembly (06) tends to flow towards the front lower corner (fc) of the fuel tank assembly (06). In this case, since the communication port (18) is configured on auxiliary chamber (15) towards rear direction, there is no possibility of escaping the fuel form the communication port (18) as illustrated in the figure 6.
In another embodiment, as illustrated in the figures 8, the communication port (18) is provided on the vertical cylindrical wall (17) of the auxiliary chamber (15). In this case, height of the flexible member (19) is maintained such that once fixed to the vertical cylindrical wall (17) of the auxiliary chamber (15), lower end of the flexible member (19) remains below the lower point of the communication port (18). More specifically, the height of the flexible member (19) is such selected that the lower end extends beyond the lower end of the vertical cylindrical wall (17) of the auxiliary chamber (15) and lay curved on joining portion of the vertical cylindrical wall (17) and horizontal on the base plate (16) of the auxiliary chamber (15) or lay horizontal on the base plate (16) of auxiliary chamber (15).

In an embodiment, the lower end of the fuel line (20) and the return fuel line (21) is maintained at sufficient distance from the flexible member (19) so that suction created by the fuel line (20) does not deflect the flexible member (19) to uncover the communication port (18) when fuel tank assembly (06) is tilted. Similarly, bubbles carried by the return fuel line (21) do not uplift the flexible member (19), thus, proper working of the communication port (18) is ensured.
It may be evident to a person skilled in the art that, the mechanism (100) for restricting fuel flow from an auxiliary chamber to the fuel tank is independent of the material or shape of the fuel tank assembly (06) or the auxiliary chamber (15). Similarly, the mechanism (100) of the present invention is not limited to the geometry of communication port (18), though the communication port (18) in circular form is preferred, however, the communication port (18) may be of rectangular or any other suitable shape.
Since, the communication port (18) is configured on the auxiliary chamber (15) towards rear direction of the automotive vehicle (01). The presented embodiment exhibits its effect when vehicle is travelling on slope slanting front side upward and remain ineffective when vehicle travelling on the slop slanting front side downward. However, if the communication port (18) is configured on the vertical cylindrical wall (17) of the auxiliary chamber (15) towards front direction and is provided with the flexible member (19) as described hereinabove to cover the communication port (18). Similar effects can be realized with the automotive vehicle (01) travelling on the slop slanting front downward.
When the automotive vehicle (01) is travelling on the slanting surface and the flexible member (19) is abut against the vertical cylindrical wall (17) of auxiliary chamber (15) covering the communication port (18), diameter of communication port (18) and the material of the flexible member (19) of the preferred embodiment is such that, the flexible member (19) does not get wedged into or

squeezed into the communication port (18) thereby reducing the chances that the communication port (18) become inoperative.
The mechanism (100) of the present invention, though, has direct application to the fuel tank structures containing fuel to run the engine unit of the automotive vehicles, however, it may be evident to those skilled in the art to use the mechanism (100) on the tank bodies holding fluid to be delivered using pumping systems, having auxiliary chamber mounted therein with communication port.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim
1. A mechanism for restricting fuel flow from an auxiliary chamber disposed
in the fuel tank back to the fuel tank of an automotive vehicle when standing or
running on the slant surface, characterized in that the auxiliary chamber
comprising:
a horizontal base plate;
a vertical cylindrical wall extending from the horizontal base plate;
a communication port extending from inside of the auxiliary chamber to the exterior thereof allowing fuel to flow between the fuel tank and the auxiliary chamber;
a flexible member attached to the vertical cylindrical wall for closing the communication port on tilting of the automobile;
at least one rubber bolt for securing the flexible member to the vertical cylindrical wall; and
a taper step like structure configured along with the rubber bolt for holding the flexible member securely to the vertical cylindrical wall,
wherein , upon flowing of the fuel in the fuel tank body towards one of the corner of the fuel tank when the automobile is standing or running on the slant surface, pressure of the fuel inside the auxiliary chamber forces the flexible member to remain abut against vertical cylindrical wall and the base plate of auxiliary chamber thereby covering the communication port until the fuel tank assembly is tilted so as to prevent the fuel in the auxiliary chamber to go back in to the fuel tank.
2. The mechanism as claimed in claim 1, wherein the communication port is provided partially on vertical cylindrical wall and partially on the base plate of the auxiliary chamber.
3. The mechanism as claimed in claim 1, wherein the communication port is provided on the vertical cylindrical wall of the auxiliary chamber.

4. The mechanism as claimed in claim 1, wherein the flexible member is made of nitrile rubber (NBR)/polyvinyl chloride (PVC) grade material.
5. The mechanism as claimed in claim 1, wherein the flexible member is having an opening in upper portion thereof for securing to the vertical cylindrical wall from interior side of the auxiliary chamber.
6. The mechanism as claimed in claim 1, wherein the vertical cylindrical wall includes an opening corresponding to the opening of the flexible member.
7. The mechanism as claimed in claim 1, wherein the rubber bolt includes a head member at one end and a stem member extending from the head member in one direction having diameter substantially same as that of the opening on the vertical cylindrical wall.