Field of the invention
[0001]This invention relates to a top end cap for uniform flow of fuel in a fuel filter.
Background of the invention
[0002] In the existing fuel filters, the fuel from the fuel tank flows inside the filter inlet which is termed as dirty fuel and drops down on the top cap top surface through the hole provided in the filter head. Once the fuel drops down due to the gravity and suction pressure created by high-pressure pump makes the fuel to suck or flow form dirty side to clean side. The fuel flows in the particular area where the inlet hole is provided on the filter head due to the design concept in the present filter. This makes one side of the filter element getting clog due to the particle embeds onto the surface by increasing the dust holding on that area and rest area is dust free area. Further flow of fuel in that area restricts the flow of fuel from dirty side to clean side of the filter due to the higher dust holding on that particular area which reduces the life of the filter element and reducing the filter changing interval frequency.
[0003] A Prior art document US20070095733 discloses a fuel pump having double filter elements that contact the fuel pump module reservoir wall will dampen vibrational energy that originates in the fuel pump and propagates through the filter elements and into the fuel pump module reservoir. The fuel filter apparatus situated within the fuel pump module reservoir has a fuel pump with a fuel filter carrier attached to an end of the fuel pump. The fuel filters that attach to the fuel filter carrier are doubled such that one lies over the other in an over-lapping or sock-like arrangement.
Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and
illustrated in the accompanying drawing:
[0005] Fig. 1 illustrates a fuel filter in a fuel supply system, in accordance with an
embodiment of the invention; and

[0006] Figs. 2(a) & 2(b) illustrates the top end cap of the fuel filter, in accordance with the present invention.
Detailed description of the embodiments
[0007] Fig.1 illustrates a fuel filter in a fuel supply system, in accordance with one embodiment of the invention. The fuel filter 12 comprises a housing 14 and a filter head 16 having an inlet 18 and an outlet 20. The fuel filter 12 comprises a top end cap 22 positioned below the filter head 16.The fuel filter 12 further comprises a filter element 24 detachably fitted inside the housing 14. The top end cap 22 comprises a first portion 26 to and a second portion 28 made around the first portion 26 for uniform flow of fuel into the housing 14.
[0008] Further the construction of the fuel filter in a fuel supply system and the components of the system is explained as follows. The fuel supply system 10 comprises a fuel tank 40 and a fuel pump 42 adapted to pump the fuel from the fuel tank 40. The system 10 comprises a high-pressure fuel pump 44 connected to the fuel filter 12. The fuel from the fuel tank 40 is pumped into the high-pressure fuel pump 44 via the fuel filter 12. From the high-pressure pump 44, the pressurized fuel is made to flow into a common rail system (not shown). The fuel filter 12 comprises the filter head 16 having the inlet 18 and the outlet 20 allows the fuel into the high-pressure pump 44 from the fuel tank 40. The fuel having the impurities is filtered in the fuel filter 12 and the filtered fuel from the outlet 20 of the fuel filter 12 flows into the high-pressure pump 44. The filter head 16 in the fuel filter is positioned in proximity to the housing 14 of the fuel filter 12.
[0009] The filter element 20 is positioned in a cylindrical shape in the housing 14. The fuel from the inlet 18 flows into an area between an inner surface of the housing 14 and an outer surface of the filter element 24. The filtered fuel flows out from the fuel filter 12 via the outlet 20. However, the shape of the filter element 20 is not restricted to the

cylindrical shape, but can be any other shape that is known in the person skilled in the art.
[0010]The housing 14 comprises a top portion and a bottom portion, wherein the top portion accommodates the top end cap 22 to hold the filter element 24 when assembled into the housing 14. According to one embodiment of the invention, the top end cap 22 is made as an integral component of the housing 14. According to another embodiment of the invention, the top end cap 22 is positioned as a separate component between the housing 14 and the filter head 16.
[0011] Fig.2 (a) & 2(b) illustrates a top end cap in a fuel filter, in accordance with the present invention. The fuel filter 12 comprises a groove 30 formed between the first portion 26 and the second portion 28 of the top end cap 22. The groove 30 is formed along the circumference of the first portion 26. A sidewall 32 in the groove 30 is made in such a way that, the fuel received from the inlet 18, fills in the groove 30. The fuel filled in the groove 30 is uniformly distributed throughout the filter element 24. The groove 30 and the sidewall 32 forms the second portion 28 of the top end cap 22. According to one embodiment of the invention, the first portion 26 and the second portion 28 of the top end cap 22 are made as a single component. The housing 14 of the fuel filter 12 and the filter head 16 comprises at least one cut-section on each, corresponding the dimensions of the second portion 28 to accommodate the top end cap 22.
[0012]According to another embodiment of the invention, the second portion 28 is attached externally to the first portion 26 of the top end cap 22. The top end cap 18 is made of a material chosen form a group of materials comprising plastic, rubber. The lines in the figure 2(b) represents the uniform flow of the fuel into the filter element 24 with the above-disclosed top end cap 22.
[0013]A method of working of the fuel filter 12 in the fuel supply system 10 is explained in detail. The fuel from the fuel tank 40 is pumped into the fuel filter 12. From the fuel

tank 40, the fuel enters the fuel filter 12 through the inlet 18 present in the filter head 16. The fuel from the fuel tank 40 flowing inside the fuel filter 12 via the inlet 18 is a dirty/impure fuel. The entered fuel drops down on to the top end cap 22 top surface through a hole provided in the filter head 16. The dirty/impure fuel drops down due to the gravity and suction pressure (created by the high pressure pump 44) on to the top end cap 22 through the hole present in the filter head 16.
[0014]The impure fuel is sucked inside and is made to flow from dirty side of the fuel filter to a cleaner side of the fuel filter 12 (which is termed as filtering of the fuel). Due to the above-disclosed design of the top end cap 22, the fuel flows in the particular area where the inlet hole is provided on the filter head 16 and collects in the groove 30 of the top end cap 22. After the groove 30 is filled with the incoming fuel from the filter head 16, the fuel flows uniformly throughout the circumference/insert the area of the filter element 24 instead of dropping down in the same portion as in the conventional filters.
[0015]With the above-disclosed new top end cap, a uniform fuel flow along the circumference of the filter element 24 is achieved. This uniform flow of fuel not only increases the efficiently of the fuel filter 12 but also reduces the filter delta pressure compared to the conventional filter design. With the disclosed design, the filter 12 changing interval frequency is increased thus providing a low-cost economical solution.
[0016] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

We Claim:
1. A fuel filter (12) in a fuel supply system (10), said fuel filter (12) comprising:
- a housing (14);
- a filter head (16) having an inlet (18) and an outlet (20);
- a top end cap (22) positioned below said filter head (16);
- a filter element (24) detachably fitted inside said housing (14), characterized in that:
said top end cap (22) comprises:
- a first portion (26) to accommodate said filter element (24), and
- a second portion (28) made around said first portion (26) for uniform flow of fuel into said housing (14).

2. The fuel filter (12) as claimed in claim 1, wherein a groove (30) is formed between said first portion (26) and said second portion (28) of said top end cap (22).
3. The fuel filter (12) as claimed in claim 2, wherein a sidewall (32) in said groove (30) is made in such a way that, said fuel received from said inlet (18), fills in said groove (30).
4. The fuel filter (12) as claimed in claim 3, wherein said fuel filled in said groove (30) is uniformly distributed throughout said filter element (24).
5. The fuel filter (12) as claimed in claim 1, wherein said first portion (26) and said second portion (28) of said top end cap (22) are made as a single component.
6. The fuel filter (12) as claimed in claim 1, wherein said second portion (28) is attached externally to said first portion (26) of said top end cap (22).

7. The fuel filter (12) as claimed in claim 1, wherein said filter head (16) comprises at least one cut-section corresponding to dimensions of said second portion of said top end cap.
8. The fuel filter (12) as claimed in claim 1, wherein said top end cap (18) is made of a material chosen form a group of materials comprising plastic, rubber.