Claims:We Claim

1. A fuel filter (10) of a fuel injection system, said fuel filter (10) comprising:
a fuel filter housing (12);
a hand primer (14) removably coupled to said fuel filter housing (12) and adapted to release compressed air out of said fuel filter housing (12), said hand primer (14) comprising:
a top cap (16) adapted to be actuated by a user to facilitate translating said top cap (16) towards said fuel filter housing (12); characterized in that
a bottom cap (18) removably secured to said fuel filter housing (12); and
a C-shaped member (20) removably positioned axially between said top cap (16) and said bottom cap (18), and a flexible diaphragm (22) secured to said C-shaped member (20) and adapted to be distended when said top cap (16) is actuated by a user in a direction of the fuel filter housing 12.

2. A fuel filter (10) for a fuel injection system in accordance with Claim 1 further comprising a top plate (24) removably secured to said C-shaped member (20).

3. A fuel filter (10) for a fuel injection system in accordance with Claim 2 further comprising a cover plate (26) removably secured to said fuel filter housing (12), said cover plate (26) adapted to house said bottom plate (18), said C-shaped member (20), and said top plate (24).

4. A fuel filter (10) for a fuel injection system in accordance with Claim 3 further comprising a screw (28) inserted within a bore 35 that is defined in said cover plate (26) and a bore 37 that is defined in said fuel filter housing (12), said screw (28) adapted to secure said cover plate (26) to said fuel filter housing (12).

5. A fuel filter (10) for a fuel injection system in accordance with Claim 1 wherein said hand primer 14 is oriented angularly with respect to a vertical axis of said fuel filter (10).

, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a fuel filter, and more specifically to a hand primer of the fuel filter of a fuel injection system.

Background of the invention
[0002] US 5868931 A describes a fuel filter assembly. The fuel filter assembly employs a hand primer and a disposable filter cartridge mounted on a filter base. The filter cartridge and filter base define a fuel flow path through the filter assembly. The filter base includes a sump for receiving fuel that has traversed the filter element. The hand primer includes a deformable member composed of an elastomeric material that cooperates with a base plate to define a cavity. The base plate is disposed intermediate to the deformable member and the base sump to separate the cavity from the fuel flow path. The base plate has a plurality of orifices to selectively provide fluid communication between the cavity and the sump. A discharge passage in fluid communication with the cavity provides means for discharging air from the fuel filter assembly.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a schematic diagram of a hand primer for a fuel filter.

Detailed description of the embodiments
[0004] Figure 1 illustrates a fuel filter 10 of a fuel injection system. The fuel filter 10 comprises a fuel filter housing 12 and a hand primer 14 removable coupled to the fuel filter housing 12 and adapted to discharge compressed air out of the fuel filter housing 12. The hand primer 14 comprises a top cap 16 that is adapted to be actuated by a user to facilitate translating the top cap 16 towards the fuel filter housing 12. A bottom cap 18 is removably secured to the fuel filter housing 12. A C-shaped member 20 is removably positioned between the top cap 16 and the bottom cap 18, and a flexible diaphragm 22 secured to the C-shaped member 20 and adapted to be distended when the top cap 16 is actuated by a user in a direction of the fuel filter housing 12.

[0005] The fuel filter 10 of the fuel injection system comprises a fuel filter housing 12. The fuel filter housing 12 comprises a hand primer 14 that is removably coupled to the fuel filter housing 12. The hand primer 14 is adapted to release compressed air out of the fuel filter housing 12. More specifically, during the starting up / low fuel condition in a fuel tank of the vehicle, the hand primer 14 is adapted to be actuated by a user to release the compressed air that is present within the fuel filter housing 12. The hand primer 14 comprises a top cap 16 adapted to be actuated by a user to facilitate translating the top cap 16 towards the fuel filter housing 12. The top cap 16 is fastened on to the fuel filter housing 12 and secured thereto by means of a screw 25. The screw 25 is threaded through a bore that is defined in the top cap 16 and is therefore used to secure the top cap 16 to the fuel filter housing 12. A spring member 27 is positioned below the top cap 16 and is adapted to restore the top cap 16 to its original undistended position when the compressive force on the spring member 27 has been withdrawn by a user. A bottom cap 18 is removably secured to the fuel filter housing 12. More specifically, the bottom cap 18 is positioned against the fuel filter housing 12 such that the bottom cap 18 may be withdrawn from the fuel filter housing 12 when the handprimer 14 is disassembled from the fuel filter housing 12.

[0006] A C-shaped member 20 is removably positioned axially between the top cap 16 and the bottom cap 18. The C-shaped member 20 comprises a flexible diaphragm 22 that is secured to the C-shaped arms of the C-shaped member 20 and is secured thereto tautly to the C-shaped member 20. When the top cap 16 is actuated by the user in the direction of the fuel filter housing 12, the flexible diaphragm 22 that is secured to the C-shaped arms of the C-shaped member is distended, thereby causing the air that is present in the fuel filter housing 12 to be discharged out of the fuel filter housing 12.

[0007] In the exemplary embodiment, the fuel filter 10 further comprises a top plate 24 that is removably secured to the C-shaped member 20 such that the top plate 24 may be withdrawn by a user when the fuel filter 10 is disassembled. A first end of a guide pin 30 is inserted through a bore that is defined in the top plate 24, a bore that is defined in the C-shaped member 20, and a bore that is defined in the bottom cap 18. More specifically, the first end of the guide pin 30 that is inserted through the bore that is defined in the top plate 24, the bore that is defined in the C-shaped member 20, and the bore that is defined in the bottom cap 18 is used to removably secure the top plate 24, the C-shaped member 20, and the bottom cap 18 together as a unitary assembly. Therefore, when it is desired to disassemble the fuel filter 10, the top plate 24, the C-shaped member 20, and the bottom cap 18 are each withdrawn from the guide pin 30.

[0008] A cover plate 26 is secured to the fuel filter housing 12. More specifically, a second end of the guide pin 30 is inserted through a bore 45 that is defined in the cover plate 26 to secure the guide pin 30 to the cover plate 26. When the cover plate 26 is positioned on the fuel filter housing 12, the guide pin 30, the top plate 24, the C-shaped member 20, and the bottom plate 18 are encapsulated by the cover plate 26 and are housed within the cover plate 26. Therefore, when the cover plate 26 is withdrawn from the fuel filter housing 12, the bottom plate 18, the C-shaped member 20, and the top plate 24 that are secured to the cover plate 26 via the guide pin 30 may each be removed after the guide pin 30 has been withdrawn from the bore 45 that is defined in the cover plate 26.

[0009] In the exemplary embodiment, a screw 28 is inserted within a bore 35 that is defined in the cover plate 26 and a bore 37 that is defined in the fuel filter housing 12. More specifically, the screw 28 is inserted within the bore 35 that is defined in the cover plate 26 and screwed on to the screw threads that are defined on the cover plate 26. Once the cover plate 26 is positioned on the fuel filter housing 12, the screw 28 that is inserted through the bore 35 that is defined on the cover plate 26 is further inserted and screwed on to the bore 37 that is defined on the fuel filter housing 12. Therefore, the screw 28 that is inserted within the bore 35 that is defined on the cover plate 26 and the bore 37 that is defined in the fuel filter housing 12 is used to secure the cover plate 26 firmly on to the fuel filter housing 12.

[0010] In the exemplary embodiment, the hand primer 14 is oriented angularly with respect to a vertical axis of the fuel filter 10. The angular orientation of the hand primer 14 with respect to the fuel filter 10 is unique to this invention as the hand primer 14 may be oriented in any direction with respect to the fuel filter 10 depending on the manufacturing requirements of the user.

[0011] A construction of the hand primer 14 is described as an example. The bottom cap 18 is removably secured to the fuel filter housing 12. More specifically, the bottom cap 18 is positioned against the fuel filter housing 12 such that the bottom cap 18 may be removed from the fuel filter housing 12. Therein, the C-shaped member 20 is removably positioned axially on the bottom cap 18. A top plate 24 is removably secured to the C-shaped member 20 such that the top plate 24 may be withdrawn by a user when the fuel filter 10 is disassembled. A first end of the guide pin 30 is then inserted through the bore that is defined in the top plate 24, the C-shaped member 20, and the bottom cap 18. The opposite second end of the guide pin 30 is inserted through the bore 45 that is defined in the cover plate 26. When the cover plate 26 is positioned on the fuel filter housing 12, the guide pin 30, the top plate 24, the C-shaped member 20, and the bottom plate 18 are encapsulated by the cover plate 26 and are housed within the cover plate 26. After the cover plate 26 is assembled on the fuel filter housing 12, the spring member 27, the top cap 16, and the screw 25 are positioned and secured to the cover plate 26. Finally, the screw 28 is inserted through the bore 35 that is defined in the cover plate 26 and the bore 37 that is defined in the fuel filter housing 12 and is used to secure the cover plate 26 to the fuel filter housing 12.

[0012] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.