Claims:We Claim

1. A handprimer (10) for a fuel filter, said handprimer (10) comprising:
a housing (12);
a primer plunger (14) inserted within said housing (12), said primer plunger (14) adapted to be translated towards said housing (12) against a resistive force of a spring member (16); characterized in that
an inlet connecter (18) secured to an inlet opening (40) of said housing (12), said inlet connecter (18) adapted to supply pressurized fuel within said housing (12) via the inlet opening (40); and
an outlet connecter (20) secured to an outlet opening (42) of said housing (12), said outlet connecter (20) adapted to withdraw pressurized fuel from said housing (12) via the outlet opening (42).

2. The handprimer (10) for a fuel filter in accordance with Claim 1 further comprising a fuel inlet valve (22) secured to an orifice (44) that is defined in said inlet connector (18), said fuel inlet valve (22) adapted to control a flow of pressurized fuel within said housing (12) via the orifice (44).

3. The handprimer (10) for a fuel filter in accordance with Claim 1 further comprising a retainer (24) positioned within the outlet connecter (20), said retainer (24) comprising a bore defined therethrough, the bore of said retainer (24) in flow communication with an orifice (46) that is defined in the outlet connector (20) and adapted to channel pressurized fuel therethrough and out of the handprimer (10).

4. The handprimer (10) for a fuel filter in accordance with Claim 3 further comprising a fuel outlet valve (26) secured to the bore that is defined within said retainer (24), said fuel outlet valve (26) adapted to control a flow of pressurized fuel out of said retainer (24) via the bore that is defined in said retainer (24).
, 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 inlet and outlet connectors of the fuel filter.

Background of the invention
[0002] US 6019890 A describes a fuel filter assembly that employs a hand primer and a disposable filter cartridge mounted to a header. The filter cartridge has a filter element which defines an interior chamber for receiving the filtered fuel. The hand primer includes a diaphragm which cooperates with the header to define a reservoir and a valve plate having a plurality of orifices and an axial opening for providing fluid communication between an exit passage of the header and the reservoir and between the chamber and the reservoir, respectively. A first check valve is mounted in the opening and a second check valve is mounted in an axial bore in the first check valve. The first and second check valves are moveable between an open position for allowing flow through the orifices of the valve plate and orifices in the first check valve, respectively, and a closed position for preventing such flow. The filter assembly is primed by pushing the diaphragm downwards, creating a high pressure which moves the first check valve to the open position and the second check valve to the closed position, causing trapped air to be expelled through the orifices and the exit passage. Removing the downwards force allows a spring to return to bias the diaphragm upwards, creating a low pressure which moves the first check valve to the closed position and the second check valve to the open position, and drawing fuel from the interior chamber.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a fuel filter in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates a handprimer 10. The handprimer 10 comprises a housing 12 and a primer plunger 14 inserted within the housing 12, the primer plunger 14 adapted to be translated towards the housing 12 against a resistive force of a spring member 16. An inlet connecter 18 is secured to an inlet opening 40 of the housing 12, the inlet connecter 18 adapted to supply pressurized fuel within the housing 12 via the inlet opening 40. An outlet connecter 20 is secured to an outlet opening 42 of the housing 12, the outlet connecter 20 adapted to withdraw pressurized fuel from the housing 12 via the outlet opening 42.

[0005] The handprimer 10 comprises a housing 12. A primer plunger 14 is inserted within the housing 12. A spring member 16 is positioned between the primer plunger 14 and the housing 12. When the primer plunger 14 is pushed downwardly by a human operator, the primer plunger 14 translates towards the housing 12 against a resistive force of the spring member 16. Therein, the air that is present within the housing 12 is expelled out of the handprimer 10, thereby creating a suction force that allows fuel to be drawn into the housing 12 for filtration. When the downward force on the primer plunger 14 is released by the human operator, the spring member 16 causes the primer plunger 14 to be translated in the upward direction and away from the housing 12 to its original position.

[0006] The handprimer 10 for the fuel filter comprises an inlet connector 18 that is secured to an inlet opening 40 of the housing 12. The inlet connector 18 is adapted to supply pressurized fuel within the housing 12 via the inlet opening 40. More specifically, the inlet connector 18 comprises a first portion 19 having a first diameter and a second portion 21 having a second diameter. The second portion 21 of the inlet connector 18 is inserted within an opening that is defined in the housing 12 and secured thereto by an interference fit or threaded arrangement. Fuel is channeled into the opening that is defined in the housing 12 by channeling fuel via the first portion 19 and the second portion 21 of the inlet connector 18 and into the housing 12.

[0007] The handprimer 10 for the fuel filter comprises an outlet connector 20 that is secured to an outlet opening 42 of the housing 12. The outlet connector 20 is adapted to withdraw pressurized fuel from within the housing 12 via the outlet opening 42. More specifically, the outlet connector 20 comprises a first portion 23 having a first diameter and a second portion 25 having a second diameter. The second portion 25 of the outlet connector 20 is inserted within an opening defined in the housing 12 and secured thereto by an interference fit arrangement or threaded arrangement. Fuel is channeled out of the opening that is defined in the housing 12 by channeling the fuel via the second portion 25 and the first portion 23 of the outlet connector 20.

[0008] The inlet connector 18 comprises a fuel inlet valve 22 that is secured thereto. More specifically, the fuel inlet valve 22 comprises a flap portion and a projection that is inserted within the flap portion. The projection that is secured to the flap portion is secured to an orifice 44 that is defined within the inlet connector 18. More specifically, when the projection of the fuel inlet valve 22 is inserted within the orifice 44 of the inlet connector 18, the flow of fuel into the housing 12 of the handprimer 10 is restricted by the flap portion of the fuel inlet valve 22. Therefore, the fuel inlet valve 22 is adapted to restrict a flow of pressurized fuel into the housing 12 via the orifice 44 through which the projection of the fuel inlet valve 22 is inserted.

[0009] The outlet connector 20 comprises a retainer 24 that is secured thereto. More specifically, the retainer 24 comprises a C-shaped portion that is inserted within the second portion 25 of the outlet connector 20. The retainer 24 is inserted within the outlet connector 20 and secured thereto by an interference fit arrangement or a threaded arrangement. The retainer 24 comprises a bore defined therethrough. The bore of the retainer 24 is in flow communication with an orifice 46 that is defined within the outlet connector 20 and adapted to channel fuel from the orifice 46 that is defined within the outlet connector 20 through the bore of the retainer 24.

[0010] The outlet connector 20 comprises a fuel outlet valve 26 that is secured thereto. More specifically, the fuel outlet valve 26 comprises a flap portion and a projection that is secured to the flap portion. The projection that is secured to the flap portion of the fuel outlet valve 26 is secured to the bore that is defined in the retainer 24. More specifically, when the projection of the fuel outlet valve 26 is inserted through the bore that is defined within the retainer 24, the flow of fuel out of the housing 12 of the handprimer 10 is restricted by the flap portion of the fuel outlet valve 26 that is positioned against a wall of the retainer 24. Therefore, the fuel outlet valve 26 is adapted to control a flow of pressurized fuel from within the housing 12 via the bore that is defined in the retainer 24.

[0011] A working of the handprimer 10 for the fuel filter is described as an example. When the plunger 14 is pushed downwardly by a human operator, the air that is present within the housing 12 is driven out of the handprimer 10. Thereby, fresh fuel is channeled from the inlet connector 18 and into the housing 12. More specifically, as the pressure of the fuel on the inlet side of the inlet connector 18 is higher than the pressure of the fuel within the housing 12 of the handprimer 10, the pressurized fuel forces against the flap portion of the fuel inlet valve 22, thereby causing the flap portion of the fuel inlet valve 22 to distend. Therein, the pressurized fuel from the inlet side of the inlet connector 18 flows through the orifice 44 of the inlet connector 18 and into the housing 12 of the handprimer 10. When the pressure of the fuel within the housing 12 of the handprimer 10 becomes greater than the pressure of the fuel entering through the inlet connector 18, the flap portion of the fuel inlet valve 22 is restored to its original position, thereby closing the orifice 44 of the inlet connector 18 and preventing fuel from flowing from the inlet connector 18 within the housing 12 of the handprimer 10.

[0012] When the fuel in the fuel filter is required to flow out, the fuel that is present within the housing 12 of the handprimer 10 applies pressure on the bore of the retainer 24. The pressure acting on the bore of the retainer 24 forces against the flap portion of the fuel outlet valve 26. Therefore, the flap portion of the fuel outlet valve 26 distends, thereby opening the orifice 46 of the outlet connector 20. Pressurized fuel from within the housing 12 of the handprimer 10 flows out of the handprimer 10 via the orifice 46 of the outlet connector 20 and the bore of the retainer 24. When the pressure of the fuel at the outlet of the outlet connector 20 is higher than the pressure of the fuel at the inlet of the outlet connector 20, the flap portion of the fuel outlet valve 26 is restored to its original position against the retainer 24. Therefore, the bore of the retainer 24 is closed, preventing any further fuel from leaking out of the outlet connector 20 via the orifice 46 that is defined in the outlet connector 20 and the bore that is defined in the retainer 24.

[0013] 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.