FUEL COMPONENT CARRIER WITH DOUBLE SLEEVE BEARING

[0001] This application claims the benefit of the earlier filing date of U.S. Provisional Application No. 61/065,443, filed on February 12, 2008, which is incorporated by reference herein in its entirety

[0002] FIELD

[0003] This invention relates to fuel component carriers that carry components in a fuel tank of a vehicle and, more particularly, to a stable carrier that ensures permanent contact with a bottom of a fuel tank even though spacing between the top and bottom of the fuel tank may vary.

[0004] BACKGROUND

[0005] A fuel delivery module is conventionally mounted in a fuel tank of a vehicle through an opening in an upper wall of the tank. The module should accurately indicate the volume of fuel remaining in the tank at any time, even when the fuel tank flexes in use, for example, due to varying fuel volume or changes in internal pressure due to external ambient conditions. Therefore, it is important that the assembly should be correctly positioned relative to the bottom of the tank in order to accurately indicate fuel level. It is known to use a so-called bottom referencing mechanism which ensures that the part of the assembly which follows the level of the fuel is always in contact with the bottom of the fuel tank.

[0006] With reference to FIG. 1 , a schematic view of a conventional single sleeve bearing 10 is shown. A shaft 14 is pressed (loaded by spring 16) into engagement with the bottom of a fuel tank. The shaft 14 defines a carrier for a fuel level sensor 11 having a float 12. The bearing 10 is movable with respect the shaft 15 based on height variations in the tank. The bearing 10 is connected to a conventional fuel tank flange (not shown). For this configuration to work well without sticking, the length A of the bearing 10 has to be sufficiently long. However, this

disadvantageously increases the moving mass of the bearing 10 that may create an unstable structure.

[0007] Thus, there is a need to provide an improved structure as a carrier for fuel component that provides more accurate and stable performance.

[0008] SUMMARY

[0009] An object of the invention is to fulfill the need referred to above. In accordance with the principles of the embodiments, this objective is achieved by a carrier for carrying a fuel component to be provided in a fuel tank of a vehicle. The carrier includes a first sleeve bearing assembly having a first shaft and a first sleeve bearing coupled with the first shaft. The first sleeve bearing is constructed and arranged to carry a fuel component thereon. The carrier includes a second sleeve bearing assembly having a second shaft associated with the first sleeve bearing such that the first sleeve bearing permits guided movement of the second shaft, and a second sleeve bearing coupled with the second shaft and associated with the first shaft such that the second sleeve bearing and second shaft can move in a guided manner with respect to the first shaft.

[0010] In accordance with another aspect of the embodiments, a carrier is provided for carrying a fuel component to be provided in a fuel tank of a vehicle. The carrier includes a first sleeve bearing assembly having a base, a first shaft coupled to the base, and a first sleeve bearing coupled with the first shaft, The carrier includes a second sleeve bearing assembly including a second shaft associated with the first sleeve bearing such that the first sleeve bearing permits guided movement of the second shaft, and a second sleeve bearing coupled with the second shaft and associated with the first shaft such that the second sleeve bearing and second shaft can move in a guided manner with respect to the first shaft. A flange is coupled to an end of the second shaft. At least one component is carried by the first sleeve bearing. A spring is associated with the first shaft such that when the base is engaged with a bottom of a fuel tank and the flange covers an opening generally at a top of the fuel tank, a biasing force of the spring and movement of the second

shaft keeps the base in contact with the bottom of the fuel tank, even though spacing between a top and bottom of the fuel tank may vary.

[0011] In accordance with yet another aspect of the embodiments, a method of providing a stable carrier for components to be mounted within a fuel tank of a vehicle provides a double sleeve bearing structure as a carrier. The structure includes first and second sleeve bearings assemblies. The first sleeve bearing assembly includes a fixed, first sleeve bearing and the second sleeve bearing assembly includes a second sleeve bearing that is movable with respect to the first sleeve bearing between a first position wherein the second sleeve bearing is generally adjacent to the first sleeve bearing, and a second position wherein the second sleeve bearing is spaced from the first sleeve bearing. A fuel component is mounted on the first sleeve bearing.

[0012] Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:

[0015] FIG. 1 is a schematic diagram of a conventional single sleeve bearing as a carrier of a level sensor provided in a fuel tank of a vehicle.

[0016] FIG. 2 is a schematic diagram of a double sleeve bearing structure as carrier structure for a fuel component shown provided in a fuel tank, in accordance with a present embodiment and shown in a first position.

[0017] FIG. 3 is a view of the double sleeve bearing structure of FIG. 2 shown in a second position.

[0018] FIG. 4 is a front view of a double sleeve bearing structure in accordance with an embodiment thereof.

[0019] FIG. 5 is a side view of the double sleeve bearing structure of FIG. 4.

[0020] FIG. 6 is an enlarged view of sleeve bearings of the double sleeve bearing structure of FIG. 5.

[0021] FIG. 7 is an enlarged plan view of the portion enclosed by box 7 in FIG. 6.

[0022] FIG. 8 is an enlarged plan view of the portion enclosed by box 8 in FIG. 6.

[0023] FIG. 9 is a view of the double sleeve bearing structure of an embodiment with the holder carrying a fuel level sensor.

[0024] FIG. 10 is an enlarged view of a clip holding the fuel level sensor to the holder of FIG. 9.

[0025] FIG. 11 is a view of the second sleeve bearing assembly shown with a flange coupled to an end of a shaft.

[0026] DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0027] Referring to FIG. 2-5 of the drawings, a double sleeve bearing structure, generally indicated at 18, is shown in accordance with an embodiment of present invention. FIGs. 2 and 3 are schematic illustrations of the structure 18 with the structure 18 carrying a fuel level sensor 11 having a float 12, while FIGs. 4 and 5 show more detailed embodiments of the structure 18. The structure 18 defines a carrier for use

in vehicle fuel tanks for carrying components such as a fuel level sensor, as explained more fully below.

[0028] The structure 18 includes a first sleeve bearing assembly, generally indicated at 19, including a base 20 and a first shaft or guide bar 22 extending from the base 20. As shown in FIG. 4, the base 20 is constructed and arranged to engage a bottom 23 of a fuel tank of a vehicle, the function of which will be explained below. As best shown in FIG. 5, the base 20 includes boss 47 constructed and arranged to receive a component such as a fluid connector 49 that can be connected to a conventional jet assembly (not shown) so that fuel can communicate with the jet assembly. Alternatively the boss 49 can receive the jet pump therein, or can carry electronic components such as sensors. The base 20 and guide bar 22 are preferably integrally formed from molded plastic suitable for use inside of a fuel tank. A first sleeve bearing, preferably in the form of a holder 24, is coupled to an end of the guide bar 22. The holder 24 is preferably press-fit to an end of the guide bar 22 to eliminate play and can be secured with a clip (not shown).

[0029] The structure 18 includes a second sleeve bearing assembly, generally indicated at 26, that includes a second sleeve bearing in the form of a guide 28, and a second shaft 30 in the form of a bracket coupled to the guide 28. As shown in FIG. 4, an axis E of the first shaft 22 and thus guide 28 is offset from an axis F of the second shaft 30 so that the shaft 30 can move along the axis F with respect to the holder 24. In the embodiment of FIGs. 4 and 5, the shaft 30 and guide 28 are preferably molded from plastic as an integral member. A spring 32 is provided between the base 20 and the guide 28, the function of which will be explained below.

[0030] With reference to FIGs. 6 and 7, the shaft 30 is guided for movement by the holder 24. The holder 24 includes a generally C-shaped portion that defines slot structure 31 that receives a generally T-shaped portion 33 of the second shaft 30. Cut-outs 35 are provided in the holder 24 to avoid interference with parting line mismatch of the shaft 30. This ensures easy and precise movement between the shaft 30 and the holder 23. As shown in FIG. 8, the guide 28 ensures that the shaft 30 is guided for movement with respect to the shaft 22. The guide bar 22 preferably has an S-

shaped profile and is received within passage 29 defined through the guide 28, to providing easy, precise movement between the guide 28 and the guide bar 22, thereby ensuring accuracy of the level sensor 11 under varying conditions in the fuel tank. The guide bar 22 is generally square in cross-section enabling the shaft 30 and holder 24 to advantageously be assembled at one of four different positions disposed 90 degrees apart, without adding or changing any of the components. With reference to FIG. 5, horizontal ribs 37, recesses and cut-outs 39 in the shaft 30 avoid interference with parting line mismatch of the guide bar 22.

[0031] With reference to FIG. 9, the holder 24 carries at least one component such as a fuel level sensor level sensor 34, secured thereto via clip structure 36 on each side of the holder 24. More particularly, with reference to FIG. 10, each clip structure 36 is resilient and engages an opening 38 in the level sensor 34. As shown FIG. 11 , an end 40 of the shaft 30 is coupled to a flange 41 that is constructed and arranged to close an opening 43 in generally in a top 45 of the fuel tank 25. Flange 41 is preferably press-fit and/or clipped to the end 40 of the shaft 30 to eliminate play. As shown by the dotted line G in FIG. 11 , the mounting location of end 40 of the shaft 30 to the flange 41 is centered with respect to the guide 28 to reduce any rocking effect.

[0032] The structure 18 is a mechanical system that adjusts to varying heights. The structure 18 with component(s) mounted on the holder 24 is placed in a fuel tank 25. In particular, the structure 18 is positioned in the fuel tank 25 so that the base 20 engages the bottom 23 of the fuel tank 25. Thereafter, the flange 41 is coupled with the end 40 of the shaft 30 and is mounted to cover the opening 43 in the fuel tank 25. Spring 32 provides a permanent biasing force and, together with movement of the second shaft 30, keeps the base 20 in permanent contact with the bottom 23 of the fuel tank 25, even though spacing between the top and bottom of the fuel tank 25 may vary depending on the weight of fuel in the tank 25, the internal pressure in the tank, or other factors.

[0033] When the component(s) carried by the holder 24 is at least a fuel level sensor 34 of the bottom-referencing type, the holder 24 maintains relative contact with the bottom 23 of the fuel tank 25 even if the fuel level in the fuel tank is changing.

[0034] With reference to FIG. 2, when the double sleeve bearing structure 18 is in a first (upper rest) condition with the sleeve bearings 24 and 28 being generally adjacent, the combined height of the sleeve bearings 24 and 28 is as high as that of the conventional bearing 10 of FIG. 1 (e.g., B + C = A). However, with reference to FIG. 3, once the system is moving away from this first condition and operating in its working range with sleeve bearing 28 spaced from sleeve bearing 24, the virtual height D of the sleeve bearings 24 and 28 (including the space there-between) is substantially greater than height A and allows for a more accurate and stable performance, with a reduced moving mass.

[0035] Noise can be reduced by matching the materials of the shaft 22 and the shaft 30. If the materials are of the same material, such as both being POM, squeaking can occur. Preferably, one of the shafts is of a material different from that of the other shaft. For example, one of the shafts 22, 30 can be of noise reducing POM and the other shaft can be of regular POM or one of the shafts 22, 30 can be nylon or the other shaft can be of regular POM. The holder 19 and shaft 30 can be of different materials as well to reduce noise.

[0036] The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the scope of the following claims.