Noise abatement filter for fuel tanks

[0002] Not Applicable.

[0003] Not Applicable.

[0004] 1. Field of the Invention

[0005] The present invention relates to baffles for fuel tanks and more particularly to a noise abatement baffle to prevent noise caused by shifting of fuel within a fuel tank.

[0006] 2. Description of the Related Art

[0007] Modern-day cars have plastic fuel tanks designed to fit around other components on the underside of a vehicle. Often these tanks are longer from the front part of the vehicle to the back than the tanks are wide. During stopping and starting of the vehicle, noise is often generated as the fuel shifts forwardly and rearwardly.

[0008] Baffles to stop fuel shifting are known devices. To put a baffle in a steel fuel tank, the bottom half of the fuel tank can have a baffle installed in it before it is welded to the top half thereof. But many modern fuel tanks are blow molded from a plastic material. It is difficult, if not impossible, to blow mold baffles into a plastic fuel tank. So there is a problem of how to install a baffle into a plastic fuel tank.

[0009] There is also a dilemma presented by the fact that a regular baffle comprising a wall with holes in it apparently does not completely solve the noise problem in a plastic fuel tank. Placing a semi-rigid foam baffle in the tank that permits flow therethrough has been determined to be difficult to install and to hold in position. Airplane tanks and race car tanks, for example, have used a polyurethane safety foam which fills the entire tank for the purpose of preventing fuel movement and for other purposes. Filling the entire tank with a polyurethane safety foam, however, has not been deemed to be practical for most passenger and commercial vehicles.

[0010] Accordingly, there is a need for a noise abatement filter for vehicle tanks which would overcome the aforementioned problems.

[0011] The present invention relates generally to a fuel tank with a baffle disposed therein at an intermediate place between the two ends thereof for preventing noise caused when fuel shifts in the fuel tank from one end to the other. In a preferred embodiment, the baffle is constructed of a fiberglass filter media material. Also in a preferred embodiment, the baffle is collapsible so that it can be inserted into an opening in the top of a plastic fuel tank and then allowed to return to its original larger height after it is in the tank whereby it will be held by a biasing pressure in a desired position within the tank.

[0012] An object of the present invention is to provide a noise abatement filter for fuel tanks.

[0013] Another object of the present invention is to provide a noise abatement filter which uses a fiberglass filter medium.

[0014] A still further object of the present invention is to provide a noise abatement filter which includes a baffle structure which is collapsible so that it will fit into an opening in the top of a fuel tank and then, once in proper position within the tank, will return to its expanded position and be held in a desired position within the tank.

[0015] Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

[0016] FIG. 1 is a perspective view of a preferred embodiment of the present invention shown inside of a plastic fuel tank with most of the fuel tank cut away to show the structure disposed therein;

[0017] FIG. 2 is a perspective view of the collapsible baffle of the present invention shown in a collapsed condition and with a pin holding it in such a position whereby it can be inserted into an opening in the top of a fuel tank as shown in FIG. 4;

[0018] FIG. 3 is a perspective view of the collapsible baffle shown in FIG. 2, but showing the locking pin removed and showing it in its installed condition except that the fuel tank is not shown in FIG. 3 as it is in FIG. 1;

[0019] FIG. 4 is a perspective view of a fuel tank of the type utilized for this invention and showing how the collapsible baffle of FIG. 2 is inserted into an opening in the top of the fuel tank;

[0020] FIG. 5 is a partial cut-away view of the fuel tank showing how the collapsible baffle is moved through the opening and to a position where a pair of opposing flanges inside the tank will hold the baffle in place;

[0021] FIG. 6 is an enlarged view similar to FIG. 5 but showing how the collapsible baffle is moved to the position between the opposing pair of flanges and with the pin holding it in the collapsed position;

[0022] FIG. 6A is a view similar to FIG. 6, but showing how springs within the collapsible baffle cause it to move back to its expanded position as shown in FIG. 3 to thereby be held in place between opposing pairs of flanges within the fuel tank;

[0023] FIG. 7 is a cross sectional view through the fuel tank showing the collapsible baffle in the position shown in FIG. 6;

[0024] FIG. 8 is a cross sectional view of the fuel tank showing the collapsible baffle in the position of FIG. 6A;

[0025] FIG. 9 is a cross sectional view showing the media and biasing springs of the collapsible baffle inside of a fuel tank which is cut away;

[0026] FIG. 10 is an exploded view of the baffle structure of the present invention;

[0027] FIG. 11 is an enlarged partial view of the baffle showing its interlocking mechanism;

[0028] FIG. 12 is an enlarged partial view of the clip mechanism that holds each half of the baffle holder together;

[0029] FIG. 13 is an enlarged partial perspective view showing the baffle in an unlocked position; and

[0030] FIG. 14 is a view similar to FIG. 13, but showing the baffle moved to the collapsed position in readiness to have a pin lock it in such position before it is inserted into a fuel tank.

[0031] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 shows a cross sectional view of a portion of a plastic fuel tank (10) having the sound abatement filter (11) of the present invention disposed therein. FIGS. 2 and 3 also show the sound abatement filter (11) in a collapsed and expanded position respectively, and the parts thereof are more completely shown in FIG. 10.

[0032] Referring to FIG. 10, a portion of the plastic fuel tank (10) is shown and a filter media (12) constructed in a preferred embodiment of a three-pound micro-light fiberglass media available from Johns Manville. The word “filter” used herein is intended to be in the context of filtering noise, fuel wave action or particulate matter. This material is described as LOI 15%, SPPI G30-99-2980. Of course this invention is not limited to this filter media, but is only the best mode. A cloth covering, such as a polyester cloth, can cover the fiberglass to make it more user friendly. It is known also that polyurethane safety foam of the type shown in the cited prior art literature is a possible substitute for the fiberglass filter media. Since this fiberglass media material (12) is somewhat flexible, it is surrounded by a cage or holder comprised of a first half (13) and a second half (14) which are snapped together by clips (15) on the holder half (14) which extend through openings (16) in the holder half (13) to hold the two halves (13) and (14) together around the filter media (12).

[0033] Metal clips (17) clip on to the cage half (14) but these clips (17) are merely to allow a magnetic device (not shown) to sense clips (17) through the plastic fuel tank (10) in order to be certain that the device (11) is in its proper position as shown in FIGS. 6A and 8 with respect to the tank (10). Compression springs (18) fit over projections (19) in the base member (20) and fit in holders (19′) in holder half (13) and therefore bias the cage halves (13) and (14) and media (12) to the upper position shown in FIGS. 3, 6A and 8. Guide slots (20′) (FIG. 11) in holder (20) receive guide projections (14′) on holder half (14).

[0034] Referring to FIG. 13, the base (20) has a projection (21) therein having an opening (22) for selectively receiving a pin (23) shown in dashed lines in FIG. 14. When the cage (13), (14) and media (12) unit is pushed down to the position shown in FIGS. 2, 6, 7 and 14, the opening (22) is aligned with an opening (24) in tab (25) of cage half (14). In the position shown in FIG. 14, the pin (23) can be manually inserted through the openings (22) and (24) and that will cause the device (11) to remain in the collapsed or second position thereof, the first position being the expanded position shown in FIGS. 3, 6A, 8, and 9. The second position is the collapsed position shown in FIGS. 2, 6, 7 and 14.

[0035] In operation, the sound abatement filter (11) as shown in FIG. 3 would be moved to the collapsed or second position as shown in FIG. 2 and the pin (23) (FIG. 14) is inserted to keep the cage halves (13) and (14) and media (12) in the collapsed position as shown in FIG. 2, whereupon the device (11) is inserted through an enlarged opening (30) in tank (10) as shown in FIG. 4. The opening (30) is large enough for a person's arm to extend therethrough and the device (11) with the pin (23) still holding it in the collapsed position, the device (11) is moved first to the position shown in FIG. 5 and then to the position shown in FIG. 6 between opposing flanges (31) and (32) on each side of the unit (11). Then the handle (26) of the pin (23) is pulled to the left as shown in FIG. 6A and the springs (18) shown in FIGS. 9 and 10 will cause the cage portion (13) and (14) to move to the position shown in FIG. 6A and lock the sound abatement filter (11) in place within the tank (10). If it is desired to remove the baffle (11), a reverse procedure would be employed.

[0036] It has been determined that the preferred embodiment disclosed herein does not reflect the sound wave of moving fuel but absorbs the energy of the wave of fuel to dissipate the sound of the moving fuel much like the way acoustical materials absorb sound energy.

[0037] Accordingly it will be appreciated that the preferred embodiment shown in FIGS. 1-14 does indeed accomplish the aforementioned objects. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.