Abstract:
A fuel-fill adapter for use in conjunction with a manually-controlled liquid supply nozzle for filling a fuel reservoir is disclosed. The adaptor mates with liquid supply nozzle as well as the filling port of the fuel reservoir. The fuel fill adaptor includes two main fluid pathways: an incoming pathway for liquid to fill the reservoir and an outgoing pathway for vapor venting or excess liquid draining. The fuel-fill adaptor includes a low-pressure differential vacuum-breaking valve to prevent the siphon effect that would otherwise naturally occur if liquid were to enter the gas venting hose. The vacuum-breaking valve permits air to enter the adaptor, wherein the air is then drawn down the drain hose instead of any additional liquid. The vacuum breaking valve can be connected to either the incoming liquid or vent/drain pathways.

Description:
STATEMENT OF RELATED CASES 
       [0001]    This case claims priority of U.S. Provisional patent application Ser. No. 61/162,492, filed Mar. 23, 2009, which is also incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH 
       [0002]    This invention was made with Government support under N00024-02-C-6309 awarded by the Department of the Navy. The Government has certain rights in the invention. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present invention relates to fuel dispensing systems for dispensing fuel in a vehicle fuel tank. 
       BACKGROUND OF THE INVENTION 
       [0004]    Countless types of equipment use internal combustion engines driven by gasoline or diesel fuel. The fuel is typically held in a reservoir, such as a tank or flexible bladder. 
         [0005]    An example of a vessel having a flexible bladder is the Navy&#39;s remote mine-hunting system (RMS). The RMS includes an unmanned, semi-submersible vehicle (“RMV”) that tows a variable depth sensor and includes various Sonars to detect, localize, classify, and identify moored and bottom mines. The semi-submersible vehicle is powered by a diesel engine and, as indicated above, includes a flexible/collapsible fuel bladder for storing diesel fuel. 
         [0006]    During the fueling process, air that is in the bladder is displaced through the fill port. Experience has shown that it is difficult to fill the bladder using a conventional automobile-type fuel nozzle. Among other difficulties, the automatic shut-off feature of such nozzles will trip prematurely. If a manual nozzle is used, diesel tends to bubble out before the bladder is full (since the fuel near the top of the bladder will be foamy). 
         [0007]    As a consequence, an improved system for delivering fuel to a reservoir, particularly a flexible bladder-type reservoir, is needed. 
       SUMMARY 
       [0008]    The present invention provides a way to completely fill a tank, such as a flexible bladder, with fuel, such as diesel, while preventing spills. 
         [0009]    The illustrative embodiment of the present invention is a fuel-fill adapter for use in conjunction with filling a fuel reservoir, especially a flexible bladder, with fuel, especially diesel. In accordance with the illustrative embodiment, a fuel fill adaptor includes two main fluid pathways: an incoming pathway for liquid to fill the reservoir and an outgoing pathway for vapor venting or excess liquid draining. 
         [0010]    The two main fluid pathways are oriented vertically and have staggered terminations to separate the incoming liquid from the displaced vapor. Both the incoming liquid and outgoing pathways are disposed within the fuel-fill adaptor which uses a single opening on the tank or bladder to be filled. 
         [0011]    The adaptor mates with and seals on the same surfaces as the cap of the fuel tank. In some embodiments, the adaptor swivels on to, or otherwise connects to one or more separate hoses for liquid filling and gas or excess liquid venting and draining. In the illustrative embodiment, connection is effected by quick disconnect (QD) fittings. 
         [0012]    In the illustrative embodiment, the adaptor is used with a manually-controlled liquid supply valve or nozzle. Automatic shutoff valves, such as those used for fueling, would shut off upon encountering a backpressure. This would require the tank or bladder to be filled very slowly or incompletely. The manually-controlled liquid supply valve therefore enables the use of high pressures and flow rates to quickly fill large containers or bladders. 
         [0013]    The vent/drain hose is positioned with its exit termination at a lower elevation than the fuel-filling adaptor. This enables the vapor vent hose to also drain any excess liquid pumped into the container before the manual valve is closed. The outlet of the vent/drain hose is directed into a suitable container, or, in some embodiments, back into the fuel-supply reservoir. 
         [0014]    The fuel-fill adaptor further includes a low-pressure differential vacuum-breaking relief valve to prevent the siphon effect that would otherwise naturally occur if liquid were to enter the gas venting hose. This siphon could potentially drain the entire container or bladder. The vacuum-breaking valve permits air to enter the adaptor, wherein the air is then drawn down the drain hose instead of any additional liquid. The vacuum breaking valve can be connected to either the incoming liquid or vent/drain pathways. 
         [0015]    The vacuum-breaking valve is set to open at a low pressure differential to ensure that once the tank/container/bladder is filled completely or overfilled, the siphon will stop when the liquid level is at the base of the adaptor and at atmospheric pressure. In this fashion, when the adaptor is removed, the bladder is consistently filled to the brim. 
         [0016]    In some embodiments, the vent/drain hose is made from a clear material so that the filling operator can readily see that the bladder is full or nearly full. Depending on the filling, liquid bubbles may be seen in the drain hose to indicate that the bladder is nearly full (before liquid is observed indicating the container or bladder is completely full). When filling an elastic bladder it is preferable to slow down or stop when bubbles are observed to minimize the amount of liquid that must be drained if the bladder is inflated due to the filling pressure being greater than atmospheric pressure. 
         [0017]    In some embodiments, the filling adaptor has a restricted fluid crossover pathway between the incoming liquid pathway and vent/drain pathway. This crossover pathway is narrow or restricted so that a small amount of the higher pressure liquid coming through will drop into the bladder and not effect the venting gas while the container or bladder is at ambient pressure. If, however, the bladder is at elevated pressure, then some of the liquid will be blown up into the vent/drain hose to serve as an early indication to the operator that the container or bladder is being pressurized and is nearly full. If the vacuum-breaking valve is connected to the liquid filling pathway of the fuel-fill adaptor, then the crossover pathway will provide another route for the incoming air from the vacuum-breaking valve to travel to the vent/drain hose and help stop the siphon sooner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  depicts a fuel-fill adapter for use in a fuel-filling system. 
           [0019]      FIG. 2  depicts a perspective view of a fuel-filling system comprising a fuel-fill adapter in accordance with the illustrative embodiment of the present invention. 
           [0020]      FIG. 3  depicts a cross-sectional view of the fuel-fill adapter of  FIG. 2 , sans handle and vent/drain hose. 
           [0021]      FIG. 4  depicts a plan view of the fuel-fill adapter of  FIG. 3 . 
           [0022]      FIG. 5  depicts a cross-sectional view of a fuel-fill adapter in accordance with the illustrative embodiment, wherein the fuel-fill adapter is disposed in the filling port of a fuel tank. 
           [0023]      FIG. 6  depicts a cross-sectional view of the fuel-fill adapter of  FIG. 4 , showing the effect of the operation of the vacuum-breaker valve. 
           [0024]      FIG. 7  depicts a fuel-fill adapter in accordance with the illustrative embodiment, wherein the fuel-fill adapter is coupled to the filling port of the fuel bladder of an RMV, and wherein the RMV is coupled to a capture device located aboard a mother ship. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]      FIG. 1  depicts prototype fuel-fill adapter  100 . This adapter is designed for use with the Navy&#39;s remote mine-hunting vehicle (RMV). 
         [0026]    Fuel-fill adapter  100  of  FIG. 1  includes body  102 , quick disconnect QD, fuel delivery pipe  104 , cap/fitting  105 , vents  106 A/B, cavity  108 , drain/vent tube  110 . In use, the fuel-fill adapter seals to a fuel-fill nozzle (not depicted) at quick disconnect QD. Cap/fitting  105  seals fuel-fill adapter  100  to fill port  122  of fuel bladder  126  within RMV  120 . When sealed to the fill port, fuel-delivery pipe  104  extends into fuel-fill elbow  124  to deliver fuel to fuel bladder  126 . 
         [0027]    Fuel-bladder vent  128  enables air to be exhausted from fuel bladder  126 . Air exhausted from the fuel bladder exits fuel-fill elbow  124  through vents  106 A and/or  106 B in cap/fitting  105 . The air enters internal cavity  108  of the fuel-fill adapter and is exhausted through drain/vent tube  110 . Vents  106 A and  106 B also provide a path for over-flowing fuel to exit the fuel-fill elbow and empty into a waste container (not depicted). 
         [0028]    Although the adapter of  FIG. 1  represents an improvement over the prior art, it is subject to several shortcomings. In particular, the adapter of  FIG. 1  is subject to a siphon effect that is created through drain/vent tube  110 . Since the waste container will typically be at a lower height than fuel bladder  126 , and since the fuel bladder is collapsible, the fuel bladder could empty due to gravity, if allowed. In fuel-fill adapter  100 , this issue is dealt with in two ways. First, the siphon effect is prevented or limited by observing the level of fuel in bladder  126  and slowing the rate at which fuel is added to the bladder when it is nearly full and then stopping the flow of fuel as soon as foam is observed in drain hose  110 . Second, the siphon can be stopped by pinching the drain hose to stop the flow and allow the portion of the hose downstream of the pinch to clear with air bubbling up from the free end of the hose. These approaches require strict attention by the person handling the filling procedure. 
         [0029]    Another problem with the fuel-fill adapter of  FIG. 1  is that it is not compatible for use on board a ship because it interferes with the existing RMV capture device (for deploying and retrieving the RMV). 
         [0030]    These shortcomings led to the development of fuel-fill adapter  200  in accordance with the illustrative embodiment of the invention, which as depicted as a part of an improved system  201  for delivering fuel to a reservoir, as shown in  FIG. 2 . 
         [0031]      FIG. 2  depicts a perspective view of fuel-filling system  201  in accordance with the illustrative embodiment of the present invention. System  201  includes fuel nozzle  230  (represented by the “handle” like structure) and fuel-fill adapter  200 . The fuel-fill adapter is depicted via cross section in  FIG. 3  and a top view in  FIG. 4 . The view of fuel-fill adapter  200  depicted in  FIG. 3  is “rotated” 90 degrees “to the right” with respect to the view depicted in  FIG. 2 . The view of fuel-fill adapted  200  depicted in  FIG. 4  is rotated ninety degrees “to the left” with respect to the view depicted in  FIG. 2 . 
         [0032]    Referring now to  FIGS. 2 ,  3 , and  4 , fuel-fill adapter comprises body  202 , fuel-delivery pipe  204 , cap/fitting  205 , vent (inlet)  206 , vent/drain tubing  210 , and vacuum-breaking valve  212 . 
         [0033]    The fuel-fill adapter further comprises several “quick disconnect” fittings to quickly and easily couple and uncouple fuel-fill adapter  200  to other elements of fuel-filling system  201 . In particular, fuel-fill adapter  200  includes quick disconnect plugs  240 ,  246 , and  254 . When the quick disconnect plugs are “in use” to connect something to some element of the system to fuel-fill adapter  200 , they will couple to quick disconnect sockets. For example, to couple fuel nozzle  230  to the fuel-fill adapter, quick disconnect socket  242  is coupled to quick disconnect plug  240 . (NPT adapter  244  is also used to couple quick disconnect socket  242  to fuel nozzle  230 .) Further, to couple vent/drain tube  210  to fuel-fill adapter  200 , quick disconnect socket  248  is coupled to quick disconnect plug  246 . This connection also uses hose barb elbow  250  and hose clamp  252 . The unused quick disconnect plug  254  is available for coupling, for example, to the fuel nozzle  230 , etc., if the specifics of the fueling application require a different orientation for fuel-filling system  201  (due to the presence of equipment near the fill port). 
         [0034]    Air inlet  358  ( FIGS. 3 and 4 ) receives vacuum-breaking valve  212  (see, e.g.,  FIG. 5 ). 
         [0035]      FIG. 5  depicts the fuel-fill adapter  200  coupled to fill port  122  of RMV  120 . (Fuel nozzle  230  is not depicted for clarity.) Fuel-delivery pipe  204  extends into fuel-fill elbow  124  of the RMV to deliver fuel  501  to the RMV&#39;s fuel bladder  126 . In the illustrative embodiment, cap/fitting  205  is threaded; gasket  560  prevents any leakage of fuel (vapor or liquid). The orientation of fuel-fill adapter  200  in  FIG. 5  is the same as in  FIG. 4 . As such, fuel  501  enters through quick disconnect socket  242  (i.e., “into the page” as shown in  FIG. 5 ). 
         [0036]      FIG. 5  also depicts the venting of air  503  from fuel bladder  126  via fuel-bladder vent  128 . The vented air enters vent inlet  206  at cap/fitting  205  and is vented from fuel-fill adapter  200  (e.g., through vent/drain tube  210 , which is not depicted in  FIG. 5 ). 
         [0037]      FIG. 6  depicts the operation of vacuum-breaking valve  212 . The purpose of the vacuum-breaking valve, which in the illustrative embodiment is a check valve, is to prevent fuel  501  from being siphoned out of fuel bladder  126 . Briefly, the vacuum-breaking valve works as follows. If a siphon is created, suction from the siphon draws air  503  through vacuum-breaking valve  212  rather than drawing fuel from bladder  126 . Air  503  is drawn through vent/drain tubing  210  (not shown). 
         [0038]      FIG. 7  depicts fuel-fill adapter  200  coupled to fill port  122  of RMV  120 , wherein the RMV is coupled to a capture device  760  located aboard a mother ship. The size and configuration of fuel-fill adapter  200  enables it to couple to filling port  122  while the RMV is coupled to the capture device. 
         [0039]      FIG. 8  depicts, via a simplified representation of fuel-fill adapter  200 , certain geometric relationships between the various ports/features. The orientation of the fuel-fill adapter depicted in  FIG. 8  is the same as that shown in  FIG. 2 . 
         [0040]    As depicted in  FIG. 8 , the three quick disconnect plugs  240 ,  246 , and  254  are co-planar, falling in the plane identified “B.” Each of these quick disconnect plugs is oriented ninety degrees away from its nearest neighbor. Quick disconnect plugs  240  and  254 , which in the illustrative embodiment define respective primary and alternative couplings to fuel nozzle  230  are 180 degrees apart; that is, they are co-linear. 
         [0041]    Air inlet  358 , which falls along axis A-A, is orthogonal to plane B in which the quick disconnect plugs lie. Likewise, fuel delivery pipe  204 , which also falls along axis A-A, is orthogonal to plane B. The conduit leading from vent  206  is parallel to fuel delivery pipe  204 . 
         [0042]    In operation, the fuel-fill adapter is used in conjunction with fuel nozzle  230  to fuel a vessel, such as an RMV, as follows: 
         [0000]    1. Position an absorbent towel, etc., near fuel-fill cap of an RMV, etc., on any surface that is desirable to protect from exposure to dripping fuel. The towel should be positioned under any quick disconnects as they are disconnected.
 
2. Remove the fuel fill cap of the RMV providing access to fuel bladder  126 .
 
3. Install fuel-fill adaptor  200  into fill port  122  of the RMV.
 
4. Attach quick disconnect socket  248  for vent/drain hose  210  to quick disconnect plug  246  on fuel-fill adaptor  200 . Position the free end of vent/drain hose  210  into a suitable drain or empty container of at least about 10 gallons.
 
5. Attach fuel-fill hose/nozzle  230  to the most easily accessible quick disconnect (e.g., quick disconnect plug  254 /quick disconnect socket  456  or quick disconnect plug  242 /quick disconnect socket  244 ) of fuel-fill adaptor  200 .
 
6. Begin pumping fuel into bladder  126 .
 
7. When fuel begins to enter vent/drain hose  210 , relax the lever of fuel nozzle  230  to a half-way position to lessen the amount of fuel that will potentially be lost.
 
8. When a steady stream of fuel is observed flowing out vent/drain hose  210 , release the lever of fuel nozzle  230  to stop pumping.
 
9. It might take about 10-60 seconds for the steady stream of fuel to be broken up by bubbles, as a function of how much extra fuel was pumped into bladder  126 .
 
10. Decouple the fuel-fill hose/nozzle  230  from fuel-fill adapter  200 ; some fuel may drip out. Any such leakage will be absorbed by the towel.
 
11. After about one minute, a “J” shape is bent into vent/drain hose  210 . Allow about ten seconds to see if fuel is accumulating in the “J” and then release the hose.
 
12. If fuel is observed accumulating in the J-shaped bend, permit the system to settle for about another minute and then repeat operation 11, as necessary. It may take about one to five minutes for fuel bladder  126  to reach equilibrium.
 
13. When fuel no longer accumulates in the bend, disconnect vent/drain hose  210 . Use gravity to empty fuel from the hose into the drain or waste container.
 
14. Decouple fuel-fill adaptor from fill port  122 .
 
15. Re-install the fuel-fill cap of the RMV per appropriate procedures.
 
16. Properly dispose of towel.
 
         [0043]    It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims.