This invention relates generally to the field of fuel system and tank assemblies in vehicles, such as gasoline or diesel tanks, and more particularly to vented fuel tanks, such as marine fuel systems found in boats.
Fuel tanks require a venting system of some type such that air within the tank has an escape pathway separate from the inlet fill pipe that is receiving the fuel. In marine applications, such as the fuel tanks found on pleasure boats and the like, the marine fuel tank is typically provided with a vent conduit connected to a vent port mounted on the side of the hull, thus providing a direct passage of fuel overboard. The vent conduit is typically of much smaller diameter than the fill conduit. Even with the smaller diameter, when the tank is approaching full capacity, a significant amount of fuel is often ejected through the vent port. While each individual incident results in only a small amount of pollution, the cumulative total of fuel spillage from thousands and thousands of boats every day produces an unacceptable amount of pollution and harm to the environment.
It is an object of this invention to provide a spill preventing system for vented marine fuel tanks that captures any fuel forced into the vent conduit prior to it being ejected through the vent port into the environment. It is a further object to provide such a system wherein any fuel forced into the vent conduit is returned to the fuel tank.
The spill preventing system for vented marine fuel tanks may comprise several embodiments, all of which embodiments include a fuel capture reservoir. In a first embodiment, the fuel tank system comprises an fill conduit to receive the fuel, a tank, a vent conduit of smaller diameter than the fill conduit, a vent port extending through the hull of the boat, and an internally mounted fuel capture reservoir disposed between the vent conduit and the vent port. In a second embodiment, the fuel tank system comprises an fill conduit to receive the fuel, a tank, a vent conduit of smaller diameter than the fill conduit, a vent port extending through the hull of the boat, an internally mounted fuel capture reservoir disposed between the vent conduit and the vent port, and a return conduit extending between the fuel capture reservoir and the fuel tank. In a third embodiment, the fuel tank system comprises a fill conduit to receive the fuel, a tank, a vent conduit of smaller diameter than the fill conduit, a vent port extending through the hull of the boat, an internally mounted fuel capture reservoir disposed between the vent conduit and the vent port, and a return conduit extending from the fuel capture reservoir back to the fill conduit. These spill preventing systems may be utilized in conjunction with charcoal or other fume suppressing enhancements, and a one-way valve may be incorporated into the return conduits to prevent flow in the wrong direction.
With reference to the drawings, the invention will now be described in detail with regard for best mode and preferred embodiments. In general, the invention is a spill preventing system for vented marine fuel tanks, whereby any fuel that is forced into the vent conduit is captured and returned to the fuel tank rather than being expelled into the environment.
A first embodiment of the spill preventing system for vented marine fuel tanks is shown in
With this construction, as fuel is delivered into the tank 10 through fill conduit 11, the rising fuel level within tank 10 causes air to pass out through the vent conduit 12, the fuel capture reservoir 15 and vent port 13. As the tank 10 becomes fully filled, backflow pressure into the fill conduit 11 results in automatic cut-off of the fuel delivery in known manner. However, this cut-off may not occur rapidly enough, in which case a quantity of fuel is forced up into the vent conduit 12. Rather than being ejected from the vent port 13 as would occur in normal situations, this fuel enters the fuel capture reservoir 15 and is retained therein, the location of the vent port 13 relative to the position of the fuel capture reservoir 15 being such that a relatively large amount of fuel will collect in the fuel capture reservoir 15 prior to the level of the fuel reaching the vent port 13. Once the fueling operation ceases, any fuel retained within the fuel capture reservoir 15 now drains back into the tank 10 through the vent conduit 12.
In a second embodiment of the invention, as shown in
A third embodiment is shown in
In order to prevent or reduce fuel vapors from passing into the environment through the vent port 13, a vapor-suppressing filter 19 may be disposed across the vent port 13 with suitable mounting means, as shown in
It is understood that equivalents and substitutions for certain elements and structures set forth above may be obvious to those skilled in art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.
This application claims the benefit of U.S. provisional patent Applications Ser. No. 61/192,071, filed Sep. 15, 2008.
Number | Date | Country | |
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61192071 | Sep 2008 | US |