Fully-integrated flow-control valve assembly for top-filled fuel tanks

A fully-integrated flow-control valve assembly for top-filled fuel tanks incorporates both a float valve assembly and a shut-off valve assembly in a single unit that screws into a threaded aperture in the top of the fuel tank. Whereas all other systems having similar function rely on an inlet valve and a level control/vent positioned apart from one another and intercoupled with a bleed line that runs either inside or outside the fuel tank, the device of the present invention directly mounts the two devices together and allows a simple installation. There is no need for a line that couples two remotely positioned units of the prior art flow-control assemblies.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates, generally, to valve assemblies and, more particularly, to flow control valve assemblies that are used to protect primarily fuel tanks from being overfilled with fuel. However, it is likely that such flow control valve assemblies may be used to protect types of containers, other than fuel tanks, from being overfilled with other kinds of fluids.

Description of the Prior Art

For many years large machinery fitted with fuel tanks have been equipped with fast fill systems to enable rapid filing of large capacity fuel tanks. The existing fast fill fuel systems rely on an air vent that prevents air from escaping the fuel tank when the required level of fuel has been attained. This causes pressure in the fuel tank to increase to a level that automatic shuts-off a fuel supply nozzle.

A major concern of this system is that when the fuel level activates the shut-off for the fuel supply nozzle, the shut-off can be overridden and fuel can continue to be forced into the fuel tank above the normal level. This can cause the fuel tank to rupture from the high pressure attained when filling.

U.S. Pat. No. 6,311,723, (by the applicant), has addressed this problem by devising a flow control valve assembly that prevents the build up of pressure within the fuel tank during and after filing. The flow control valve assembly also prevents the supply fuel nozzle from being overridden thus preventing the possibility of overfilling. U.S. Pat. No. 6,311,723 is hereby incorporated by reference.

The control valve assembly of U.S. Pat. No. 6,311,723 uses float valve to determine when the level of fuel in the fuel tank is at a desired level. When the desired level of fuel has been attained, the float valve is used to block the flow of fuel through a bleed pipe to stop the flow of fuel through a control valve. An open breather is provided within the fuel tank to allow gas to escape from the fuel tank during filling to prevent the fuel tank rupturing.

The flow control valve assembly operates very effectively on machinery that is predominately stationary. However, when the control valve assembly is mounted to vehicles' fuel tanks, such as those located in trucks and excavators, some difficulties may experienced during movement of the vehicle.

One problem that may be experience is that the float valve may become broken. The float valve comprises a float that is mounted on a pivotally movable elongate arm. This arm can break due to the large forces that are exerted on the arm by the surging fuel caused by movement of the vehicle.

In the event that the control valve assembly fails, in this or any other manner, the fuel supply nozzle will continue to fill the tank and pass fuel through the open breather until the nozzle is shut-off manually. This may lead to many hundreds or even thousands of liters of fuel being wasted and the spilt fuel being disposed.

Another problem that occurs is fuel is passed through the open breather during movement of the vehicle. Fuel surges cause fuel to flow through the open breather and escape the fuel tank. Again, this wastes fuel and is environmentally unfriendly. Further, the spilt fuel also creates a fire vehicle hazard.

Another problem associated with prior-art flow control valves is that they are typically used in bottom-filled tanks. This requires that the float assembly be located inside the tank near the top thereof, while the flow control valve is located near the bottom of the tank near where the fuel nozzle couples to the receiver. In order for the float assembly to control the flow control valve, a small-diameter bleed line is used to couple the flow control valve assembly—that is near the bottom of the tank—to the float assembly that is near the top of the tank. The bleed line can be routed either internal or external to the tank, depending on the design of the unit. The use of such a two-piece assembly precludes the use of such a device in smaller tanks.

What is needed is a fully-integrated flow control assembly that mounts at the top of the fuel tank. In such a fully-integrated unit, the float assembly and the flow control valve assembly are both installed within the tank near the top thereof. Only an inlet/vent head protrudes from the top of the tank. Installing the fully-integrated assembly is much simpler than installing the separate float and control valve assemblies, as there is no need to make a connection between the two devices.

SUMMARY OF THE INVENTION

The present invention provides a fully-integrated flow-control valve assembly for top-filled tanks. Rather than installing a float and bleed control valve assembly at the top of the tank, installing a main fluid flow control valve assembly at the bottom of the tank and connecting the two assemblies with a fluid bleed line that is typically routed within the tank, the fully-integrated flow-control valve assembly is installed vertically, as a single unit, within the tank near the top thereof. The float and bleed control valve assembly is combined with a main fluid flow control valve assembly as a single unit, and only an inlet/vent head protrudes from the top of the tank.

The fully-integrated flow control assembly has been designed primarily for use in fuel tanks used for heavy equipment having diesel internal combustion engines. Thus, the invention will be described in this context of such use. Nevertheless, it is likely that such a flow control valve assembly may find use for other applications where there is a need to protect types of containers, other than fuel tanks, from being overfilled with other kinds of fluids.

The fully-integrated flow control assembly includes an inlet/vent head, an inlet/vent body secured to the inlet/vent head with a plurality of screws, an inlet drop tube secured to the inlet/vent body, a bleed control body secured to the inlet drop tube, an inlet body secured to the bleed body, an inlet piston housed within the inlet body, a sealing sleeve fitted between an inlet piston and the inlet body, a control spring, an inlet cap secured to the inlet body, a bleed housing fitted between the inlet body and the bleed body, a bleed stem fitted through the bleed control body, a seal on the bleed stem, a float attachable to the bleed stem, at least one float guide fitted through a float, an upper housing segment secured attachable to the inlet/vent body, at least one lower housing segment attachable to upper housing segment, and a lower housing segment cap attachable to the lower housing segment.

Fluid enters the fully-integrated flow control valve assembly either through a hose that couples a remote fuel receiver to the fuel inlet or through a receiver that is directly connected to the fuel inlet. The fuel passes through an inlet passage, enters the inlet drop tube, passes through a central duct in the bleed control body and exerts a force on the face of the inlet piston, thereby overcoming the force of the control spring and pushing the inlet piston down, thereby allowing fuel (fluid) to pass through an escape passage and into the lower housing segment, and subsequently into the bottom of the tank.

A small amount of the fluid that is exerting force on the face of inlet piston flows into a bleed circuit through a central aperture in the inlet piston. This bleed fluid flow into a spring chamber within the inlet housing that is created by the gap between the inlet piston and the inlet cap. The bleed fluid then flows from the spring chamber through slots in the inlet cap into a first annular bleed channel, and then into a first vertical bleed passage in the side wall of the inlet body. The bleed fluid then flows from the first vertical bleed passage into a second annular bleed channel and into a second vertical bleed passage in the side wall of the bleed housing. The bleed fluid then flows from the second vertical bleed passage to the third annular bleed channel created between the bleed body and the bleed housing. The bleed fluid enters a third vertical bleed passage between the bleed body and the bleed housing, and exits through a passage created between the bleed body and the bleed stem, and spills into a fourth annular bleed channel. From the fourth annular bleed channel, the bleed fluid finds its way into the tank through at least one of several vent slots in the side wall of the upper housing segment. As fluid fills the tank, exiting the lower housing segment through the lower housing segment cap, air from the tank is allowed to escape through a vent passage, a vent channel and the vent port which is either directly or remotely coupled to a filtration device that prevents the entry of dust and grit from outside the tank. As fuel is drained from the tank air is allowed to reenter through the same port and passages.

Once a the fluid in a filling tank reaches a predetermined level, the float is raised, guided by at least one float guide and the bleed stem. The float lifts the bleed stem bringing seal in contact with a sealing face in the bleed body, thereby sealing all bleed channels and passages. This causes an equalization of pressure on both sides of the inlet valve, which then allows the control spring to push the inlet valve closed, thereby stopping the flow of fuel into the tank. The increase in pressure from the stoppage of fuel flow is sensed by the nozzle at the filling point, which immediately cuts off the flow of fluid passing through the nozzle.

PREFERRED EMBODIMENT OF THE INVENTION

The new fully-integrated flow control assembly100will now be described in detail, with reference to the attached drawing figures.

The device is comprised of an inlet/vent head101, an inlet/vent body102attachable to inlet/vent head101by a series of six screws103, an inlet drop tube104attachable to inlet/vent body102, a bleed body105attachable to inlet drop tube104, an inlet body106attachable to bleed body105, an inlet piston107housed within inlet body106, a sealing sleeve109fitted between inlet piston107and inlet body106, a control spring108, an inlet cap110attachable to inlet body106, a bleed housing111fitted between inlet body106and bleed body105, a bleed stem113fitted through bleed body105, a seal114on bleed stem113, a float113attachable to bleed stem113, at least one float guide115fitted through float113, an upper housing segment116attachable to inlet/vent body102, at least one lower housing segment117attachable to upper housing segment116, and a lower housing segment cap118attachable to lower housing segment117.

The device is attachable to the top of a fuel tank, mounted vertically. The inlet/vent body102has a central internal thread102B that enables the inlet drop tube104to be threadably connected thereto. In addition, the inlet/vent body102has an outer internal thread102C that enables the upper housing segment116to be threadably connected thereto. Furthermore, the inlet/vent body102has an external thread102D that enables the fully-integrated flow control assembly100to be screwed into a female threaded opening in the top of a fuel tank (not shown). Fluid enters either through a hose directly connected to inlet101A and remotely connected to a receiver or through a receiver directly connected to inlet101A, flows through central aperture102F in the inlet/vent body102, through a central conduit104A in inlet drop tube104, through a central duct105A in bleed control body105, and exerts a force on the face of inlet piston107, thereby overcoming the upward force exerted by control spring108, which pushes the inlet piston107toward a closed position, thereby allowing the fluid to flow around the inlet piston107, through passage106A, into the lower housing segment117, through the lower housing segment cap118, and into the tank.

A small amount of the fluid exerting force on the face of inlet piston107flows into a bleed circuit through the central aperture107A in the inlet piston107. This bleed fluid flows into the spring chamber106B of the inlet housing106created between the inlet piston107and the inlet cap110. The bleed fluid then flows from the spring chamber106B through slots110A in the inlet cap110, into a first annular bleed channel106C, and into a first vertical bleed passage106D in the side wall of the inlet body106. The fluid then flows from the first vertical bleed passage106D into a second annular bleed channel106E and into a second vertical bleed passage111A in the side wall of the bleed housing111. The fluid then flows from the second vertical bleed passage111A to a third annular bleed channel105B of U-shaped cross section that is created between the bleed body105and the bleed housing111. The fluid enters a third vertical bleed passage111B between the bleed body105and the bleed housing111, and exits through the passage105C created between the bleed body105and the bleed stem113spilling into a fourth annular bleed channel105D. From the fourth annular bleed channel105D, the fluid finds its way into the tank through at least one of the vent slots116A in the side wall of the upper housing segment116.

As fluid fills the tank, exiting the lower housing segment117through the lower housing segment cap118, air is allowed to vent through at least one vent passage102A, through vent channel102E, and, finally, through the vent port101B which is either directly or remotely connectable to a filtration device. As fuel is drained from the tank air is allowed to enter through the same port and passages. Once a the fluid in a filling tank reaches a predetermined level, the float112, which surrounds the inlet drop tube104, is raised, guided by at least one float guide115and the bleed stem113. The float lifts the bleed stem bringing seal114in contact with a bleed valve seat105E in the bleed body105, thereby closing the bleed fluid path to the tank. This causes an equalization of pressure on both sides of the inlet valve107, which enables the control spring108to push the inlet piston107closed so that a sealing shoulder107B on the inlet piston107contacts an inlet valve seat105F at the bottom end of the bleed control body105, thereby stopping flow into the tank.

What makes this fully-integrated flow control assembly100unique is that all other similar systems rely on an inlet valve and a level control/vent remotely positioned with respect to one another, and being connectable to each other with a fluid bleed line. This device directly mounts the two devices together and allows a simple installation.

Although only a single embodiment of the invention is shown and described herein, it will be obvious to those having ordinary skill in the art that changes and modifications may be made thereto without departing from the scope and the spirit of the invention as hereinafter claimed.