Patent Description:
Diesel Exhaust Fluid ("DEF") helps meet EPA <NUM> NOx emissions standards. Most large diesel engine vehicles manufactured since <NUM> utilize Selective Catalytic Reduction (SCR) requiring DEF injected into the exhaust stream to reduce NOx emissions in the engine's exhaust. Unlike diesel fuel, DEF freezes at approximately -<NUM> degrees Celsius (<NUM>° Fahrenheit). When DEF freezes, it can expand up to <NUM>%. When disposed within a container or tank, such as a flow meter, expansion of the DEF can result in significant damage.

Freeze plugs or expansion plugs are often used in the engine block of a car to prevent damage when water or coolant freezes. A freeze plug is a round plug that is pressed into a hole formed in the engine block and it is designed to "pop out" to allow for expansion of the water upon freezing. A fuel dispenser with a freeze plug is known from <CIT>. Another freeze plug is disclosed in <CIT>. However, there are several problems with current freeze plugs: they can introduce additional leak points, and they often fail to "pop out. " Additionally, traditional freeze plugs are not designed for use when the system is in operation. Therefore, once a freeze plug has "popped out," the system must receive maintenance before it can be placed back in service. For these reasons, it is not practical or reasonable to use a traditional freeze plug in a fuel dispenser.

Accordingly, there remains a need for improved methods and devices for preventing cracking of a fluid-filled chamber.

Methods and devices are provided for preventing cracking of a fluid-filled chamber. In one embodiment, an anti-fracture expansion device is provided that includes a cap having external threads configured to mate with threads formed within a bore in a housing. A cuff is disposed within the cap and is freely rotatable relative to the cap. The device also includes a piston having a proximal end slidably disposed within the cuff and extending distally from the cuff. The piston is configured such that, when the cap is threadably mated to a bore in a sealed fluid-filled housing, the piston slides relative to the cuff and cap when a pressure within the fluid-filled housing increases to thereby expand a volume of the fluid-filled chamber.

The device can have any number of additional features and/or variations. For example, the proximal end of the piston can include a stabilizing sleeve that is slidably disposed within the cuff. The stabilizing sleeve and the cuff can define a chamber therebetween, such as a sealed chamber. An external surface of the stabilizing sleeve can be in a sealing engagement within an internal surface of the cuff.

As another example, the piston can include a sleeve having at least one opening formed therein for allowing fluid to flow therethrough. The sleeve can be slidably disposed around an elongate shaft having a distal end with at least one fluid inlet port, an inner lumen extending therethrough, and a proximal end with at least fluid outlet port that is aligned with the at least one opening formed in the sleeve such that fluid can flow through the elongate shaft and exit from the proximal end.

As yet another example, the device can include a bearing assembly disposed between the cuff and the cap for allowing rotation of the cuff relative to the cap. The device an also include a spring that biases the piston away from the cap. Furthermore, the device can include a fluid-filled housing having a bore formed therein and having threads formed within the bore that mate with the threads on the cap. The piston can be disposed within the housing when the cap is threadably disposed within the bore.

In another embodiment, a fuel dispenser is provided that includes a hydraulics cabinet having fuel dispensing components disposed therein, an electronics compartment having electronics configured to process payment for fuel dispensed by the fuel dispensing components, and at least one dynamic anti-fracture device disposed internally within a fluid-filled chamber of the fuel dispenser. The dynamic anti-fracture device can be configured to allow a volume of the fluid-filled chamber to increase when a pressure of the fluid within the fluid-filled chamber exceeds a predetermined threshold pressure.

The fuel dispenser can have any number of additional variations or features. For example, the fluid-filled chamber can include a fluid inlet and a fluid outlet, and the dynamic anti-fracture device can be configured to control fluid flow through one of the fluid inlet and the fluid outlet. As another example, the dynamic anti-fracture device can maintain a check valve disposed within a fluid inlet of the fluid-filled chamber in an open position for allowing fluid to flow into the fluid-filled chamber. In other aspects, the dynamic anti-fracture device can include a compressible ball seated within an opening of the fluid-filled chamber. The ball can be configured to compress when the pressure of the fluid within the fluid-filled chamber exceeds the predetermined threshold pressure. Additionally, the ball can be configured to control a flow of fluid through the opening when the pressure of the fluid is less than the predetermined threshold pressure.

In another embodiment, a dynamic anti-fracture device and valve assembly is provided and includes a housing having an inlet, an outlet, and an inner chamber in fluid communication with the inlet and the outlet. An anti-fracture device is at least partially disposed within the inner chamber and is configured to control fluid flow through the inlet of the housing and to increase a volume of the inner chamber when a pressure within the inner chamber exceeds a predetermined threshold pressure.

This invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:.

Various exemplary methods are devices are provided for preventing fracture of a fluid-filled chamber or tank. The devices are referred to as anti-fracture expansion devices. In general an anti-fracture expansion device can be disposed internally within a fluid-filled chamber such that during a freeze event displaced fluid can compress or flow into the anti-fracture expansion device, thereby reducing the likelihood that the chamber will rupture. The internal disposition of the expansion device prevents it from interfering with other components that may be connected to or adjacent to the fluid chamber, thereby conserving space. In certain embodiments, the expansion device can have a dual function wherein it can act as a flow control valve in addition to functioning as an anti-fracture expansion device.

<FIG> illustrate one embodiment of an anti-fracture expansion device <NUM> that includes a piston assembly <NUM> that is slidably disposed within a cylinder or cuff <NUM> so as to accommodate displaced fluid during a freeze event. The illustrated anti-fracture expansion device <NUM> can also include a cap <NUM> that is coupled to the cuff <NUM>, and that includes threads <NUM> on an external surface thereof for threadably mating with threads formed in a bore of a fluid-filled housing. The illustrated piston assembly <NUM> includes a piston <NUM> and a centering sleeve <NUM> extending from the piston <NUM>, however a person skilled in the art will appreciate that the sleeve <NUM> is optional and other centering techniques can be provided.

The cap <NUM> can have a variety of configurations, but in general is in the form of a hollow cylindrical housing with a sealed proximal end 20p. As noted above, the cap <NUM> includes external threads <NUM> for mating with a threaded bore in a fluid-filled housing, and a cavity <NUM> for receiving the cuff <NUM>. An inner protrusion <NUM> is configured to mate, e.g., via friction, with an internal lumen <NUM> of a bearing <NUM> that is seated within the cavity <NUM> of the cuff <NUM>. The bearing <NUM> allows the cap <NUM> to rotate independent of the cuff <NUM>, while still fixing the cuff <NUM> to the cap <NUM>.

The piston assembly <NUM> can have a variety of configurations, but in general has a cylindrical piston head <NUM> with a central opening <NUM> extending therethrough. The central opening <NUM> is configured to receive an inner shaft <NUM> of the cuff <NUM>. Internal sealing elements <NUM> can be disposed therein to form a seal between the central opening <NUM> of the piston head <NUM> and the inner shaft <NUM> of the cuff <NUM>. External sealing elements <NUM> can also be provided around the piston head <NUM> to form a seal between the outer-facing surface of the piston head <NUM> and the inside of the cuff <NUM>. A sleeve <NUM> can extend distally from the piston head <NUM>. The sleeve <NUM>, if provided, can facilitate alignment of the piston assembly <NUM>, as will be discussed in more detail below. In other embodiments, the cuff <NUM> may not have an inner shaft <NUM>, and the piston head <NUM> may not have a central opening <NUM>. In that event, the piston head <NUM> would need to be configured such that it would remain longitudinally aligned during sliding movement within the cuff <NUM>.

As best shown in <FIG>, the cuff <NUM> is generally cylindrical and has a cylindrical cavity <NUM> formed therein for receiving the piston head <NUM>. The cavity <NUM> is open at the distal end 30d and closed at the proximal end 30p. As shown in <FIG>, the proximal end 30p can include a recess or cavity <NUM> that is configured to receive the protrusion <NUM> formed within the cap <NUM>. A bearing assembly <NUM> can be disposed therebetween for allowing free rotation of the cap <NUM> relative to the cuff <NUM>. In an exemplary embodiment, the bearing assembly <NUM> is a radial ball bearing having inner and outer bearing races 51a, 51b with balls <NUM> therebetween such that the inner and outer bearing races 51a, 51b can rotate independently. The outer-facing surface of the outer bearing race 51b can form a friction fit within the cavity <NUM> at the proximal end 30p of the cuff <NUM>. The inner-facing surface of the inner bearing race 51a can similarly form a friction fit with the protrusion <NUM> within the cap <NUM>, thus mating the two components. The bearing assembly <NUM> thus allows the cap to be rotated to threadably mate with a housing without causing corresponding rotation of the cuff <NUM>.

As shown in <FIG> and <FIG>, the cuff <NUM> can also include an inner shaft <NUM> formed therein for slidably receiving the piston assembly <NUM> therearound, as will be discussed in more detail below. A number of external sealing rings <NUM>, e.g., o-ring(s), can be disposed around the cuff <NUM> to form a seal between the cuff <NUM> and the fluid-filled housing. Additional sealing rings can be provided to form a seal between the cuff <NUM> and other components as may be needed.

A biasing element (not shown) can be disposed between the piston head <NUM> and the cuff <NUM>, and it can be configured to bias the piston <NUM> away from the cuff <NUM> and into a distal position during normal operation. In certain embodiments, the biasing element can be a spring (or equivalent), or alternatively/additionally the assembled device may form a sealed air-tight volume between the piston head <NUM> and the cuff <NUM>, in which case the air pressure within the assembly would act as a biasing element. If a spring (or equivalent) is used, then the piston head <NUM> and cuff <NUM> can form a pressurized volume, but they do not need to, e.g., the cuff could vent to atmosphere. The pressure exerted on the piston head <NUM> by the biasing element may be varied or selected based on fluid pressure variances which may occur during normal operating conditions. Regardless of the configuration of the biasing element, it should apply a force to the piston head <NUM> that is sufficient to prevent movement of the piston <NUM> during normal operating conditions, but that allows movement of the piston <NUM>, and thus expansion of the chamber volume, during a freeze event. In certain exemplary embodiments, the biasing element provides a pressure in the range of <NUM> bar to <NUM> bar (<NUM> to <NUM> psi).

When fully assembled, the piston <NUM> and cuff <NUM> are fully inserted into a fluid filled housing, and the threaded cap <NUM> is threaded into a bore in the housing to seal the housing. During normal operation, the piston <NUM> will remain in a distal position within the cuff <NUM>, as shown in <FIG>, either due to the spring-bias or the pressure within the cuff. The force that maintains the piston <NUM> in the distal position can be designed to be greater than the normal operating pressure of the fluid within the fluid-filled housing to accommodate possible pressure fluctuations.

During a freeze event, fluid within the housing will increase the pressure within the chamber. As the pressure increases and eventually exceeds the force that maintains the piston in the distal position, it will force the piston <NUM> to move proximally into the cuff <NUM>, thereby expanding the chamber volume and relieving pressure within the housing, thus preventing cracking or other damage to the housing. When the fluid begins to thaw, the fluid pressure on the piston <NUM> will decrease, and the biasing element can move the piston <NUM> in the distal direction back to its initial position.

While the anti-fracture expansion devices disclosed herein can be used in numerous applications, including automotives, home and industrial heating and cooling systems, etc., in an exemplary embodiment, the devices are used in a fuel dispenser. <FIG> illustrate one embodiment of a fuel dispenser <NUM>. The fuel dispenser <NUM> generally includes an electronics compartment <NUM> and a pump compartment <NUM>. The electronics compartment <NUM> houses electronics for facilitating payment for fuel and for facilitating the dispensing of the fuel. The electronics include, for example, a fuel controller configured to control dispensing of the fuel from the pump compartment, a communication unit configured to transmit and receive wired and/or wireless communications, a display <NUM> configured to show information (e.g., media content, payment information, etc.) thereon, a memory configured to store data therein, and a payment terminal (e.g., a card reader, etc.) configured to process customer payment. Only the display <NUM> is shown in <FIG>. Similar components can be located on the other side of the electronics compartment <NUM>.

The pump compartment <NUM> houses a pump configured to pump fuel from a fuel tank or other reservoir and has therein a fuel meter configured to monitor fuel flow. The pump compartment <NUM> can include other components to facilitate fuel dispensing, such as valves, a strainer/filtering system, a vapor recovery system, etc. The pump compartment <NUM> is isolated from the electronics compartment <NUM> within the fuel dispenser <NUM> to facilitate safety, security, and/or maintenance, as will be appreciated by a person skilled in the art. Fuel is thus not allowed to flow from the pump compartment <NUM> to the electronics compartment <NUM>.

The fuel dispenser <NUM> is configured to be connected to the fuel tank or other reservoir containing fuel. When filling up the tank of a motor vehicle, the fuel is pumped from the tank or reservoir by the pump located in the pump compartment <NUM> and ultimately to a nozzle <NUM> via a fuel pipe (not shown) and a fuel hose <NUM>. When each fuel hose <NUM> is not in use, the fuel hose <NUM> hangs along the fuel dispenser <NUM>, and its associated nozzle <NUM> is seated in a nozzle boot <NUM>. The illustrated fuel dispenser <NUM> is configured to have two hoses <NUM> and two nozzles <NUM> on one side of the dispenser <NUM> and two hoses <NUM> and two nozzles <NUM> on the other side of the dispenser <NUM>, but as will be appreciated by a person skilled in the art, the fuel dispenser <NUM> can include any number of hoses and nozzles. A person skilled in the art will also appreciate that the fuel dispenser can have various other configurations.

The anti-fracture expansion devices disclosed herein can be employed in a number of different locations within a fuel dispenser. <FIG> illustrates the fuel dispenser <NUM> of <FIG>, showing some of the internal components of the pump compartment <NUM>. In one embodiment, an expansion device can be located in a meter assembly. <FIG> illustrates one embodiment of a metering assembly <NUM> disposed within the pump compartment, and <FIG> illustrates the metering assembly <NUM> of <FIG>, as well as an additional embodiment of a metering assembly <NUM>. In another embodiment, as further shown in <FIG>, an expansion device can be disposed within a nozzle <NUM> of the fuel dispenser <NUM>. A person skilled in the art will appreciate that the anti-fracture expansion devices disclosed herein can be incorporated into any meter assembly known in the art, or into any fluid-filled location within a fuel dispenser that is susceptible to damage due to a freeze event.

<FIG> illustrate an embodiment of an anti-fracture expansion device employed in a filtering and metering assembly <NUM> shown in <FIG>. The expansion device is identical to the device <NUM> discussed above with respect to <FIG>, however in this embodiment the device <NUM>' includes a fluid delivery shaft <NUM> and a valve assembly <NUM> located at the distal end of the shaft.

As best shown in <FIG>, the fluid delivery shaft <NUM> is in the form of an elongate hollow shaft having a proximal end 60p with a threaded protrusion <NUM> extending proximally therefrom for mating with threads formed within the inner shaft <NUM> of the cuff <NUM>, which is disposed within the central opening <NUM> of the piston head <NUM>, thereby fixing the position of the fluid delivery shaft <NUM> relative to the cuff <NUM>. The proximal end 60p can also include several fluid outlets <NUM> formed therein and spaced around a perimeter thereof for allowing fluid to exit the shaft <NUM> and to flow into the surrounding chamber. The fluid outlets <NUM> align with the cutouts in the sleeve <NUM>, though they need not be aligned to permit fluid flow.

The distal end of the fluid delivery shaft <NUM> can be configured to couple to the valve assembly, and as shown in <FIG> the distal end 60d includes a head <NUM> formed thereon that is received within a nut <NUM> of the valve assembly <NUM>. The head <NUM> functions as a sealing ring to form a seal with the nut <NUM>. The head <NUM> can also function to open a valve by pushing against it, which will be discussed below. An opening <NUM> is formed in the head <NUM> for allowing fluid flow into the inner lumen of the fluid delivery shaft <NUM>. A stop flange <NUM> can be located just proximal of the head <NUM> for functioning as a stop to control an insertion depth of the head <NUM> into the nut <NUM>.

The valve assembly has a nut <NUM>, as mentioned above, that is threaded on the distal portion for threadably mating with a threaded bore in a wall of the fluid-filled housing, i.e., the filter/strainer housing of the meter assembly. A valve seal <NUM> is received within a distal end of the lock nut <NUM> and is biased proximally toward the closed position.

In use, the valve assembly is installed into the chamber of a fluid-filled housing via threading or some other means of securing the assembly into the chamber. As the anti-expansion device <NUM>' is attached to the fluid-filled chamber, the head <NUM> on the fluid delivery shaft <NUM> is inserted into the lock nut <NUM> such that the sealing rings on the fluid delivery shaft form a seal with the internal wall of the lock nut. As the cap <NUM> is threaded into the chamber, the device moves distally until the cap is secure. The stop flange <NUM> on the fluid delivery shaft <NUM> will abut the lock nut <NUM>. In this position, the head <NUM> will push the valve seal <NUM> distally, thereby moving the valve seal <NUM> from the closed position to an open position. Fluid can thus flow past the valve seal <NUM> and into the fluid delivery shaft <NUM>, which guides the fluid into the chamber in a controlled manner. If the cap is removed, the pressure on the valve seal is released, and the seal will close. This serves as a safety mechanism to prevent unwanted outflow during maintenance operations.

A person skilled in the art will appreciate that the valve assembly need not include a lock-nut, specifically. There are any number of variations that could be used to secure the valve seal within the chamber, e.g., the valve could be connected to a plate that is welded or champed to the chamber.

During normal operation, fluid enters through the chamber inlet and the valve opening, flows into the distal opening of the fluid delivery shaft <NUM>, traverses the length of the shaft <NUM>, and exits through the fluid outlets <NUM> in the shaft and the cutouts in the sleeve <NUM>. The elongate cut-outs in the sleeve <NUM> align with the fluid outlets <NUM> in the fluid delivery shaft <NUM> to allow fluid to pass therethrough, regardless of the position of the piston assembly <NUM>. At that point, the fluid may be filtered, treated, stored, etc., as desired. For example, a filter or strainer can be disposed within the chamber around the fluid delivery shaft <NUM> for filtering the fluid as it flows therethrough. Once treatment has been completed, the fluid may be released through an outlet to be passed through a metering system.

Claim 1:
A fuel dispenser (<NUM>), comprising
a hydraulics cabinet having fuel dispensing components disposed therein;
an electronics compartment having electronics configured to process payment for fuel dispensed by the fuel dispensing components; and
at least one anti-fracture expansion device (<NUM>) disposed internally within a fluid-filled chamber of the fuel dispenser,
characterized in that the anti-fracture expansion device (<NUM>) comprises a cap (<NUM>) having a piston (<NUM>) slidably coupled thereto and disposed within the fluid-filled chamber, the piston (<NUM>) being configured to slide relative to the cap (<NUM>) when the pressure of the fluid within the fluid-filled chamber exceeds the predetermined threshold pressure to allow a volume of the fluid-filled chamber to increase.