Patent Description:
This document relates, generally, to a refillable fuel cell, and in particular, to refillable fuel cell and a transfer station transferring fuel to the refillable fuel cell.

Power tools may be driven in response to power supplied from, for example, an electrical power source supplying power to the tool through a cord, a compressed air source supplying compressed air to the tool through a hose, a battery supplying stored electrical power to the tool, fuel supplied from a tank for combustion by, for example, an engine of the tool, and the like. Tools driven by electrical power and/or compressed air may operate, essentially, as long as a source of power is available, but may be cumbersome due to the attachment of the tool to the cord and/or the hose supplying power to the tool, and/or may be limited by the availability of the electrical power and/or compressed air within the range of the tool afforded by the length of the cord and/or the hose. The use of a battery to supply power to the tool may eliminate the need for a cord or hose attachment of the tool to the power source, but may have a relatively limited operating period within the life of the battery, and may be relatively heavy and less nimble. Cordless, combustion powered tools may provide an alternative having increased power and/or run time compared to corded and/or battery powered tools. Other types of fuel transfer stations have previously been described for example in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> an <CIT>. A problem with all of these previously described fuel transfer stations is the arrangement of the pump in relation to the other parts in the transfer station, which limits the area for the user and makes it harder to access the pump.

A closed loop fuel transfer station is disclosed in accordance with independent claim <NUM>. Advantageous embodiments can be found in the dependent claims.

A fuel cell, or fuel canister, for a combustion powered tool, in accordance with implementations described herein, may be removably coupled to a combustion powered tool. The fuel cell may be removed from the tool, and coupled to a fuel transfer station. A fuel transfer station, in accordance with implementations described herein, may provide for refilling, or replenishment, of fuel in the fuel cell, so that the refilled fuel cell, or fuel canister, may be reattached to the tool. In some implementations, the fuel cell may be refilled or replenished with a liquid hydrocarbon fuel such as, for example, propane, from the fuel transfer station. In some implementations, the fuel cell, or fuel canister, may be received in a housing of the tool. In some implementations, the fuel cell, or fuel canister, may be coupled to a housing of the tool. In some implementations, a metering valve coupled to the fuel cell, or fuel canister, may dispense a previously defined amount, or volume, of liquid fuel from the fuel cell, or fuel canister, to the tool in response to an actuation of the tool. In some implementations, a flow through valve coupled to the fuel cell, or fuel canister, may provide a substantially continuous flow of fuel from the fuel cell, or fuel canister, to the tool for sustained operation of the tool.

Numerous different types of tools may be powered by a hydrocarbon fuel, such as, for example, propane, delivered by a fuel cell, or fuel canister, and fuel transfer station, in accordance with implementations described herein. For example, handheld combustion powered equipment, such as, for example, an impact tool, a crimping tool, a fastening tool, and the like may receive a metered flow of fuel provided by a refillable fuel canister for operation, in accordance with implementations described herein. Other types of combustion powered equipment, such as, for example, cutting tools, surface finishing tools, driving tools, and the like, as well as equipment such as lawnmowers, blowers, trimmers, power washers, and the like, may receive a continuous, or free flow of fuel provided by a refillable fuel canister, in accordance with implementations described herein. A fuel canister, and a fuel transfer station, in accordance with implementations described herein, may allow a depleted fuel canister to be refilled and reconnected to the combustion powered equipment, rather than discarded and replaced with a new fuel canister. This may provide substantial cost savings, may enhance user convenience and utility, and may reduce waste. Additionally, operation of this type of combustion powered equipment on a hydrocarbon based fuel such as propane, rather than a traditional gasoline powered arrangement, may allow for indoor operation of the combustion powered equipment, further enhancing user convenience and utility.

In some situations, a main tank, or a supply tank, and a fuel canister to be refilled may be connected in an open loop fuel transfer system, to provide for refilling of the fuel canister from the supply tank. In many situations, the supply tank and the fuel canister may be at substantially the same pressure and temperature, generating a vapor lock condition between the supply tank and the fuel canister, and inhibiting fluid flow between the supply tank and the fuel canister. In this situation, a flow of fluid, for example, a flow of fuel in a liquid state, from the supply tank to the fuel canister, may be facilitated by, for example, allowing a direct vent to atmosphere (or to a secondary pressure vessel) from the fuel canister. This venting to the atmosphere may lower the pressure in the fuel canister, generating a pressure differential that allows for fluid flow from the supply tank to the fuel canister. However, this venting of a fluid fuel at high vapor pressure may create a combustible mix with air, may pose a freeze/frostbite hazard due to off-gassing, may lead to asphyxiation, may waste fuel, and may have other undesirable consequences. A closed loop fuel transfer system may provide for safer, more effective, more efficient transfer of fluid, for example, liquid fuel, from a supply tank to a fuel canister to be refilled.

A schematic view of an example closed loop transfer station <NUM> is shown in <FIG>. A fluid flow line <NUM>, such as, for example, a tube or pipe, may connect one or more supply tanks <NUM> and a fuel canister <NUM>. The supply tank(s) <NUM> may contain fuel, for example, fuel in a fluid state such as, for example, liquid propane, for refilling of the fuel canister <NUM>. A pump <NUM> may be connected to the fluid flow line <NUM>. The pump <NUM> may be, for example, a piston type, air cylinder manual pump, as illustrated in the example shown in <FIG>, or other type of pumping mechanism that can generate a sufficient pressure gradient needed to push fuel into the fuel canister <NUM>. As shown in the exemplary arrangement illustrated in <FIG>, a first check valve <NUM> may be positioned adjacent to a connection between the supply tank <NUM> and the fluid flow line <NUM>, for example, between an outlet of the supply tank <NUM> and an inlet of the pump <NUM>. The first check valve <NUM> may prevent unintended, or inadvertent, flow of fuel between the supply tank <NUM> and the fluid flow line <NUM>. A second check valve <NUM> may be positioned adjacent to a connection between the fuel canister <NUM> and the fluid flow line <NUM>, for example, between an outlet of the pump <NUM> and an inlet of the fuel canister <NUM>, and also between the first check valve <NUM> and an inlet of the fuel canister <NUM>. The second check valve <NUM> may prevent unintended, or inadvertent, flow of fuel between the fuel canister <NUM> and the fluid flow line <NUM>. A quick disconnect coupler <NUM> may facilitate the connection of the fuel canister <NUM> to the line fluid flow <NUM>, and the detachment of the fuel canister <NUM> from the fluid flow line <NUM>. A pressure relief valve <NUM> may be coupled to the fluid flow line <NUM>, to provide for pressure relief in the event of over-filling, or over pressurization in the fuel transfer station <NUM>. In some implementations, one or more filter(s) <NUM> may be coupled to the fluid flow line <NUM>. In the exemplary arrangement shown in <FIG>, the filter <NUM> is coupled at a portion of the fluid flow line <NUM> proximate the outlet of the supply tank <NUM>.

As shown in the arrangement illustrated in <FIG>, in some implementations the closed loop fuel transfer station <NUM> may provide for connection of more than one supply tank <NUM> to the fluid flow line <NUM>. In the example shown in <FIG>, the fuel transfer station <NUM> provides for connection of a first supply tank 200A and a second supply tank 200B to the fluid flow line <NUM>. In this arrangement, backflow at a first inlet portion 110A of the fluid flow line <NUM> may be prevented by the check valve 130A, and backflow at a second inlet portion 110B of the fluid flow line <NUM> may be prevented by the check valve 130B. This arrangement may allow for only the first supply tank 200A to be connected to the fuel transfer station <NUM>, to transfer fuel from the first supply tank 200A to the fuel canister <NUM>, without backflow at the second inlet portion 110B. Similarly, this arrangement may allow for only the second supply tank 200B to be connected to the fuel transfer station <NUM>, to transfer fuel from the second supply tank 200B to the fuel canister <NUM>, without backflow at the first inlet portion 110A. In a situation in which both the first supply tank 200A and the second supply tank 200B are connected to the fuel transfer station <NUM>, operation of the pump <NUM> in the manner described above may draw substantially equivalent amounts of fluid from the first supply tank 200A and the second supply tank 200B simultaneously. If one of the supply tanks 200A, 200B is emptied or disconnected (i.e., fluid flow from one of the supply tanks 200A, 200B is in some manner interrupted or discontinued) then operation of the pump <NUM> may draw fluid from the remaining supply tank 200A, 200B. Placement of the first and second supply tanks 200A, 200B at respective inlet sides of the check valves 130A, 130B, and placement of the fuel canister <NUM> at an outlet side of the check valve <NUM>, ensure that fluid can only flow into a canister <NUM> connected to the fuel transfer station <NUM> at the outlet side of the check valve <NUM>.

<FIG> is a top perspective view of an example fuel transfer station, in accordance with implementations described herein. <FIG> is a bottom perspective view of the example fuel transfer station shown in <FIG>, with portions of a base housing and pump housing removed. <FIG> provides a cross sectional view of a pump installed in the base housing. <FIG> is a cross sectional view of the fuel transfer station, taken along line A-A of <FIG>. <FIG> is an exploded perspective view of the fuel transfer station. As shown in <FIG>, the fuel transfer station <NUM> may include a frame <NUM> coupled to a base <NUM>. The frame <NUM> may provide a support structure for the supply tank <NUM> and the pump <NUM>. Fluid flow line(s) <NUM> may be housed within the base <NUM> and/or coupled beneath the base <NUM>. Connection ports <NUM> may be included in the base <NUM>, and may be coupled to the fluid flow line <NUM>. For example, a first connection port 165A may provide for connection of the supply tank <NUM> to the fuel flow line <NUM>, and a second connection port 165B may provide for connection of the fuel canister <NUM> to the fuel flow line <NUM>. As shown in more detail in <FIG>, the example pump <NUM> may include a piston <NUM> received in a cylinder <NUM>, and coupled to a handle <NUM>, with an interior of the cylinder <NUM> being in communication with the fluid flow lines <NUM>. The example pump <NUM> may be actuated through manual manipulation of the handle <NUM>, causing reciprocation of the piston <NUM> in the cylinder <NUM>. Upward movement or expansion of the piston <NUM> in the cylinder <NUM> may decrease pressure in the flow lines <NUM> behind check valve <NUM> in connection with the pump <NUM> to draw fluid from the supply tank <NUM> into the cylinder <NUM> and into the flow lines <NUM>. Conversely, downward movement or contraction of the piston <NUM> in the cylinder <NUM> may increase a pressure of fluid contained in the cylinder <NUM>, and force the fluid from the cylinder <NUM> through the fluid flow lines <NUM> and into a fuel canister <NUM> removably connected to the second connection port 165B. The alternate opening and closing of the first check valve <NUM> and the second check valve <NUM> during cycling of the pump <NUM> may facilitate the transfer of fluid from the supply tank <NUM> to the fuel canister <NUM>.

A pressure relief valve <NUM> (see <FIG>) may be actuated to provide for pressure relief in the event of over-filling, or over-pressurization. The pressure relief valve <NUM> may be set to a prescribed pressure, for instance, by selection of a spring constant to set a cracking pressure. During actuation of the pump <NUM>, pressure may be increased in the transfer station <NUM> and in the fuel canister <NUM>. Exposure of a pressure that is greater than or equal to the previously prescribed cracking pressure may cause the pressure relief valve <NUM> to open and/or vent to atmosphere. In some implementations, the pressure relief valve <NUM> may be manually actuated, for example, by depression of a pressure relief button <NUM> provided on the base <NUM> of the fuel transfer station <NUM>. For example, in some implementations, the pressure relief valve <NUM> may be a spring loaded poppet valve, that is actuated, or opened, in response to an applied force, for example, an external force applied at the pressure relief button <NUM> and transferred to the pressure relief valve <NUM>. Upon removal of the external force, the spring may bias the pressure relief valve <NUM> back to a closed state, to maintain pressure in the fluid flow lines <NUM>.

The fluid flow line(s) <NUM> may be made of a rigid material, or a semi-rigid material, or a flexible material that is capable of maintaining structural integrity while conveying fluid under pressure, and that is capable of supporting connections with check valves and couplings with connectors to the supply tank <NUM> and the fuel canister <NUM>, to be described in more detail below.

The example pump <NUM> shown in <FIG> employs a manual, piston or air cylinder type pumping mechanism, simply for ease of discussion and illustration. However, a fuel transfer station, in accordance with implementations described herein, may employ other types of pumping mechanisms, such as, for example, electro-mechanical pumps, pneumatic pumps, and the like, to generate a pressure gradient that causes fuel to flow between the supply tank <NUM> and the fuel canister <NUM>. In some implementations, the pressure gradient to cause the fuel to flow between the supply tank <NUM> and the fuel canister <NUM> may be generated by a thermal device that, for example, applies heat to the supply tank <NUM> and/or applies cooling to the fuel canister <NUM>.

For example, as shown in <FIG>, in some implementations, a thermal device <NUM>, in accordance with implementations described herein, may include a thermal jacket <NUM> that may be coupled to the supply tank <NUM>. The thermal jacket <NUM> may be detachably coupled to an outer peripheral portion of the supply tank <NUM> by a fastening device such as, for example, hook and loop fasteners, clips, snaps, elastic fittings, and other such fastening devices. As shown in <FIG>, in some implementations, a power supply cord <NUM> may convey power from an external source of power to the thermal jacket <NUM>. As shown in <FIG>, in some implementations, a power storage device <NUM> such as, for example, a battery, may supply power to the thermal jacket <NUM>. The thermal jacket <NUM> may selectively apply heat to the supply tank <NUM>, to increase the temperature of the supply tank <NUM> and generate a pressure gradient between the supply tank <NUM> and the fuel canister <NUM>. The resulting pressure gradient may cause fuel to flow from the supply tank <NUM> to the fuel canister <NUM>. In some implementations, the heat applied by the thermal jacket <NUM> to the supply tank <NUM> may cause the temperature of the supply tank <NUM> to increase by a relatively small amount, for example, just a few degrees warmer than the fuel canister <NUM>. This relatively small increase in the temperature of the supply tank <NUM> may generate a temperature gradient sufficient to cause fuel to flow from the supply tank <NUM> to the fuel canister <NUM>, and provide for relatively rapid filling of the fuel canister <NUM> without the need for a pump as described above.

As shown in <FIG>, in some implementations, the thermal device <NUM> may include a thermal jacket <NUM> that may be coupled to the fuel canister <NUM>. The thermal jacket <NUM> may be detachably coupled to an outer peripheral portion of the fuel canister <NUM> by a fastening device such as, for example, hook and loop fasteners, clips, snaps, elastic fittings, and other such fastening devices. As shown in <FIG>, in some implementations, a power supply cord <NUM> may convey power from an external source of power to the thermal jacket <NUM>. As shown in <FIG>, in some implementations, a power storage device <NUM> such as, for example, a battery, may supply power to the thermal jacket <NUM>. The thermal jacket <NUM> may selectively apply cooling to the fuel canister <NUM>, to decrease the temperature of the fuel canister <NUM> and generate a pressure gradient between the supply tank <NUM> and the fuel canister <NUM>. The resulting pressure gradient may cause fuel to flow from the supply tank <NUM> to the fuel canister <NUM>. In some implementations, the cooling applied by the thermal jacket <NUM> to the fuel canister <NUM> may cause the temperature of the fuel canister <NUM> to decrease by a relatively small amount, for example, just a few degrees cooler than the supply tank <NUM>. This relatively small decrease in the temperature of the fuel canister <NUM> may generate a temperature gradient sufficient to cause fuel to flow from the supply tank <NUM> to the fuel canister <NUM>, and provide for relatively rapid filling of the fuel canister <NUM> without the need for a pump as described above.

<FIG> illustrates the example fuel transfer station <NUM> with a supply tank <NUM> positioned for connection to the first connector 165A, and a fuel canister <NUM> connected to the second connector 165B. The supply tank <NUM> may also be oriented in a substantially inverted position so as to induce fluid flow from an outlet of the fuel tank <NUM> into the first connector 165A. In the example shown in <FIG>, the supply tank <NUM> has a relatively large capacity compared to that of the fuel canister <NUM>. For example, in the example arrangement shown in <FIG>, the supply tank <NUM> may have a bulk fuel capacity of approximately <NUM> pounds (<NUM>,<NUM>) of liquid fuel (for example, propane), whereas the fuel canister <NUM> may be sized for use in a handheld tool. <FIG> illustrates that the fuel transfer station <NUM> may accommodate supply tanks 200A and 200B, having a variety of different fuel capacities, based on, for example, storage constraints, fuel requirements for a particular job site, and the like. Similarly, the fuel transfer station <NUM> may accommodate fuel canisters 300A, 300B and 300C for refilling that have a plurality of different fuel capacities based on, for example, the types of equipment in use, storage constraints and other such factors. Hereinafter, refilling of an exemplary fuel canister <NUM> such as the fuel canister 300A shown in <FIG>, which is sized for use with a piece of handheld equipment, such as a cordless combustion powered hand tool, will be described, simply for ease of discussion and illustration.

<FIG> illustrate an exemplary fuel canister assembly that may be connected to the fuel transfer station <NUM> for refilling. A cap portion <NUM> may be positioned at a top end portion of the fuel canister <NUM>. An adapter <NUM> may be removably coupled to the cap portion <NUM>, as shown in <FIG>. The cap portion <NUM> of the canister <NUM> may be adapted to allow for connection of a plurality of different types of adapters <NUM> to the fuel canister <NUM>, depending on, for example, the tool and/or piece of equipment to which the fuel canister <NUM> is to deliver fuel. In some implementations, a fuel metering valve which provides a previously defined amount, or volume, of fuel, may be housed within the cap portion <NUM> of the canister <NUM>. In some implementations, a free flow of fuel may pass through the cap portion <NUM> of the fuel canister <NUM>. In some implementations, a release mechanism provided on the cap portion <NUM> may be manipulated or actuated to release the adapter <NUM> from the cap portion <NUM> of the fuel canister <NUM>, as shown in <FIG>. In some implementations, a quick disconnect coupler <NUM> including a body portion 355A (in one of the cap portion <NUM> or the adapter <NUM>) and a stem portion 355B (in the other of the cap portion <NUM> or the adapter) may provide for the quick coupling of the adapter <NUM> to the cap portion <NUM> of the fuel canister <NUM>, and the quick decoupling of the adapter <NUM> from the cap portion <NUM> of the fuel canister <NUM>. A plurality of different cap portions <NUM> and/or different adapters <NUM> may interface with various different pieces of equipment to deliver fuel to the combustion powered equipment. A similar arrangement of a quick disconnect coupler <NUM> including a body portion 355A (in one of the fuel canisters <NUM> or the connection port 165B) and a stem portion 335B (in the other of the fuel canister <NUM> or the connection port 165B) may be used to releasably couple the fuel canister <NUM> to the fuel transfer station <NUM>.

In some implementations, the connection between the adapter <NUM> and the cap portion <NUM> of the fuel canister <NUM>, and the connection between the fuel canister <NUM> and the connection port 165B of the fuel transfer station <NUM>, may be specifically keyed, or patterned, so that only designated adapters <NUM> may be connected to the fuel canister <NUM>, and only designated fuel canisters <NUM> may be coupled to the fuel transfer station <NUM>, by inserting the stem portion 355B into the body portion 355A of the quick disconnect coupler <NUM>, for example in the correct orientation and/or in the correct sequence of movements. For example, when connecting the fuel canister <NUM> to the fuel transfer station <NUM> for filling (as shown in <FIG>), the connection between the cap portion <NUM> of the fuel canister <NUM> and the connection port 165B is specifically keyed, or patterned, so that only designated fuel canisters <NUM> may be connected to the fuel transfer station <NUM> by inserting the stem portion 355B into the body portion 355A of the quick disconnect coupler <NUM>, for example in the correct orientation and/or in the correct sequence of movements. In some implementations, the keying, or patterning, between the body portion 355A and the stem portion 355B of the quick disconnect coupler <NUM> may include a unique geometry, a unique interface including geometric alignment such as insertion of spaced prongs into a corresponding cavity, and the like. In some implementations, engagement between the body portion 355A and the stem portion 355B of the quick disconnect coupler <NUM> may rely on the insertion of the stem portion 355B into the body portion 355A, followed by a movement, such as a relative rotation of the stem portion 355B and the body portion 355A, for full engagement. Keyed engagement in this manner may, in turn, allow for a secure connection during the flow of fluid, such as, for example, fuel in a pressurized state, into the fuel canister <NUM> in a filling operation, and out of the fuel canister <NUM> in a dispensing operation.

<FIG> illustrates an example interface between the fuel canister <NUM> and the fuel transfer station <NUM>, for example, between the fuel canister <NUM> and the connection port 165B of the fuel transfer station <NUM>. The fuel canister <NUM> may be aligned with the connection port 165B of the fuel transfer station <NUM>, for example in an inverted position with respect to the fuel transfer station <NUM>, as shown in <FIG>. In the example interface shown in <FIG>, the keying features to ensure proper connection of an appropriate fuel canister <NUM> to the fuel transfer station <NUM> may include the alignment of pins <NUM> (in one of the connection port 165B or the fuel canister <NUM>) with corresponding recesses <NUM> (in the other of the connection port 165B or the fuel canister <NUM>). This alignment may also include alignment of a geometry, or surface contour <NUM> of the connection port 165B with a corresponding geometry, or surface contour <NUM>, of the fuel canister <NUM>. In the example shown in <FIG>, the keyed interface includes two pins <NUM>, and two corresponding recesses <NUM>, simply for ease of discussion and illustration. However, more, or fewer, pins <NUM> and corresponding recesses <NUM> may be included in the keyed interface. Further, in the example shown in <FIG>, the two pins <NUM> are provided in the connection port 165B, and the two corresponding recesses <NUM> are formed in the fuel canister <NUM>, simply for ease of discussion and illustration. However, the pins may be provided on the fuel canister <NUM>, and the corresponding recesses <NUM> may be formed in the connection port 165B, and/or some of the pins <NUM> may be provided on the fuel canister <NUM> and some of the pins <NUM> in the connection port 165B, with corresponding recesses formed in the connection port 165B and the fuel canister <NUM>.

In some implementations, the keying of the interface may include, for example, a contouring of an outer peripheral portion of the fuel canister <NUM>, for example, a contouring of an outer peripheral portion of the cap portion <NUM> of the fuel canister <NUM>, mated with a complementary contouring of an inner peripheral portion of the connection port 165B. For example, in some implementations, the cap portion <NUM> of the fuel canister <NUM> may include a contoured portion <NUM> (see, for example, <FIG>), for example, at an outer peripheral portion of the cap portion <NUM>. The connection port 165B may include a contoured portion <NUM> (see, for example, <FIG>), for example, at an inner peripheral portion of the connection port 165B. A shape, or contour, of the contoured portion <NUM> of the connection port 165B may correspond to, or be complementary to, the contoured portion <NUM> of the fuel canister <NUM>, so that the contoured portion <NUM> of the fuel canister <NUM> and the contoured portion <NUM> of the connection port <NUM> may be engaged when the fuel canister <NUM> is coupled in the connection port <NUM> (see, for example, <FIG>). This complementary contouring of the outer peripheral portion of the fuel canister <NUM> and the inner peripheral portion of the connection port 165B may help to ensure that only appropriate fuel canisters <NUM> are coupled to the fuel transfer station <NUM> for refilling, and may provide for proper alignment of the fuel canister <NUM> in the connection port 165B.

In some implementations, or in addition to keyed interface described previously, the quick disconnect coupler <NUM> may have unique geometry for mating the body portion 355A with the stem portion 355B. Furthermore, other variations separate from or in addition to the examples described above may also be considered.

As described above, fuel canisters <NUM> having various different sizes and/or capacities, such as, for example, the exemplary fuel canisters 300A, 300B and 300C shown in <FIG>, may be connected to the fuel transfer station <NUM> for refilling. In particular, <FIG> illustrate the exemplary fuel canisters 300A, 300B and 300C, having different sizes and/or capacities, coupled to a common connection port 165B or interface at the outlet of the fuel transfer station <NUM>. In <FIG>, the smallest fuel canister 300A, is coupled in the connection port 165B, and is secured in the connection port 165B through mechanical engagement of the valve structure extending between the connection port 165B and the fuel canister 300A, including, for example, the keyed interface described in detail with respect to <FIG>. In some implementations such as those with a quick disconnect coupler <NUM>, shut-off features may be integrated into valve mechanisms of the stem portion 355B and/or the body portion 355A. The shut-off features may be spring loaded, and may allow fluid flow when the stem portion 355B is engaged with body portion 355A, and may shut-off the fluid flow path upon disengagement of, or a break in connection between the body portion 355A and the stem portion 355B of the coupler <NUM>.

As shown in <FIG>, in some implementations, the fuel canister(s) 300B/300C may be inserted in to the connection port 165B of the fuel transfer station <NUM>, and then turned, or twisted, for example in the direction of the arrow A, to complete the connection or engagement between the fuel canister 300B/300C and the connection port 165B. In this arrangement, the fuel canister 300B/300C may be disengaged from the connection port 165B by turning or twisting the fuel canister 300B/300C in the direction opposite the arrow A. As shown in <FIG>, in some implementations, the fuel canister(s) 300B/300C may be snapped into the connection port 165B of the fuel transfer station <NUM> to complete the connection or engagement between the fuel canister 300B/300C and the connection port 165B. In this arrangement, the fuel canister 300B/300C may be disengaged from the connection port 165B by, for example, manipulating a release button <NUM> on the base <NUM> of the fuel transfer station <NUM>.

<FIG> illustrate the connection of the fuel canister <NUM> into the connection port 165B of the fuel transfer station <NUM>, and <FIG> is a cross sectional view taken along line B-B of <FIG>, illustrating a connected state of the fuel canister <NUM> to the fuel transfer station <NUM>. <FIG> is a cross sectional view taken along line C-C of <FIG>, illustrating a connected state of the supply tank <NUM> to the fuel transfer station <NUM>. Once the fuel canister <NUM> to be filled is securely connected to the fuel transfer station <NUM>, fuel may be transferred from the supply tank <NUM> to the fuel canister <NUM>. As described above, the pump <NUM> may be actuated to generate a pressure gradient, or pressure differential, between the supply tank <NUM> and the fuel canister <NUM>, that pushes, or urges, or guides fluid, for example, liquid fuel such as propane, from the supply tank <NUM> to the fuel canister <NUM>. In response to the connection of the supply tank <NUM> and the connection of the fuel canister <NUM> to the fuel transfer station, and the pressure gradient generated by the pumping action of the pump <NUM>, the first check valve <NUM> may be opened to allow flow from the supply tank <NUM>, through the first check valve <NUM> into the fluid supply line <NUM> toward the fuel canister <NUM>. The pressure gradient may continue to urge the flow of liquid fuel in the direction of the fuel canister <NUM>, through the second check valve <NUM>, and into the fuel canister <NUM>. The pressure gradient may be maintained, for example, through sustained pumping if necessary, and fuel may continue to flow into the fuel canister <NUM> in this manner until the fuel canister <NUM> is full, and/or until the fuel canister <NUM> has reached a desired fill level.

In some implementations, the desired fill level may be visually detected through a clear portion (for example, transparent or translucent) of the outer wall <NUM> of the fuel canister <NUM> (see, for example, <FIG>). In some implementations, the fill level of the fuel canister <NUM> may be measured by a pressure gauge and/or assessment of force applied to the handle <NUM> of the pump <NUM>. To avoid over-filling, or over-pressurization, the pressure relief valve <NUM> may have a prescribed cracking or opening pressure that causes the pressure relief valve <NUM> to be actuated, or opened, to relieve pressure in the fluid flow lines <NUM>. In the event that the fuel canister <NUM> approaches an over-filled or over-pressurized state, the fuel canister <NUM> may include a pressure relief valve <NUM>, or vent <NUM> (see, for example, <FIG>), having a prescribed cracking or opening pressure.

In accordance with independent claim <NUM>, a release mechanism <NUM> is actuated to release the engagement between the fuel canister <NUM> and the connection port 165B of the fuel transfer station <NUM>. The release mechanism <NUM> may be installed in the base <NUM> of the fuel transfer station <NUM>. The release mechanism <NUM> includes a release button <NUM> accessible from an exterior of the fuel transfer station <NUM>. The release button <NUM> may be coupled to, or extend into, a release arm <NUM>. In response to depression of the release button <NUM>, a distal end portion of the release arm <NUM> may contact, and exert a corresponding force on a release pad <NUM> of the cap portion <NUM> of the fuel canister <NUM>. The force exerted on the release pad <NUM> of the cap portion <NUM> of the fuel canister <NUM> may release engagement of the fuel canister <NUM> in the connection port 165B, allowing for disengagement of the fuel canister <NUM> from the fuel transfer station <NUM>. When the release pad <NUM> of the cap portion <NUM> of the fuel canister <NUM> is pushed, a sliding lock of the quick disconnect coupler <NUM> that attaches the body portion 355A with the stem portion 355B, may allow for separation and disengagement. Other quick disconnect mechanisms or attach/detach mechanisms may also be utilized that include locking shafts, collars, spring loaded detents, and the like for release of coupled connectors.

As shown in <FIG>, In some implementations, at least a portion of an outer wall <NUM> of the fuel canister <NUM> may be made of an optically transparent, or translucent material such as, for example, a polycarbonate, polyvinyl chloride, chlorinated polyvinyl chloride, and like materials. This may allow a level of fuel in the fuel canister <NUM> to be visually detected. Visual detection of the amount of fuel in the fuel canister <NUM> may allow the user to determine how much equipment operation time remains before the fuel canister <NUM> will have to be replaced and/or refilled, allowing the user to more accurately schedule tasking, plan work flow and the like. Similarly, visual detection of the amount of fuel in the fuel canister <NUM> may allow the user to determine when the fuel canister <NUM> has reached a desired fill level during the refilling process on the fuel transfer station <NUM>, also preventing over-filling of the fuel canister <NUM>. In some implementations, essentially the entirety of the outer wall <NUM> of the fuel canister <NUM> may be made of a transparent, or translucent material, as shown in <FIG>. In some implementations, one or more previously defined portions of the outer wall <NUM> of the fuel canister <NUM> may be made of a transparent, or translucent material, defining windows <NUM> providing for visibility into the interior of the fuel canister <NUM> through which a fuel level may be visually detected, as shown in <FIG>. In some implementations, portions of the outer wall of the fuel canister <NUM> may be covered by a sleeve <NUM>, or over-mold <NUM> to, for example, improve handling and installation, while leaving other portions of the transparent, or translucent outer wall <NUM> of the fuel canister <NUM> exposed, as shown in <FIG>, so that a fuel level in the interior of the fuel canister <NUM> may be visually detected. In some implementations, a fuel canister <NUM> having an outer wall <NUM> made of a transparent, or translucent material as described above may be designed to provide for pressure relief through, for example, controlled cracking at a particular pressure differential versus atmospheric pressure, thus enhancing safety when filling and maintaining a pressurized fluid in the fuel canister <NUM>. Use of these types of materials in the outer wall <NUM> of the fuel canister <NUM> may also provide advantages in cost and/or weight when compared to metals used in pressure vessels.

In some situations, fuel may exist in the fuel canister <NUM> in a liquid and gaseous mixture. Particularly, in the case of propane fuel, propane may have a relatively high vapor pressure and may be subject to volume change due to varying density n accordance with changes in environmental conditions such as temperature, causing the fluid volume in the fuel canister <NUM> to expand or contract in response. Over-fill protection, included in the design of the fuel canister <NUM> may help alleviate these effects, providing a measure of safety against a failure, or burst of the pressure vessel defined by the fuel canister <NUM>. In some implementations, a compressible material may be incorporated into the fuel canister <NUM>, to account for expansion of the fuel contained in the fuel canister due to environmental changes. For example, a compressible material <NUM> such as, for example, a compressible rubber, a compressible polymer, and the like, may be incorporated into the fuel canister <NUM>, as shown in <FIG>.

In the example shown in <FIG>, the compressible material <NUM> is positioned on an outer circumferential portion of a dip tube <NUM> inside the fuel canister <NUM>. In this example, the compressible material <NUM> is in the form of pieces, or strips, or masses, of compressible material <NUM> surrounding, or partially surrounding, the dip tube <NUM>. An empty fuel canister <NUM>, as shown in <FIG>, may be filled with fuel, for example, from the fuel transfer station <NUM> as described above, at a first temperature Ti. At the first temperature T1, the fluid in the fuel canister is at a first pressure P1, as shown in <FIG>. Elevation of the temperature to a second temperature T2 (greater than the first temperature T1) may cause the fluid in the fuel canister <NUM> to expand, so that the fluid is at a second pressure P2 (greater than the first pressure P1). In response to the elevated pressure P2, the compressible material <NUM> may contract. This contracting of the compressible material <NUM> increases the volume inside the fuel canister <NUM>, making this additional volume available to absorb the expansion of the fluid in the fuel canister <NUM> due to the elevated pressure, thus avoiding an over pressure condition, or an over fill condition, which may cause a safety hazard.

<FIG> are cross sectional views of the fuel canister <NUM>, with compressible material <NUM> in the interior of the fuel canister <NUM>. In the example shown in <FIG>, the compressible material <NUM> is positioned along an inner circumferential surface of the fuel canister <NUM>. In the example shown in <FIG>, portions, or pieces, or strips, of the compressible material <NUM> are positioned intermittently along the inner circumferential surface of the fuel canister <NUM>. In the example shown in <FIG>, the compressible material <NUM> is in the form of spherical balls or discs in the interior of the fuel canister <NUM>. However, the compressible material <NUM> may be in the form of other types of three-dimensional masses having different shapes and/or contours, and are not necessarily spherical balls. In each of these examples, as the temperature and pressure increase, from T1 to T2, and from P1 to P2, respectively, the compressible material <NUM> in the fuel canister <NUM> is compressed in response to the increased pressure, providing additional volume to accommodate the corresponding expansion of the fluid in the fuel canister <NUM>.

The compressible material may have properties that are compatible with the fuel to be contained in the fuel canister <NUM>. The type, and configuration and/or volume of compressible material <NUM> may be designed so as to accommodate a previously set change in volume due to increased pressure after filling. For example, in some implementations, the type and/or configuration and/or volume of the compressible material <NUM> may be set to accommodate sufficient change in volumetric mass density (e.g., greater than <NUM>%) of the fluid in the canister <NUM> after filling. Similarly, mechanical properties of the compressible material <NUM> may be taken into consideration, so that the compressible material <NUM> responds elastically in a relatively high pressure range (expected to be experienced from the fluid in the fuel canister <NUM>), and continue to compress up to an expected vapor pressure before yielding.

As noted above, the use of polycarbonate, polyvinyl chloride, chlorinated polyvinyl chloride, and like materials for the outer wall <NUM> of the fuel canister <NUM>. These types of materials may provide for pressure relief in the event of an over-fill, or over-pressurization condition in the fuel canister <NUM>, through, for example, controlled cracking at a particular pressure differential. In this situation, the fuel canister <NUM> and material of the outer wall <NUM> may be such that a small crack propagates in response to a particular pressure differential, resulting in a controlled release of fuel when heated or over-pressurized, thus avoiding a comparatively violent burst or tear and sudden release of gas which may be experienced with a metal canister in a similar situation. To achieve similar effects, a burst disc, perforated side wall, or previously thinned or weakened portion of fuel canister <NUM> may be included to provide for preferential failure of said device during over-pressurization.

As described above, in some implementations, the fuel canister <NUM> may include a pressure relief valve <NUM>. In some implementations, the pressure relief valve <NUM> may be included in the outer wall portion of the fuel canister, as shown in the example illustrated in <FIG>. In some implementations, the pressure relief valve <NUM> may be included in the cap <NUM>, as shown in the example illustrated in <FIG>. The pressure relief valve <NUM> may be, for example, a spring loaded poppet valve, or other similar type of valve. The pressure relief valve <NUM> may be actuated to provide for pressure relief in the event of over-filling, or over-pressurization. For example, the pressure relief valve <NUM> may be actuated in response to detection that pressure in the fuel canister <NUM> is greater than or equal to a previously defined pressure level. Once the pressure level in the fuel canister <NUM> is below the previously defined pressure level, the spring may bias the pressure relief valve <NUM> back to a closed state.

In some situations, a smaller and/or more portable device for transferring fuel from a supply tank to a fuel canister to refill the fuel canister may further enhance utility and convenience for the user. As shown in <FIG>, in some implementations, a fuel transfer station <NUM> or device may include a pump <NUM> attached to a base <NUM>. The base <NUM> may be positioned on a support surface such as, for example, a floor surface, a work bench surface, and the like. A supply tank <NUM> may be coupled to a first connection port 1165A of the frame <NUM>, in an inverted manner to facilitate the selective flow of fuel out of the supply tank <NUM>. A refillable fuel canister <NUM> may be coupled to a second connection port 1165B of the frame <NUM>. Fluid flow lines (not shown in detail in <FIG>) may be housed within the connecting structure, extending between the first connection port 1165A/supply tank <NUM> and the second connection port 1165B/fuel canister <NUM>, to facilitate the selective flow of fuel from the supply tank <NUM> to the fuel canister <NUM>. The pump <NUM> may include a piston shaft <NUM> having a piston (not shown in <FIG>) at an end portion thereof that reciprocates within a cylinder <NUM> in response to reciprocal movement of a handle <NUM>. Fluid flow lines may be defined within the frame <NUM> to connect the first connection port 1165A/supply tank <NUM> and the second connection port 1165B/fuel canister <NUM>. A first check valve (not shown in detail in <FIG>) and a second check valve (not shown in detail in <FIG>) may be positioned in the fluid flow lines, to selectively control the flow of fluid between the first connection port 1165A/supply tank <NUM> and the second connection port 1165B/fuel canister <NUM>. A pressure relief valve <NUM> may be in communication with the fluid flow lines, to relieve system pressure in the event of an over-filling or over-pressurization condition. With the base <NUM> supported on the support surface, the user may grasp the handle <NUM> and operate the pump <NUM>, causing fluid to flow from the supply tank <NUM> to the fuel canister <NUM>. The flow of fluid between the first connection port 1165A/supply tank <NUM> and the second connection port 1165B/fuel canister <NUM> may be controlled in a similar manner previously described in detail with respect to <FIG>. Similarly, the features of the fuel canister <NUM> and the connection thereof to the fuel transfer station <NUM> via the connection port 1165B may be similar to the features of the fuel canister <NUM> and the connection thereof to the fuel transfer station via the connection port 165B described in detail with respect to <FIG>. In the fuel transfer station <NUM> shown in <FIG>, the more substantial frame <NUM> described above with respect to <FIG> is replaced by rigid fluid flow lines connected to the pump <NUM>. The use of a relatively small supply tank <NUM>, for example, a one pound (<NUM>,<NUM>) supply tank <NUM>, may allow the fuel transfer station <NUM> shown in <FIG> to be easily transported, easily utilized, and easily stored.

In some implementations, the transfer of fuel from a supply tank to a fuel canister to be filled may be further simplified by one or more adapters which may provide for the transfer of fuel, essentially directly, from the supply tank to the fuel canister. For example, as shown in <FIG>, a fuel transfer nozzle <NUM> may be coupled to a supply tank <NUM>. A fuel canister <NUM> may then be coupled to, or connected to the supply canister <NUM>, such that a nozzle tip <NUM> of the fuel transfer nozzle <NUM> is inserted into a fill valve <NUM> (see <FIG>) in an end portion of the fuel canister <NUM>. Insertion of the nozzle tip <NUM> into the fill valve <NUM> and depression of the nozzle tip <NUM> may actuate, or open, the fuel transfer nozzle <NUM>, and may actuate, or open, the fill valve <NUM>, allowing fuel to flow from the supply tank <NUM>, through the fuel transfer nozzle <NUM> and the fill valve <NUM>, and into the fuel canister <NUM>. An exemplary fuel transfer nozzle <NUM> will be described in more detail with respect to <FIG>. An exemplary fill valve <NUM> will be described in more detail with respect to 14A and 14B. The insertion of the nozzle tip <NUM> of the fuel transfer nozzle <NUM> into the fill valve <NUM>, to provide for the flow of fuel from the supply tank <NUM>, through the fuel transfer nozzle <NUM> and the fill valve <NUM> and into the fuel canister <NUM>, is illustrated schematically in <FIG>.

<FIG> are perspective views of the exemplary fuel transfer nozzle <NUM>, in accordance with implementations described herein. <FIG> is a cross sectional view of the exemplary fuel transfer nozzle <NUM> in an unactuated state. <FIG> is a cross sectional view of the exemplary fuel transfer nozzle <NUM> in an actuated state. <FIG> is a schematic illustration of the supply tank <NUM> and the fuel canister <NUM> in a disconnected state, and <FIG> is a schematic illustration of the supply tank <NUM> and the fuel canister <NUM> in a connected state, in which fuel can flow from the supply tank <NUM> to the fuel canister <NUM>, and may be aided by the effects of gravity.

A coupler <NUM> may provide for coupling, for example, threaded coupling, of the fuel transfer nozzle <NUM> to an outlet port of the supply tank <NUM>. An inlet tip <NUM> may engage an outlet flow passage of an outlet port of the supply tank <NUM>, to selectively allow fuel to flow from the supply tank <NUM> into the fuel transfer nozzle <NUM>. In some implementations, the fuel transfer nozzle <NUM> may include a lubrication port <NUM>, allowing for the periodic lubrication of the internal components of the fuel transfer nozzle <NUM>, and for the addition of lubricant to the fuel canister <NUM>. In some situations, it may be advantageous when lubricant is mixed with the fuel and/or dissolved into the fuel, as the lubricant may then be transferred from the fuel canister <NUM> to the attached equipment, providing lubricity as fuel is dispensed.

In the unactuated state shown in <FIG> and <FIG>, a valve <NUM> positioned in a flow path <NUM> within the fuel transfer nozzle <NUM> may remain closed, such that fuel does not flow from the supply tank <NUM>, through the flow passage <NUM> and out through the nozzle tip <NUM>. An application of force on the nozzle tip <NUM> in the direction of the arrow Fl, i.e., depression of the nozzle tip <NUM> in a direction into the fuel transfer nozzle <NUM>, may cause the valve <NUM> to open, and allow fuel to flow through the fuel transfer nozzle <NUM> and out through the nozzle tip <NUM>, as shown in <FIG> and <FIG>. The nozzle tip <NUM> may move in the direction F2, due to the biasing force of a spring <NUM> at the end portion of the nozzle tip <NUM>, in response to removal of the force applied to the nozzle tip <NUM> (for example, removal of the nozzle tip <NUM> from the fill valve <NUM>), closing the valve <NUM> and returning the fuel transfer nozzle <NUM> to the unactuated state shown in <FIG>.

As shown in <FIG>, insertion of the nozzle tip <NUM> into the fill valve <NUM> compresses the spring <NUM> of the fuel transfer nozzle <NUM> and the spring <NUM> of the fill valve <NUM>, allowing fuel to flow from the supply tank <NUM> into the fuel canister <NUM>. Removal of the nozzle tip <NUM> from the fill valve <NUM> releases the spring <NUM> of the fuel transfer nozzle <NUM> such that fuel no longer flows through the fuel transfer nozzle <NUM>, and releases the spring <NUM> of the fill valve <NUM>, such that fuel no longer flows through the fill valve. In some implementations, it may be advantageous that the nozzle tip <NUM> not create a gas tight seal with the fill valve <NUM>, such that some gas pressure may be relieved as liquid fuel is transferred.

<FIG> is a perspective view of an exemplary fill valve <NUM>, and <FIG> is a bottom view of an exemplary fuel canister <NUM>, in accordance with implementations described herein. As shown in 14A and 14B, the fill valve <NUM> may be installed in an end portion, for example, a base portion, of the fuel canister <NUM>. The fill valve <NUM> may include an inlet portion <NUM> that receives the nozzle tip <NUM> of the fuel transfer adapter <NUM>. The fill valve <NUM> may be selectively actuated by the spring <NUM>, to allow fuel to selectively flow through the fill valve <NUM> and into the fuel canister <NUM>. When the nozzle tip <NUM> of the fuel transfer nozzle <NUM> is received in the inlet portion <NUM> of the fill valve <NUM>, and a force is applied to overcome the applicable spring and gas pressure forces, as shown in <FIG>, both the valve <NUM> of the fuel transfer nozzle <NUM> and the fill valve <NUM> of the fuel canister <NUM> may be open. With both valves <NUM>, <NUM> in the open position, fuel may flow from the supply tank <NUM> to the fuel canister <NUM>.

In some implementations, the flow of fuel from the supply tank <NUM> to the fuel canister <NUM> may be facilitated by the force of gravity (based on, for example, a relative positioning of the supply tank <NUM> in a somewhat inverted position above the fuel canister <NUM>), as illustrated in the relative orientation of the supply tank <NUM> and the fuel canister <NUM> shown in <FIG>.

The exemplary fuel transfer system shown in <FIG> may provide for provide a simplified mechanism for fuel transfer, and may simplify the filling of an individual fuel canister, particularly in a usage environment in which time and/or space and/or equipment availability are limited.

However, in some situations, it may be difficult to achieve a substantially complete filling of the fuel canister <NUM> using the exemplary fuel transfer system shown in <FIG>. In situations in which such a smaller, inline type fuel transfer system may be desired, a fuel transfer station, in accordance with implementations described herein, may include a manual inline pumping system including as few as one single check valve, as illustrated in <FIG>. Such a fuel transfer system including an inline pumping system may provide for essentially complete filling of the fuel canister, in a relatively compact form, while utilizing a reduced number of parts.

As shown in <FIG>, a fuel transfer station, in accordance with implementations described herein, may include an inline fuel transfer pump <NUM> connected between the supply tank <NUM> and the fuel canister <NUM>. In some implementations, a single check valve <NUM> may be installed along an inlet portion <NUM> of the inline fuel transfer pump <NUM>. For example, in some implementations, the single check valve <NUM> may be coupled between the inlet portion <NUM> and a piston <NUM> of the inline transfer pump <NUM>, as shown in <FIG>. In some implementations, the single check valve <NUM> may be coupled at a connection between the supply tank <NUM> and the inlet portion <NUM> of the inline transfer pump <NUM>, as shown in <FIG>. In either of the exemplary installation positions shown in <FIG>, the single check valve <NUM> may allow for flow in a single direction, for example in the direction of the arrow A. That is, in either of the exemplary arrangements illustrated in <FIG>, the single check valve <NUM> may only allow fuel to flow from the supply tank <NUM> to the fuel canister <NUM>.

The manual inline transfer pump <NUM> may include the piston <NUM> reciprocally received in a cylinder <NUM>. The inlet portion <NUM> may be coupled between the outlet of the supply tank <NUM> and the piston <NUM>, to direct fuel from the supply tank <NUM> into an interior of the cylinder <NUM>. A fuel transfer nozzle <NUM> may be coupled to an outlet end portion of the cylinder <NUM>. The fuel transfer nozzle <NUM> may be selectively engaged with a fill valve <NUM> provided in an end portion of the fuel canister <NUM>, so as to selectively direct fuel from the interior of the cylinder <NUM> into the fuel canister <NUM>.

In some implementations, the fuel transfer nozzle <NUM> described with respect to <FIG> may be similar to the fuel transfer nozzle <NUM> described above with respect to <FIG>. In some implementations, the fill valve <NUM> described with respect to <FIG> may be similar to the fill valve <NUM> described above with respect to <FIG>.

In the exemplary arrangement shown in <FIG>, the inline fuel transfer pump <NUM> is in a first state. In the first state, the fuel transfer pump <NUM> is connected to the supply tank <NUM>, and is fully extended due to the pressure exerted by the fluid contained in the supply tank <NUM>, and flowing out of the supply tank <NUM> and into the inlet portion <NUM> of the pump <NUM>. In the exemplary arrangement shown in <FIG>, the inline fuel transfer pump <NUM> is in a second state. In the second state, the pump <NUM> has been compressed, pushing fuel contained within the interior of the cylinder <NUM> out through the fuel transfer nozzle <NUM>, and into the fuel canister <NUM> through the fill valve <NUM>. That is, in transitioning from the first state to the second state, the piston <NUM> moves, or reciprocates, within the cylinder <NUM> (i.e., the piston <NUM> is manually pumped, or moved, within the cylinder <NUM>) to eject the fuel contained within the cylinder <NUM> out of the pump <NUM> through the fuel transfer nozzle <NUM>, and into the fuel canister <NUM> through the fill valve <NUM>.

A reciprocating action, for example, a manual reciprocating action, or reciprocal may be applied to the pump <NUM> to cause a corresponding reciprocal movement of the piston <NUM> in the cylinder <NUM> to draw fuel from the supply tank <NUM> into the cylinder <NUM> in a first direction, and to draw fuel out of the cylinder <NUM> and into the fuel canister <NUM> in a second direction. This reciprocating action may be repeated, and the fuel transferred out of the pump <NUM> and refilled into the pump <NUM>, in this manner until the fuel canister <NUM> is filled. The check valve <NUM> may prevent the supply tank <NUM> from being pressurized due to this reciprocal action. Rather, only the outlet portion of the pump <NUM> (i.e., at the fuel transfer nozzle <NUM>) is pressurized.

In some implementations, the flow of fuel from the supply tank <NUM> to the fuel canister <NUM> may be facilitated by the force of gravity (based on, for example, a relative positioning of the supply tank <NUM> in a somewhat inverted position above the fuel canister <NUM>).

The exemplary check valve <NUM> included in the fuel transfer station including the inline pumping system <NUM> shown in <FIG> is just one illustrative example of a check valve that may be incorporated into a fuel transfer station, in accordance with implementations described herein. Other check valves capable of controlling the flow of fluid between a supply tank and a fuel canister to be filled may also be appropriate.

The exemplary fuel transfer system shown in <FIG> may provide a simplified mechanism for fuel transfer, and may simplify the filling of an individual fuel canister, particularly in a usage environment in which power, such as, for example, electrical power, time and/or space and/or equipment availability are limited.

Claim 1:
A closed loop fuel transfer station (<NUM>), comprising:
a first connection port (165A; 1165A);
a second connection port (165B;1165B);
a fluid flow line (<NUM>) connecting the first connection port and the second connection port, the flue flow line having an inlet portion (110A) proximate the first connection port and an outlet portion proximate the second connection port;
a first coupler configured to detachably couple a supply tank (<NUM>;<NUM>;<NUM>;<NUM>) to the fluid flow line at the first connection port;
a second coupler configured to detachably couple a refillable fuel canister (<NUM>;<NUM>;<NUM>;<NUM>) to the fluid flow line at the second connection port;
a first check valve (<NUM>) at the inlet portion of the fluid flow line;
a second check valve (<NUM>) at the outlet portion of the fluid flow line; and
a pump (<NUM>;<NUM>) in fluid communication with the fluid flow line, so as to selectively pressurize the fluid flow line,
characterized in that the second connection port includes a keying feature, the keying feature including a contoured inner section defined on an inner peripheral portion of the second connection port, the contoured inner section being configured to selectively engage with a movable release pad (<NUM>) on a corresponding outer peripheral portion of the fuel canister,
and in that the fuel transfer station further comprises a release mechanism (<NUM>) extending into the second connection port, the release mechanism including:
a release arm (<NUM>); and
a release button (<NUM>) at a proximal end portion of the release arm,
wherein a distal end portion of the release arm is configured to depress the release pad on the outer peripheral portion of the fuel canister in response to actuation of the release button at the proximal end portion of the release arm, releasing engagement of the contoured inner section and the release pad to release the fuel canister from the second connection port.