WO2017079805A1

WO2017079805A1 - Liquid fuel dispensing system and method

Info

Publication number: WO2017079805A1
Application number: PCT/AU2016/051087
Authority: WO
Inventors: Assa GAFNI
Original assignee: Fueldroid Pty Ltd
Priority date: 2015-11-11
Filing date: 2016-11-11
Publication date: 2017-05-18

Abstract

A system for dispensing liquid fuel into a container having an opening includes a nozzle having an inlet for receiving liquid fuel from a fuel source, a spout from which to dispense liquid fuel, a valve for controlling the flow of liquid fuel through the fuel path, an actuator to open and close the valve, and a shut-off system. The spout is shaped to extend through the opening and being in communication with the inlet, such that the nozzle defines a fuel path between the inlet and an outlet end of the spout. The valve is movable between a fully open position, and a closed position in which the valve prevents liquid fuel flowing through the fuel path. The actuator is operable to place the valve into the fully open position such that the system dispenses liquid fuel at an initial flow rate. The shut-off system is to release the valve from open positions in response to the presence of liquid fuel at a sensing point on the spout. A flow-reduction control system is configured to detect a state associated with the level of liquid fuel within the container. The flow- reduction control system is configured to automatically limit the rate at which liquid fuel can be dispensed from the nozzle to a lower flow rate that is less than the initial flow rate when the liquid level within the container is below the sensing point, and the flow- reduction control system determines that the detected state satisfies at least one pre- determined condition.

Description

Liquid Fuel Dispensing System and Method

Field of the invention

The present invention relates to a liquid fuel dispensing system and method.

Background

Liquid fuel dispensers for refuelling a vehicle typically have a nozzle with a spout that is to be inserted through an opening of a fuel tank of the vehicle when refuelling the vehicle. At commercial filling stations (which are also known by other names, such as "service stations", "gas stations", "fuelling stations"), liquid fuel, for example petrol or diesel, is stored in main storage tanks, and is transported to the nozzle via the fuel dispenser. Filling stations can use suction pumps located in the fuel dispensers to draw the fuel from the main storage tanks for discharge via the nozzle. Alternatively, pumps can be located in, or beside, the main storage tank to deliver the fuel under pressure to the fuel dispenser.

To reduce the likelihood of a user overfilling the tank of a vehicle, and the consequential fuel spillage, nozzles of liquid fuel dispensers typically have a shut-off mechanism that is able to stop fuel discharging from the nozzle in certain circumstances, such as when the tank is about to overflow. A common shut-off mechanism uses a Venturi-based mechanism that operates on a valve in the liquid fuel flow path through the nozzle. The mechanism has a vapour path from an inlet - which is positioned at or near the outlet end of the spout - back to the valve of the shut-off mechanism. When liquids enter the vapour path the pressure within the vapour path increases. When the pressure increases above a pre-determined threshold, a mechanical trip in the shut-off mechanism causes the valve to be released from its open position. The valve is spring biased, so that when released the valve returns to its closed position. In this way, the shut-off mechanism is able to stop the discharge of liquid fuel from the nozzle. The valve of the shut-off mechanism is moved into its open position by movement of a switching lever a user of the fuel dispenser manually operates to open and close a primary valve of the nozzle. Liquid can enter the vapour path when the liquid fuel level within the tank reaches the inlet end of the vapour path. Liquid fuel flowing into the fuel tank is often turbulent, and has a tendency to splash, and/or form a "foam" or "froth" with air/fuel vapour entrained in in the liquid fuel. Thus, an alternative way that the pressure in the vapour path can increase is for a quantity of the liquid component of the foam to enter the vapour path.

While these Venturi-based shut-off mechanisms are generally reliable and cost- effective, there is a high likelihood of the shut-off mechanism ceasing the discharge of fuel prematurely; that is, when the liquid fuel volume within the fuel tank is less than the fuel tank capacity below the inlet to the vapour path. For instance, the fuel tanks of many automotive vehicles have a lead pipe that forms a neck extending from an opening positioned on a side of the vehicle to the main part of the tank. When the liquid fuel flow rate into the tank is sufficiently high, gases in the tank are trapped in main part of the tank by liquid fuel immediately beneath or around the lower end of the lead pipe. A shut-off mechanism is an essential safety feature that cannot be removed. Unfortunately, while discharging liquid fuel at a low flow rate would allow consumers to fill a tank to more of its maximum capacity, this would take much longer to fill the tank, which would reduce filling efficiency. In turn, this would result in an increase in user frustration and potentially lost revenue for filling station operators.

Accordingly, it is desired to address the above, and/or at least provide a useful alternative.

Summary of the invention

The present invention provides a system for dispensing liquid fuel into a container having an opening, the system comprising:

a nozzle having:

an inlet for receiving liquid fuel from a fuel source,

a spout from which to dispense liquid fuel, the spout being shaped to extend through the opening and being in communication with the inlet, such that the nozzle defines a fuel path between the inlet and an outlet end of the spout,

a valve for controlling the flow of liquid fuel through the fuel path, the valve being movable between a fully open position, and a closed position in which the valve prevents liquid fuel flowing through the fuel path, an actuator to open and close the valve, the actuator being operable to place the valve into the fully open position such that the system dispenses liquid fuel at an initial flow rate, and

a shut-off system for releasing the valve from open positions in response to the presence of liquid fuel at a sensing point on the spout; and a flow-reduction control system that is configured to detect a state associated with the level of liquid fuel within the container, and is configured to automatically limit the rate at which liquid fuel can be dispensed from the nozzle to a lower flow rate that is less than the initial flow rate when:

the liquid level within the container is below the sensing point; and the flow-reduction control system determines that the detected state satisfies at least one pre-determined condition.

Thus, during filling the container, if liquid fuel is being dispensed at a flow rate that exceeds the lower flow rate when the flow-reduction control system determines that the detected state satisfies at least one pre-determined condition, the flow rate will automatically be reduced to the lower flow rate.

Preferably, the pre-determined condition is associated with a headspace in the container between the liquid fuel level within the container, and the sensing point. Alternatively or additionally, the pre-determined condition is indicative of the rate at which the headspace is reducing while liquid fuel is being dispensed into the container at the initial flow rate. In some embodiments, the state detected by the flow-reduction control system is at least one of:

the velocity of liquid fuel level within the container approaching the outlet end of the spout, the presence of liquid fuel level within the container at the outlet end of the spout, the volume of the headspace,

a change in gas pressure in the container,

the velocity of gas flow exiting the container through the opening, and

a change in sound generated from within the container during filling of the container, and

the dynamic density of gas in the headspace.

Thus, in some instances, the detected state is a physical property associated with the level of liquid fuel within the container. In some other instances, the detected state is an event or characteristic that is representative of the level of liquid fuel within the container.

In some instances, the flow-reduction control system can be configured to measure a state associated with the level of liquid fuel within the container, and to automatically limit the rate at which liquid fuel can be dispensed from the nozzle to the lower flow rate when the liquid level within the container is below the sensing point, and the flow-reduction control system determines that the measured state satisfies at least one pre-determined condition.

Preferably, the flow-reduction control system includes at least one sensor for detecting or measuring the state.

The at least one sensor can include one of: a capacitive-type level probe, a resistance-type level probe, radar, optical sensor, infrared sensor, vibration sensor, microphone, particle velocity probe, and pressure sensor.

In one form, the flow-reduction control system comprises a head unit that includes the at least one sensor. The head unit can be mountable on or near the nozzle, or can be integral with the nozzle. The system can also include a transducer that emits energy that is measurable by the at least one sensor. In some examples, the emitted energy can be in the form of electro-magnetic waves, sound waves, or gas pressure waves. In some embodiments, the system further comprises:

a pump with a pump inlet that is in communication with a source of liquid fuel, and a pump outlet that is in communication with the nozzle inlet; and

a controller for controlling operation of the pump, the controller being configured to operate the pump to dispense fuel from the nozzle at the initial flow rate,

wherein, when the detected state satisfies the pre-determined condition, the controller automatically adjusts the pump operation so as to limit the rate at which liquid fuel can be dispensed from the nozzle to the lower flow rate.

In such embodiments, the controller can be configured to analyse data received by the at least one sensor, and identify data that indicates that the detected state satisfies at least one pre-determined condition.

In certain alternative embodiments, the flow-reduction control system can include a processor that is configured to analyse data received by the at least one sensor and identify data that indicates that the detected state satisfies the at least one pre-determined condition, and the controller is configured to receive a flow reduction signal from the flow- reduction control system,

whereby, when the flow-reduction control system determines that the detected state satisfies the pre-determined condition, the flow-reduction control system sends a flow reduction signal to the controller, and

wherein upon receipt of a flow reduction signal the controller automatically adjusts the pump operation so as to limit the rate at which liquid fuel can be dispensed from the nozzle to the lower flow rate. In some further alternative embodiments, the flow-reduction control system can further include: a processor that is configured to analyse data received by the at least one sensor and identify data that indicates that the detected state satisfies the at least one predetermined condition; and

a flow regulator that is in communication with the processor, the flow regulator being disposed between the outlet of the pump and the inlet of the nozzle, and being operable to limit the rate of liquid fuel flowing to the nozzle,

whereby, when the flow-reduction control system determines that the detected state satisfies the pre-determined condition, the flow-reduction control system sends a flow reduction signal to the flow regulator, and

wherein upon receipt of a flow reduction signal the flow regulator operates to limit the rate of liquid fuel flowing to the nozzle so as to limit the rate at which liquid fuel can be dispensed from the nozzle to the lower flow rate.

The processor may be disposed in the head unit, or at a location spaced from the head unit.

In embodiments in which the system has a head unit, the head unit can include a communications module that receives an input from the at least one sensor, and generates and sends data to one of the controller or the processor. The communications module can be physically interconnected so as to communicate with the controller or the processor through wires or optical fibres.

The communications module, and the controller or the processor can be interconnected for wireless data transmission.

In embodiments in which the detected state is container-generated sound from within the container while being filled, and the sensor is at least one microphone that is arranged to receive the container-generated sounds, the flow-reduction control system can further include a processor configured to analyse the container-generated sounds received by the microphone and identify container-generated sounds that satisfy the predetermined condition. The pre-determined condition can be that the container-generated sound is indicative of the presence of liquid fuel approaching the opening of the container. Alternatively or additionally, the container-generated sound is indicative of the presence of liquid fuel within a neck of the container.

In some embodiments, the pre-determined condition includes a change in the amplitude of the container-generated sound received by the microphone. In one example, that change can be an increase in the amplitude of the container-generated sounds. Alternatively or additionally, the pre-determined condition includes a change in the frequency spectrum of the container-generated sound received by the microphone. Alternatively or additionally, the pre-determined condition includes the container- generated sound matching a pre-determined pattern in amplitude and/or frequency variation over time. In one example, the pre-determined condition may include an increase in the weighted average amplitude of the container-generated sound received by the microphone over a pre-determined time period. In another example, the pre-determined condition may include the frequency spectrum of the container-generated sound received by the microphone matching a pre-determined profile.

The sound can be air-borne sound, and/or sound vibration transferred into the nozzle.

The microphone can be located on or proximate to the nozzle. Alternatively, the flow-reduction control system can include a plurality of microphones that are disposed to receive sound and/or vibrations at different locations on and/or around the nozzle.

The flow-reduction control system can be configured to suppress noise received by the microphone. The microphone can be structured and/or shaped to suppress noise by limiting the receipt of sound that is extraneous to the container-generated sound. The processor can filter the sound received from the microphone to reduce sound that is extraneous to the container-generated sound. The processor can include a filter that filters any one of white noise, wind noise, frequencies outside a pre-determined range, and at least some sound associated with liquid fuel flowing through the fuel path at the initial flow rate.

In embodiments in which the flow-reduction control system includes a plurality of microphones, a first of the microphones can be positioned on the nozzle to receive predominantly container-generated sound, and one or more additional microphones can be positioned to receive at least sound that is extraneous to the container-generated sound, and the processor can be configured to compare the sound vibrations received by the microphones to cancel extraneous sound from the sound vibrations received by the first microphone.

The or each microphone can be a moving-coil-type microphone, carbon microphone, piezoelectric microphone, fibre optic microphone, and/or MEMS microphone. In certain embodiments, the microphone may be installed on a printed circuit board (PCB).

In certain alternative embodiments, the shut-off system includes a first vapour tube that extends rearwardly along the nozzle with respect to the liquid fuel flow direction from a first vapour inlet at the outlet end of the spout, and a first venturi mechanism that is operably connected to the valve, whereby liquid fuel entering the first vapour tube causes the first venturi mechanism to release the valve from an open position; and

the flow-reduction control system includes a second vapour tube that extends rearwardly along the nozzle with respect to the liquid fuel flow direction from a second vapour inlet at the outlet end of the spout, a flow-rate regulator for regulating the flow of liquid fuel through the fuel path, and a second venturi mechanism that is operably connected to the flow-rate regulator, whereby liquid fuel entering the second vapour tube causes the second venturi mechanism to move the flow-rate regulator so as to restrict the fuel flow path and thereby limit the rate of liquid fuel passing through the fuel flow path, wherein the first vapour inlet is disposed rearwardly of the second vapour inlet with respect to the outlet end of the spout and with respect to the liquid fuel flow direction.

In one form the flow-rate regulator is configured to cause the valve to adopt a partially closed position. ln some alternative embodiments, the flow-rate regulator can include a restrictor located within the fuel path of the nozzle, the restrictor having a first position in which liquid fuel is able to flow through the flow path at the initial flow rate, and a second position in which the restrictor limits the rate of liquid fuel flow through the flow path to the lower flow rate,

wherein the flow-rate regulator is configured to displace restrictor from the first position into the second position when liquid fuel enters the second vapour tube. Preferably, movement of the actuator to open the valve also causes the restrictor to move into the first position.

The restrictor can be any one of a valve, a pinch valve, an orifice plate, or the like. In some embodiments, the flow-reduction control system is configured to vary the flow rate of liquid fuel after reducing the rate at which liquid fuel is being dispensed to the lower flow rate. The flow-reduction control system can be configured to reduce the rate at which liquid fuel is being dispensed to the lower flow rate, and then further reduce the rate at which liquid fuel is being dispensed.

The present invention also provides a method for dispensing liquid fuel into a container having an opening, the method involving:

inserting a spout of a nozzle through the opening, the nozzle having a fuel path that extends between an inlet of the nozzle and an outlet end of the spout, a valve for controlling the flow of liquid fuel through the fuel path, an actuator to open the valve, and, a shut-off system for releasing the valve from open positions in response to the presence of liquid fuel at a sensing point on the spout;

operating the actuator to open the valve such that the nozzle dispenses liquid fuel at an initial flow rate;

using a flow-reduction control system, detecting a state associated with the level of liquid fuel within the container; and

when the flow-reduction control system determines that the detected state satisfies at least one pre-determined condition and prior to the liquid level within the container reaching the sensing point, automatically limiting the rate at which liquid fuel can be dispensed from nozzle to a lower flow rate that is less than the initial flow rate.

Brief description of the drawings

In order that the invention may be more easily understood, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 : is a schematic view of a liquid fuel dispensing system in accordance with a first embodiment of the present invention;

Figure 2: is an enlarged view of Region // in Figure 1 ;

Figure 3: is an amplitude profile of acoustic sound vibration of a vehicle fuel tank being filled using a known fuel dispensing system;

Figure 4: is the amplitude profile of Figure 3 after processing by the system according to Figure 1 ;

Figure 5: is an enlarged view of Region V in Figure 4;

Figure 6a: is a frequency-sound pressure spectrum chart of sound vibrations noise at Time X in the profile of Figure 4;

Figure 6b: is a frequency-sound pressure spectrum chart of sound vibrations noise at Time Y in the profile of Figure 4;

Figure 7: is a nozzle of a liquid fuel dispensing system in accordance with a second embodiment of the present invention; and

Figure 8: is a process flow chart illustrating steps of a method of dispensing liquid fuel in accordance with a third embodiment of the present invention.

Detailed description

Figures 1 and 2 show schematically a system 10 for dispensing liquid fuel into a container C having an opening D. The system 10 has a nozzle 12, and a flow-reduction control system, which is described in further detail below. The nozzle 12, which is shown in further detail in Figure 2, has an inlet 14 that receives liquid fuel from a fuel source, such as a fuel dispenser 16, and a spout 18 that is shaped to extend through the opening D of the container C. The nozzle 12 defines a fuel path between the inlet 14 and an outlet end 20 of the spout 18. In this way, the spout 18 is configured to dispense liquid fuel received from the fuel dispenser 16. The nozzle 12 also has a valve 22 for controlling the flow of liquid fuel through the fuel path. The valve 22 is spring biased towards a closed position, and is movable into a fully open position (as shown in Figure 2). In the closed position, the valve 22 closes the fuel path to prevent liquid fuel flowing through the fuel path. The nozzle 12 has an actuator - which in this embodiment is in the form of switching lever 24 - that a user of the system can operate to manually open and close the valve. Thus, a user can operate the switching lever 24 to place the valve into the fully open position such that the system 10 dispenses liquid fuel. When the valve is in the fully open position, liquid fuel is discharged (in other words, dispensed) at a maximum flow rate. As will be appreciated, the maximum flow rate is governed by the pressure of liquid fuel at the inlet 14, and by the shape of the nozzle 12 along the flow path.

A shut-off system 26 is provided for releasing the valve 22 from open positions so as to move into the closed position in response to the presence of liquid fuel at a sensing point on the spout 18. The shut-off system 26 is described in further detail below.

The flow-reduction control system is operatable in certain circumstances to automatically limit the rate at which liquid fuel can be dispensed from the spout 18. In addition, the flow-reduction control system is configured to detect a state associated with the level of liquid fuel within the container C. To this end, the flow-reduction control system is configured to automatically limit the rate at which liquid fuel can be dispensed from nozzle 12 to a lower flow rate that is less than the initial flow rate when:

a. the liquid level within the container C is below the sensing point; and b. the flow-reduction control system determines that the detected state satisfies a pre-determined condition. In use, the system 10 can be operated to dispense liquid fuel at an initial flow rate; for example, the maximum flow rate. As the volume of liquid fuel within the container C approaches the capacity of the container C, the flow-reduction control system causes the liquid fuel flow rate to be automatically limited to the lower flow rate. This in turn reduces the likelihood of the system 10 incorrectly determining that the container C has been filled to its capacity, and allows continued dispensing of liquid fuel at (or below) the lower flow rate. Consequently, there is greater prospect of a user filling the container completely before the shut-off system 26 closing the valve 22. For example, the maximum flow rate of the system 10 may be approximately 35 to

40 litres/minute. The lower flow rate can be of the order of 1 to 10 litres per minute. Passenger vehicles typically have a fuel tank with a maximum capacity in the order of 40 to 80 litres. When filling a passenger car fuel tank using prior art fuel dispensing systems, the shut-off system can often falsely determine that the fuel tank is full, when there is approximately 2 to 5 litres capacity available. The system 10 of this embodiment has the advantage of increasing the likelihood of users filling their vehicle fuel tanks to capacity.

The shut-off system 26 of this embodiment uses a Venturi-based valve release mechanism, that includes a vapour tube 44 that has a vapour inlet 46 formed in the spout 18 adjacent the outlet end 20 of the spout 18. The vapour tube 44 extends rearwardly along the spout 18 from the vapour inlet 46 to a venturi mechanism 48 that is operably connected to the valve 22. Liquid fuel entering the vapour tube 44 via the vapour inlet 46 causes the venturi mechanism 48 move so as to release the valve 22 from an open position to its closed position. In this way, the vapour inlet 46 forms the sensing point of the shut-off system 26. The lower flow rate is preferably sufficient as to sustain operation of the venturi mechanism 48 such that when the nozzle 12 is dispensing liquid fuel at the lower flow rate the shut-off system 26 is still able to release the valve 22 when liquid fuel reaches the sensing point. As will be appreciated from the description that follows, the system 10 has the advantage that the flow-reduction control system does not override the shut-off system 22. In addition, the flow-reduction control system does not override the operation of the valve 22 by movement of the switching lever 24. ln certain embodiments, the system 10 can be configured to enable the lower flow rate to be adjusted. The pre-determined condition is associated with a headspace in the container between the liquid fuel level, and a sensing point of the shut-off system adjacent the outlet end of the spout. The term "headspace" is to be understood to be the gaseous space within the container C, that is below the sensing point of the shut-off system 26 and above the liquid fuel level immediately adjacent the opening D. In this specification, the expression "liquid fuel level" will be understood to mean the total level of a liquid fuel within the container. Further, the expression "liquid fuel level" will be understood the liquid height within the container, in which the liquid height represents the higher of the uppermost liquid fuel-gas interface within the container, and the uppermost level of a foam of liquid fuel with entrained air/fuel vapour.

In the embodiment of Figures 1 and 2, the flow-reduction control system includes a head unit 28 that includes the a sensor, which is in the form of a microphone 30. The head unit 28 in this embodiment is mounted on the nozzle 12. In this particular example, the head unit 28 is retrofitted about the spout 18.

Within the fuel dispenser 16, there is provided a pump 32 with an inlet 34 that receives liquid fuel from a source, such as an underground storage tank 36. A pump outlet 38 is in communication with the nozzle inlet 14 via a flexible hose 40. The fuel dispenser 16 also contains a controller 42 for controlling the operation of the pump 32. The controller 42 is configured to operate the pump 32 in order to supply to the nozzle 12 for dispensing. In this embodiment, the controller 38 is also configured to receive a flow reduction signal from the head unit 28. When the flow-reduction control system determines that the detected state satisfies the pre-determined condition, the flow- reduction control system sends a flow reduction signal to the controller 42. Upon receipt of a flow reduction signal, the controller 42 operates the pump 32 to dispense fuel from the nozzle 12 at the lower flow rate. The fuel tanks of many automotive vehicles have a lead pipe, which forms a neck N extending from the opening D (which may be positioned on a side of the vehicle) to the main part of the tank. When the liquid fuel level is within the neck N, liquid fuel dispensed into the tank (in other words, the container C) from the nozzle 12 can splash liquid fuel providing a disturbance that acts as a Helmholtz resonator. This creates an audible "bubbling" sound, that is different to the sound of splashing that occurs when the liquid fuel level is below the neck N, and in the main part of the tank.

As will be appreciated, when the liquid fuel flow rate into the container C is sufficiently high gases can be temporarily trapped in part of the container C (for example, by baffles, not shown, that are provided within the container). In this scenario the headspace volume is only part of the entire gaseous volume within the container C, at that particular moment. In this particular embodiment, the pre-determined condition is indicative of the rate at which the headspace is reducing while liquid fuel is being dispensed into the container C at the initial flow rate. Bubbles of gas being displaced from the container and bursting at the liquid fuel level within the neck N also create an audible bubbling sound.

The microphone 30 is positioned to receive the container-generated sounds (such as the audible "bubbling" sound described above). Accordingly, in this embodiment the detected state is the presence of container-generated sounds that are representative of the liquid fuel level within the neck N of the container C.

The flow-reduction control system includes a processor 50 that analyses the container-generated sounds received by the microphone 30, and identifies container- generated sounds that satisfy the pre-determined condition. In this particular embodiment, the processor 50 is provided in the head unit 28. However, in some alternative embodiments, the processor 50 can be provided within the fuel dispenser 16. In some further alternative embodiments, the processor of the flow-reduction control system may be integral with the pump controller 42.

The processor 50 of the flow-reduction control system of this embodiment filters the sound received from the microphone 30 to reduce sound that is extraneous to the container-generated sound, such as white noise, wind noise, noise generated by (and within) the fuel dispenser 16, and liquid fuel flowing through the nozzle 12, and other sounds. Hereinafter, sound that is extraneous to the container-generated sound is referred to as "background noise". To this end, the processor 50 filters "background noise" by supressing frequencies that are recorded by the microphone 30.

Figure 3 shows an amplitude profile of raw acoustic sound vibration of a vehicle fuel tank being filled using a prior art fuel dispensing system. As is evident from Figure 3, fuel is dispensed for approximately 1 :07 (that is, 1 minute and 7 seconds). The container- generated "bubbling" sound is produced in the final stage of filling, which is approximately 5 seconds in length.

Figures 4 and 5 show an amplitude profile of the acoustic sound vibration of a vehicle fuel tank being filled, that has been processed by the processor 50 of the system 10 according to Figures 1 and 2. In this example, the processor 50 applies filters and gain modulation to reduce background noise. In this way, much of the background noise in the first stage of filling (from time = 0:00 to time = 1 :02) is supressed. The container- generated sounds have a relatively greater amplitude, as is evident by comparing times X and Y in Figure 4, and in Figure 5.

Figure 6a shows frequency-amplitude spectrum chart of sound vibrations noise at time X in the profile of Figure 4, and Figure 6b shows a frequency-amplitude spectrum chart of sound vibrations noise at time Y in the profile of Figure 4. As is evident, the container-emitted sounds in this example have prominent sounds in the ranges of 3,000 Hz to 5,000 Hz, and 9,000 Hz to 15,000 Hz. In this example, an increase of received acoustic sound vibration by the microphone 30 in these ranges that exceeds a pre-determined threshold (such as >-70 dB) and for a pre-determined period (such as longer than 0.5 seconds) may be in combination the pre-determined condition that is to be satisfied for the flow-reduction control system to reduce the flow rate.

Once the processor 50 identifies that the detected state satisfies the predetermined condition, the flow-reduction control system generates and sends a flow reduction signal to the controller 42. Upon receipt of the flow reduction signal, the controller 42 automatically operates the pump 32 such that liquid fuel can be dispensed from the nozzle 12 at flow rates up to the lower flow rate.

In the embodiment of Figures 1 and 2, the processor 50 communicates wirelessly with the controller 42. To this end, the processor 50 and controller 42 can use a short- range, wireless communications protocol that enables unique pairing of the processor 50 and 42. For example, the wireless communications protocol can be any of: ANT, ANT+, Bluetooth, Bluetooth Low Energy (which is also known as Bluetooth Smart), ZigBee and Wi-Fi.

In some alternative embodiments, the system may have a physical connection between the processor and the controller (i.e. using electrically conductive wires, or optical fibre). In some further alternative embodiments, the raw data acquired by a sensor mounted on the nozzle may be communicated to a processor that is provided within the fuel dispenser.

Figure 7 is a partial view of a nozzle 1 12 of a system according to a second embodiment of the present invention. The nozzle 1 12 includes an inlet and switch lever (both of which are omitted from Figure 7 for clarity), and a spout 1 18 that is shaped to extend through the opening of a container. The nozzle 1 12 defines a fuel path P between the inlet and an outlet end 120 of the spout 1 18. Further, the nozzle 1 12 has a spring- biased valve 122 for controlling the flow of liquid fuel through the fuel path. The valve 122 is spring biased towards a closed position, and is movable into a fully open position. In Figure 7, the valve 122 is shown in its open position in solid lines, and the broken lines represent the position of the valve 122 in its closed position. In the closed position, the valve 122 closes the fuel path P to prevent flow of liquid fuel.

As described in connection with Figures 1 and 2, a user can operate an actuator - for example, a switching lever - to open the valve 122 such that the system dispenses liquid fuel.

The shut-off system 126 includes a first vapour tube 144 that extends rearwardly along the nozzle 1 12 with respect to the liquid fuel flow direction from a first vapour inlet 146 formed at the outlet end 120 of the spout 1 18. A first venturi mechanism 148 is operably connected to the valve 122. Liquid fuel entering the first vapour tube 144 causes the first venturi mechanism 148 to move so as to release the valve 122 from an open position. As will be appreciated, the spring-bias of the valve 122 will cause the valve 122 to close. Thus, liquid fuel flow through the nozzle 1 12 is stopped.

The nozzle 1 12 also has a flow-reduction control system. In this embodiment, the flow-reduction control system includes a second vapour tube 152 that extends rearwardly along the nozzle 1 12 with respect to the liquid fuel flow direction from a second vapour inlet 154 formed at the outlet end 120 of the spout 1 18. The second vapour inlet 154 is disposed forwardly of the first vapour inlet 146 with respect to the outlet end 120 of the spout 1 18. Further, the flow-reduction control system includes a flow-rate regulator 156 for regulating the flow of liquid fuel through the fuel path P, and a second venturi mechanism 158.

The flow-rate regulator 156 includes a restrictor 160 located within the fuel path P of the nozzle 1 12. The restrictor 160 has a first position in which liquid fuel is able to flow through the flow path at the maximum flow rate (subject to the position of the valve 122), and a second position in which the restrictor 160 limits the rate of liquid fuel flow through the flow path P to a lower flow rate. The flow-rate regulator 156 is configured to displace the restrictor 160 from the first position into the second position when liquid fuel enters the second vapour tube 152. In Figure 7, the restrictor 160 is shown in its first position in solid lines, and the broken lines represent the position of the restrictor 160 in its second position. In the second position, the restrictor 160 partially closes the fuel path P to limit flow of liquid fuel.

The flow-rate regulator 156 includes a spring (not shown) to bias the restrictor 160 towards its second position. In addition, movement of the switching lever causes the flow- regulator 156 to move the restrictor 160 into its first position.

The second venturi mechanism 158 is operably connected to the flow-rate regulator 156. To this end, when liquid fuel enters the second vapour tube 152, the second venturi mechanism 158 moves so as to cause the flow-rate regulator 156 to displace restrictor 160 from its first position into its second position.

Because the first vapour inlet 146 is disposed rearwardly of the second vapour inlet 154 with respect to the outlet end 120 of the spout 1 18, liquid fuel rising within the container C will reach the second vapour inlet 154 (as indicated by liquid level L_R in Figure 7) before the first vapour inlet 146 (as indicated by liquid level L_s in Figure 7). As will be appreciated, the first vapour inlet 146 is the sensing point that causes the shut-off system to close the valve 122 and stop liquid fuel flow through the nozzle 1 12. The second vapour inlet 154 is a triggering point that causes the flow-reduction control system to restrict the flow of liquid fuel through the nozzle 1 12. Accordingly, in this embodiment the state that is detected by the flow-reduction control system is the proximity of the liquid fuel level to the second vapour inlet 154. Further, in this embodiment, the measurement is a simple 2-state measurement; that is, the presence or otherwise of liquid fuel at the triggering point.

With sufficient separation of the first and second vapour inlets 146, 154, the liquid fuel in the container will be allowed to settle, such that continued filling at the lower flow rate is allowed to occur without the shut-off system closing the valve 122 until the container is filled to capacity.

Figure 8 is a process flow chart illustrating steps of a method 200 of dispensing liquid fuel in accordance with a third embodiment of the present invention. For convenience, the method 200 is described with reference to use of the nozzle 1 12 illustrated in Figure 7.

The method involves:

• inserting the spout 1 18 of the nozzle 1 12 through the opening of the container - step 202;

· operating the switching lever to open the valve 122 such that the nozzle dispenses liquid fuel at an initial flow rate - step 204; • using the flow-reduction control system, measuring or detecting proximity of the liquid fuel level to the outlet end 120 of the spout 1 18 - step 206; and

• when the flow-reduction control system determines that the liquid fuel level within the container is at the second vapour inlet 154 and prior to the liquid fuel level within the container reaching the first vapour inlet 146, automatically limiting the rate at which liquid fuel can be dispensed to a lower flow rate - step 208. With continued filling after step 206, the liquid fuel level within the container will reach the first vapour inlet 146, which will cause the shut-off system to close the valve 122. When the switch lever is released, the first venturi mechanism 148 is reset.

Figure 8 includes steps encompassed in rectangle S in dashed lines. The steps in the rectangle S represent a fail-safe of the system. That is, in the unlikely event that the second venturi mechanism 158 fails to reduce the flow rate to the lower flow rate by moving the flow-rate regulator 156, the shut-off system operates to release the valve 122 by movement of the first venturi mechanism 148 when the liquid fuel level reaches the first vapour inlet 146.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. The invention has been described by way of non-limiting example only and many modifications and variations may be made thereto without departing from the spirit and scope of the invention.

Claims

CLAIMS:

1 . A system for dispensing liquid fuel into a container having an opening, the system comprising:

a nozzle having:

an inlet for receiving liquid fuel from a fuel source,

a valve for controlling the flow of liquid fuel through the fuel path, the valve being movable between a fully open position, and a closed position in which the valve prevents liquid fuel flowing through the fuel path,

an actuator to open and close the valve, the actuator being operable to place the valve into the fully open position such that the system dispenses liquid fuel at an initial flow rate, and

a shut-off system for releasing the valve from open positions in response to the presence of liquid fuel at a sensing point on the spout; and

a flow-reduction control system that is configured to detect a state associated with the level of liquid fuel within the container, and is configured to automatically limit the rate at which liquid fuel can be dispensed from the nozzle to a lower flow rate that is less than the initial flow rate when:

the liquid level within the container is below the sensing point; and

the flow-reduction control system determines that the detected state satisfies at least one pre-determined condition.

2. A system according to claim 1 , wherein the pre-determined condition is associated with a headspace in the container between the liquid fuel level within the container, and the sensing point.

3. A system according to either claim 1 or 2, wherein the pre-determined condition is indicative of the rate at which the headspace is reducing while liquid fuel is being dispensed into the container at the initial flow rate.

4. A system according to any one of claims 1 to 3, the state detected by the flow- reduction control system is at least one of:

the velocity of liquid fuel level within the container approaching the outlet end of the spout,

the presence of liquid fuel level within the container at the outlet end of the spout, the volume of the headspace,

a change in gas pressure in the container,

the velocity of gas flow exiting the container through the opening, and

the dynamic density of gas in the headspace.

5. A system according to any one of claims 1 to 4, wherein the flow-reduction control system includes at least one sensor for detecting the state.

6. A system according to claim 5, wherein the at least one sensor includes one of: a capacitive-type level probe, a resistance-type level probe, radar, optical sensor, infrared sensor, vibration sensor, microphone, particle velocity probe, and pressure sensor.

7. A system according to any one of claims 1 to 6, wherein the system further comprises:

8. A system according to any one of claims 1 to 6, wherein the system further comprises:

a pump with a pump inlet that is in communication with a source of liquid fuel, and a pump outlet that is in communication with the nozzle inlet; and a controller for controlling operation of the pump, the controller being configured to operate the pump to dispense fuel from the nozzle at the initial flow rate,

and wherein the flow-reduction control system further includes a processor that is configured to analyse data received by the at least one sensor and identify data that indicates that the detected state satisfies the at least one pre-determined condition, and the controller is configured to receive a flow reduction signal from the flow-reduction control system,

wherein upon receipt of a flow reduction signal the controller automatically adjusts the pump operation so as to limit the rate at which liquid fuel can be dispensed from the nozzle to the lower flow rate.

9. A system according to any one of claims 1 to 6, wherein the system further comprises:

and wherein the flow-reduction control system further includes:

a processor that is configured to analyse data received by the at least one sensor and identify data that indicates that the detected state satisfies the at least one predetermined condition; and

10. A system according to any one of claims 1 to 9, wherein the detected state is container-generated sound from within the container while being filled, and the sensor is at least one microphone that is arranged to receive the container-generated sounds, and the flow-reduction control system includes a processor configured to analyse the container-generated sounds received by the microphone and identify container- generated sounds that satisfy the pre-determined condition.

1 1 . A system according to claim 10, wherein the container-generated sound is indicative of the presence of liquid fuel within a neck of the container.

12. A system according to either claim 10 or 1 1 , wherein the pre-determined condition includes a change in the amplitude of the container-generated sound received by the microphone.

13. A system according to any one of claims 10 to 12, wherein the pre-determined condition includes a change in the frequency spectrum of the container-generated sound received by the microphone.

14. A system according to any one of claims 10 to 13, wherein the pre-determined condition includes the container-generated sound matching a pre-determined pattern in amplitude and/or frequency variation over time.

15. A system according to any one of claims 10 to 14, wherein the flow-reduction control system is configured to suppress noise received by the microphone.

16. A system according to claim 15, wherein the processor is configured to filter sound received from the microphone to reduce sound that is extraneous to the container- generated sound.

17. A system according to either claim 15 or 16, wherein the processor includes a filter that filters any one of white noise, wind noise, frequencies outside a pre-determined range, and at least some sound associated with liquid fuel flowing through the fuel path at the initial flow rate.

18. A system according to any one of claims 1 to 9, wherein the shut-off system includes a first vapour tube that extends rearwardly along the nozzle with respect to the liquid fuel flow direction from a first vapour inlet at the outlet end of the spout, and a first venturi mechanism that is operably connected to the valve, whereby liquid fuel entering the first vapour tube causes the first venturi mechanism to release the valve from an open position; and

19. A system according to claim 18, wherein the flow-rate regulator includes a restrictor located within the fuel path of the nozzle, the restrictor having a first position in which liquid fuel is able to flow through the flow path at the initial flow rate, and a second position in which the restrictor limits the rate of liquid fuel flow through the flow path to the lower flow rate,

wherein the flow-rate regulator is configured to displace restrictor from the first position into the second position when liquid fuel enters the second vapour tube.

20. A system according to claim 19, wherein the restrictor is any one of a valve, a pinch valve, an orifice plate, or the like.

21 . A system according to any one of claims 1 to 20, wherein the flow-reduction control system is configured to vary the flow rate of liquid fuel after reducing the rate at which liquid fuel is being dispensed to the lower flow rate.

22. A method for dispensing liquid fuel into a container having an opening, the method involving: