The present invention relates to a FOB detection unit for a beverage dispensing system, a beverage dispensing system comprising a FOB detection unit and a method of dispensing beverage by providing a beverage dispensing system comprising a FOB detection unit.

Introduction The dispensing of draught beverages such as draught beer is typically achieved by providing the beverage in a pressurized beverage container referred to as a keg and allowing the beverage to flow via a beverage line to a beverage tap. Traditionally, steel containers connected to a carbon dioxide supply have been used, however, nowadays collapsible polymeric containers also exist, one example being disclosed in the applicant's own international application WO2009/024147.

Beverage containers for use with draught beverage dispensing systems comprise carbonated beverage and pressurized gas. When the beverage container is nearly empty, a significant amount of gas may enter the beverage line and mix with the remaining beverage in the beverage line and this may result in a large amount of foam escaping from the beverage tap during tapping. A beverage glass filled with an excessive amount of foam may be less appealing and must in many cases be discarded. Further, foam may remain in the beverage line so that the first beverage glass filled after installing a new and full beverage container will have an excessive amount of foam as well.

In order to stop the dispensing of the beverage before a significant amount of foam has entered the beverage line, a so-called FOB detection unit may be used. FOB stands for Foam On Beer and a FOB detection unit is thus a foam on beer detection unit. The purpose of the FOB detection unit is to detect the presence of foam in the beverage line and to stop the beverage dispensing before the foam reaches the beverage tap. The FOB detection unit comprises a chamber having a beverage container connector and a beverage tap connector. The chamber has a float body and when the chamber is filled with beverage, the float body will float on the beverage and there will be a free fluid passage between the beverage container connector and the beverage tap connector, whereas when gas enters the chamber, the float body will close off the passage between the beverage container connector and the beverage tap connector and thereby prevent foam from reaching the beverage tap. When a new full beverage container has been installed, the FOB detection unit is vented where after beverage dispensing may be resumed.

The prior art document GB 2 431 146 A describes an example of state of the art FOB detection unit having a vent valve and a float body.

The prior art document GB 2 236 180 A describes an example of state of the art FOB detection unit using a beam of light for detecting the presence of a bubble in a beverage duct.

The manual venting of the FOB detection unit is a time consuming task which also typically results in some spillage of beverage. There is also a risk that the beverage becomes contaminated. Yet further, there is a risk that the user forgets to perform this task which is necessary in order to be able to continue beverage dispensing.

Thus, the object according to the present invention is to provide technologies for the automatic venting of the FOB detection unit.

Summary of the invention

The above object together with numerous other objects which are evident from the detailed description will according to a first aspect of the present invention be achieved by a FOB detection unit for a beverage dispensing system, the FOB detection unit comprising:

a lower chamber having a beverage tap connector located at a bottom part of the lower chamber, a gas outlet located at a top part of the lower chamber opposite the beverage tap connector, and a beverage container connector located at a middle part of the lower chamber between the beverage tap connector and the gas outlet, the gas outlet comprises a membrane being non-permeable to liquids such as beverage and permeable to gases such as air and carbon dioxide, the lower chamber further comprising a float body, the float body being movable between a beverage dispensing position and a non-beverage dispensing position, the float body defining the beverage dispensing position when the lower chamber is filled with beverage, the float body defining the non-beverage dispensing position when the lower chamber is filled by gas, when the float body is in the beverage dispensing position, the float body is located spaced apart from the beverage tap connector allowing fluid communication between the beverage container connector and the beverage tap connector, and when the float body is in the non-beverage dispensing position, the float body is blocking the beverage tap connector preventing fluid communication between the beverage container connector and the beverage tap connector,

a venting chamber connected to the gas outlet of the lower chamber, the venting chamber being connected to the atmosphere surrounding the FOB detection unit via a venting opening and communicating with the lower chamber via the gas outlet, and

an upper chamber having a gas supply connector, the gas supply connector comprising a flow restrictor, the upper chamber being separated from the venting chamber via a pressure sensitive member, the pressure sensitive member being movable between a closed position and an open position, the pressure sensitive member defining the closed position when the resulting pressure force acting on the pressure sensitive member from the upper chamber exceeds the resulting pressure force acting on the pressure sensitive member from the venting chamber and the lower chamber, the pressure sensitive member defining the open position when the resulting pressure force acting on the pressure sensitive member from the venting chamber and the lower chamber exceeds the resulting pressure force acting on the pressure sensitive member from the upper chamber, when the pressure sensitive member is in the closed position, the pressure sensitive member blocks fluid communication between the lower chamber and the venting chamber via the gas outlet, and when the pressure sensitive member is in the open position, the pressure sensitive member allows fluid communication between the lower chamber and the venting chamber via the gas outlet.

The present FOB detection unit is preferably used in a draught beer system. The beverage tap connector is connected to the beverage tap via an optionally chilled beverage tube. The beverage tap which may be located e.g. on a bar counter typically comprises a beverage valve connected to the beverage tube and a handle for controlling the beverage valve and thereby controlling the dispensing of the beverage. The beverage container connector is likewise connected to the beverage container via another optionally chilled beverage tube. When the beverage dispensing system is in use, the lower chamber is filled with carbonated beverage and the float body having a specific density which is lower than the beverage is located spaced apart from the beverage tap connector located at the bottom part of the lower chamber. The beverage, which is under pressure, enters the lower chamber via the beverage container connector located at the middle part of the lower chamber and provided the beverage tap is open, the beverage flows out of the lower chamber via the beverage tap connector without being obstructed by the float body. The gas supply connector of the upper chamber is normally connected to the same gas supply as the beverage container of the beverage dispensing system and thus receives the same pressure as the beverage, albeit with a delay due to the flow restrictor. In case a conventional steel keg is used, the gas supply connector may preferably be connected to a carbon dioxide inlet of the keg connector which is connected to the beverage container and serves to introduce carbon dioxide gas from a gas bottle into the beverage container and extract beverage from the container. In case a collapsible container is used, the gas supply connector may preferably be connected to the pressure chamber. Alternatively, the gas supply connector is connected to a separate gas supply.

During use, when the lower chamber is filled with beverage, the gas outlet at the top part of the lower chamber is closed off by the pressure sensitive member since the upwardly oriented force from the beverage in the lower chamber is counteracted by the downwardly oriented force from the upper chamber having a pressure which is equal to the beverage pressure. As the area of the gas outlet is smaller than the area of the pressure sensitive member, the resulting force on the pressure sensitive member will be directed toward the lower chamber such that the pressure sensitive member closes off the gas outlet. Additionally, the pressure in the venting chamber is equal to the atmospheric pressure which additionally contributes to a resulting downwardly oriented pressure force acting on the pressure sensitive member and closing off the gas outlet and keeps the gas outlet closed off in case of minor pressure fluctuations in the beverage line caused e.g. by the opening and closing of the beverage tap. Thus, as long as the beverage dispensing system is pressurized, the gas opening remains closed thus preventing any loss of carbonation of the beverage and preventing any foreign particles from entering the lower chamber.

When the beverage container is nearly empty, gas bubbles and foam will enter the beverage line and consequently the lower chamber of the FOB detection unit via the beverage container connector. As the specific density of the float body is greater than the specific density of the foam, the float body will close off the beverage tap connector as soon as the foam is adjacent the beverage tap connector, preventing any foam from entering the beverage line leading to the beverage tap. Consequently, the beverage dispensing is interrupted even if the beverage tap is open.

The user, e.g. the bartender, thus understands that the beverage container is empty and proceeds with the exchange of the beverage container. The gas supply is interrupted and the old beverage container is removed. The lower, intermediate and upper chambers are thus depressurized. Thereafter a new full beverage container is connected via the beverage line to the beverage container connector of the lower chamber. Subsequently, the pressure supply is enabled for pressurizing the beverage container and the upper chamber. As the upper chamber is pressurized from the pressure supply via the gas supply connector and the flow restrictor, the pressure increase in the upper chamber will be much slower than the pressure increase in the lower chamber which is pressurized directly from the beverage container via the beverage line and the beverage container connector without any flow restrictor. Thus, the pressure force acting on the pressure sensitive member from the lower chamber will exceed the pressure force acting on the pressure sensitive member from the upper chamber even though the area of the gas outlet is smaller than the pressure sensitive member and thus the pressure sensitive member will move upwards and open the gas outlet so that gas from the lower chamber may flow into the venting chamber and proceed to the atmosphere via the venting opening. As the gas flows out of the gas outlet, the beverage flows into the lower chamber via the beverage container connector and thus replaces the gas in the lower chamber. At the same time, the float body will move upwards as the beverage flows into the lower chamber and thus allows beverage dispensing to be resumed. As the gas outlet is located at the top of the lower chamber, the beverage will not reach the gas outlet until all of the gas has flowed out of the lower chamber. The flow restrictor of the gas supply connector and the size of the upper chamber may advantageously be adapted such that as the beverage reaches the gas outlet, the pressure force acting on the pressure sensitive member from the gas pressure in the upper chamber is sufficiently high for closing the gas outlet of the lower chamber and thereby prevent any fluid from flowing from the lower chamber to the venting chamber.

By providing the gas outlet with a membrane which is non-permeable to liquids and permeable to gasses, i.e. a hydrophobic membrane, it may be ensured that no beverage at all enters the venting chamber. This keeps the venting chamber completely free from beverage and essentially eliminates the need for cleaning the venting chamber. The risk of microbiological buildup is thereby reduced. Waterproof and gas permeable membranes may for example be made using interwoven PTFE fibers (PTFE = polytetrafluorethylene). Other examples of waterproof and gas permeable membranes are found in EP271 1609. As the beverage reaches the waterproof and gas permeable membrane at the gas outlet, no more gas will flow through the gas outlet and thus the pressure automatically drops, causing the pressure sensitive member to close off the gas outlet as the pressure in the upper chamber will be greater than the pressure in the intermediate chamber.

The FOB detection unit has thereby returned to its steady state, in which the lower chamber is filled, the float body is located spaced apart from the beverage tap connector and, provided the beverage tap is opened, the beverage flows from the beverage container connector to the beverage tap connector. The gas outlet is sealed off by the pressure sensitive member and the pressure acting from the upper chamber. In this way, the venting of the lower chamber occurs automatically and the gas outlet is only open during the venting operation and thus the risk of foreign objects entering the beverage is essentially eliminated and the beverage within the lower chamber is prevented from degassing through the membrane which is non-permeable to liquids and permeable to gasses and thus will be kept fresh and carbonated within the lower chamber which is thus sealed off from the atmosphere.

According to a further embodiment of the first aspect, the gas outlet and/or the venting opening comprise a flow restrictor.

In the basic embodiment, the closing of the gas outlet by the pressure sensitive member may depend on various circumstances such as the pressure and the gas in the pressure supply, the beverage in the container, the temperature, the atmospheric pressure etc. In order to optimize the closing of the gas outlet by the pressure sensitive member, the gas outlet and/or the venting opening may comprise a flow restrictor.

The flow restrictor on the gas outlet may e.g. be small enough for restricting the flow of beverage through the beverage outlet and thereby limit the amount of beverage which may escape via the venting opening before the gas outlet is closed off by the pressure sensitive member. It may alternatively comprise a net or the like in order to allow gas flow but restrict the flow of liquids due to the surface tension. The venting opening may also include a flow restrictor in order to allow a pressure buildup in the venting chamber as long as gas flows out of the gas outlet. As soon as the beverage reaches the flow restrictor at the gas outlet, the pressure in the venting chamber will fall and provoke the closing of the gas outlet by the pressure sensitive member.

According to a further embodiment of the first aspect, the pressure sensitive member comprises a flexible member.

Preferably, the pressure sensitive member is made of a polymeric material such as rubber or the like. In this way, the sealing capability of the pressure sensitive member will be high.

According to a further embodiment of the first aspect, the flexible member comprises a first sealing flange extending into the venting chamber and the gas outlet comprises a second flange extending into the venting chamber, the first flange sealing against the second flange when in the closed position.

In order to achieve a larger contact area and thereby a better sealing quality between the gas outlet and the flexible member, they may include mutually contacting flanges.

According to a further embodiment of the first aspect, the gas outlet defines a larger flow area than the venting opening and the gas supply connector.

By allowing more gas to flow from the lower chamber to the venting chamber than from the gas supply to the upper chamber and from the venting chamber to the outside, the venting chamber will pressurize faster than the upper chamber when the beverage dispensing system is re-pressurized after a new beverage container has been installed. This ensures that the venting chamber has a higher pressure than the upper chamber which causes the pressure sensitive member to be open, i.e. allow fluid communication between the lower chamber and the venting chamber as long as gas remains in the lower chamber.

According to a further embodiment of the first aspect, the venting opening defines a larger flow area than the gas supply connector. By allowing more gas to flow from the lower chamber to the venting chamber than from the gas supply to the upper chamber and from the venting chamber to the outside, it may be ensured that the pressure in the venting chamber falls quickly to atmospheric pressure when all of the gas has been vented from the lower chamber. This in turn ensures that the pressure sensitive member is capable of closing the gas outlet as soon as all gas has been removed from the lower chamber.

According to a further embodiment of the first aspect, the lower chamber defines a larger internal volume than the venting chamber and the upper chamber. The lower chamber is typically larger than the venting chamber and the upper chamber in order to have sufficient space for accommodating the float body and ensure a proper operation of the float body. A larger lower chamber also ensures that all foam and gas will be accommodated therein and hindered to proceed to the tap. According to a further embodiment of the first aspect, the upper chamber defines a larger internal volume than the venting chamber.

The upper chamber is typically larger than the venting chamber so that the pressure build-up in the upper chamber is slower than the pressure build-up in the venting chamber, thereby preventing a premature closing of the pressure sensitive member.

According to a further embodiment of the first aspect, the FOB detector unit comprises an FOB signaling device, the FOB signaling device comprising a first detector part located at the float body and a second detector part located at the beverage tap connector, the FOB signaling device generating a signal indicating the non-beverage dispensing position when the first detector part is located adjacent the second detector part and indicating the beverage dispensing position when the first detector part is located spaced apart from the second detector part, the first detector part preferably constituting an RF transmitter and the second detector part preferably constituting an RF receiver.

The FOB detection unit may include electronics for determining and informing the user about the empty beverage container. The FOB signaling device described above uses electronics, e.g. an RF transmitter for determining the position of the float body, i.e. whether the float body is located in the closed position adjacent the beverage tap connector, or spaced apart from the beverage tap connector allowing fluid communication through the beverage tap connector. The electronic signal generated thereby may be used for informing the user so that the user may change the beverage container, however, it may also be used to control other automatic features. The above object together with numerous other objects, which are evident from the detailed description, will according to a second aspect of the present invention be achieved by a beverage dispensing system comprising a FOB detection unit according to the first aspect, the beverage dispensing system comprising a beverage tap, a gas supply and a beverage container, the gas supply, the gas supply connector and the beverage container connector being connected to the beverage container, the beverage tap being connected to the beverage tap connector of the FOB detection unit.

It is evident that the above mentioned FOB detection unit according to the first aspect may be used in conjunction with a beverage dispensing system including a beverage tap, a gas supply and a beverage container.

According to a further embodiment of the second aspect, the gas supply supplies gas having a pressure of between 1 and 5 bar above atmospheric pressure, preferably between 2 and 4 bar above atmospheric pressure, more preferably between 2.5 and 3 bar above atmospheric pressure

According to a further embodiment of the second aspect, the beverage container is collapsible and located within a pressure chamber, the gas supply supplies air to the pressure chamber. The beverage container may be of the collapsible type, such as a polymeric beverage container, and accommodated in a pressurized pressure chamber. The beverage container is connected to the beverage container connector of the FOB detection unit via a beverage line. The pressure chamber is pressurized via the pressure supply which thus supplies pressurized air to both the pressure chamber and the upper chamber of the FOB detection unit.

According to a further embodiment of the second aspect, the beverage container is non- collapsible and the gas supply supplies carbon dioxide to the beverage container.

Alternatively, the beverage container may be of the non-collapsible type, such as a steel beverage container. The beverage container is connected to the beverage container connector of the FOB detection unit via a beverage line and directly pressurized via the gas supply which thus supplies carbon dioxide directly into the head space of the beverage container. The gas supply also supplies pressurized carbon dioxide to the upper chamber of the FOB detection unit.

According to a further embodiment of the second aspect, the beverage dispensing system further comprising a cleaning device, the beverage container connector being connected to a valve which in turn being connected to the beverage container and the cleaning device, the valve being capable of defining a beverage position and a cleaning position; when in the beverage position, the beverage container connector being connected to the beverage container and closed off from the cleaning device; when in the cleaning position, the beverage container connector being connected to the cleaning device and closed off from the beverage container.

The FOB detector may be used together with a cleaning device in order to be able to clean the beverage line including the FOB detection unit. Any gas, such as carbon dioxide or air, which may enter the beverage line during cleaning, flushing or when changing between cleaning fluid, flushing fluid and beverage dispensing, will be automatically vented in the FOB detection unit.

The above object together with numerous other objects, which are evident from the detailed description, will according to a third aspect of the present invention be achieved by a method of dispensing beverage by providing a beverage dispensing system comprising a FOB detection unit, the FOB detection unit comprising: a lower chamber having a beverage tap connector located at a bottom part of the lower chamber, a gas outlet located at a top part of the lower chamber opposite the beverage tap connector, and a beverage container connector located at a middle part of the lower chamber between the beverage tap connector and the gas outlet, the gas outlet comprises a membrane being non-permeable to liquids such as beverage and permeable to gases such as air and carbon dioxide, the beverage container connector being connected to a pressurized beverage container, the beverage container including beverage and pressurized gas, the beverage tap connector being connected to a beverage tap of the beverage dispensing system, the lower chamber further comprising a float body,

a venting chamber connected to the gas outlet of the lower chamber, the venting chamber being connected to the atmosphere surrounding the FOB detection unit via a venting opening, and

an upper chamber having a gas supply connector, the gas supply connector being connected to a gas supply of the beverage dispensing system and comprising a flow restrictor, the upper chamber being separated from the venting chamber via a pressure sensitive member,

the method comprising the steps of:

operating the beverage tap for dispensing beverage from the beverage container and subsequently allowing pressurized gas from the beverage container via the beverage container connector into the lower chamber thereby causing the float body to block the beverage tap connector and prevent fluid communication between the beverage container connector and the beverage tap connector,

disconnecting the gas supply from the gas supply connector and the beverage container from the beverage container connector, thereby allowing the lower chamber, the venting chamber and the upper chamber to assume atmospheric pressure,

connecting a new beverage container to the beverage container connector,

connecting the gas supply to the gas supply connector and simultaneously pressurizing the beverage container by using the gas supply, thereby:

causing the resulting pressure force acting on the pressure sensitive member from the venting chamber and the lower chamber to exceed the resulting pressure force acting on the pressure sensitive member from the upper chamber thereby allowing pressurized gas to flow from the lower chamber to the outside of the FOB detection unit via the venting chamber and the venting opening, and allowing beverage from the new beverage container to enter the lower chamber via the beverage container connector,

subsequently causing the float body to be spaced apart from the beverage tap connector and allow fluid communication between the beverage container connector and the beverage tap connector, and

subsequently causing the resulting pressure force acting on the pressure sensitive member from the upper chamber to exceed the resulting pressure force acting on the pressure sensitive member from the venting chamber and the lower chamber, thereby preventing fluid communication between the lower chamber and the venting chamber.

It is evident that the method according to the third aspect may include any of the features mentioned above in relation to the first aspect and/or the second aspect.

Brief description of the drawings

FIG. 1A is a perspective view of a beverage dispensing system with a steel keg.

FIG. 1 B is a perspective view of a beverage dispensing system with a collapsible keg

FIG. 1 C is a perspective view of a beverage dispensing system with multiple kegs.

FIG. 2A is a side view of a FOB detection unit during beverage dispensing.

FIG. 2B is a side view of a FOB detection unit when the beverage container is empty.

FIG. 2C is a side view of a FOB detection unit when the container is disconnected.

FIG. 2D is a side view of a FOB detection unit when a new container is connected.

FIG. 2E is a side view of a FOB detection unit at the end of the venting.

FIG. 2F is a side view of a FOB detection unit during beverage dispensing.

FIG. 3A is a perspective view of an alternative FOB detection unit when open.

FIG. 3B is a side view of an alternative FOB detection unit when open.

FIG. 4A is a perspective view of an alternative FOB detection unit when closed.

FIG. 4B is a side view of an alternative FOB detection unit when closed.

Detailed description of the drawings FIG. 1A shows a perspective view of a beverage dispensing system 10. The beverage dispensing system 10 includes a beverage container 12. The beverage container 12 is in the present case of the conventional non-collapsible steel type. The beverage container 12 is connected via a beverage line 14 to a FOB detection unit 16. The FOB detection unit 16 is in turn connected via another beverage line 14' to a beverage tap 18. The beverage tap 18 includes a beverage valve (not shown) and a handle 18' for controlling the beverage valve. The handle 18' is normally in a vertical position in which the beverage valve is closed, however, when the handle 18' is swung into a horizontal position opening the valve, the beverage will flow from the beverage container 12 through the beverage tap 18.

The beverage container 12, which is stored in a chilled location, is connected to a gas supply 20 via a gas line 22. The gas supply supplies carbon dioxide and in the present case constitutes a carbon dioxide bottle and a pressure regulator. The pressure is typically about 3 bar above atmospheric pressure.

The beverage container 12 is also connected to the FOB detection unit 16 via another gas line 22' and a flow restrictor 24. The flow restrictor 24 restricts the flow of gas into the FOB detection unit 16. The gas and the pressure is otherwise the same which pressurizes the beverage container 12.

The connection between the beverage container 12 and the beverage line 14 and also the separate connection between the beverage container 12, the gas line 22 and the other gas line 22' is made via a keg connector 23. When the keg connector 23 is removed from the beverage container 12 for exchanging the beverage container 12, the beverage container 12 and the other gas line 22' are depressurized, while the gas line 22 is interrupted. Thereby, also the FOB detection unit 16 is depressurized. FIG. 1 B is a perspective view of a beverage dispensing system 10' with a collapsible keg, also known as a collapsible container. The collapsible keg is stored within a pressure chamber 12' and is thus not visible in the present view. The functional principle is, however, similar to the previous embodiment, i.e. the present technology is equally applicable in relation to collapsible containers, i.e. polymeric containers accommodated within a pressure chamber 12' using air as pressure medium. The pressure chamber 12' is pressurized via an air compressor 20'. As the beverage is forced out of the beverage container by the gas pressure, the beverage containers will collapse or compress. When opening the beverage tap 18, the beverage is forced from the beverage container via the beverage line 14, the FOB detection unit 16 and the beverage line 14' to the beverage tap 18. The beverage line 14, the FOB detection unit 16 and the beverage line 14' are in the present embodiment enclosed within an insulating cover 27, however, this may be considered optional. The other pressure line 22' is connected from the pressure chamber 12' to the FOB detection unit 16 via a flow restrictor, similar to the previous embodiment. When the pressure chamber 12' is depressurized and opened for exchanging the beverage container, the other pressure line 22' will be depressurized as well.

A cleaning device 29 supplying a cleaning fluid and subsequently a flushing fluid under pressure may be connected to the beverage line 14. A valve 31 is provided which is selectable between at least a beverage mode and a cleaning mode. In the beverage mode, the beverage line 14 is connected to the beverage container whereas in the cleaning mode, the beverage line 14 is connected to the cleaning device 29. By opening the beverage tap 18 in the cleaning mode, cleaning fluid will flow through the beverage line 14, the FOB detection unit 16, the beverage line 14 and the beverage tap 18 which thus will be cleaned. Afterwards, flushing fluid, such as water, is caused to flow through the beverage Iine14, the FOB detection unit 16, the beverage line 14 and the beverage tap 18 in order to remove any residual cleaning fluid.

FIG. 1 C is a perspective view of a beverage dispensing system 10" with multiple kegs. In this embodiment, a plurality of pressure chambers 12'a/b/c are connected via a respective FOB detection unit 16a/b/c to a single common beverage tap 18. The beverage containers will normally not be drained exactly simultaneously in identical setups due to small variations in pressure and flow resistance. Thus, one beverage container will always empty first. When one beverage container is empty, the beverage dispensing from said container will be stopped by the associated FOB detection unit whereas the remaining containers may continue to dispense beverage as the empty beverage container is replaced. In this way, the beverage dispensing may continue without interruption and as the FOB detection unit is automatic as will be explained in more detail below, the only manual labor required is the exchange of the container. FIG. 2A shows a side view of a FOB detection unit 16 during beverage dispensing. The FOB detection unit comprises a lower chamber 26, a venting chamber 28 and an upper chamber 30. The beverage enters at the middle part of the lower chamber 26 via a beverage container connector 32 which is connected to the beverage line (not shown) from the beverage container (not shown). In the current state, the lower chamber 26 is completely filled with beverage. The beverage flows as indicated by the arrows through the lower chamber 26 and out via a beverage tap connector 34 located at the bottom of the lower chamber 26 to the beverage line (not shown) leading to the beverage tap (not shown).

The lower chamber 26 is connected to the venting chamber 28 located above the lower chamber 26 via a gas outlet 36. The gas outlet 36 comprises a waterproof gas permeable membrane allowing gasses and preventing liquids passing through between the lower chamber 26 and the venting chamber 28. The venting chamber comprises a venting opening 38 to the atmosphere outside the FOB detection unit 16.

The lower chamber 26 further comprises a spherical float body 40. As the lower chamber is completely filled with beverage, the float body 40 is located adjacent the gas outlet 36 and spaced apart from the beverage tap connector 34. The lower chamber 26 comprises a seat 42 for accommodating the float body 40 in the present state while allowing beverage to flow unhindered between the beverage container connector 32 and the beverage tap connector 34 and allowing access to the gas outlet 36.

The venting chamber 28 is separated from the upper chamber 30 by a flexible pressure sensitive member 44. The pressure sensitive member 44 as well as the upper part of the gas outlet 36 are preferably made of rubber. The area of the pressure sensitive member 44 is larger than the flow area of the gas outlet 36. The upper chamber 30 is connected to the gas supply (not shown) of the beverage dispensing system via a gas supply connector 46 and a flow restrictor 24 for receiving pressurizing gas as shown by the arrow. Thus, under steady state conditions, the upper chamber 30 and the lower chamber 26 have the same pressure being equal to the beverage container pressure, whereas the venting chamber has atmospheric pressure.

The resulting pressure force on the pressure sensitive member 44 will thus be directed towards the gas outlet 36 as the area of the gas outlet 36 is smaller than the area of the pressure sensitive member 44, thereby causing the pressure sensitive member to close off the gas outlet 36 preventing any fluid from passing between the lower chamber 26 and the venting chamber 28. The pressure sensitive member 44 further comprises a flange 48 cooperating with a corresponding flange 50 of the gas outlet 36 for sealing off the gas outlet 36.

FIG. 2B shows a side view of a FOB detection unit 16 when the beverage container (not shown) is empty. In this situation, gas and foam will enter the beverage line and flow into the lower chamber 26 via the beverage container connector 32. The float body 40, being lighter than the beverage but heavier than the gas, will move downwards to the beverage tap connector 34 and seal off the beverage tap connector 34 at a sealing ring 52. The beverage dispensing will thus be interrupted before the gas and foam enters the tap (not shown).

FIG. 2C shows a side view of a FOB detection unit 16 when the beverage container (not shown) is disconnected. Consequently, also the gas supply (not shows) is disconnected. The result is that the complete FOB detection unit 16 is de-pressurized, i.e. the lower chamber 26, the venting chamber 28 and the upper chamber 30 all assume atmospheric pressure. FIG. 2D is a side view of a FOB detection unit when a new beverage container (not shown) has been connected. After the new beverage container (not shown) has been connected, the gas supply (not shown) is re-connected to the beverage container (not shown) and to the upper chamber 30 of the FOB detection unit 16 at the same time. The pressure increases immediately in the lower chamber 26 to the pressure of the beverage container (not shown); however, the pressure in the upper chamber 30 increases much slower due to the flow restrictor 24.

The resulting pressure force from the lower chamber 26 onto the pressure sensitive member 44 will thus exceed the counterforce resulting from the pressure within the upper chamber 30 and thus the pressure sensitive member 44 will move upwards in the direction of the upper chamber 30 as shown by the arrow and gaseous communication is established between the lower chamber 26 and the venting opening 38 via the venting chamber 28. The gas and foam present in the lower chamber 26 will thus automatically escape without any interaction by the user through the gas outlet 36 into the venting chamber 28 and thru the venting opening 38 to the atmosphere as shown by the arrow. At the same time, the beverage will enter the lower chamber 26 via the beverage container connector 32 and the float body 36 will rise towards the seat 42 enabling fluid communication through the beverage tap connector 34.

FIG. 2E is a side view of a FOB detection unit 16 at the end of the venting. As the beverage again fills the complete lower chamber 26, the beverage is hindered by the waterproof gas permeable membrane at the gas outlet 36. Consequently, the pressure in the venting chamber 28 sinks towards atmospheric pressure while the pressure in the upper chamber 30 continues to rise towards the beverage container pressure. This generates a resulting pressure force on the pressure sensitive member 44 in the direction towards the lower chamber 26 as shown by the arrow and consequently the gas outlet 36 will be sealed off. FIG. 2F shows a side view of a FOB detection unit 16 during beverage dispensing. The steady state is resumed and the situation is identical to FIG. 2A

FIG. 3A shows a perspective view of an alternative FOB detection unit 1 16 when open. The working principle of the present embodiment is identical to the previous embodiment, except that the present float body 140 has a non-spherical shape, i.e. a cross shape. This shape allows the float body 140 to move in the vertical direction only, and thus prevents any rotational movement of the float body 140. The reference numeral in the present embodiment referring to parts which are identical to or serve the same purpose as the corresponding part of the previous embodiment has been given the same reference numeral with the addition of 100.

FIG. 3B shows a side view of an alternative FOB detection unit 1 16 when open. The float body 140 comprises an RF transmitter 154 and the beverage tap connector comprises an RF receiver. When the float body 140 defines the present open position, the RF receiver 156 will not detect the RF transmitter and will send a corresponding signal to the user indicating that the beverage dispensing system is ready for use.

FIG. 4A shows a perspective view of an alternative FOB detection unit 1 16 when closed. FIG. 4B shows a side view of an alternative FOB detection unit 1 16 when closed. When the float body 140 defines the present closed position, the RF receiver 156 will detect the RF transmitter and will send a corresponding signal to the user indicating that the beverage container is empty and needs to be exchanged before the beverage dispensing system is ready for use. It is evident that other electronic means may be used for detecting the position of the float body 140, such as magnets, proximity detectors, optical detectors or just a simple permanent magnet and reed-relay. Further, the sender may be located on the top of the float body and the receiver may be located at the gas outlet, or a combination of the above.

It is apparent to the skillful individual that the FOB detector according to the present invention may be modified in numerous ways. For instance, features from the different disclosed embodiments may be combined to form modified embodiments which should be considered to be encompassed within the present specification.

Reference numerals with reference to the drawings

10. Beverage dispensing system

12. Beverage container

14. Beverage line

16/1 16. FOB detection unit

18. Beverage tap

20. Gas supply

22. Beverage line

23. Keg connector

24. Flow restrictor

25. Cooling device

26/126. Lower chamber

27. Insulation

28/128. Venting chamber

29. Cleaning device

30/130. Upper chamber

31 . Valve

32/132. Beverage container connector 34/134. Beverage tap connector

36/136. Gas outlet

38/138. Vent

40/140. Float body

42. Seat

44/144. Pressure sensitive member

46/146. Gas supply connector

48/148. Flange

50/150. Flange

52/152. Sealing ring

154. RF transmitter

156. RF receiver