Patent Grant
9266708
This application is a national phase filing, under 35 U.S.C. §371(c), of International Application No. PCT/EP2013/051576, filed on Jan. 28, 2013, the disclosure of which is hereby incorporated by reference in its entirety.
Not Applicable
The present invention relates to a method of dispensing carbonated beverage, a collapsible beverage container and a beverage dispensing system.
Beverage dispensing systems are typically used in beverage dispensing establishments for efficiently dispensing large quantities of beverage. Typically, beverage dispensing systems are used to dispense carbonated alcoholic beverages such as draught beer and cider. However, also non-alcoholic carbonated beverages such as soft drinks may be dispensed using a beverage dispensing system. Beverage dispensing systems are mostly for professional users such as in establishments like bars, restaurants and hotels, however, increasingly also for private users such as in private homes.
Professional beverage dispensing systems typically dispense beverage provided in large beverage containers. Such beverage containers may hold 20-50 liters of beverage for a professional beverage dispensing system for allowing typically 50-100 beverage dispensing operations before needing to exchange the beverage container. Conventional beverage containers are made of solid materials such as steel and re-filled a number of times. Recently, beverage containers have been made collapsible and for single use only due to hygiene concerns when refilling solid beverage containers. An example of a beverage dispensing system using collapsible beverage containers is the DraughtMaster™ system provided by the applicant company. Such beverage dispensing systems using collapsible beverage containers typically have the beverage container installed in a pressure chamber. Some examples of prior art beverage dispensing systems follow below:
In WO 2007/019848, a beverage dispensing system is described. The beverage dispensing system comprises a pressure chamber, which is adapted to accommodate a beverage container of collapsible material.
In WO 2009/024147, a module for a modular beverage distribution system is disclosed. Each system comprises a frame, a pressure chamber and connectors for receiving pressure fluid and for supplying the pressure fluid to the pressure chamber and to the neighbouring module. The system has a separate rinsing line. By using a specially designed discharge valve, alternatively rinsing fluid or beverage may enter the tapping line. Rinsing fluid is provided from a separate pressurized reservoir. The discharge valve includes safety features for avoiding mixing rinsing fluid and beverage.
In WO 2010/029122, a method of cleaning the tapping line of a beverage dispensing system is disclosed in which a cleaning and flushing cartridge for internal use is described. The cleaning and flushing cartridge is installed in the pressure chamber similar to a beverage container and dispensed similar to a beverage.
WO 2010/060946 and WO 2011/117192 both relate to a method of cleaning the tapping line of a beverage dispensing system in which a cleaning and flushing cartridge for external use is described. The cleaning and flushing cartridge is installed outside the pressure chamber and has a pressure fluid source connected. The rinsing and flushing fluid is dispensed similar to a beverage.
WO 2010/060949 relates to a beverage dispensing system having a first and a second detector for generating a control pressure. The method comprises evaluating the control pressures from the control pressure outputs of detectors for determining the operational mode of the beverage dispensing system.
In WO 2010/020644, a method of installing a collapsible beverage container in a beverage distribution unit is disclosed. The method comprises the steps of positioning the collapsible beverage container in a sloped position, pivoting the collapsible beverage container in a rotational motion around a support surface and sliding the collapsible beverage container on the support surface.
When using long dispensing lines, a significant amount of beverage will remain in the tapping line when the beverage container is empty. In order to avoid that this beverage flows backwards through the tapping line, it is contemplated that a non-return valve may be used in the tapping line. Further, in order to prevent dripping, a spring loaded valve may be used. An example of a beverage dispenser including a plurality of valves is DE 296 04 703 U1, in which an electrical liquor dispensing system is disclosed. The tapping line has a non-return valve and a spring loaded lid. The liquor is propelled from a container through the tapping line by an electrical pump and explicitly not by pressurized gas.
When dispensing beverage from the beverage dispensing system using a collapsible beverage container, a pressure fluid, typically a gas, is allowed to enter the pressure chamber. During the dispensing of beverage from the pressure chamber, the pressure fluid acts on the collapsible beverage container and forces the beverage out of the pressure chamber while simultaneously crumpling the collapsible beverage container. The volume of the crumpled collapsible beverage container is thereby reduced corresponding to the amount of the dispensed beverage. The collapsible beverage container is made of flexible and preferably disposable materials such as thermoplastic materials.
The interior of the collapsible beverage container is divided into a beverage space constituting carbonated beverage and initially occupying the majority of the interior of the beverage container and a head space filled with gas, primarily constituting CO2 gas.
While performing a dispensing operation, the force applied to the beverage container by the pressure in the pressure chamber causes the beverage to flow out of the beverage container and into a tapping line. The tapping line leads to a dispensing device which may be located at a distant location such as one floor above the pressure chamber. The dispensing device typically has a tapping valve and a tapping handle for allowing an operator to control the tapping valve and thereby the beverage dispensing operation. The operator, such as a bartender or barmaid, uses the tapping device to control the rate of beverage dispensing.
A problem often observed when the beverage space of the beverage container is empty or almost empty is that the gas of the head space starts entering the tapping line. Such gas will result in gas bubble formation in the tapping line. The presence of gas bubbles in the tapping line will cause excessive frothing and aeration of the carbonated beverage at the tapping valve of the dispensing device. The carbonated beverage dispensed will thus be very foamy and will have a less than optimal taste and appearance. Typically, this beverage therefore has to be disposed of. This is also an indication for the bar employee to exchange the empty and crumpled collapsible beverage container with a new collapsible beverage container filled with beverage.
However, gas will still remain in the tapping line even after the beverage container has been exchanged. This will result in excessive foaming also for the first one or two servings of carbonated beverage. This beverage must be disposed of as well. Thus, the total loss of beverage may amount to 2-4 servings for each beverage container, i.e 1-2 at the beginning of each container and 1-2 at the end of each container, resulting in a loss of about 10% of the beverage included in a typical 20 liter collapsible beverage container.
In case a modular beverage dispensing system is used, i.e. a system wherein a single tapping line is fed from a multitude of collapsible beverage containers, the problem is even larger since the beverage spaces of the different collapsible beverage containers may be empty at different times, resulting in even more beverage lost.
The object of the present invention is thus to dispense beverage while preventing that any gas from the head space is entering the tapping line.
The above object together with numerous other objects, which will be evident from the below detailed description, are according to a first aspect of the present invention obtained by a method of dispensing carbonated beverage, the method comprising the steps of:
The beverage dispensing system may be a non-modular system in which one pressure chamber is connected to one dispensing device via a single tapping line, or a modular system in which a plurality of pressure chambers are selectively connected to one or more dispensing devices via one or more tapping lines. The pressure chamber is typically a pressure proof container connected to a fluid pressure source, typically a high pressure air source. The pressure chamber typically has a pressure lid in order to be able to insert and remove the collapsible beverage container. The collapsible beverage container is typically made of a semi rigid metallic or polymeric material having a thickness such that it is capable of retaining its shape during transport and handling but which may collapse and crumple when subjected to an outer pressure. In most cases a blow molded plastic container will be used. The beverage container may be initially sealed during transport and handling. In a new collapsible beverage container, i.e. a non crumpled container, the beverage space typically occupies about 90% to 95% of the total volume of the beverage container and the head space is occupying the remaining 5%-10%.
The tapping line leads from the collapsible beverage container within the pressure chamber to the dispensing device outside the pressure chamber. The dispensing device typically comprise a tapping valve and an tapping handle for the user to be able to selectively dispense or not dispense beverage by switching between the beverage dispensing position in which the tapping valve is open and the non-beverage dispensing position in which the tapping valve is closed.
The first elevated pressure to be maintained in the pressure chamber is established after the collapsible beverage container has been installed in the pressure chamber. The first elevated pressure is typically held substantially constant until the collapsible beverage container is to be exchanged at which time the pressure is let out. The first elevated pressure acts uniformly on the wall of the collapsible beverage container in order to establish the second elevated pressure inside the collapsible beverage container. The second elevated pressure is thus the pressure within the beverage. The first elevated pressure is thus transmitted via the wall of the collapsible beverage container to establish the second elevated pressure. In the present context the applicant has surprisingly found out that the second elevated pressure will be smaller than the first elevated pressure and that the difference between the first elevated pressure and the second elevated pressure is constituted by the pressure required to crumple the collapsible beverage container, i.e. the crumpling pressure, for overcoming the internal resistance against a change of the shape of the wall. Further, it has surprisingly found out that the crumpling pressure is dependent on the level of crumpling of the collapsible beverage container, i.e. a new (full) non-crumpled collapsible beverage container will have a much lower resistance against crumpling than an already crumpled beverage container. Thus, the crumpling pressure increases during beverage dispensing as the volume of the beverage space and thereby the total volume of the collapsible beverage container is reduced. The increase in crumpling pressure is non-linear for most materials and most collapsible beverage containers will exhibit an exponential increase in the required crumpling pressure when the beverage space of the beverage container is almost empty. This effect may be explained by the fact that the first few beverage dispensing operations of a new collapsible beverage container will result in an elastic deformation of the wall of the collapsible beverage container. Such elastic deformation is linear in nature. When the beverage space of the collapsible beverage container is almost empty and the collapsible beverage container is significantly crumpled, the deformation of the wall of the collapsible beverage container will exhibit a plastic deformation, which is non-linear and requires a significantly higher crumpling pressure. Thus, the second elevated pressure will be reduced. In the present context it is understood that the crumpling characteristic of a typical collapsible beverage container will be at least somewhat stochastic, i.e. two seemingly identical collapsible beverage containers may crumple slightly differently depending on the internal wall structure of each collapsible beverage container.
The above fact may be utilized by employing an interruption valve. The interruption valve is preferably situated in the tapping line adjacent the beverage container. As long as the second elevated pressure is higher than the specific non-zero pressure reference, the interruption valve will be open and allow beverage to pass when the dispensing device assumes the beverage dispensing position. Later, when the collapsible beverage container is almost empty and thus seriously crumpled, the crumpling pressure will have increased, and, provided that the first elevated pressure is held substantially constant, the second elevated pressure will be much smaller. When the second elevated pressure falls below the specific non-zero pressure reference, the interruption valve will be closed and beverage will not be allowed to pass even when the dispensing device assumes the beverage dispensing position. This will allow a very well defined end of the beverage dispensing operations when the collapsible beverage container is empty or nearly empty.
The non-zero pressure reference is chosen such that the beverage dispensing is interrupted well before the beverage space is empty such that there is no risk that gas from the head space will enter the tapping line. The specific non-zero pressure reference may thus not be zero, since this would mean that the container crumpling pressure is equal to the first pressure, which first pressure is typically sufficient to completely flatten the collapsible beverage container. In case the first elevated pressure is not significantly higher than the crumpling pressure such that the second elevated pressure is allowed to approach zero, the beverage dispensing will be very slow due to the lack of driving pressure and such situations should also be avoided. Yet further, in case the specific non-zero pressure reference is higher than the first pressure, the interruption valve will always be closed and beverage dispensing never allowed.
By choosing a suitable specific non-zero pressure reference, the interruption valve may be closed when the second elevated pressure is still high enough for dispensing and the beverage space still includes a small amount of beverage. In this way, no gas will be introduced into the tapping line. When a new collapsible beverage container is installed, the tapping line will be free from gas and the first servings of carbonated beverage will not suffer from any excessive foaming. The only lost beverage will be the small amount remaining in the crumpled beverage container, however, this amount will be much smaller than the amount of carbonated beverage lost due to excessive foaming. Calculations made by the applicant using a typical 20 liter beverage container have shown that the average loss amounts to a few per mille only, compared to several percent using the prior art beverage dispensing systems. Taking into account the total amount of carbonated beverage dispensed worldwide, a vast amount of carbonated beverage can be saved.
According to a further embodiment of the first aspect, the interruption valve is located in the collapsible beverage container, the tapping line or the dispensing device. In one preferred embodiment, the interruption valve is located in the collapsible beverage container. In this way there is no need for any modifications of the permanent parts of the beverage dispensing system. In the case that the interruption valve is located in the beverage container, it is contemplated that it may be used for sealing the beverage container during transport and handling, thereby omitting the need for a separate seal. It is further contemplated that the interruption valve may be provided as a re-usable accessory which is mounted on the collapsible beverage container. In another preferred embodiment, the interruption valve is preferably fixedly mounted in the tapping line adjacent the collapsible beverage container. In this way, ordinary collapsible beverage containers may be used. The pressure in the tapping line may be considered to be equal to the pressure within the collapsible beverage container, at least at a location adjacent the collapsible beverage container. However, in case the tapping line leads to another floor of a building, it is contemplated that the pressure will fall. In yet another preferred embodiment, the interruption valve is located in the dispensing device. In this way, a visual indication may be given that the beverage container is empty. In this embodiment, a non-return valve may be used adjacent the beverage container to avoid a return flow of beverage. Further, the pressure may be slightly lower at the interruption valve than inside the collapsible beverage container depending on the height difference between the collapsible beverage container and the dispensing device.
According to a further embodiment of the first aspect, the interruption valve employs a loaded spring or a sealed pressurized gas volume in order to establish the specific non-zero pressure reference. When the second elevated pressure falls below the specific non-zero pressure reference, the interruption valve changes from the open position to the closed position. The specific non-zero pressure reference may be established by a loaded spring having a suitable spring constant and pre-load such that the valve remains open when the second elevated pressure is higher than the specific non-zero pressure reference but closes rapidly when the second elevated pressure falls below the specific non-zero pressure reference. Alternatively, a sealed pressurized gas volume may substitute the spring.
According to a further embodiment of the first aspect, the interruption valve is fluidly connected to the first elevated pressure of the pressure chamber via a pressure regulator for establishing the specific non-zero pressure reference. A particular beneficial solution is to make the specific non-zero pressure reference dependent on the first elevated pressure via a pressure regulator acting as a pressure reduction valve. In this way, the non-zero pressure reference may be made dependent on the first elevated pressure, i.e. the pressure in the pressure chamber. In this way, the first elevated pressure may be increased while still allowing the interruption valve to be closed when the collapsible beverage container has been crumpled to such extent that only a very small amount of beverage remains.
According to a further embodiment of the first aspect, the interruption valve includes a pressure probe for determining the second elevated pressure and an electromagnetic valve for assuming the open and closed positions, respectively, dependent on the second elevated pressure. The pressure probe may be mounted in the tapping line in order to constantly monitor the second elevated pressure. As soon as the second elevated pressure falls below the specific non-zero pressure reference, an electrical signal may be sent to the electromagnetic valve in order for the interruption valve to close. It is contemplated that a control unit may be used to compensate the specific non-zero pressure reference in order to take account of any changes in the first elevated pressure.
According to a further embodiment of the first aspect, the first elevated pressure is in the range of 2-5 bar above atmospheric pressure, preferably 3-4 bar above atmospheric pressure. Such pressures are suitable for achieving a good driving pressure for the beverage which will overcome the crumpling pressure of the collapsible beverage and still allow beverage to be dispensed at a reasonable velocity at a higher location than the location of the beverage container.
According to a further embodiment of the first aspect, the second elevated pressure is in the range of 1-4 bar above atmospheric pressure, preferably 2-3 bar above atmospheric pressure. By considering the crumpling pressure, the second elevated pressure must still allow beverage to be dispensed at a reasonable velocity at a higher location than the location of the beverage container.
According to a further embodiment of the first aspect, the beverage container is positioned in an upside down orientation within the pressure space such that the beverage space is located adjacent the tapping line and the head space is located spaced apart from the tapping line. With upside down position is meant a position in which the outlet of the beverage container is directed downwardly. In this way, the beverage space will be located adjacent the outlet and the head space will be located as far as possible from the outlet and consequently the head space will not reach the outlet until the beverage space is depleted. This will also completely avoid the use of a ascension pipe.
According to a further embodiment of the first aspect, specific non-zero pressure reference is in the range of 0.1-3 bar, preferably 0.5-1 bar, absolute pressure. For most cases such pressure values will be suitable in order to achieve a well defined end of beverage dispensing when the collapsible beverage container is empty or almost empty.
According to a further embodiment of the first aspect, the crumpling pressure being dependent on the level of crumpling of the collapsible beverage container, the crumpling pressure being in the range of 0-1 bar absolute pressure when the beverage container is in an initial non-crumpled state whereas the crumpling pressure is in the range of 2-5 bar when the beverage container is in a crumpled state in which the volume of the beverage container is reduced to 5% of the volume of the beverage container in the initial non-crumpled state. As already stated above, the crumpling pressure is dependent on the level of crumpling, i.e. the more crumpled the beverage container is, the higher pressure is required in order to further crumple the beverage container. Initially, the crumple pressure will be very low, or even zero, since the deformation will be elastic and thereby have a linear relationship with the applied force. However, when only 5% of the original volume remains, the applied force is very high and additional deformation will require even higher force since the deformation may be permanent, i.e. a plastic deformation. The crumpling pressure thus typically is exponentially dependent on the dispensed volume of beverage. Thus, the collapsible beverage container is typically made using such material, volume and wall thickness such that when only 5% of the volume remains, i.e. the crumpling pressure is in the range of 2-5 bar.
According to a further embodiment of the first aspect, when the interruption valve assumes the closed position, the beverage space has a volume of between 1 and 100 ml, preferably between 10 and 50 ml, such as 40 ml. In order to avoid gas entering the tapping line, at least a tiny amount of beverage should remain in the beverage container when the interruption valve assumes the closed position. However, too much beverage remaining in the beverage container would constitute a waste since such beverage will not be dispensed. Thus, in order to have a safety margin in order to take into account the stochastic differences in the crumpling behavior of different collapsible beverage containers, it is preferred to allow about 40 ml of beverage to remain in the beverage container when the interruption valve assumes the closed position
According to a further embodiment of the first aspect, the collapsible beverage container is made of the flexible material constituting a thermoplastic material such as PET. PET is a suitable material since it is sufficiently flexible to be crumpled, it is suitable for food and beverage and it may be disposed of in an environmentally friendly way, e.g. by combustion or recycling.
The above object together with numerous other objects, which will be evident from the below detailed description, are according to a second aspect of the present invention obtained by a collapsible beverage container for use together with a beverage dispensing system, the beverage dispensing system comprising a pressure chamber for accommodating the collapsible beverage container, the pressure chamber being capable of maintaining a first elevated pressure within the pressure chamber, the collapsible beverage container being made of a flexible material and including a beverage space consisting of carbonated beverage and a head space consisting of gas, the first elevated pressure acting on the collapsible beverage container for crumpling the collapsible beverage container at a container crumpling pressure and establishing a second elevated pressure within the collapsible beverage container, the first elevated pressure being equal to the sum of the second elevated pressure and the container crumpling pressure, the collapsible beverage container including an interruption valve defining an open position and a closed position, the open position allowing carbonated beverage to flow out from beverage space when the pressure chamber is pressurized, the closed position preventing carbonated beverage to flow out from the beverage space, the interruption valve assuming the open position when the second elevated pressure exceeds a specific non-zero pressure reference, the interruption valve assuming the closed position when the second elevated pressure falls below the specific non-zero pressure reference.
The collapsible beverage container according to the second aspect includes the interruption valve. It is contemplated that the collapsible beverage container according to the second aspect, which includes the interruption valve, may be used together with any of the methods described above in connection with the first aspect.
The above object together with numerous other objects, which will be evident from the below detailed description, are according to a third aspect of the present invention obtained by a beverage dispensing system comprising:
The beverage dispensing system according to the third aspect includes the interruption valve in the tapping line. It is contemplated that the beverage dispensing system according to the third aspect may be used together with any of the methods described above in connection with the first aspect. The beverage dispensing system according to the third aspect constitutes an alternative solution to the collapsible beverage container according to the second aspect.
The above object together with numerous other objects, which will be evident from the below detailed description, are according to a fourth aspect of the present invention obtained by a beverage dispensing system comprising:
The beverage dispensing system according to the fourth aspect includes the interruption valve in the dispensing device. It is contemplated that the beverage dispensing system according to the fourth aspect may be used together with any of the methods described above in connection with the first aspect. The beverage dispensing system according to the fourth aspect constitutes an alternative solution to the collapsible beverage container according to the second aspect and to the beverage dispensing system according to the third aspect.
Each of the modules 12a, 12b, 12c, is connected to a tapping line 18 and a gas supply line 20. An optional rinsing line may be available as described in more detail in the above mentioned WO 2009/024147. The tapping line 18 and the gas supply line 20 are mounted near the bottom wall 61″ of each module. Each module 12a, 12b, 12c comprises for each of the above mentioned lines 1820 an inlet constituting a first type connector, an outlet constituting a second type connector and a branch pipe constituting a third type connector. The branch pipe leads to the discharge valve of each module. The outlets of the first module 12a are directly connected to the inlets of the second module 12h and the outlets of the second module 12b are directly connected to the inlets of the third module 12c.
The gas supply line 20 is connected directly to a pressure generator 22. The gas supply line 20 is further connected to a pressure chamber 24 of the beverage dispensing module 12a via a security valve (not shown). The gas supply line 20 is connected to a pressure inlet 26 of the beverage dispensing module 12b via a pressure outlet 28. The fluid path 4T may also provide driving pressure to the discharge valve which is shown in
The tapping line inlet 30 of the beverage dispensing module 12a is left without connection, however a check valve is provided to prevent beverage from flowing out. The tapping line inlet 30 of the first module 12a is connected to the tapping line 18, which is connected to a tapping line inlet 30′ of the beverage dispensing module 12b via the tapping line outlet 32 of the beverage dispensing module 12a. The tapping line outlet 32′ of the beverage dispensing module 12b is similarly connected to a tapping line inlet 30″ of the beverage dispensing module 12c. The tapping line outlet 32′ of the tapping line 18 of the beverage dispensing module 12c is connected via a cooling system 34 to a dispensing device (not shown). The tapping line 18 is connected to a discharge valve of each beverage dispensing module 12a, 12b, 12c, as shown in
The closure element 46 is located in a specific space in the collapsible beverage container 48 between an inlet constriction and an outlet constriction. The inlet constriction and the outlet constriction both provide openings or apertures for allowing beverage to flow from the collapsible beverage container 48. Both the inlet constriction and the outlet constriction constitute valve seats, which the closure element 46 may seal against. The closure element 46 will either establish a seal against the inlet constriction or the outlet constriction, or remain in the intermediate position, shown in which constitutes the beverage dispensing position.
When the rod or piston 42 is in the beverage dispensing position, i.e. in the active or intermediate position, the closure element 46 is located in the intermediate position between the inlet constriction and the outlet constriction as the bottom end of the closure element 46 is resting on a top surface of the coupling housing sealing gasket 50 which, as is evident from
When the coupling housing 44, and thereby also the rod or piston 42, is separated from the beverage container 48, the beverage, indicated by the signature of “circles” in the figure, will exert a force on the closure element 46 pushing the closure element 46 against the outlet constriction defining the closed position, i.e. the second passive position, thereby sealing off the beverage container 48.
As shown in
The pressure chamber may be pressurized only when beverage dispensing is allowed, i.e. when a beverage container 48 has been installed and the pressure chamber has been swung into vertical orientation. Consequently, the pressure inside the pressure chamber may be used for holding the rod or piston 42 in the beverage dispensing position shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 12153871 | Feb 2012 | EP | regional |
| 12154154 | Feb 2012 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/051576 | 1/28/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2013/113657 | 8/8/2013 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5009082 | Abraham, III | Apr 1991 | A |
| 5240144 | Feldman | Aug 1993 | A |
| 8028857 | Rasmussen | Oct 2011 | B2 |
| 8109115 | Pippia et al. | Feb 2012 | B2 |
| 8479955 | Vesborg et al. | Jul 2013 | B2 |
| 20040011828 | Van Der Klaauw et al. | Jan 2004 | A1 |
| 20100176147 | Segers | Jul 2010 | A1 |
| 20100276452 | Vesborg et al. | Nov 2010 | A1 |
| 20130081443 | Rasmussen et al. | Apr 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 2736281 | Feb 1979 | DE |
| 29604703 | Jul 1996 | DE |
| WO2007019848 | Feb 2007 | WO |
| WO2009024147 | Feb 2009 | WO |
| WO2010020644 | Feb 2010 | WO |
| WO2010029122 | Mar 2010 | WO |
| WO2010060946 | Jun 2010 | WO |
| WO2010060949 | Jun 2010 | WO |
| WO2011002295 | Jan 2011 | WO |
| WO2011117192 | Sep 2011 | WO |
| Entry |
|---|
| International Search Report on corresponding PCT application (PCT/EP2013/051576) from International Searching Authority (EPO) dated Mar. 22, 2013. |
| Number | Date | Country | |
|---|---|---|---|
| 20150028052 A1 | Jan 2015 | US |
