BEVERAGE CONTAINER
TECHNICAL FIELD
Recently, there has been considerable interest in systems for dispensing beverages from cans and other small containers to give a similar appearance to beverages dispensed from draught. In particular, when dispensing beverages from draught, small bubbles are intimately mixed with the body of the beverage as it is dispensed, and after these gradually separate out to form a close-knit creamy head.
BACKGROUND ART
Two commercially successful systems are described in patent specifications GB-B-2 ,183 , 592 and WO-91/07326. In both of these, the can or other container includes a hollow insert located in the container. In the filled container, the insert contains fluid under pressure and, upon opening the container, a stream of gas or beverage and gas is jetted into the beverage in the container. This jetting causes shear in the beverage which, since the beverage is super-saturated, leads to the evolution of small bubbles of gas. These bubbles act to seed the generation of further bubbles so that as the beverage is dispensed from the container, it is dispensed as a creamy liquid with small bubbles dispersed throughout. After being dispensed into a glass, the small bubbles gradually rise, and the beverage separates to provide a liquid phase and a thick creamy head on the surface.
It has been found that jetting gas only gives improved shear, and therefore improved head formation compared to jetting gas and beverage. According to O-91/07326 a separate closed insert provided in the beverage container contains pressurised gas. The insert includes a means responsive to the opening of the container to allow communication between the inside of the insert and the beverage in the container and gas from the insert jets into the beverage via this means causing shear in the beverage and liberation of gas.
Particular examples of means responsive to the opening of the container disclosed in the prior art include burst disks which burst due to the pressure differential between the inside of the insert and the atmospheric pressure subsisting in the container after it is opened, manually openable valves or puncturing devices which open after closure of the container, or pressure responsive valves which open due to a pressure differential between the gas inside the insert and the atmospheric pressure subsisting in the container after opening. SUMMARY OF THE PRESENT INVENTION
According to the present invention, a container for a carbonated beverage includes a separate insert including a means for communication between the inside of the insert and the container, the means for communication abutting a seat to close the insert, and a hinged portion surrounding the means for communication and arranged so that, upon opening the container, the means for communication flexes about the hinged portion away from the seat causing gas to jet from the inside of the insert.
The advantage of this arrangement is that the communication means is closed prior to opening of the container which ensures substantially no beverage enters the insert prior to opening the container. It is advantageous that the hinges are arranged to resist the communication means from flexing back towards the seat after opening of the container. This ensures that the communication means remains open and therefore prevents residual pressure in the insert after opening of the container. In this case, the hinge may comprise two concentric pivotal hinge portions around the communication means, the hinge portions being interconnected by an inclined web. This gives an arrangement in which the communication means has two stable positions, one in which the aperture abuts the seat, and one in which the aperture is spaced from the seat.
Upon opening the container, the means for communication may be arranged to move away from the bottom of the insert so that any beverage which has entered the insert is below the means for communication and therefore is not jetted into the main body of beverage in the container.
The means for communication may be a simple orifice provided in a top or side wall of the insert. In this case a downpipe may be provided around the orifice, extending towards the bottom of the insert in its normal position. The bottom of the downpipe abuts a seating to close the insert. Alternatively, a wall of the insert may be shaped so that the orifice itself contacts an opposed side wall of the insert. These arrangements are simple and inexpensive. Alternatively, the insert may include a one-way valve as the communication means, and in this case preferably a duckbill valve. The use of a one-way valve further ensures minimal ingress of beverage into the insert.
It is preferred that the insert includes a plurality of communication means. As fluid is jetted through each communication means, the provision of a plurality of such means ensures better seeding of bubbles in the main body of beverage due to the additional jets.
The insert preferably also includes a means to allow the insert to be charged with an inert gas. This means may be a gas permeable membrane which allows gas from the carbonated beverage to charge the insert after sealing the container over a period of time. In this case, the hinge may advantageously be formed from thinner material than the remainder of the insert, thereby acting as a hinge, and allowing the permeation of gas through the hinge to charge the insert. Alternatively, the insert may include a means which initially resists a high pressure difference to allow the insert to be pre-charged, yet changes its state to allow the hinged to flex upon opening the container. Such charging systems are known from WO-A-91/07326.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a first example of an insert; Figure 2 shows the insert of Figure 1 in a hinged position; Figure 3 shows a modification of the insert of Figure 1 including a plurality of communication means;
Figure 4 shows a second example of an insert; and Figure 5 shows a modification of the insert shown in Figure 4. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Figures 1 and 2 show a first example of an insert 1 according to the present invention for use in a the container. The insert 1 includes a small aperture 2 in the insert's top 3. A downpipe 4 is provided around the aperture 2 extending from the top of the insert 3 towards the insert's bottom 5. A hinge 6 is provided in the top 3 of the insert 1. The pressure on the outside of the insert 1 is initially equal to or greater than the pressure within the insert, and therefore the hinge 6 ensures the downpipe 4 is urged towards the bottom 5 of the insert 1, and abuts the bottom 5 of the insert 1. This prevents ingress of beverage into the insert 1.
The insert 1 is charged to a super-atmospheric pressure equal to that in the sealed container. This charging may be achieved by including a gas permeable membrane (not shown) in a wall of the insert 1. Gas from the carbonated beverage gradually permeates through the membrane to charge the insert 1. Alternatively, gas may seep into the insert 1 through the downpipe 4. In these examples, to minimise liquid ingress during this charging, the container is advantageously inverted. The insert 1 may however be pre-charged with inert gas prior to filling and sealing the container. In this case, the hinge 6 is initially able to withstand a pressure difference between the inside of the insert 1 and the surrounding atmosphere, but be modified, for example due to the high temperatures
during pasteurisation, to flex at a low pressure difference upon opening the container.
When the container is opened, the pressure in the container will rapidly vent to the atmosphere. At this time, the pressure inside the insert 1 will be greater than that in the container, and accordingly the top 3 of the insert 1 will lift upwards about the hinge 6 as shown in Figure 2, lifting the downpipe 14 away from the bottom 15 of the insert. Gas from inside the insert 1 then jets through the aperture 12 into the beverage causing shear in the beverage and the resultant liberation of gas bubbles. As the top 3 of the insert 1 flexes outwards, the bottom of the downpipe 4 lifts clear of the bottom 5 of the insert 1, and clear of any beverage 17 which may have leaked into the insert 1. This ensures that substantially no beverage 7 is jetted upon opening the container.
As shown best in Figure 3, the hinge 6 is formed by two concentric weakened portions 8,9 surrounding the aperture 2 and connected by an inclined web 10. Due to the inclined web 10, the top 3 of the insert 1 has only two stable positions, a lower position as shown in Figure 3 and an outwardly flexed position in which the top 3 lies above the height of the side walls of the insert 1. In either stable position, a high pressure differential across the top 3 of the insert 1 will be required to displace the top 3. Accordingly, when the container is opened and the top 3 of the insert 1 flexes outwards to unseat the aperture 2, the top 3 is flexed to the outwardly flexed position. As the pressure in the insert 1 falls towards that of the container, the top 3 remains in the outwardly flexed position as a high force is required to displace the top 3. Accordingly, the insert 1 remains open, so there is no residual pressure in the insert 1.
Figure 4 shows an alternative insert 20 which is substantially the same as that shown in Figures 1 and 3 except a plurality of apertures 2 and associated down pipes 4 are provided.
Figure 5 shows a second example of an insert 11 for use in a container according to the present invention. In this case, the insert 11 includes a depressed top 12 including an aperture 13 so that in its normal state, the aperture 13 is close to the bottom 14 of the insert 11. Upon opening the container, the pressure inside the insert 11 exceeds the pressure in the container, and accordingly the top 12 flexes outwards about the hinge portion 15, lifting the aperture 13 clear of the bottom 14 of the insert 13 and allowing gas to jet through the aperture 13. In this case, the hinge 15 is as described with respect to Figure 3.
Figure 6 shows a variation of the insert 11 of Figure 4. In this case, the aperture 13 is replaced by a one-way duckbill valve 16. The duckbill valve 16 abuts the bottom 14 of the insert 11. This abutment ensures no back leakage of the valve 16. The top 12 of the insert 11 is arranged to flex about a hinge 15 to lift the duckbill valve 16 clear of the bottom 12 of the insert 11 upon opening the container. As no fluid or gas from the beverage may enter the insert via the one-way valve 16, a portion of the insert 11 includes a gas permeable membrane 17, through which gas from the beverage enters the insert to pressurise the insert. The insert shown in Figures 1 to 4 may also include a duckbill valve in each restricted orifice. The use of the one-way valve helps ensure no liquid enters the insert, since the one-way valve constitutes an extra barrier to prevent ingress of beverage.