GB2310190A

GB2310190A - Liquid foaming insert

Info

Publication number: GB2310190A
Application number: GB9701837A
Authority: GB
Inventors: Karl Mondszein
Original assignee: Lawson Mardon USA Inc
Current assignee: Amcor Specialty Cartons Americas LLC
Priority date: 1996-02-17
Filing date: 1997-01-29
Publication date: 1997-08-20
Anticipated expiration: 2017-01-29
Also published as: GB9701837D0; GB2310190B

Description

LIQUID-FOAMING INSERT The present invention relates to a foaming insert for containing a gas inside a container of pressurised liquid, such that when the container is opened, the gas is jetted from the insert to cause foaming of the liquid.

Such inserts are used, in particular, for beverages containing dissolved gas and especially for beer.

Details of the construction and operation of an insert generally of this type are disclosed in GB-A-2280887. The insert disclosed in GB-A2280887 comprises an upper plastics moulding connected to a lower plastics moulding to form a chamber for containing gas. In use, the insert floats in the liquid with the upper moulding above the lower moulding.

The upper moulding has a gas inlet for charging the chamber with the gas. The inlet is provided with a one-way duckbill valve, which allows gas from the headspace in the container to enter the chamber during equalisation of pressure, but prevents the from leaving the chamber via the inlet after equalisation. The lower moulding has a gas outlet coaxially aligned with the inlet, the outlet having a one-way duckbill valve that allows the gas in the chamber to escape from the chamber when the container is opened to release the pressure in the container, but prevents the liquid from entering the chamber via the gas outlet.

The duckbill valves are usually of an elastomeric, or rubber-based material and are made separately from the upper and lower mouldings.

Separate, fiddly assembly steps are therefore required to fit the small valves in the mouldings of the insert.

The present invention seeks to reduce the number of separate parts which must be assembled together to make such a liquid-foaming insert and to avoid the need for mounting separate valves, so that a cheaper and more reliable insert can be made.

The present invention achieves this object by providing a liquidfoaming insert for containing pressurised gas inside a liquid container, such that when the container is opened, gas is jetted from the insert into the liquid, the insert comprising an upper moulding connected to a lower moulding to form a chamber for containing gas, the upper moulding having a gas inlet including a one-way valve for admission of gas to the chamber, the lower moulding having a gas outlet including a one-way valve for allowing the gas to be jetted from the insert, wherein when pressure outside the insert is above that outside the insert, wherein each one-way valve comprises a resiliently flexible sealing ring formed as part of a respective one of the mouldings and a peg forming part of the other moulding and extending through the sealing ring, each ring sealing around the corresponding peg and permitting flow between the ring and the peg in the open position of the one-way valve.

An insert according to the present invention will now be described in further detail with reference to the accompanying figures, in which: Fig 1 shows a disassembled insert according to the invention; and Fig 2 shows an assembled insert according to the invention.

Referring to Fig 1, the insert comprises an upper moulding 10 and a lower moulding 20, each roughly of hemispherical shape, with opposed flats at the top 60 and the bottom 61 respectively. To form the generally spherical assembled insert 100 as shown in Fig 2, the mouldings are brought together so that a shaped, peripheral flange 11 formed on the upper moulding 10 snap fits into a corresponding peripheral recess 21 formed in the lower moulding 20. Alternative means of connection, e.g.

gluing or heat bonding of the mouldings 10,20 may, however, be used.

When connected together, the mouldings 10,20 form a chamber 50 (Fig 2) for containing a gas.

Each one-piece moulding 10,20 is injection moulded from plastics, such as polypropylene. Each moulding has a peg formation 12,22 and a ring formation 13,23 formed as integral parts of the moulding respective and each offset from the axis of the insert extending through the top and bottom 60,61. In the assembled insert 100, the peg 12 of the upper moulding 10 extends within the moulding from the top 60 towards the lower moulding 20. The peg 22 of the lower moulding 20 extends within the moulding from the bottom 61 towards the upper moulding 10. Each peg 12,22 has a conical or frustoconical distal end 12a,22a.

The ring 13 of the upper moulding 10 also extends within the moulding from the top 61. The ring is of frustoconical form and is resiliently flexible, so as to receive and seal around the peg 22 as illustrated in Fig 2. The ring 23 of the lower moulding 20 extends from a portion 62 of the bottom forming an end wall of a recess 63. The ring extends away from the chamber into the recess. The ring 23 is also of frustoconical form and is resiliently flexible and seals around the peg 22.

Cooperation of the sealing ring 13 of the upper moulding 10 and the peg 22 of the lower moulding 20 provides a chamber inlet 30 having a one-way valve 31, the valve 31 being closed when the upper moulding ring 13 is sealed against the lower moulding peg 22 as shown in Fig 2.

The resiliently flexible ring 13 can, however, be moved away from the peg 22 to open the valve 31 by the pressure of gas from the headspace in the container, as described in GB-A-2280867. The one-way valve 31 prevents the inert gas from escaping from the chamber through the inlet 30 after charging.

Cooperation of the lower moulding sealing ring 23 with the upper moulding peg 12 provides a chamber outlet 40 having a one-way valve 41, the valve being closed when the lower moulding ring 23 is sealed against the upper moulding peg 12 as shown in Fig 2. Pressure in the container maintains the valve in closed position.

In use, the insert 100 is provided in a sealed, pressurised container of liquid, e.g. as disclosed in GB-A-2280867. The insert floats on the liquid contained inside the container, which may be a can of beer, with the upper moulding 10 in the headspace and the lower moulding 20 in the liquid. The lower moulding is of thicker, or denser material to ensure that the insert floats in this orientation.

On opening of the container, pressure is relieved, so that gas is jetted from the outlet 40, the valve 41 being opened by the pressure differential. The jetted gas causes nucleation, so that dissolved bubbles are released from the liquid. Where the liquid is beer, this produces a head on the beer.

The peg 12 of the upper moulding 10, has a shoulder 12b spaced from the ring 23 of the lower moulding 20, within the recess 63. This is a safety device to prevent violent separation of the two parts, if the snap fitting of the flange 11 should fail.

The insert 100 has only two parts, which can be simply connected together so that assembly is extremely simple. The valves are integrally formed with the body, so that they cannot come adrift, as is possible in the prior art, causing failure and possible danger, if the valve is swallowed.

Claims

1. An insert for containing pressurised gas inside a liquid container, such that when the container is opened, gas is jetted from the insert into the liquid, the insert comprising an upper moulding connected to a lower moulding to form a chamber for containing gas, the upper moulding having a gas inlet including a one-way valve for admission of gas to the chamber, the lower moulding having a gas outlet including a one-way valve for allowing the gas to be jetted from the insert, wherein when pressure outside the insert is above that outside the insert, wherein each one-way valve comprises a resiliently flexible sealing ring formed as part of a respective one of the mouldings and a peg forming part of the other moulding and extending through the sealing ring, each ring sealing around the corresponding peg and permitting flow between the ring and the peg in the open position of the one-way valve.

2. An insert according to Claim 1, substantially as herein described with reference to the accompanying drawings.

3. A container containing liquid under pressure with a headspace containing gas, and an insert according to Claim 1 floating on the liquid with the gas inlet in the headspace and the gas outlet in the liquid, the insert containing gas from the headspace under pressure in equilibrium with the pressure in the container, whereby on opening the container, gas is jetted into the liquid from the gas outlet.

4. A container according to Claim 3, wherein the liquid is beer.