GB2208683A

GB2208683A - Liquid container

Info

Publication number: GB2208683A
Application number: GB8818630A
Authority: GB
Inventors: Leonard Sharples
Original assignee: Splicerite Ltd
Current assignee: Splicerite Ltd
Priority date: 1987-08-15
Filing date: 1988-08-05
Publication date: 1989-04-12
Also published as: GB8719360D0; GB8818630D0

Abstract

A liquid container (10) comprises an outer housing (11), and an elastomeric bag (12) arranged in the housing to hold a charge of liquid. The bag is capable of being expanded as it is filled with liquid until at least part of its outer surface engages with the inner wall of the housing. A dispenser outlet permits dispensing of the liquid product from the bag, and pressurised gas, or a source of pressurised gas, is introduced into the interior of the housing (11) so as to apply a compressive force to the bag such that, upon operation of the dispenser outlet, the liquid can be discharged from the bag under the action of the pressurised gas. The elasticity of the bag may be sufficient to permit its expansion during filling with liquid, but if additional pumping action is required, greater elasticity may be provided in the bag so that bag contraction also contributes to the pumping action exerted on the liquid during dispensing. <IMAGE>

Description

LIQUID CONTAINER This invention relates to a liquid container having an outer housing and an elastomeric bag arranged within the outer housing to be charged with the liquid contents of the container.

In one known form of container of this type, which is known as a "bag in a bottle", the bag undergoes resilient expansion as it is charged with a liquid, usually a beverage, until the bag comes into contact with the inner wall of the outer housing. The liquid contents can then be discharged, upon opening of an oulet tap, by resilient contraction of the bag.

To date, containers of this type have been of relatively small volume, because there is a problem in achieving complete discharge of all of the liquid contents.

In this respect, it will be appreciated that the pumping effect created by the resilient contraction of the bag will diminish progressively and when the bag has contracted to, say, only 1206 to 130% of its relaxed or non-deformed size, there will be very little pumping action available to discharge the final portion of the liquid contents.

Furthermore, unless provision is made to ventilate the interior of the outer housing i.e. the space between the outer surface of the diminishing volume of the bag and the inner wall of the housing (for example as disclosed in W087/01099), the negative pressure generated in this space will also tend to reduce the pumping action which can be produced by the bag contraction.

For the storage of larger volumes of beverages, such as beer, it is usual to employ a keg or cask, and to discharge the beverage it is necessary to connect-up a gas bottle, and this has certain disadvantages. First of all, there is a time and cost penalty in having to use a separate component to drive-out the product. Secondly, it will be a matter of common experience that much of the beer first discharged from a fresh keg is over-frothy and is unacceptable to customers, with resulting loss of sales value.

The present invention has therefore been developed primarily, though not exclusively, with a view to provide for the storage of large volumes of beverages, such as five gallons of beer, in a way which does not rely upon an external and separate permanently connected gas bottle during liquid discharge, and yet which enables the cheapness and ready operation of an elastomeric bag to be improved by functioning more efficiently in the discharge of the liquid product.

According to one aspect of the invention there is provided a liquid container which comprises: an outer housing; an elastomeric bag arranged in the housing to receive a charge of liquid product to be stored in the container and being capable of expanding to contain the liquid; a dispenser outlet operable to dispense the liquid from the bag; and, a gas-generating source arranged in or on the container and operable to introduce a propelling gas into the container to act between the inner wall of the outer housing and the outer surface of the bag whereby, upon opening of the dispenser outlet, liquid can be dispensed from the bag under the combined action of the propelling gas and the contraction of the bag.

Thus, in a container according to this aspect of the invention, the bag can readily be filled with liquid, during which time it expands so as substantially to fill the available internal space of the outer housing (preferably by direct filling of the bag with liquid), and the liquid can then be discharged from the bag by virtue of the elastic energy stored in the expanded bag and also the action of the propelling gas on the outer surface of the bag.

The relative contributions to the pumping action, made by the bag contraction and by the action of the propelling gas, can be selected according to requirements. In some circumstances, it may be desirable for the major part of the pumping action applied to the liquid to be derived mainly during the initial stages by bag contraction, though in other case the action may be derived mainly from the propelling gas acting on the outer surface of the bag. In the latter case, although the bag is elastomeric, its properties of elasticity may be selected so as to be sufficient only to permit necessary expansion of the bag as it is filled with liquid, since the main pumping action will be derived from the action of the propelling gas on the outer surface of the bag.

The gas generating source may take any convenient form, including liquified propelling gases, and may be contained in a rupturable sachet or the like.

Advantageously, the sachet is arranged so as to be unruptured prior to first use of the container, and preferably means is provided which is operable to rupture the sachet upon first use. This may comprise, for example, means which is effective to rupture the sachet upon or preparatory to first operation of the dispenser outlet of the container.

The contents of the sachet will be such as to be capable of generating a gas, upon rupture, and may comprise therefore a liquified propelling gas, or constituents which are brought into action upon rupture, such as a solid and liquid reactant brought into contact with each other.

In the case of a sachet containing a liquified propelling gas, the sachet takes up a very small volume, and therefore allows substantially complete expansion of the bag (for liquid storage) within the space available in the outer housing. However, as the bag contracts in order to discharge the liquid, the liquified gas converts more and more of its liquid content into gaseous form so as to fill the space being made available by bag contraction.

This has a dual function, in that firstly it avoids the generation of negative pressure within the outer housing.

which would reduce the pumping ability of the bag, and secondly it applies gaseous pressure to the outer surface of the bag, thereby compensating for any loss of pumping ability of the bag.

The quantity of liquified gas introduced will be such that, upon contraction of the bag to near its relaxed size (when it could exert minimal pumping action on the residual liquid content by virtue of its now near exhausted resilient contraction), the quantity of gas liberated from the liquified gas is sufficient to vent virtually the entire contents of the bag.

In a further aspect of the invention there is provided a liquid container which comprises: an outer housing; an elastomeric bag arranged in the housing and holding a charge of liquid product stored in the container, the bag having been expanded from its natural shape until at least part of its outer surface engages at least partly with the inner wall of the housing; a dispenser outlet operable to dispense the liquid from the bag; and, pressurised gas filling the remainder of the interior of the housing so as to apply a compressive force to the bag whereby, upon operation of the dispenser outlet, the liquid can be discharged from the bag under the action of the pressurised gas.

Preferably, the inherent elasticity of the bag is such that the contraction of the bag also assists in the discharge of the liquid from the bag.

Any suitable means may be provided to introduce the pressurised gas which fills the remainder of the interior of the housing, and this may comprise a source of compressed gas which can be connected via a suitable inlet fitting on the outer housing, and which will supply the pressurised gas preferably after filling and expansion of the bag.

Alternatively, a liquified gas source may be provided which liberates a gas to fill the remainder of the interior of the housing in any convenient way. For example, an inlet fitting may be provided on the outer housing, near to an inlet point for introducing the liquid product into the bag, but outwardly of the filling mouth of the bag so as to introduce liquified gas, or liberated gas, between the bag and the inner wall of the housing.

Alternatively, an inlet fitting may be provided in a side wall of the outer housing, and this will be advantageous if, as may be provided, at least one groove or rib is arranged on the outer periphery of the bag or the inner wall of the housing, so that when the bag expands to its maximum size, there will still be a free space or spaces into which the liquified gas can be introduced from externally of the housing.

However, when a liquified gas source stores the liquified gas in the outer housing of the container according to either aspect of the invention, this may be arranged conveniently in a small rupturable capsule or the like which is arranged at some convenient position on the inner wall of the outer housing. Then, upon expansion of the bag during charging with liquid, the capsule does not interfere with the free expansion of the bag and no contact is made with the capsule until the bag has completed, or nearly completed its expansion. The capsule then ruptures, and liquified gas then migrates into any small space available between the outer periphery of the bag and the inner wall of the housing.

The liquified gas used to assist in the discharge of the liquid contents may be any of those commercially available for use as propellents in aerosol dispensers.

Preferably, valve means is provided on the container which is operable to permit charging of the bag with liquid product may take any suitable form, so as to introduce the liquid, such as pressurised beverage, through an inlet fitting to the mouth of the bag.

To permit liquid discharge, the dispenser outlet may comprise a separate outlet of the valve means, having its own control valve or tap which, upon opening, allows the bag to discharge the liquid by resilient contraction.

In use of a container according to the invention, the gas introduced into the container will exert a pressure on the bag at all times, and this will be consistent throughout dispensing. Virtually the entire liquid content of the bag can be dispensed, and the progressive evaporation of the liquified gas within the container may produce a cooling effect, which may also be advantageous with regard to the dispensing of certain types of liquid beverage.

The outer housing may be made of similar material to existing constructions of kegs and casks for storing beer and lager, and therefore may be made of metal, plastics or wood.

No separate pumps or gas bottles are required for the dispensing of the liquid, there being merely the requirement for a dispenser head.

There is also no need to provide the usual dip tube provided with a beer keg, and the inside surface of the bag may have small ribs to allow the product to reach the dispenser aperture without entrapment.

The gas that is introduced between the outer surface of the bag and the inner wall of the housing (keg) exerts an even pressure throughout the dispensing action, and does not necessarily come into contact with the product.

While a container according to the invention is particularly suitable for dispensing beverages, clearly the concept can be applied in the dispensing of other liquids, such as in the dispensing of liquid sprays used in agriculture or in the garden, such as fertilizers and weed killers.

One embodiment of liquid container according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawing which is a diagramatic side view.

Referring now to the drawing, there is shown a liquid container which is designated generally by reference 10 and which comprises a rigid or semi-rigid outer housing 11 and an elastomeric bag 12 arranged within the outer housing 11 so as to be capable of being charged with the liquid contents of the container. The bag 12 is made of elastomeric material so as to be capable of expanding many times beyond its un-deformed and relaxed state as shown in the drawing, so that it can occupy substantially the entire free space defined within the inner wall of the outer housing 11.Following charging of the bag with a liquid, such as beer, controlled amounts of liquid can then be discharged via a discharge outlet (not shown) having a control valve or tap, the liquid being discharged under a pumping action generated by the tendency of the elastomeric bag 12 to contract back towards its undeformed shape.

Accordingly, valve means (not shown in detail) is provided which is operable to permit the charging of the bag 12 with liquid product so as to cause the bag to expand until it is constrained by the inner wall of the outer housing 11, but this valve means (including a valve controlled discharge outlet) also being operable to permit discharge of the liquid product from the container under resilient contraction of the bag.

In the drawing. a product access point is designated by reference 13, above the mouth 14 of the bag 12, and this is a diagramatic illustration of means for charging the bag with liquid, and also for permitting discharge of the liquid content when required. Thus, the valve means includes a dispenser outlet (not shown) which is openable to dispense the liquid from the bag.

The inherent elasticity of the bag 12 may be such that it is capable of expelling the greater part of the liquid content therein as it contracts. However, the pumping action which can be generated by the contraction of the bag will tend to diminish, and the invention therefore provides means for assisting the driving-out of the liquid content, and especially when the bag has contracted nearly back to its undeformed shape. Also, in some cases, the inherent elasticity of the bag may be reduced, so that it only needs to be capable of expanding upon filling with liquid, and the additional means will be utilised for the necessary pumping action.

To this end, a gas source is provided e.g. a liquified gas source for storing liquified propelling gas in the space between the inner wall of the outer housing 11 and the outer surface of the bag 12, when expanded.

Alternatively. the gas source means serves for introducing a propelling gas (which may be liquified initially) into the space between the inner wall of the outer housing 11 and the outer surface of the bag. The liquified propelling gas takes up a very small volume, when in the container 10, and therefore allows substantially complete expansion of the bag (for liquid storage) within the space available in the outer housing 11. However, as the bag 12 contracts in order to discharge the liquid, the liquified gas converts more and more of its liquid content into gaseous form, so as to fill the space being made available. This has a dual function, in that firstly it avoids the generation of negative pressure within the outer housing, which would reduce the pumping ability of the bag, and secondly it applies gaseous pressure to the outer surface of the bag 12, thereby to compensate for any loss of pumping ability of the bag.

In the drawing, a liquified gas can be introduced by way of an inlet fitting 15 provided on the outer housing 11 near to the inlet point 13 for introducing the liquid product into the bag, the fitting 15 being located outwardly of the filling mouth 14 of the bag 12 so as to introduce the liquified gas between the outer surface of the bag 12, when expanded, and the inner wall of the housing 11. The inlet fitting 15 also includes a valve (not shown) which can be operated to allow evacuation of the air from the space surrounding the expanding bag during charging of the bag with liquid.

Alternatively, an inlet fitting may be provided in a side wall of the outer housing 11, and this will be particularly advantageous if at least one groove or rib is arranged on the outer periphery of the bag, or the inner wall of the housing (neither of which is shown), so that when the bag 12 expands to its maximum size, there will still be a free space or spaces into which the liquified gas can be introduced from externally of the housing.

When the liquified gas source serves to store the liquified gas in the outer housing, this may be arranged conveniently in a small rupturable capsule or the like which is arranged at some convenient position on the inner wall of the outer housing 11. By way of example, a rupturable sachet 16 is shown in the bottom of the container. Then, upon expansion of the bag during charging with liquid, the capsule does not interfere with the free expansion of the bag, and no contact is made with the capsule until the bag has completed, or nearly completed its expansion. The capsule then ruptures, and liquified gas then migrates into any small space available between the outer periphery of the bag and the inner wall of the housing. The liquified gas then gradually converts into gaseous form as the bag contracts.Alternatively, a rupturable sachet 17 (shown only diagramatically) may be arranged to be unruptured until first use of the container, or upon breaking of a security seal preparatory to first operation of the dispenser outlet.

As an alternative, the liquified gas used may be one which is capable of liberating gaseous carbon dioxide, upon availability of sufficient space for expansion, and this will then create a gaseous carbon dioxide propelling charge surrounding the outer surface of the bag 12, and promoting the contraction of the bag during liquid discharge. In the event that the bag 12 is not entirely impermeable to outward migration of gaseous carbon dioxide derived from the liquid product, such as beer, the surrounding gaseous carbon dioxide atmosphere can serve to maintain the gaseous carbon dioxide presence in the liquid stored within the bag.

Claims

1. A liquid container which comprises: an outer housing; an elastomeric bag arranged in the housing to receive a charge of liquid product to be stored in the container and being capable of expanding to contain the liquid; a dispenser outlet operable to dispense the liquid from the bag; and, a gas-generating source arranged in or on the container to introduce a propelling gas into the container to act between the inner wall of the outer housing and the outer surface of the bag whereby, upon opening of the dispenser outlet, liquid can be dispensed from the bag under the combined action of the propelling gas and the contraction of the bag.

2. A container according to Claim 1, in which the major part of the pumping action applied to the liquid is derivable mainly during the initial stages by bag contraction.

3. A container according to Claim 1, in which the main pumping action applied to the liquid is derived from the action of the propelling gas on the outer surface of the bag, whereby the properties of elasticity of the bag are selected so as to be sufficient only to permit necessary expansion of the bag as it is filled with liquid.

4. A container according to any one of the precedings claims, in which the gas generating source is contained in a rupturable sachet.

5. A container according to Claim 4, in which the sachet is arranged so as to be unruptured prior to first use of the container, and means is provided operable to rupture the sachet upon first use.

6. A container according to Claim 5, in which said means is effective to rupture the sachet upon or preparatory to first operation of the dispenser outlet of the container.

7. A container according to Claim 5 to 6, in which the sachet contains a liquified propelling gas, or constituents which are brought into action to generate gas upon rupture.

8. A container according to any one of Claims 1 to 7, in which the bag is arranged to expand as it is filled with liquid until at least part of its outer surface engages with the inner wall of the housing

9. A liquid container which comprises: an outer housing; an elastomeric bag arranged in the housing and holding a charge of liquid product stored in the container, the bag having been expanded from its natural shape until at least part of its outer surface engages at least partly with the inner wall of the housing; a dispenser outlet operable to dispense the liquid from the bag; and, pressurised gas filling the remainder of the interior of the housing so as to apply a compressive force to the bag whereby, upon operation of the dispenser outlet, the liquid can be discharged from the bag under the action of the pressurised gas.

10. A container according to Claim 9, including an inlet fitted on the outer housing to permit filling of the housing with pressurised gas after filling and expansion of the bag.

11. A container according to Claim 9, including a liquified gas source provided on or in the housing and arranged to liberate a gas to fill the remainder of the interior of the housing after the bag has been charged with liquid.

12. A container according to Claim 11, in which the liquified gas source is stored in a rupturable capsule.

13. A container according to Claim 10, in which the inlet fitting is provided on the outer housing, near to an inlet point for introducing the liquid into the bag, but outwardly of the filling mouth of the bag so as to introduce liquified gas, or liberated gas, between the bag and the inner wall of the housing.

14. A container according to Claim 10, in which the inlet fitting is provided in a side wall of the outer housing, and at least one groove or rib is arranged on the outer periphery of the bag or the inner wall of the housing, so that when the bag expands to its maximum size, there will still be a free space or spaces into which the liquified gas can be introduced from externally of the housing.

15. A method of charging a container with a liquid product, said container comprising: an outer housing; an elastomeric bag arranged in the housing for holding a charge of liquid product to be stored in the container; and.

a dispenser outlet operable to dispense the liquid product from the bag; in which the method comprises filling the bag with the liquid product so as to expand the bag from its natural shape as it is filled until at least part of the outer surface of the bag engages at least partly with the inner wall of the housing; and, introducing a pressurised gas, or a source of pressurised gas, into the interior of the housing so as to apply, or to be capable upon liberation of the gas, to apply a compressive force to the bag such that, upon operation of the dispenser outlet, the liquid product can be discharged from the bag under the action of the pressurised gas.

16. A container according to Claim 1 or Claim 8 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawing.