Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
w O 94/21533 ~ 1 ~ 8 ~ ~ ~ PCT/GB94/00552
A BEVERAGE CONTAINER WITH MEANS FOR FROTHING THE BEVERAGE
Field of invention
This invention relates generally to carbonated beverages
including alcoholic beverages such as stout and
traditional ales which are sold in packaged form ie in
sealed bottles and cans.
Background to the invention
It is known to package carbonated drinks and other
beverages such as alcoholic drinks containing dissolved
gases typically carbon dioxide and nitrogen in pressurised
containers such as spun aluminium cans and provide a small
supplementary chamber within the can normally at the lower
end within which there is trapped under pressure a
quantity of gas which when the can is broached and vented
to atmosphere, causes a stream of bubbles to emit from a
small orifice in the wall of the supplementary chamber so
as to cause local nucleation sites in the beverage and
form a good reliable foamy head on the beverage not only
within the can but also as it is dispensed into a drinking
vessel.
One proposal involved injecting gas under pressure into
the secondary chamber from outside the can using a
hypodermic needle type of device and then resealing the
can after the supplementary chamber had been pressurised.
Other procedures have utilised the pressure which
WO94/21~33 r~ ~ PCT/GB94/00552
-- 2 --
currently exists in such cans after the can has been
filled and sealed and which is generally created by
nitrogen dosing using liquid nitrogen just before the top
is fitted to the can. Since the supplementary chamber is
preferably located at the bottom of the can so that the
bubbles which emanate from the chamber have maximum froth
producing effect, the can has to be inverted so as to
cause communication between the secondary chamber and the
gas in the head space so that the latter can permeate into
the secondary chamber through the tiny orifice through
which the gas will bubble when the can is depressurised.
Whilst it is commonplace to invert cans on canning lines
prior to pasturisation, can inversion can represent
something of a problem since the cans are primarily
designed to stand on their base and not on their top.
Should a can become unstable as a result of passing
through a can twist, and fall or jam, it represents a
considerable hazard since a fallen can on such a line can
result in damage and certainly a serious stoppage of the
line.
It is therefore an object of the present invention to
provide an alternative design of insertable secondary
chamber which does not require can inversion to achieve
pressurisation. This may become desirable in the future
if differently styled cans are introduced which are less
stable in an upended condition.
Summary of the invention
A beverage package is provided comprising a cannister
which is pressurised after being partly filled with a
beverage having gas dissolved therein, and a secondary
WO94/21533 2 ~ ~ 6 ~ ~ PCT/GB94100552
.
chamber therein comprising a housing within which gas can
be trapped, a restricted orifice in the wall thereof
through which gas or other fluid trapped within the
container can be forced under the influence of internal
pressure within the housing when the cannister is
depressurised when opened for dispensing, means for fixing
the housing at a desired height within the cannister such
that the housing is normally submerged below the surface
of the beverage in the cannister and is separated from any
gaseous head space at the top of the cannister above the
beverage, passage means extending from the housing into
the upper regions of the cannister so as to permanently
communicate with the head space when the can is upright,
and non-return valve means in the passage means or in the
housing, or both, so that gas can only flow from the head
space into the housing and not vice versa.
It will be seen that by utilising such a secondary chamber
within the cannister, any beverage which enters the
secondary chamber via the restricted orifice during the
filling process will be expelled via the restricted
orifice if the level of beverage therein rises above the
orifice. By positioning the orifice relatively low down
in the housing so the volume thereof which can become
filled with beverage can be reduced thereby optimising the
volume of the housing available for gas to be stored
therein under pressure and which when the can is broached
is available for forming the head on the beverage.
Preferably the non-return valve and passage means has a
lower resistance to fluid flow than does t'ne restricted
orifice so that the secondary chamber is preferentially
charged with gas. Selection of appropriate cross-section
areas for the passage means and the restricted orifice
WO94/21S33 - PCT/GB94/00552
.
~ 4 -
will ensure that it is predominently gas from the
headspace which enters the container and not beverage via
the restricted orifice.
Further steps may be taken during the can filling process
to ensure a gas charge by restricting or blocking the
restricted orifice in the wall of the container by a
temporary bung such as by using a dissolving plug of
material such as gelatine or by using a bursting disc
designed to fracture only from internal overpressure
caused by the eventual opening and depressurisation of the
cannister, or a second non-return valve operating in an
opposite sense to the first.
A particular advantage of such an arrangement is that the
housing container may be made relatively small in cross-
section so as to pass straight through a narrow restricted
end of a can or bottle and may be provided with resilient
fingers to centre the device within the cannister and by
making the passage means a relatively rigid structure
which extends upwardly to engage the underside of the lid
when the latter is fitted in place, the passage means for
communicating between the head space and the secondary
chamber housing can be used to maintain its position at
the lower end of the cannister.
This particular feature is of considerable importance
since not only is the cannister handling subse~uent to
filling and sealing simplified (in that it does not now
have to be inverted to cause the secondary chamber to
become pressurised), but the step of inserting the
secondary chamber into the cannister does not now require
relative angular movement of one part relative to another,
to enable the secondary chamber housing to be located and
~094/21533 2 ~ ~ 8t 6 ~ 5 PCT/GBg4/00552
secured in position within the cannister as has
characterised previous devices. The only requirement is
that any resiliently deformable fingers adapted to centre
the device within the cannister are sufficiently flexible
to allow the device to be pushed through a restricted
opening into the main part of the cannister.
Although the design of the housing forming the secondary
chamber is relatively unimportant, it is of course
possible that beverage can enter the secondary chamber and
become trapped therein. To this end the container is
preferably constructed so as to have a well within which
any beverage or liquid which has somehow entered t~e
container will be contained well clear of the exit
orifice. In addition to the well, the secondary chamber
housing preferably includes internal passage means
communicating between the restricted orifice at one end
and an upper region of the housing so that a considerable
depth of liquid can exist within the container before
there is any possibility of the beverage in the housing
being able to leave through the orifice instead of gas.
Thus although it is intended that there will be little or
no beverage within the secondary chamber housing should
any beverage enter the chamber its effect will be
minimised.
Where a second passage means or tube extends internally of
the housing as aforesaid, there will be a tendency for
this second passage to fill with beverage, so that when
the cannister is depressurised on broaching the slug of
beverage within the tube has to be forced through the
restricted orifice ahead of any gas. However the quantity
of liquid will never be greater than the volume of the
second passage or tube and by making its cross-section
WO94/21~33 PCT/GB94/00552
.
6~ - 6 -
relatively small, it will be seen that the volume of
liquid which has to be displaced before gas can exist will
not only be minimal but also consistent. Thus unlike
previous secondary chamber designs (where the volume of
liquid to be ejected can vary considerably depending on a
number of factors) the present design renders each
pressurised can consistent in performance to all other
similarly constructed cans.
The invention will now be described by way of example,
with reference to the accompanying drawings, in which:
Fig 1 is a diagrammatic cross-section elevation of a can
having a capsule containing gas under pressure and a
passage means associated therewith in accordance with the
invention;
Fig 2 is a bottom view of the capsule in the can;
~ig 3 is a top view of the capsule in the can;
Fig 4 is a diagrammatic cross-section elevation of another
secondary chamber embodying the invention;
Fig 5 is a top plan view of the other embodiment; and
Fig 6 is a perspective view of the secondary chamber shown
in Figures 4 and 5.
In Figures 1 to 3 the can is designated 10 and the
beverage within the can is designated 12. Above the
beverage is a headspace 11 of gas under pressure. A
capsule containing some of this gas under pressure for
head generation on dispensing is designated 14. A small
~094/21533 ~ 8~5 PCTIGB94/OOS5
orifice 16 in a lower frusto-conical wall of the capsule
14 allows gas to leave the capsule 14 when the can 10 is
broached in a conventional manner to dispense the
beverage.
Within the capsule 14 and leading upwardly from the
orifice 16 extends a tube 18. This tube extends almost to
the lid 20 of the capsule 14 so as to render the capsule
less sensitive to orientation of the can during dispensing
and thereby prevent any beverage which has entered the
capsule from closing off the orifice as it swills around
within the capsule during dispensing.
In accordance with the invention a filler tube 22 extends
through the lid 20 of the capsule 14 up to and into the
head-space 21 above the beverage 12 and which contains gas
under pressure typically in the range 2 to 4 bar.
Although the tube 12 extends into the headspace 11 when
the can is in its normal upright position, clearly if the
can is tilted or upended this will no longer be the case
and to this end a non-return valve 24 is provided to
prevent gas which has entered the capsule from leaving
it.
Preferably the non-return valve 24 is closed with a small
positive pressure as by a light spring so that in the
event that the can is inverted, there is little tendency
for liquid to penetrate past the non-return valve and
enter the chamber 14.
In order to minimise the entry of beverage into the
capsule, the orifice 16 may be closed with a plug of
soluble material such as gelatine or may be covered by a
bursting disc designed to fracture only from internal
WO94/21533 - - PCT/GB94/00552
overpressure caused by the eventual opening of the package
for consumption.
The tube 20 is shown extending to engage the underside of
the lid 26 and the upper end of the tube may be closed and
one or more openings such as 28 are provided in the wall
of the tube above the valve 24 so as to allow gas to enter
the tube 22 from the head space 11.
Three equidistant flexible fingers 20, 32, 34 extend
generally radially from around the capsule to engage the
inside wall of the can 10. In this way the capsule will
be held centrally within the can and will be held near the
bottom of the can by virtue of the upstanding tube 22.
Although not shown, a non-return valve may be associated
with the orifice 16 typically in the form of a small
buoyancy member which lodges against the orifice to close
it off when the capsule is submerged in a liquid. However
in the presence of an over-pressure (such as will exist
when the can is broached), the pressure of the gas within
the capsule will displace the small buoyancy member away
from the orifice to enable gas from within the capsule to
be expelled and form the string of bubbles needed to
produce the head formation. The advantage of such a
device is that there will then be little tendency for any
beverage to enter the capsule, and the latter will be
charged predominently with gas all derived from the
headspace 11 with the can 10 whilst the latter is in its
upright position.
Although the invention is of primary application to
alcoholic beverages on which a head is desired when
dispensed, it is equally applicable to non-alcoholic
~ 094/21533 ~f~4~ PCTIGB94/00552
carbonated beverages and the like.
The tube 22 allows the capsule 14 to be filled with gas
during the can filling process. To this end the capsule
is inserted into the can immediately before filling with
the beverage. The beverage is poured in until the
headspace 11 exists. A source of liquid nitrogen under
pressure is attached to the upper end of the protruding
tube 22 and a small charge of liquid nitrogen is injected
into the tube and thereby into the capsule 14.
Immediately thereafter the lid 26 is secured by seaming in
known manner to the can.
The liquid nitrogen charge within the capsule will boil
and evaporate to form gas which because of the non-return
valve 24 will all bubble out through the orifice 16 until
the headspace pressure and the pressure of the gas
remaining within the capsule are equal. In this way the
capsule will be charged wholly from within and if a
gelatine or like seal or a bursting disc seal or a
flotation member normally closing off the orifice 16 is
provided, capsule interior will remain totally dry and
contain only gas. The presence of the non-return valve 24
will prevent the ingress of beverage to the capsule 14,
and all of the volume of the capsule will therefore be
available for storing gas under pressure until the can is
broached when the gas will exit as a stream of bubbles
through the orifice 16 to form the foaming head.
As seen in Figure 3, the tube 22 is off centre so that the
device is assymetrical.
..
An alternative symmetrical design of device is shown in
Figures 4 to 6. Here the tube is relocated so as to be
WO94/21533 PCT/GB94/00552
.
2~ S _ 10
central of the capsule.
In Figure 4, the capsule is 36 and the tube 38. The upper
end of 38 indicated as opening 39 and one way valve 41.
The internal tube 18 is also relocated so as to be coaxial
with the tube 38 as shown at 40. The orifice 16 is
replaced by a small orifice 42 in an extension 44 of the
tube 40 which protrudes centrally through the base of the
capsule 36.
Radial wings 48, 49, 50 extend from the capsule 36 to
engage the inside of the can 10.
Upwardly inclined radial fingers 52, 54, 56 extend from
the upper end of the tube 38 to engage the can just below
the lid 58.
The upper end of the tube 38 is located just below the lid
58 so that the capsule is held in position at the bottom
of the can, even though its bouyancy tends to force it
upwards.
