Note: Descriptions are shown in the official language in which they were submitted.
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METHOD, DEVICE, AND CAPSULE FOR PREPARING
A FOAMY LIQUID FOOD
FIELD OF THE INVENTION
The present invention relates to the preparation of a liquid food from a
capsule containing dry food substance. More particularly, the invention
relates to a
method for preparing a foamy liquid food such as a hot beverage with an
enhanced
head of foam that is obtained from mixing a diluent with soluble powder within
a
predosed capsule. The invention also relates to a device adapted for such a
method.
The invention also relates to a predased capsule adapted for such a method.
BACKGROUND OF THE INVENTION
Foamed beverages such as espresso, cappuccino and latte prepared
from dispensing machines are becoming more and more popular. Methods of
preparation of such products from a predosed capsule are also known. The
principle
of using pre-metered and pre-packed portions of coffee and the like for the
preparation of coffee-based beverages has the advantages to facilitate the
preparation
of the beverage while ensuring that the dose-to-dose quality and strength of
the
beverage remains constant for the same conditions of preparations (dosage,
temperature, pressure, time, etc.). It also provides more convenience to the
user. The
capsule usually sits in a leak-tight enclosure of a special coffee-type
machine and hot
water is passed through the capsule under pressure. The underside of the
capsule
perforates under the build-up of pressure to release the extracted liquid. The
use of
roast-and-ground powder in capsules is commercialized to make coffee cups of
high
quality.
EP 0 512470 B1 describes aprocess for extracting sealed cartridges in
a cartridge holder in which a mixture of water and air is injected into the
cartridge
under a pressure of 1 to 20 bar to deform the extraction face. The extraction
face of
the cartridge is deformed against a relief surface of the cartridge holder
comprising
relief elements and recessed elements, the extraction face tearing at the
location of
these relief elements and/or these recessed elements on reaching the breaking
stress to
enable liquid to be subsequently removed after extraction of the coffee under
a
pressure of 1 to 20 bar.
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This process proves to be very effective for extracting a beverage
liquid from an extractable, non-soluble material such as roast and ground
coffee.
Since the product is not soluble within the cartridge, the bed of material
maintains an
elevated inside resistance and pressure tends to build up to a relatively high
range as
more water enters the cartridge. The combination of high pressure, temperature
and
extraction time is key for extracting the fine aroma compounds from the coffee
bed
until the extraction face can tear to allow release of the extracted liquid in
the cup.
For soluble products, water does not serve to extract solids and coffee
aroma compounds but it is supposed to solubilize all the solids. Dilution of
the solids
is essentially obtained by thorough mixing within the capsule during a
sufficient time
up to a complete dilution. Furthermore, mixing should be carried out while
entrapping sufficient air to form a good foam or froth upon releasing in the
cup.
Foam generation of soluble powder is complex and may also be dependent on the
physical release conditions of the solution through the capsule. These
physical
conditions involve the level of shear created and pressure release through the
openings. The building-up of pressure and the timing for release are also
selected to
obtain a sufficient mixing and air entrapment in the solution. The problem is
that,
when liquid starts entering the capsule, the powder starts dissolving and the
solution
tends to evacuate. As solids content in the capsule decreases, the resistance
created
by the powder in the capsule decreases proportionally. As a result, the
solution tends
to evacuate too quickly the capsule and at a too low pressure, without
sufficient
mixing having been carried out. As mixing is insufficient, lumps may form in
the
delivered solution, insufficient amount of air is entrapped and the resulting
amount of
foam created is poor.
US 3,292,527 to Stasse relates to an apparatus and a cartridge adapted
to deliver in succession different drinks or beverages without allowing the
drink or
beverage to contact the basic elements of the apparatus. The cartridge may
contain
fine soluble powder and has a perforated bottom side that creates a pressure
drop
capable of retarding the outflow through the orifice. Such a perforated
arrangement
by itself, even when small, does not produce sufficient shear and does not
retain
sufficient pressure inside to be capable of generating a properly whipped or
foamed
beverage.
EP 0 468 080 to Fond also relates to a process of extraction of a
cartridge for roast and ground coffee wherein the cartridge has an apertured
bottom
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side to deliver the extracted liquid along an extensive surface. This process
is for
roast-and-ground but would not properly apply to soluble powder such as
instant
coffee powder for the same reasons as for US 3,292,527.
WO 01/58786 to Halliday relates to a cartridge for the preparation of
whipped beverages of "espresso" type in machines operating at low pressure
characterized in that the cartridge incorporates in the beverage flow path,
prior to or at
the outlet, means for producing a jet of beverage, at least one inlet for air
and means
to generate a pressure reduction of the jet of beverage whereby in use air
from the air
inlet is incorporated into the beverage as a plurality of small bubbles. Due
to the low
pressure inside the cartridge, air must be added by specific air inlets. Such
a cartridge
specifically involves many parts and, hence, is tricky, complex and expensive
to
produce.
A need exists for a system to produce a food liquid, such as a coffee-
based product, having superior whipped or foam characteristics obtained from a
capsule-type system, and for the system to employ a relatively simple and low
cost
cartridge that can generate a substantially complete dissolution of the
soluble food
product and a high amount of foam.
SUMMARY OF THE INVENTION
The present invention satisfies these needs. The invention relates to a
device for preparing a foamy liquid food from a capsule containing a
premetered dose
of food soluble substance or "predosed" capsule. The capsule intended for the
device
has an entry side adapted to be traversed by a flow of water entering the
capsule, and
a discharge side adapted to be traversed by a flow of beverage exiting the
capsule.
The device comprises water supply to provide water within the capsule. Water
is
provided through the entry side, mixes with the soluble substance in the
capsule and a
beverage is delivered through the discharge side. A beverage and foam
conditioner is
adapted to open the capsule for release of the beverage and to engage against
the
discharge side to hold pressure within the capsule so that the soluble
substance can
thoroughly mix with water and entrap gas within the capsule to dispense a
foamy
beverage.
Therefore, complete dissolution and foam generation assisted by an
engagement member capable of holding pressure inside the capsule and
controlling
release of the beverage. The system of the invention holds the beverage within
the
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capsule until thorough mixing is obtained and sufficient gas is entrapped in
the
mixture to prevent release of the partially dissolved substance too early for
complete
dissolution. For physically achieving such an effect, the liquid and foam
conditioner
comprises at least one engaging surface adapted to create a tight surface
contact with
a certain area of the discharge surface of the capsule. As a result, a
sufficiently
retarded discharge of the beverage through the discharge side is created that
benefits
complete dissolution and the generation of foam.
The engaging surface is preferably of a convex shape adapted to
conform to the surface area of the discharge surface by providing a tight fit
between
the engaging surface and the surface area of the discharge side. A tight fit
ensures a
flow resistance so that a pressure can be reached and maintained inside the
capsule.
Preferably, the convex shape is adapted to form an inward deformation
along a surface area of the discharge side. As resulting from such a
deformation, the
contact between the engaging surface and the discharge side is improved and
made
even tighter so that product within the capsule can be held until to aclueve a
better
mixing up to complete dissolution and an effective gas entrapment. Due to the
relatively high internal pressure created in the capsule, gas may be entrapped
both in
dissolved form as a liquid and in gas form, such as in small bubbles.
Preferably, the engaging surface is adapted to engage the discharge
side along the surface area without creating substantial tearing between said
engaged
surface area of the discharge side of the capsule and the engaging surface of
the
device. The benefit of no substantial tearing by the engaging surface,
particularly
outside of the area immediately around the opening member, resides in that
sufficient
contact can be maintained between the discharge surface and the engaging
surface to
be able to properly retard release of the beverage. Therefore, the engaging
surface
has preferably a bulged profile as opposed to a sharp profile to avoid tearing
of the
discharge side. The profile may preferably be a bulged surface of dome-shape,
preferably of an angle from 5 to 45 degrees as measured from the tangential to
the
base of the dome or to the plane perpendicular to the axis of the capsule. The
engaging surface should engage along a sufficiently large area of the
discharge side to
properly control release of the beverage without risking to accidentally tear
the
capsule which would cause release of the beverage in an uncontrolled manner.
Preferably, the engaging surface is adapted to deform a surface area of at
least 30% of
the whole discharge side of the capsule, even more preferably of from 50 to
90% of it.
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In order to better control release of the opening member, it is preferred
that an opening member of the device is provided that is distinct from the
engaging
surface. The opening member engages the discharge side of the capsule to form
an
opening in the capsule capable of releasing the beverage out of the capsule.
The
opening member function is thus performed separately from the pressure holding
function to ensure a more accurate control of the release. Therefore, the
contact
surface can be made extensive to properly hold the product inside the capsule
while
the discharge opening can be limited in size. An opening of limited size
promotes
shearing of the flow traversing the opening which, in consequence, contributes
to
generate a better foam in the cup.
In a first embodiment, the opening member comprises a puncturing
member adapted to puncture a hole in the discharge side of the capsule. The
puncturing member may be at least one cutting edge, a pin, or other member
that
perforates the material of the discharge side in a precise location point.
Several
puncture points may be envisaged but one seems to be enough according to the
results
of numerous tests carried out so far.
In an alternative, the device may also adapt to open a precut capsule.
For that the opening member may comprise a finger adapted to open a capsule
with a
precut gate and wherein the finger is adapted to force opening of a precut
gate of the
capsule.
The capsule is preferably received in a capsule holder of a cup-shape
that comprises the engaging surface and the opening member in its inner bottom
side.
In a preferred embodiment, the engaging surface of the liquid and foam
conditioner is disposed around the opening member. As a result, the outflow
coming
out of the opening in the capsule is restricted to some extent by the engaging
surface
that surrounds the opening. The restrictions created also participate more
efficiently
to hold the product longer in the capsule and generate additional shear stress
on the
beverage flow coming out of the opening.
A better control of the release and more shear stress can be performed
when the engaging surface of the liquid and foam conditioner has a restricted
passage
for the liquid mixture. The restricted passage may preferably be channels,
corrugations provided onto the engaging surface, or be obtained by a
relatively high
intrinsic roughness of the engaging surface, or combinations thereof.
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A reservoir may also preferably be positioned in recess of the surface
engagement member at the exit of the opening. The reservoir creates a
separation
between the opening member and the engaging surface. It also provides some
clearance for the liquid to properly exit the capsule and air to enter the
capsule. Its
function is to form a buffer chamber for the liquid and to prevent cut
fragments of foil
of the capsule to block the restricted passages (i.e., channels, corrugations,
etc.). The
opening member preferably protrudes from the bottom of the reservoir such that
the
opening is carried out as the capsule deforms along the engaging surface and
within
the reservoir.
Water can be sullied to the inside of the capsule by piercing the entry
side with at least one needle-like water injector. The water injector may have
any
suitable shape. The water injector may preferably have a piercing tip with
water
holders forming a certain positive inclination with the longitudinal axis of
the injector
to direct one or several flows of water in outward direction that promotes
turbulence
within the capsule. In an alternative way, for pre-opened capsules, water may
also be
supplied or injected through the discharge side without injectors being
necessary but
through simple water lines properly coupled to the pre-openings of the entry
side of
the capsule. The entry side may be the top side of the capsule or,
alternatively, or in
addition, may be the sidewall of the capsule. Therefore, water can be injected
from
different off centered locations, e.g., the top side and/or sidewall, which
cause vortex
inside the capsule to enhance the powder mixing with water and gas.
The device of the invention comprises a holder for holding the capsule
in a tight sealed manner to be able to carry out the preparation of the
beverage within
the capsule in a clean, fluid-tight sealing and pressurized way. The holder
preferably
comprises a removable lower holder member of cup shape that engages an upper
supply water assembly adapted to cover the capsule. The lower holder member
and
upper water supply assembly together with a sealing member form a fluid-tight
enclosure upon closing around the capsule_ The lower holder and the upper seat
member have complementary connections that enable to create a tight
compressing
sealing connection around the capsule. The connections may be of a ramp or
bayonet
type or any other suitable types.
A preferred method for preparing a foamy liquid food comprises:
providing and retaining a capsule containing a dose of food soluble
substance, wherein the capsule has an entry side adapted to be traversed by a
flow of
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water entering the capsule, a discharge side adapted to be traversed by a flow
of
beverage exiting the capsule,
supplying water through the entry side within the capsule and mixing
water with the food substance within the capsule,
releasing the beverage while engaging a surface against the discharge
side to hold sufficient pressure within the capsule so that the soluble
substance can
thoroughly mix with water and entrap gas within the capsule and,
dispensing a foamy beverage.
In a preferred aspect of the method, engaging a surface against the
discharge side is made by inwardly engaging a portion of the discharge side
with an
engaging surface, preferably a bulged surface, to create a tight contact
without
tearing of the discharge side as resulting from such a tight contact. Even
more
preferably, the bulged surface causes a deformation without tearing of the
engaged
portion of the discharge side of the capsule.
Preferably, beverage is dispensed by passing through the opening of
the discharge side of the capsule, then, restrictions provided in the engaging
surface
and/or on the portion of the discharge side of the capsule in contact with the
engaging
surface. The restrictions are provided for controlling the release of beverage
through
the engaging surface, creating shearing and promoting foam generation. The
restrictions may be channels, corrugations and the like.
Preferably, the opening of the capsule is made by puncturing in the
discharge side of the capsule. In an alternative, the opening is made by a
finger that
pushes inward a precut member of the discharge side sufficiently to allow the
beverage coming out of the capsule. Opening of the discharge side is carried
out by at
least one opening member that is distinct from the engaging surface that
creates tight
contact.
In another aspect, the invention relates to a predosed capsule adapted
for the preparation of a foamy beverage according to the aforementioned method
wherein, it contains a food soluble substance and comprises an entry side
adapted to
be traversed by a flow of water entering the capsule, a discharge side adapted
to be
traversed by a flow of beverage exiting the capsule wherein the discharge side
is
adapted to be opened by an opening member and to resist contact with the
engaging
surface to create a tight fit with the engaging contact to hold pressure
within the
capsule sufficiently and control release of a foamy beverage.
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The capsule of the invention may be formed of a discharge side which
has a plain wall adapted for puncture by a puncturing member of the dispenser
to
release the beverage. Such a capsule may be a fully closed capsule made of
puncturable metallic or plastic material.
In an alternative, the capsule comprises a discharge side wherein at
least one opening member is provided to open by a finger of the dispenser.
Hence,
the openable member may have a precut to ease the opening by the finger.
Preferably, the openable member has at least one precut line. Preferably, the
openable
member comprises a plurality of precut lines arranged to form a pattern with
solid
regions against two adjacent precut lines. The finger preferably does not open
widely
the openable member but just holds the openable member in an open
configuration,
such as by pressing on inwardly on the openable member, with the openable
member
remaining attached to the discharge side by at least two slightly spaced apart
solid
regions. As a result, this enables to create just small passages for the
beverage to
release and a higher degree of shear stress is promoted.
In yet another embodiment, the capsule is pre-opened. The discharge
side has at least two separate contiguous layers, each one having at least one
passage
for the beverage. The passage of one layer being spaced apart from the passage
of the
other layer. In such configuration, there is no need for a specific opening
member of
the device and, hence, product cross-contamination is reduced. These two
layers may
be sealed along the outer edge of the capsule. The offset passages and
interface
between the layers form a tortuous path for the beverage that both participate
to the
pressure building up inside the capsule when the engaging surface of the
device
contacts the discharge side and allow release of the beverage by providing
shear stress
at the interface of the two layers. Channels or other restriction could be
added at the
interface of the two layers, i.e., at least in the thickness of one of the
layers, to
promote shear stress and control pressure inside the capsule.
The discharge side can be made of a flexible and tear resistant material
that withstands deformation without tearing upon contacting the engaging
surface of
the beverage and foam conditioner of the device. Preferred materials for the
discharge side is aluminum or aluminum alloy or a laminate of plastic and
aluminum,
or even full plastic. The thickness of the discharge side may vary as a
function of the
material or laminate. For an aluminum based material, the thickness is
preferably of
from S to 100 microns, even more preferably of from 15 to 75 microns.
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The capsule of the invention is conceived to serve as a mixing bowl for
the powder to reconstitute a liquid beverage by thorough mixing with a
diluent,
preferably water or eventually mills, while entrapping sufficient gas that
upon release
at normal atmosphere generates multiple fine bubbles that confers an enhanced
head
of foam in the cup. For that, the enclosure of the capsule should be sized to
address
the powder capacity issue, as well as the gas capacity issue. An overall
volume of the
capsule's enclosure of from 20 to 100 cm3, and 25 to 45 cm3 is preferred. The
capsule
should already contain a suitable amount of gas, such as air, OZ, COZ, N2 or
any other
inert gas or combinations thereof. Preferably, the ratio powder volume to gas
volume
ranges of from 1:50 to 1:1. Preferably, for coffee powder, the ratio powder
volume to
gas volume is preferably comprised of from 1:50 to 1:5, even more preferably
1:30 to
1:10. For soluble high load powder including milk powder such as chocolate and
cappuccino (also soup), the ratio powder volume to gas volume is preferably of
from
1:2 to 4:1. More headspeace, i.e., a lower powder air volume, allows better
initial
powder dissolution especially for powders with lower solubility and/or
generate
viscous mass after it is mixed with water. With other types of food products,
such as
capsules with roast and ground coffee, where much of the content of the
capsule is not
dissolved upon the production of a beverage or other food product, the ratio
of
powder to gas volume can be above 5:1 or even 10:1.
In a preferred construction for the capsule, the capsule comprises a cup
member that constitutes the entry side and sidewall of the capsule and a lid
that
constitutes the discharge side of the capsule. The cup member comprises a
peripheral
edge that extend outward the sidewall to form a connection surface for the lid
constituting the discharge side. Connection of the lid along the edges can be
carried
out by any suitable pressure resistant structure such as an adhesion, a
welding, a
crimping, or a combinations thereof. The general shape of the capsule or cup
member
can take any suitable shape, such as frustoconical, cylindrical, pyramidal,
cubic, etc.
Preferably, the outer surface of the discharge side has a passage
oriented to control release of the liquid between the discharge side and the
engaging
surface.
The present invention allows the preparation of a liquid food from a
capsule containing dry food substance. A method is provided for preparing a
foamy
liquid food such as a hot beverage with an enhanced head of foam that is
obtained
from mixing a diluent with soluble powder within a predosed capsule.
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One embodiment of the invention is a system for preparing a liquid
food. In the system, a containment portion is configured for containing a food
ingredient and for receiving a liquid supplied to flow through in contact with
the food
ingredient to produce a liquid-food mixture. A boundary wall has a wall
surface
extending along a peripheral portion of the containment portion. Also, at
least one
elongated channel extends along the wall surface and disposed downstream of
the
containment portion for receiving the liquid mixture and directing the liquid
mixture
to an outlet for providing the mixture as a liquid food.
In the preferred system, the channel has a cross-section configured to
create shear stress in the flow of the liquid mixture sufficient to create
foam in the
liquid food. The cross-section of the channel has a width and a depth that is
at least
25% of the width thereof, preferably at most about 150%, and more preferably
around
100%.
The channel has a cross-sectional area normal to the flow of the liquid
mixture of about between 0.01 mm2 and 2.25 mm2, and more preferably less than
about 1 mm2. Preferred dimensions of the channel cross-section are 0.1 mm to
l5.mm of depth and width, more preferably less than about 1 mm, and most
preferably between about 0.2 mm and 0.5 mm, with a preferred embodiment having
0.25 mm of depth and width. The channel may have a square cross-section,
rectangular, or other shapes, including rounded and circular cross-sections
with a
radius in the ranges of depth and width listed above.
Preferably, the channel comprises a plurality of channels extending
from a common area on the boundary wall. The channels have a length along that
at
least about an eighth of the dimension of the containment portion in the
direction of
the channel length, more preferably at least about a quarter as of said
dimension. A
preferred embodiment of the channel has a length of at least about 50% of the
dimension of the boundary wall in the direction of the channel length.
The containment portion may comprise a food capsule that is
receivable in an extraction chamber of a food preparation unit configured for
feeding
water into the capsule and comprising the outlet. The channel of this
embodiment
preferably comprises a slit extending partially through the boundary wall. A
second
wall can be disposed adjacent and substantially parallel to the boundary wall,
with the
channel formed by a slit extending substantially completely through one of the
walls.
Additionally, the food ingredient can comprise a predosed portion of a coffee,
tea,
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cocoa, or milk product, or a combination thereof, in an amount for preparing a
single
serving of a beverage.
The containment portion can also comprises an extraction chamber of a
food preparation device, with the containment portion configured for receiving
a
capsule that contains the food ingredient. A liquid feeder is preferably
configured for
feeding liquid into the capsule in the extraction chamber, and the outlet is
connected
with the extraction chamber downstream of the channel and configured for
delivering
the liquid food product.
In an embodiment of the invention, the boundary wall is configured for
supporting a capsule wall of the capsule that is disposed thereagainst when
the
capsule is pressurized with liquid. The boundary wall preferably includes a
bulged
portion surrounded by a recessed portion, with the bulged portion configured
for
deforming the capsule wall into the capsule for supporting the wall to reduce
or
prevent rupture thereof when the capsule is pressurized. A preferred bulged
portion
comprises a dome, and has a lateral width along the boundary wall that is at
least one
fifth of the lateral width of the boundary wall facing a face of the capsule,
more
preferably at least about one half, and most preferably at least about 75%, or
the
lateral width may be 100% thereof. Outlet openings of the extraction chamber
downstream of the channel and outside and adjacent the bulged portion drain
the
liquid food to the outlet.
The system can be a beverage dispensing machine with the outlet
configured for filling a drinking cup at a dispensing location. A hot water
supply with
a heater and a pump are preferably connected to inject the water into the
capsule.
An embodiment of the invention includes an opening member disposed
within the contour of the boundary wall and being configured for producing an
opening in the capsule when the capsule is pressurized. The opening member can
be
configured for piercing the capsule wall. The opening member may alternatively
be
configured for displacing a moveable openable portion from a closed
configuration in
which the openable portion closes the capsule to an open configuration in
which the
capsule is open to release the mixture.
A reservoir is preferably provided in the extraction chamber within the
boundary wall and in which the opening member is disposed. The reservoir is
disposed fluidly communicated upstream of the channel and configured for
receiving
the liquid mixture from the capsule and feeding the mixture to the channel and
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configured and dimensioned for allowing the maintenance of the supportive
association between capsule wall and the boundary wall when the capsule is
pressurized and the liquid is flowing out of the capsule. The reservoir allows
the
capsule to a opened without restricting the flow locally near the opening
location,
especially when the capsule is opened by piercing. The reservoir preferably
has a
lateral width of up to about 50% of the width of the bulge portion or of the
boundary
wall, and more preferably between about 1/4 and 1/16 of the width or diameter.
In a
preferred embodiment, the reservoir is round and has a diameter of about 1/8
inches
and a depth of about 1/8 inches. The preferred diameter or width is between
about
1/16 inches and 1/4 inches, and the depth is preferably between about 1/32
inches and
1/8 inches, in dispensers where single servings or cups of a beverage are
produced at a
time.
The channel is preferably open at one longitudinal side thereof, such as
the top side that is open to the interior of the extraction chamber, or if the
channel is
part of the cartridge, the side that faces out of the cartridge, although the
channel in
the cartridge may be provided in face thereof. The open side is preferably
closed
upon contact of the boundary wall with the wall of a food capsule or an
extraction
chamber, respectively, when the capsule is pressurized.
The channel is preferably open at one longitudinal side thereof, such as
the top side that is open to the interior of the extraction chamber, or if the
channel is
part of the cartridge, the side that faces out of the cartridge, although the
channel in
the cartridge may be provided in face thereof. The open side is preferably
closed
upon contact of the boundary wall with the wall of a food capsule or an
extraction
chamber, respectively, when the capsule is pressurized.
Other features and advantages of the invention will become apparent
from the following description in conjunction with the accompanying drawings
provided solely by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a cross-sectional diagrammatic view of the device and capsule
as positioned in the device in the beverage preparation stage;
Fig. 2 is a cross-sectional view of the holder of the device and the
capsule when inserted in the holder before closure of the device;
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Fig. 3 is a top view of the holder showing the beverage and foam
conditioner;
Fig. 4 is a perspective view of a capsule of the invention;
Fig. 5 is a perspective view of a used capsule after beverage
preparation;
Fig. 6 is a view of a capsule lid according to a variant of the invention;
Fig. 7 is a view of the capsule of Fig. 6 along line A-A;
Fig. 8 is a view of a capsule lid according to another variant of the
invention;
Fig. 9 is a view of the capsule of Fig. 8 along line B-B;
Fig. 10 is a cross-sectional view of a capsule according to another
variant of the invention;
Fig. 11 is a view of the inner layer of the discharge side of the capsule
of Fig. 10;
Fig. 12 is a view of the outer layer of the discharge side of the capsule
of Fig. 10;
Fig. 13 is a cross-sectional view of a capsule according to yet another
variant of the invention;
Fig. 14 is a view of the inner layer of the discharge side of the capsule
of Fig. 13;
Fig. 15 is a view of the outer layer of the discharge side of the capsule
of Fig. 13;
Fig. 16 illustrate a graph of typical profiles of pressure, water flow rate
and temperature during the preparation of a liquid food from a capsule and
device of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1 to 3, the invention illustrates a device 101 for
preparing a liquid food such as a beverage and the like from a single-use
capsule 102.
In this embodiment, the capsule 102 is a closed capsule that contains a dry
food,
preferably a substance that is soluble by addition of a diluent such as hot
water, milk
and the like to form a foamy, frothy beverage. Suitable foamy, frothy
beverages are,
for instance, coffee with crema, cappuccino with a milk based foamy head, late
or
cocoa. In the embodiment, the capsule 102 has a frustoconical shape with an
inverted
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cup part 120 and a lid part 121. The lid part 121 provides the discharge side
of the
capsule whereas the top 122 of the inverted cup part provides the entry side
of the
capsule. The cup part 120 has preferably a peripheral lip extending outwardly
onto
which is attached the edge of the lid part 121. The connection at the lip may
be
carried out by sealing or crimping or both. The shape of the capsule for the
general
purpose of the invention and the capsule could also take frustoellipsoidal,
frustospherical or cylindrical shapes, as well as other suitable shapes.
The device comprises a cup-shaped holder 110 adapted to receive the
capsule 102 in a suitable seat 111. The seat 111 has a bottom side comprising
beverage and foam conditioner 112 adapted to open the capsule 102 for release
of the
beverage and hold pressure within the capsule. More particularly, the beverage
and
foam conditioner comprise a bulged engaging member 114 that protrudes slightly
from the bottom surface 115 of the seat. The bulged engaging member 114 forms
an
engaging surface 116, as more apparent in Fig. 3, that is intended to snuggly
engage a
portion of the discharge side 121. The bulged engaging member has a general
rounded profile of preferably large average radius. The configuration and
geometry
of the bulged member should be determined in the perspective of creating a
tight
contact with the underside of the lid when the capsule is pressurized with
water
without risk of tearing off the lid material along the engaging surface. The
bulged
member may provide a contact against 20 to 99% of the total surface of the
discharge
side 121, preferably, 40 to 80% of the total surface. As preferred example,
the
bulged member has the following geometry: diameter "D" of from 20 to 70 mm,
average radius of from 30 to 150 mm, maximum height (relative to surface 15)
of
from 5 to 20 mm.
In the center of the bulged member 114 is located an opening member
140 in the form of a small pin or r~eedle that is intended to puncture a hole
in the lid
121 of the capsule in a precise location. The pin or needle is located in a
reservoir
141 that separates it from the engaging surface 116. The pin 140 may protrude
from
the bulged member or be flush with the bulged member or be even slightly inset
relative to the bulged member. If the pin protrudes from the bulged member,
the
capsule can be perforated, or starts partially being perforated, at the time
it is seated in
the holder by the user since the pin is the first part of the holder entering
into contact
with the lid. If the pin is flush or inset, the capsule opens by the effect of
the pressure
building up within the capsule. The pin is relatively thin, with a tip
configured for
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WO 2004/026091 PCT/EP2003/008455
puncturing the capsule, but preferably blunt enough to prevent the user from
getting
injured in case of contact with it. The pin's tip may be slightly rounded but
still
providing a suitable puncturing effect on the lid. More than one pin could be
provided to increase the opening if necessary.
The reservoir 141 that surrounds the opening member 140 serves as a
buffer part for the liquid to flow and to avoid blockage from the capsule
punctured
edges. The reservoir can be of a relatively small size, preferably 0.01 to 0.1
time the
diameter of the engaging bulged surface D and of a depth of from 0.01 to 0.5
times
the height of the bulged surface.
In order to release the pressure in a more controlled manner, channels
116 are provided at the surface of the bulged member 114 which preferably
extend
radially. The channels offer a privilege path for the liquid to flow between
the
engaging surface and the lid in a substantially radial direction. The channels
preferably extend from the reservoir to the peripheral line of the bulged
member as
better shown in Fig. 3. The channels are between 101 and 108, preferably 102
to 104.
The channels also produce additional shear stress on the liquid for increasing
the
production of froth on the liquid. Another equivalent pressure control device
could
replace the channels such as small corrugations or the rugosity of the bulged
member
could also be increased. The structure of the pressure control device should
preferably be such that it does not substantially tear the lid.
The beverage exiting the capsule 102 finds its way out of the holder
110 by outlets 117, 118 that are situated in the bottom wall of the outlet,
preferably at
or close to the periphery of the bulged member. Channels 116 may be
distributed in a
preferred way to direct the flow through the outlets 117, 118 but this is not
mandatory. The outlets could also be provided through the bulged member itself
and
made thinner and more numerous to replace the channels to create shearing on
the
liquid exiting the device.
Fig. 1 shows the capsule as in operational conditions of beverage
preparation when the device is closed in a fluid tight relation around the
capsule and
water flows within the enclosure of the capsule. The device comprises an upper
water
supply assembly 103 adapted to cooperate in closure with the lower holder 110.
A
cup or bell-shaped member 130 of the assembly 103 is arranged to engage in
closure
the sidewall 120 and top wall 122 of the capsule down to the sealing ring 150
of the
holder. More precisely, the lower edge of the member 130 holds on the lip 123
of the
CA 02498811 2005-03-11
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cup shaped part of the capsule against the ring 150 placed underneath the lip.
The
bell like member is securely attached to an upper base member 131 of the
assembly
that supports at its periphery attachment 134 of ramp type complementary to
the
bayonet type portion 119 of the lower holder 110.
The water supply is carried out by a needle like water injector 132
with water outlets 133 arranged in such a way that the water is injected a few
millimeter below the upper side 122 of the capsule and are thus remote from
the
pierced zone created by the penetration of the injector. The outlets may be
disposed
for directing water ejected from the injector at an outward orientation with a
positive
inclination angle 8 relative to the longitudinal axis of the injector so as to
promote
dispersion of water as well as a vortex effect inside the enclosure of the
capsule. In a
possible variant (not shown), water could, as well, be injected from the
sidewall of the
capsule in one or more points.
Upon closing of the water supply assembly, the lid of the capsule tends
to press on the bulged engaging surface so as to deform inwardly. Further
deformation and tight contact are obtained after water is injected within the
capsule
and pressure has started to build up inside. Such a tight fitting between the
discharge
side of the capsule and the device enables to control and retard release of
the beverage
by holding sufficient pressure within the capsule until the soluble substance
can
thoroughly mix with water by creation of turbulence and vortex and, therefore,
a
sufficient amount of gas can be entrapped as resulting from these turbulence
and
vortex for a certain time.
The pressure inside the capsule may vary from 1 to 15 bar, preferably 4
to 10 bar. A pressure of at least 4 bar should preferably be maintained of
from 10 to
30 seconds, preferably 10 to 20 seconds to enable the water and powder to
thoroughly
mix together and gas to be entrapped in the mixture in sufficient amount. The
pressure is maintained sufFciently within the range, as defined, by a pump of
the
device that compensates for some liquid draining through the discharge side.
However, the pressure can easily be maintained by the pump as resulting from
the
engaging surface retarding the liquid release in the cup. As the water pump is
stopped, pressure in the capsule drops and the engagement of the discharge
surface
and bulged member decreases, i.e., the contact between the lid 121 and the
dome
surface 116 is loosen, thus promoting complete draining of the residual liquid
food
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WO 2004/026091 PCT/EP2003/008455
through the opening of the discharge side. The profiles of pressure, water
flow rate
and temperature are shown in Fig. 16 as one achievable example.
Figs. 6 and 7 illustrate a possible variant of the capsule of the present
invention in a configuration wherein the discharge side 121 of the capsule
comprises
an integrated openable member 124 against which a finger 140 of the device can
act
in pushing engagement to release liquid from the capsule. More preferably, the
openable member is formed of at least one, preferably, a plurality of precut
lines or
slits 125. These precut lines or slits are adapted for release of the liquid
once a
pressure is exerted in the vicinity of them that would enlarge the section of
the lines or
slits. For example, these precut lines or slits 125 may be arranged to form a
geometrical pattern such as a circular pattern, with solid regions 126
inserted between
two adjacent precut lines or slits 125. Release of liquid is promoted by a
pressure
exerted by the finger having a smaller section against the openable member.
The
pressure exerted on the openable member tends to flex the openable member
inward
to enlarge the section of the slits sufficiently so that liquid mixture can
drain
therethrough. The dimension and configuration of the finger is determined to
achieve
a certain sufficient flexure of the openable member by the finger without
breaking of
the solid interconnecting regions so that the total opening area is sufficient
for liquid
release but maintained sufficiently small for creating shear stress and for
limiting the
risks of bits of material falling into the serving cup. The precut lines
should be of a
sufficiently small width, e.g., less than 200 microns, so that no significant
amount of
liquid could drain without a positive pressure exerted thereon by a finger of
the
device. In the present context, the "precut lines" refer to any local cutting
zone made
entirely or partially (e.g., weakening zones) through the thickness of the
material of
the discharge wall. If the precut lines are weakening zones, they should be
able to
break to form opening areas under the pressure exerted by the finger. The
capsule of
Figs. 6 and 7 is capable of fitting the beverage preparation device of Figs. 1
to 3,
possibly with the central puncturing tip being replaced by a non-puncturing
finger tip
of suitable length and diameter, or a rough textured surface, to achieve the
intended
release function.
Figs. 8 and 9 show another possible variant of the capsule with the lid
comprising a built-in passages) to control release of the liquid beverage at
the
interface between the engaging surface, e.g., the bulged member, and the
discharge
outer surface 121. These passages may comprise channels 127, 128 oriented from
the
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WO 2004/026091 PCT/EP2003/008455
vicinity of the openable member, preferably from a cutting line 125, in a
substantially
radial direction therefrom. The orientation of the channels promotes the exit
of the
liquid beyond the engaging surface to ensure a sufficient flow of liquid while
frothing
the liquid. The passages could also be formed by corrugations or similar
recessed or
protruding structures preferably oriented in a similar direction. The passages
on the
capsule's surface can replace partly or wholly the passages located on the
engaging
surface. The passages could also be provided in a puncturable capsule.
Figs. 10 to 12 show yet another embodiment of the capsule with a
discharge side or lid 121 comprising two adj acent layers 210, 211 sealed
along the
edge 123 of the capsule. Each layer has passages 212-214 for the beverage for
the
beverage to pass through the layers. The passages may include holes, slits or
similar
apertures. The passages 212, 213 of the W ternal layer are offset with respect
to the
passages 214 of the outer layer so as to create a tortuous path for the
beverage through
the discharge side 121. Channels 215, in shape of a straight line or any other
curve
configuration, may be added in one or the other internal surfaces of the
layers, e.g.,
the internal surface of the inner layer 210, to create shear and control the
desired
pressure inside the capsule. As a result of this variant, there is no need for
an opening
member of the device and product cross-contamination can be significantly
reduced
accordingly. The beverage and foam conditioner of the preparation device can
be
simplified since only the engaging surface, i.e., the bulged surface, is
retained to hold
on the discharge side 121, but the opening member and reservoir are removed.
Good
results could also be obtained without using an engaging surface to support
the
discharge side provided the discharge side is of sufficient rigidity to
support the
internal pressure without breaking or tearing at the channels. The elongated
channels
are thus sized to maintain a certain pressure in the capsule, to create shear
which
forms the required amount of foam and to condition the bubbles' sizes (i.e.,
let only
pass the thinner bubbles) in order to make a stable, dense and non "soapy"
foam. The
device may comprises a holding element on which the bottom edge of the capsule
can
take support while leaving the outlet 214 uncovered for a direct delivery of
the
beverage in the cup.
Figs. 13 to 15 show yet another embodiment in the same vain as the
one of Figs 22 to 24. A difference resides in the number and location of the
passages
216, 217 of the two layers. The inner layer rnay be built with only one
passage 216
while the outer layer may have a single passage 217, both passages 216, 217
being
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WO 2004/026091 PCT/EP2003/008455
transversally offset one another. Good results could also be obtained without
supporting the discharge side with an engaging surface provided the discharge
side is
of sufficient rigidity to support the internal pressure without breaking at
the channels.
In that case, the device comprises a holding element on which the bottom edge
of the
capsule can take support while leaving the outlet 217 uncovered for a direct
delivery
of the beverage in the cup.
While illustrative embodiments of the invention are disclosed herein, it
will be appreciated that numerous modifications and other embodiments may be
devised by those skilled in the art. Therefore, it will be understood that the
appended
claims are intended to cover all such modifications and embodiments that come
within the spirit and scope of the present invention.
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