HK1180925B

HK1180925B - Method for brewing beverage and cartridge containing infusible material

Info

Publication number: HK1180925B
Application number: HK13108141.6A
Authority: HK
Inventors: Anthony Edward Quinn; Osvaldo Maffei; Robert Wim Bronwasser; Raffaele Zandona
Original assignee: 埃卡特拉研究与开发英国有限公司
Priority date: 2010-07-14
Filing date: 2011-06-23
Publication date: 2017-11-24

Description

Method for brewing a beverage and cartridge containing infusible material

Technical Field

The present invention relates to a method for brewing a beverage in a brewing chamber having a removable cartridge containing an infusible ingredient. Furthermore, the invention relates to a cartridge for preparing a beverage. The invention also relates to an apparatus suitable for preparing a beverage using the cartridge of the invention.

Background

Apart from water, tea is the most widely consumed of all beverages. The global average human consumption of tea is estimated to be 0.1 litres/day. In addition, other brewed beverages such as fruit infusions, iced tea and coffee are increasingly consumed worldwide. In western countries, brewed beverages are often prepared at home, but there is an increasing trend for consumers to consume such beverages outside of home (e.g., at cafes and bars). Tea bags are a widely used solution for providing hot tea in these environments-longer brewing times and mess after brewing are barriers to consuming hot tea outside the home. Therefore, there is a need for alternative brewing methods, especially for the outside-home market.

Brewing devices for preparing coffee, tea, chocolate or any other beverage are known in the art.

WO2007/042485a1 discloses a device for brewing a beverage comprising an infusion container and a cartridge containing an infusible substance. The cartridge may be connected to the infusion container. An openable and closable passage is located below the cartridge, forming an air-tight connection between the infusion container and the passage.

WO88/02612 describes a brewing device comprising an infusion chamber with a movable base, and the base is provided with a filter. The device is provided with an air pump that can draw air up through the filter into the chamber during steeping, or can be used to pressurize the steeping chamber for discharging steeped liquid through the filter.

WO02/43540a1 discloses a tea brewing machine having a housing, a vessel for receiving leaf tea, a hot water supply for supplying hot water to the vessel, means for physically agitating the leaf tea within the vessel to maximise the rate and extent of infusion, and a siphon structure for siphoning the infusion out of the vessel prior to dispensing. In one embodiment, the hot water is pumped into the brew vessel as a jet of water.

US2007/0034083a1 discloses a brewing device for preparing brewed products and infusions such as coffee, tea, roasted barley coffee, camomile tea and the like. In one embodiment, hot water contained in the hopper flows downward through the valve to create an umbrella effect to force the downward flowing water against the walls of the brew chamber to elute them from the brew residue.

GB2217976A discloses an apparatus for brewing beverages in which an infusible ingredient is introduced into a container having a filter base. The piston pushes air through the filter to agitate the ingredients and water and after brewing draws out the brew while retaining the infusible ingredients on the filter.

Additionally, cartridges or containers containing infusible material are known in the art. They generally provide a convenient and quick way of brewing a beverage such as coffee or tea for consumer use. The cartridge or container is typically designed for a single use and is discarded after the beverage is brewed. Typically, the cartridge is used in conjunction with a brewing device that is particularly suited to the particular cartridge. A good example of a popular coffee containing cartridge is the Nespresso coffee cartridge. Typically, the cartridge or container serves as the brew chamber and filter: the solids remain in the cartridge and they are not released from the cartridge.

EP808598a1 discloses a cartridge containing ground coffee, which is connectable to the bottom of a holder; the holder is filled with hot water and the coffee is brewed by dripping water through the cartridge. The ground coffee is retained in the cartridge.

EP1440913a1 discloses a cartridge containing a beverage ingredient in a storage chamber. The aqueous medium may flow into the cartridge, come into contact with the beverage ingredients, and exit the cartridge through the hole in the pierceable closure. The beverage ingredients may be soluble or insoluble and may be used to prepare a cup of coffee, tea, chocolate or milk beverage.

WO03/073896a1 discloses a sealed container for extracting water-soluble contents, in particular for brewing coffee. To brew a beverage, an orifice is passed through the upper lid to inject hot water and steam into the container. The body of the container provides both a function of filtering the contents and a function of discharging the extracted liquid.

WO2009/081427a1 discloses a filter for use in an apparatus for preparing hot beverages. The container is connected to a boiler in which the water is heated. Between these two elements a filter unit containing ground coffee is positioned. Water from the boiler is forced upwards through the filter into the upper container, into which the beverage is introduced, and wherein the filter unit retains the ground coffee inside the filter unit.

This system has several disadvantages that will be addressed by the present invention. Existing systems typically include a cylindrical brewing chamber into which product is introduced at one end (top) and from which leaf residue is removed from the other end (bottom). Often, the bottom of the infusion chamber consists of a sieve or filter which is cleaned after infusion. The use of such systems to brew multiple varieties of infusions, such as black tea, flavored tea and herbal infusions sequentially through the same brewer can result in tainting of flavors from one brew to the next. In addition, when the leaves are introduced from the top, the product may get stuck above the water level, resulting in waste and tainting of the leaves.

Alternatively, there are systems for brewing beverages in disposable packages. Taint is minimized when brewing beverage liquid in the package and the package with the leaves is subsequently discarded. Since the package is smaller than the final cup volume, the water must flow through the package-the ratio of leaves to water is limited, just as the contact time between the leaves and the water is limited. Therefore, only very fine chopped leaves can be used.

Third, existing systems typically have a significant length of tubing between the filter and the point at which the soaked liquid is dispensed. This carries a large internal surface area and due to its configuration (e.g., U-tubes and other non-drainable areas) may be difficult to effectively flush between infusions.

Finally, existing devices may contain one or more valves or other mechanical elements that come into contact with the brewed beverage. The inclusion of such movable elements in the device is disadvantageous as each mechanically movable element in the device is eventually worn and may break. Furthermore, such elements, when in contact with the brewed beverage, may still contain traces of the brewed beverage or precipitates from the beverage, which are difficult to remove even after rinsing. Such deposits can cause tainting of flavour from one brew to another, since when a second brew is released from the brew chamber into the cup, (part of) the deposits from the first brew that are attached to the movable part may be flushed into the cup with the second brew. This is disadvantageous because a perfect beverage without the taste from a previous brew will not be provided to the consumer.

Disclosure of Invention

It is therefore an object of the present invention to provide a method for brewing a beverage that overcomes the drawbacks of the prior art as referred to above, and a cartridge that can be used in the method and contains infusible material from which the beverage is to be brewed.

The present invention overcomes these disadvantages by providing a method for brewing a beverage using a brewing machine equipped with a brewing chamber that is open at the bottom. The brew chamber may be closed at the bottom by a removable cartridge containing infusible material to brew the beverage. The cartridge is introduced into the brew chamber by connecting the cartridge to the brew chamber. The cartridge contains an opening in a bottom portion that includes a filter. The cartridge serves as the bottom of the brewing chamber during the brewing process. Gas introduced into the brewing chamber through the opening of the cartridge causes agitation of the infusible material in the water, resulting in an efficient brewing process. After the brewing process is complete, the brewed beverage is discharged through the opening and infusible material is retained on the filter. After this process, the cartridge may be removed from the brew chamber.

As a further advantage, the brewing device does not contain movable valves and other movable apparatus parts that come into contact with the brewed beverage and may break during use over time. Furthermore, the need for mechanical valves or U-tubes, siphons positioned after the filter is eliminated. In addition, a funnel for emptying the brew chamber to fill a cup or jug or jar is not required, as the beverage can be dispensed directly through the filter of the cartridge. In addition, fewer parts of the apparatus need to be cleaned between infusions, which is advantageous because less cleaning time is required and because of reduced taint between infusions of different tastes and flavors.

A further advantage of the method according to the invention is that all infusible material is introduced and mixed with water. Furthermore, all infusible material is removed from the infusion chamber after infusion. As the screen is integrated into the cartridge, cross-flavor between the various infused products is limited. The cartridge forms an integral and unitary part of the brew chamber. No additional cleaning means other than rinsing is required.

With reference to fig. 1, without limitation, in a first aspect, the invention provides a method for brewing a beverage in a brewing apparatus, wherein the apparatus comprises a brewing chamber 21, the brewing chamber 21 comprising a side wall 22, a bottom rim 25, a top wall 23 and an opening 24, the method comprising the steps of:

a) the top rim 3 of the cartridge 1 containing the infusible granular ingredient 2 is connected to the bottom rim 25 of the infusion chamber,

so that a watertight connection is achieved;

wherein the cartridge 1 comprises side walls 4 and a bottom wall 5 and is made of a water impermeable material,

and wherein the bottom wall comprises an opening 6 and a filter 7;

b) drawing gas out of the infusion chamber through the opening 24 and simultaneously through the opening 6 and the filter 7 of the capsule;

c) at least partially simultaneously with step b) filling the infusion chamber with water through the inlet 26 and infusing the beverage by mixing the water and the infusible particulate material 2 in the infusion chamber 21; and

d) the extraction of gas from the infusion chamber is ended and the infused beverage is discharged through the opening 6 and the filter 7.

With reference to figures 2 to 11, which are non-limiting, in a second aspect, the invention provides a cartridge for connection to an infusion chamber for infusing a beverage, comprising a first element 51 and a second element 71,

wherein the first element 51 comprises a side wall 52 and a bottom wall 53,

wherein the side wall 52 and the bottom wall 53 are made of a water-impermeable material,

wherein the bottom wall 53 comprises a protuberance 54 directed towards the outside of the first element 51,

wherein the bottom wall includes an opening 55,

wherein the opening includes a water permeable filter 56,

wherein the top is optionally closable by a seal 58, wherein the seal 58 is attachable to an upper edge 59 of the sidewall 52,

and wherein the bottom wall 53 comprises one or more recesses 60 directed towards the inside of the first element 51,

and wherein, the second member 71 comprises a bottom wall 72,

wherein the bottom wall 72 is made of a water-impermeable material,

wherein the bottom wall 72 includes an opening 73 that can interlock with the ridge 54, to form a water tight connection,

wherein the bottom wall 72 comprises one or more protuberances 74 capable of interlocking with a corresponding one or more recesses 60,

and wherein the second element 71 is movable relative to the first element 51 about the corresponding notch 60 and protuberance 74.

With reference to figures 2 to 11, which are not limitative, in a preferred embodiment of the first aspect of the invention, the invention also provides a method for brewing a beverage in a brewing apparatus using a cartridge according to the first aspect of the invention, wherein the apparatus comprises a brewing chamber 21 and means for connecting the cartridge to the brewing chamber, the brewing chamber 21 comprising a side wall 22, a bottom rim 25, a top wall 23 and an opening 24,

the method comprises the following steps:

a) optionally, the seal 58 is released from the cartridge,

wherein the protuberance 54 of the first element 51 is interconnected with the opening 73 of the second element 71 to close the bottom wall 53 of the first element 51;

b) placing the cartridge into the brewing machine and connecting the top edge 59 of the first element of the cartridge to the bottom edge 25 of the brew chamber such that a water-tight connection is achieved;

c) optionally, prior to or simultaneously with step b), moving the second element 71 of the cartridge relative to the first element 51 of the cartridge such that the filter 56 is exposed to the atmosphere;

d) drawing gas out of the brew chamber through the opening 24 or through the optional opening 26 and simultaneously drawing gas into the brew chamber through the opening 55 of the cartridge and the filter 56;

e) at least partially simultaneously with step d) filling the infusion chamber 21 with water and infusing the beverage by mixing the water with infusible particulate material in the infusion chamber 21; and

f) the extraction of gas from the infusion chamber is terminated and the infused beverage is discharged through the opening 55.

With reference to figures 2 to 11, which are non-limiting, in a third aspect, the invention provides an apparatus for brewing a beverage using a cartridge according to the second aspect of the invention, the apparatus comprising a brewing chamber and means for connecting the cartridge to the brewing chamber such that a water-tight connection is formed, and

means for moving the second element 71 of the cartridge relative to the first element 51 of the cartridge about the respective recess 60 and protuberance 74,

wherein the device comprises a retainer which fits in a gap 75 between the first element 51 and the second element 71, and

wherein the retainer is movable relative to the first member 51 to increase the width of the gap 75 between the first member 51 and the second member 71.

Referring to non-limiting fig. 2 to 11, in a fourth aspect, the present invention provides a method for opening a cartridge according to the second aspect of the invention, wherein the protuberance 54 of the first element 51 of the cartridge is interconnected with the opening 73 of the second element 71 to close the bottom wall 53 of the first element 51, wherein the second element 71 moves from the first element 51 about the corresponding recess 60 and protuberance 74 to expose the filter 56 to the atmosphere.

Drawings

The following drawings illustrate the invention and are not to be construed as limiting the invention.

Figure 1 is a schematic view of an infusion chamber and cartridge for use in a method according to a first aspect of the invention.

Figure 2 is a side view of a preferred cartridge according to the second aspect of the invention.

Figure 3 is a top plan view of a preferred cartridge according to the second aspect of the present invention.

Figure 4 is a bottom view of a preferred cartridge according to the second aspect of the present invention.

Figure 5 is a side view of a preferred cartridge according to the second aspect of the present invention, taken at the line a-a' indicated in figure 3. In the closed position so that the protuberance 54 closes the opening 7).

Figure 6 is a side view of a preferred cartridge according to the second aspect of the present invention, taken at the line a-a' indicated in figure 3. In the open position so that the protuberance 54 does not close the opening 73.

Figure 7 is a bottom view of the first element 51 of a preferred cartridge according to the second aspect of the present invention.

Figure 8 is a detailed view of the protuberance 74 of the second element 71 and the recess 60 of the first element 51 of the preferred cartridge according to the second aspect of the present invention.

Figure 9 is a detailed view of the protuberance 74 of the second element 71 and the recess 60 of the first element 51 of the preferred cartridge according to the second aspect of the present invention; in the closed position; including element 77.

Figure 10 is a detailed view of the protuberance 74 of the second element 71 and the recess 60 of the first element 51 of the preferred cartridge according to the second aspect of the present invention; in the open position; contains an element 77 that prevents the second member 71 from moving upward relative to the first member 51.

Figure 11 is a detailed view of the protuberance 74 of the second element 71 and the recess 60 of the first element 51 of the preferred cartridge according to the second aspect of the present invention; in the open position; notches 78 that fit in holes 63 and 64 prevent second member 71 from moving upward relative to first member 51.

Definition of

Unless defined otherwise, all scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. All percentages are by weight unless otherwise indicated.

Any numerical range indicated herein is intended to include the corresponding endpoints, unless otherwise indicated. The gas flow referred to herein is determined under normal conditions (at a pressure of 1 atmosphere =101,325 Pa). All numbers expressing quantities of materials or temperatures used in the specification are to be understood as being modified, optionally, by the word "about".

Beverage preparation: as used herein, the term "beverage" refers to a substantially aqueous drinkable composition suitable for human consumption. Preferably, the beverage comprises at least 85% water, more preferably at least 90%, and most preferably from 95 to 99.9% by weight of the beverage.

The soakable material is: as used herein, the term "infusible material" refers to a substance that, when mixed with an aqueous liquid, releases some substance into the liquid thereby forming a beverage.

And (3) brewing: as used herein, the term "brewing" refers to adding liquid to infusible material to form a beverage. The brewing can be performed at any temperature. Soaking liquid: as used herein, the term "brew" refers to a beverage formed as a result of a brewing process by which certain substances are released from infusible material into a liquid, thereby forming a brew.

Stirring: as used herein, the term "agitation" refers to the process used to mix the infusible material and the liquid. Agitation may be achieved by mechanical means (e.g. by agitation) or by the action of water (herein referred to as "water agitation") or by the action of air (herein referred to as "air agitation").

Washing: as used herein, the term "flush" refers to the removal of infusible material or brewing liquid residue from any equipment associated with the brewing process, particularly the brewing chamber.

Tea: as used herein, the term "tea" refers to leaf material from the species camellia sinensis or assam tea from the species castanopsis sclerophylla. It also includes Leiboga tea available from Aspalatum lineate. "tea" is also intended to include products of blending any two or more of these teas. The leaf material may be substantially fermented (i.e. black tea), semi-fermented (i.e. oolong tea) or substantially unfermented (i.e. green tea). The tea may be flavoured and/or flavoured tea.

Leaf tea: as used herein, the term "leaf tea" refers to a tea product comprising one or more tea sources in substantially un-infused form.

Tea-based beverage: as used herein, the term "tea-based beverage" refers to a beverage comprising at least 0.01% by weight tea solids. Preferably, the tea-based beverage comprises from 0.04 to 3 wt% tea solids, more preferably from 0.06 to 2 wt%, most preferably from 0.1 to 1 wt%.

Tangential direction: as used herein, the term "tangential" has the same meaning as understood by those skilled in the art, i.e., it refers to a line that can be drawn on a curve at any given point, the line being a straight line that touches the curve at that point. In the simplest example of a curve (i.e., a circle), any straight line that touches the curve at an angle of 90 degrees to the radius is "tangential". The term "substantially tangential" refers to a line that touches a curve within 15 degrees, preferably within 10 degrees, most preferably within 5 degrees of a line that is tangential to the curve.

Infusible material particle size and grade:

for the purposes of the present invention, the infusible material particle size is characterized by a mesh size using the following convention: taylor mesh size is used throughout; the "+" before the mesh indicates the particles retained by the screen; the "-" before the screen mesh indicates the particles passing through the screen mesh. For example, if the particle size is described as-5 +20 mesh, the particles will pass through a 5 mesh screen (particles less than about 4.0 mm) and will be retained by a 20 mesh screen (particles greater than about 841 microns).

Leaf particle size may additionally or alternatively be characterized using the grades listed in international standard ISO 6078-. These ratings are discussed in detail in our european patent specification EP 1365657B1 (especially paragraph [0041] and table 2), which is incorporated herein by reference.

Detailed Description

Method for brewing a beverage

so that a watertight connection is achieved;

and wherein the bottom wall comprises an opening 6 and a filter 7;

Referring to non-limiting fig. 1, the brew chamber 21 includes a side wall 22, the side wall 22 being positionable substantially vertical, but deviations from the vertical position are within the scope of the present invention. The side wall 22 may be straight or curved, or may take any shape suitable for the infusion chamber and attractive to the consumer or operator. The infusion chamber 21 can have any suitable shape, preferably it has a cylindrical shape with a circular top. The top wall 23 may be secured to the side wall 21, or it may be a loose top cover that may be connected to the side wall 22 and cover the brew chamber. The top wall may be a lid connectable to the top edge of the wall 21. The infusion chamber 21 has no bottom wall: in the method according to the invention, the cartridge 1 with infusible material 2 can be connected to the infusion chamber 21 and can thus become an integral part of the infusion chamber. The cartridge is removable from the brew chamber.

In the context of the present invention, "connecting the cartridge to the infusion chamber" or "connection between the cartridge and the infusion chamber" is to be understood as having the broadest possible meaning. The linkage may have the following meanings: the cartridge is joined to the infusion chamber, for example, by tightly securing the cartridge to the infusion chamber using clamps to form a leak-free seal between the cartridge and the infusion chamber, or by any other mechanical means. The linkage may also have the following meanings: the cartridge is joined with the brewing chamber by pressing the top edge of the cartridge against the lower edge of the brewing chamber by exerting a force on the cartridge to form a leak-free seal between the cartridge and the brewing chamber.

A brewing apparatus suitable for performing the method according to the first aspect of the present invention preferably further comprises an air pump and connecting means between the opening 24 and the air pump. The opening 24 may be located in the side wall 22 of the infusion chamber or in a lid or top 23 of the infusion chamber. Preferably, the opening 24 is located above the normal beverage level in the brew chamber so that no liquid is drawn out when gas is withdrawn from the headspace. The connection means between the opening 24 and the air pump may comprise one or more pipes, valves, tubes, connectors, valves and other devices known to the skilled person. Preferably, the air pump is capable of either drawing air out of the brew chamber or blowing air into the brew chamber.

The infusion chamber can be made of any material suitable for use in the preparation of infused hot beverages. Preferably, the infusion chamber is made of glass or plastic material or metal. Preferably, the brewing chamber comprises a transparent side wall 22, so that the brewing process is visible to the operator or consumer. Thus, the side walls of the infusion chamber are preferably made of glass, plexiglass, pyrex or other transparent heat-resistant plastic. The material is preferably not deformed when water is added to the infusion chamber, so as to prevent leakage at the connection between the infusion chamber and the cartridge. The volume of the brew chamber is not limited to a particular size. Preferably, however, the volume is about the same as the volume of a single cup of beverage, i.e. about 150 to about 350 ml, preferably between 200 and 300 ml. The size of the infusion chamber (including the volume of the cartridge) is chosen so that the infusion chamber can also contain bubbles formed by the suction of gas through the openings 6 during the infusion process. In addition, the volume of the brew chamber is selected such that water does not flow out of the brew chamber through the openings 24 and/or 26. The infusion chamber is preferably cylindrical in shape, having a circular cross section and a vertical wall 22. Alternatively, the wall 22 may be conical, with the diameter being greater at the top than at the bottom, or vice versa. The brew chamber may also have a waist, or may be wider in the middle than at the top and bottom.

By introducing the cartridge into the brewing chamber, the cartridge becomes an integral part of the brewing chamber and it will form the bottom section of the brewing chamber. Thus, the material from which the cartridge is made has properties suitable for use in connection with a brewing process. For example, if the beverage to be brewed is tea, the cartridge should be capable of withstanding a temperature of at least 100 ℃ for a period of time of preferably at least 10 minutes, more preferably at least 5 minutes. This requirement limits the materials suitable for use in the manufacture of the cartridge. For example, materials like plastics having a softening or melting point below 100 ℃ are not suitable as cartridge materials. In addition, the material of the cartridge may be selected such that it does not deform when water is added to the brew chamber, so as to prevent leakage at the connection between the brew chamber and the cartridge.

The top rim 3 of the cartridge 1 may be attached to the bottom rim 25 of the brew chamber by any suitable closure means, provided that a water-tight connection is achieved. Examples of such closure means are bayonet closures (bayonetcclosure) or screw closures. Alternatively, the cartridge may be connected to or separated from the brewing chamber by means of movement in a direction parallel or substantially parallel to the bottom edge of the brewing chamber. In this case, the bottom rim may comprise one or more holders or clamps in which the cartridge is fitted, which ensure a watertight connection between the top rim 3 of the cartridge and the bottom rim 25 of the infusion chamber. The watertight connection may be achieved using a flat silicone seal, an O-ring or a cartridge-embedded seal, or any other sealing method known to those skilled in the art for achieving a watertight connection. Alternatively, the connection may be achieved by pressing the cartridge firmly against the brewing chamber such that a leak-free seal is formed between the cartridge and the brewing chamber.

Preferably, the cartridge has a disc shape. The cartridge is preferably a disposable package, but may also be a reusable element. The cartridge may be closed at the top side using a seal, for example a seal made of aluminium foil or laminated aluminium/PE foil sealed to the top rim 3 of the cartridge 1. The seal may be a peel seal preferably having a thickness of less than 100 microns. If the optional seal is an aluminium/PE foil, the aluminium layer is at the top and the PE layer is in contact with the flange of the cartridge. The sealing method may be heat sealing, ultrasonic sealing, or an adhesive may be used. Preferably, the top rim 3 of the cartridge comprises a flange which can be used to attach an optional top seal to the cartridge. Preferably, the seal is removed from the cartridge by pulling on a lip which is attached to the flange and can be easily broken away from the flange, and a lip portion of the seal is attached to the lip so that when the lip is torn off the flange, the seal is also simultaneously peeled off the cartridge. Such a top rim 3 with an optional flange may also play a role in attaching the top rim 3 of the cartridge to the bottom rim 25 of the brew chamber. The brewing apparatus may be provided with means for fastening the flange to the bottom rim of the brewing chamber. These means may be, for example, clamps, or may be a press for pressing the cartridge against the infusion chamber.

If the cartridge is closed by the seal, the seal is removed prior to connecting the cartridge to the brew chamber. Such removal of the top seal may be performed manually, for example, by a brewing machine operator. Alternatively, the apparatus may be designed such that the seal is removed with the appliance of the apparatus prior to connecting the top rim 3 of the cartridge 1 to the bottom rim 25 of the brew chamber 21.

In addition, the bottom portion of the cartridge may be sealed so that the filter 7 is covered and protected from external conditions until use. The optional seal may be made of the same material as the optional top seal and may be attached to the bottom portion similar to the attachment of the optional top seal. The optional seal keeps the infusible material of the package fresh and also in the cartridge during shipping and other handling. Such optional seal should be removed before the cartridge is used in the method according to the invention.

Instead of sealing the bottom of the cartridge, the cartridge may be packaged in a closed single package and the infusible material kept fresh. The package may be made of any material suitable for use with a soakable material, for example, plastic such as polyethylene or aluminum, including laminates of plastic and aluminum.

Alternatively, the opening 6 of the cartridge 1 may be closed by a second element of the cartridge which is connected to the cartridge and is movable relative to the first element of the cartridge. Such a cartridge would be opened by moving the second element away from the first element to expose the filter 7 to the exterior in order to open the cartridge before it would be used in a method according to the first aspect of the invention.

When used inside a brewing apparatus, the bottom wall 5 of the cartridge 1 and the filter 7 may be substantially flat and/or horizontal. Alternatively, the surface may be inclined towards the centre of the bottom wall 5 so as to form a cone for guiding the brewed beverage firstly through the filter and secondly through the opening 6. Such a shape may also facilitate mixing and flow patterns inside the brewing chamber.

The cartridge is dimensioned so that the top rim 3 fits to the bottom rim 25 of the infusion chamber. Preferably, the cartridge is disc-shaped. The height or thickness of the cartridge is preferably about 0.5 to 3 cm, preferably between 1 and 2 cm, and it depends primarily on the dry volume of infusible material that needs to be contained in the cartridge. The internal volume of the cartridge is preferably in the range from 5 to 50 ml, preferably from 10 to 40 ml. The size and volume of the cartridge is not only dependent on the size of the brew chamber. The cartridge should also have an internal volume such that it can contain sufficient dry infusible material for preparing a quality beverage, and on the other hand, should be able to retain used infusible material that remains on the filter 7 after discharge of the brewed beverage.

Depending on the material from which the cartridge is made, the thickness of the walls 4 and base 5 will preferably be in the range between 0.1 and 2 mm, preferably between 0.5 and 1.5mm, most preferably between 0.7 and 0.9 mm. Preferably, the material from which the cartridge is made comprises polypropylene (PP), for example a PP/PET laminate, more preferably it comprises polypropylene homopolymer. Alternatively, the cartridge comprises aluminium.

The size of the opening 6 depends on the one hand that the opening should be wide enough to discharge the brewed beverage and on the other hand small enough to retain the liquid during the brewing process by sucking gas through the opening 6 without dripping. Therefore, it is necessary to closely match the capacity of the preferred gas pump capable of withdrawing gas from the headspace. In addition, the size of the filter 7 determines this interaction.

The filter 7 in the cartridge is designed such that infusible material remains in the filter when the brewed beverage is discharged, so that the beverage provided to the consumer is a clear liquid. The filter 7 may be made of any suitable material that can withstand the conditions normally applied for brewing beverages. For example, if the beverage to be brewed is tea, the filter should be able to withstand a temperature of at least 100 ℃. This requirement limits the materials suitable for use in making the filter. For example, materials like plastics having a softening or melting point below 100 ℃ are not suitable as filter materials. Suitable materials are for example the same as those used for the walls and bottom of the cartridge.

The filter 7 may be an integral part of the cartridge. For example, if the cartridge is made of a plastics material and is prepared by a moulding process, the filter may be moulded as an integral part of the cartridge together with the walls 4 and base 5 of the cartridge. Preferably, this means that the filter 7 may be a flat plate with holes. Alternatively, the filter may be secured into the cartridge after the walls 4 and bottom 5 have been prepared, for example by gluing a woven cloth or film to the bottom 5 to cover the opening 6. In this case, the filter may be a flexible material, such as a woven, non-woven or perforated film.

Most preferably, the filter 7 is integrally moulded in the cartridge as part of the base 5, and preferably the filter material is the same as the construction material of the base 5 of the cartridge. In another preferred embodiment the filter 7 is made of the same material as a conventional tea bag, e.g. cellulose with a PET/PP layer, or woven or non-woven PET.

The filter openings are sized so that the filter effectively retains the used infusible material after the brewing process. The shape of the pores in the filter may take any shape, for example, channels having a square or rectangular or octagonal cross-section. Alternatively, the channel may be shaped as a cylinder with a circular or elliptical cross-section. Alternatively, the aperture in the filter may be a channel having a conical shape with the wider opening of the cone being in the interior of the filter (which is defined as the area of the filter surface facing the interior of the cartridge and in contact with the infusible material), or vice versa (the wider opening being outside the filter). Alternatively, the bore may also be shaped as a cylinder with a waist. The shape of the filter pores depends on the desired flow rate of the beverage and the flow conditions at the time of discharge of the beverage. Furthermore, the size of the filter pores may depend on the size of the infusible particulate material used to brew the beverage. If the infusible particulate material has a relatively small particle size, the desired size of the filter pores is also relatively small, and vice versa. This means that the size of the filter pores is preferably between 0.1 and 1 mm. This may for example result in filter pores of between 0.25 and 0.35 mm, or between 0.4 and 0.9 mm, or between 0.5 and 0.7 mm, or between 0.8 and 1.0 mm, or any other dimension between 0.1 and 1 mm, inclusive. The shape of the holes in the filter may be square, rectangular, circular, octagonal or any other suitable shape. In this context, the size of the filter pores is understood to mean the largest cross-sectional dimension of the filter pores. For example, for a circular shape this represents the diameter, and for a rectangular shape this represents the length of the diagonal between two opposing corners.

Preferably, the filter is an integral part of the base of the cartridge and is integrally moulded in the base of the cartridge by a moulding process. In this case, the cartridge and the filter are made of the same material. Most preferably, the thickness of the bottom 5 of the cartridge is about 0.8 mm. In a preferred embodiment, the filter 7 in the bottom part comprises a cylindrical hole with a waist, wherein the diameter of the filter hole is about 0.9 to 1.0 mm, preferably about 0.95 mm, at the top side of the bottom part 5 (inside the cartridge); wherein the diameter of the waist is 0.7 to 0.9 mm, preferably about 0.8 mm; and wherein the diameter of the filter pores is about 0.9 to 1.0 mm, preferably about 0.95 mm, at the bottom side of the bottom 5 (outside the cartridge). The waist is preferably located at the middle of the bottom wall. The total cross-sectional area of the filter apertures of the cartridge is preferably between 1 and 4 square centimetres, more preferably between 1.5 and 3.5 square centimetres, most preferably between 2 and 3 square centimetres. The number of holes depends on the size of the holes and is preferably between 200 and 1000, more preferably between 300 and 900, most preferably between 400 and 800.

In another preferred embodiment, the filter 7 in the bottom part comprises a cylindrical hole with a waist, wherein the diameter of the filter hole is about 0.65 to 0.8mm, preferably about 0.75 mm, at the top side of the bottom part 5 (inside the cartridge); wherein the diameter of the waist is 0.5 to 0.65 mm, preferably about 0.6 mm; and wherein the diameter of the filter pores is about 0.65 to 0.8mm, preferably about 0.75 mm, at the bottom side of the bottom 5 (outside the cartridge). The waist is preferably located at the middle of the bottom wall. In the case of small filter pore sizes, the required number of pores may be greater than with relatively large filter pore sizes in order to have a sufficiently large surface area for the beverage to be discharged after brewing.

These preferred dimensions of the filter holes are determined with respect to the infusion chamber, the volume of which is about the same as the volume of a single cup of beverage, i.e. about 150 to 350 ml, preferably between 200 and 300 ml. In the case of a brewing chamber with a greater or lesser volume, the required cross-sectional area of the corresponding filter will increase or decrease.

Preferably, the gas that is drawn out of the headspace of the infusion chamber in step b) is drawn out by a gas pump, which is preferably integrated into the infusion apparatus together with the connection between the headspace and the gas pump. The gas flow rate of the preferred gas pump capable of pumping gas out of the headspace of the brewing chamber in step b) should be such that the flow rate of gas subsequently drawn into the brewing chamber prevents the beverage from dripping out of the opening 6 before the gas flow is finished. Thus, there is an interplay between the gas flow rate, the volume of the brew chamber, and the cross-sectional area of the filter aperture. Preferably, the gas flow rate of the unloaded pump is between 2 and 10 litres/minute, preferably between 3 and 8 litres/minute, more preferably between 4 and 6 litres/minute (all at a pressure of 1 atmosphere). As soon as gas is extracted from the head space of the infusion chamber in step b), gas is sucked into the infusion chamber through the opening 6 and the filter 7 to prevent underpressure in the infusion chamber.

In step c) of the method according to the first aspect of the invention water is introduced into the infusion chamber. This introduction of water is at least partially simultaneous with the withdrawal of gas from the infusion chamber in step b). This means that the introduction of water in step c) can be started at the same time as the extraction of gas from the infusion chamber in step b) is started. Step c) may also be started later than step b). The addition of water to the brew chamber may be stopped earlier than and at the same time as the end of the extraction of gas from the headspace in step d). While the water is inside the brewing chamber, the brewing process starts in step c), as the infusible material is extracted by the water.

By drawing gas out of the headspace of the brew chamber, gas is drawn in simultaneously through the opening 6 of the cartridge and the filter 7. This results in the formation of bubbles rising in the infusion liquid when the infusion chamber is filled with water, preferably hot water, while gas is being inhaled. The bubbles cause agitation of the brew in the brew chamber. The flow of the brewing liquid and the bubbles causes an upwelling of infusible material resulting in mixing of the ingredients with the brewing liquid to facilitate and improve the infusion process. In addition, the infusible material is also mixed with the water by filling the brew chamber with water, resulting in a flow of water from the openings 24 and/or 26 to the cartridge and thus rotation of the infusible material due to the flow of water. This results in infusible material being discharged from the cartridge and mixed with water, thereby optimizing brewing efficiency. Furthermore, the gas drawn through the opening 6 of the cartridge also retains the beverage in the brew chamber, as the flow of gas into the cartridge from the bottom prevents the beverage from leaking through the opening 6.

Preferably, at the start of the brewing process, the flow of gas out of the headspace is relatively high so as to cause the infusible material in the cartridge to spin up and mix with the water. During brewing, the gas flow may be reduced, as mixing will continue with a smaller gas flow. This method saves energy compared to maintaining the gas flow at a continuous high flow rate. In the case where the infusion chamber has a volume preferably between 150 and 350 ml and the holes in the filter 7 have a cross-sectional area between 1 and 4 square centimetres, the initial gas flow is preferably between 4 and 6 litres/minute, then reduced to preferably 2 to 4 litres/minute (all at a pressure of 1 atmosphere).

The water added to the infusion chamber in step c) of the method of the invention will generally be warm or hot water. In the context of the present invention, this means that the temperature of the water when added to the infusion chamber is preferably between 80 ℃ and 100 ℃, more preferably between 85 ℃ and 95 ℃. Preferably, the water will be heated in a boiler present inside the brewing device. The water can also be heated in an external boiler before being supplied to the brewing device. Typically, the water temperature will drop by a few degrees during the brewing process. For example, if the water has a temperature of about 90 ℃ in the boiler, it may have a temperature of about 85 ℃ in the brewing chamber. Typically, the brewing chamber will be filled quickly with water, for example within 5 seconds, so that there is sufficient time available to brew the beverage. Alternatively, the water temperature may be maintained at ambient temperature or even cooled to a temperature below ambient temperature in order to brew a cold beverage, such as iced tea.

The brewing time depends on the gas extracted from the headspace of the brewing chamber: the brewing time in step c) of the method according to the invention may range from about 15 seconds to about 5 minutes and may be varied by the skilled person in order to prepare a good quality beverage. Preferably, the brewing time is less than 4 minutes, preferably less than 3 minutes, preferably less than 2 minutes, and more preferably less than 1 minute. More preferably, the brewing time is between 18 and 45 seconds, more preferably between 20 and 40 seconds. The brewing time may be optimized based on the infusible material, the desired strength of the beverage, and a minimum or maximum desired waiting time for an operator of the brewing apparatus.

After the beverage has achieved its desired strength, the brew is dispensed through the opening 6 of the cartridge 1. This dispensing is triggered by the end of the drawing of gas out of the headspace of the infusion chamber and thus ceases to draw gas through the opening 6 into the cartridge and the infusion chamber. This causes the brewed beverage to flow through the openings and the infusible material remains behind the filter 7. The beverage is preferably discharged under gravity. Preferably, during discharge of the beverage, gas can also be blown into the headspace of the brewing chamber through the opening 24 or 26 or another opening. The gas creates an overpressure, which results in an acceleration of the liquid discharge. Finally, a clear beverage is obtained without leaving a solid part of the infusible material in the beverage.

In general, the term "gas" is understood in the context of the present invention as air. However, in some cases, other gases or gas mixtures may also be drawn into the brew chamber. Examples of other gases that may be used are nitrogen or oxygen.

Gas may be drawn out of the infusion chamber by a gas pump, which may form an integral component of the infusion apparatus. Alternatively, such a pump may be an external pump, as long as gas can be sucked out of the headspace.

The optional blowing of gas into the headspace for discharging the beverage can be achieved by reversing the flow direction of the preferred gas pump, which can draw gas out of the headspace, such that the gas pump blows gas into the headspace of the brew chamber. Alternatively, the brewing apparatus may include a gas pump for pumping gas out of the brewing chamber and a gas pump for blowing gas into an upper portion of the brewing chamber. Gas can be pumped out through the opening 24. Gas may also be blown into the brewing chamber through the opening 24 or alternatively through another opening in the upper portion of the wall 22 of the brewing chamber 21 or another opening in the lid 23 of the brewing chamber 21.

The opening 6 of the cartridge preferably has a cross-sectional area such that the contents of the brew chamber can be discharged in a time period of about 4 to 10 seconds, preferably 5 to 8 seconds. Preferably, the discharge time is not too short, otherwise the beverage will splash into the cup or bin as it is discharged. On the other hand, the discharge time is preferably not too long, since otherwise the consumer would take too long to wait for the brewed beverage to fill the cup of the cartridge. Preferably, the opening 6 is circular and has a diameter of between 0.5 and 4 cm, preferably between 0.8 and 3 cm, more preferably between 1 and 2.5 cm. The maximum size of the opening 6 of the cartridge is also limited by the gas flow: if the opening 6 is too large, the flow rate of gas drawn into the brewing chamber is too low to keep the brewed beverage inside the brewing chamber and an undesired leakage of beverage will occur. Alternatively, the opening is not circular, but annular, or any other shape such as square or rectangular or octagonal, having the same preferred cross-sectional area as the circular shape.

The discharge time will also depend on the filter size, the volume of the brew chamber, and the particle size of the infusible material. Some components may cause more filter clogging than others, and as a result may result in lower discharge rates. Typical discharge rates are between 1.5 and 3 liters/minute, preferably between 1.8 and 2.5 liters/minute.

The infusible material can be any suitable ingredient for brewing a hot beverage. Particularly suitable ingredients to be used in connection with the cartridge in the method according to the invention are tea, herbs, coffee and cocoa. Most preferred for use as infusible material is tea and/or herbal composition. In this context, tea is understood to mean the leaves of the plant chinese tea, commonly understood by consumers as tea. In addition to tea leaves and/or herbal compositions, the infusible material preferably can also contain ingredients that provide a particular aroma to the brewed beverage, such as pieces of spices, lemons or other fruits. The tea leaves may be flavoured, for example with bergamot oil, to provide a comte tea or any other flavouring. The tea can also be flavored with fruit. The tea may be green tea or black tea. Herbal compositions can be used to make so-called herbal infusions. Non-limiting examples of herbal infusions are peppermint and chamomile. In addition, any combination of tea, herbs, fruits and flavors is possible.

The particle size of the infusible material is selected so that preferably the beverage can be brewed within the brewing time and preferably so that the infusible particulate material has a particle size greater than the pore size of the filter 7. Thus, the infusible material remains on the filter when the beverage is drained in step d) of the method according to the invention. Preferably, the infusible material is reduced in size by cutting or grinding or chopping or crushing or by any other suitable method such that the infusible particulate matter has an average particle size of between 0.1 and 10 millimeters, corresponding to a mesh size of about 150 to about 2.5. Preferably, the minimum size of the infusible material corresponds to the size of the filter pores. For example, in the case of filter pores having a size of about 0.6 millimeters, the infusible material has also been cut to a size of at least 0.6 millimeters (about 28 mesh). More preferably, the infusible material has been cut to a size of between 1 and 8 millimeters (about 16 and 3 mesh), most preferably between 1 and 5 millimeters (about 16 and 4 mesh). However, the infusible material may comprise some very fine material or dust that will be able to pass through the filter. The infusible material preferably has a good tendency to float in water rather than floating in water. This means that, preferably, the infusible material is able to be wetted when water is added to the infusion chamber in step c) of the method according to the invention.

In a preferred embodiment, the infusion chamber 21 contains one or more additional water inlets located near the lower edge 25 of the infusion chamber 21. The optional water inlet may be used to introduce water at the beginning of a brew cycle to agitate and mix infusible material from the cartridge with the introduced water. The optional water inlet is preferably arranged at an angle of at least 45 degrees with respect to the wall 22, more preferably at least 60 degrees, more preferably at least 75 degrees with respect to the wall 22. Most preferably, the optional lower water inlet is arranged substantially perpendicular to the wall 22. The optional water inlet is preferably connected via piping and tubing to the same water supply connected to the openings 24 and/or 26.

The amount of dry infusible material in the cartridge prior to use is preferably such that a quality beverage can be brewed which is neither too strong nor too weak and which does not take too much time to brew. This means that preferably the amount of infusible material is between 0.5 and 5 grams per cartridge, preferably between 1 and 4 grams, more preferably between 1.5 and 3.5 grams per cartridge.

Alternatively, the brew chamber may be cleaned free of small portions of infusible material that may remain after the beverage is discharged, e.g., some portions that may adhere to the inner wall of the brew chamber. Thus, in the next step of the method according to the first aspect of the invention, the brewing chamber may be cleaned by rinsing with water. In addition, this water also serves to flush the brewed beverage from the wet infusible material that remains on the filter after the liquid is drained. The flushing water is also discharged through the opening 6, leaving the infusible material on the filter 7. The advantage of the rinsing step is that no off-flavour between the brew occurs, resulting in a good quality beverage. The inner walls of the brewing chamber are effectively cleaned by the introduction of rinsing water, cleaning both the infusible material, which may adhere to the inner walls, and the remainder of the brewed beverage. Since the device has no moving parts below the opening 6 of the cartridge, no deposition of beverage or flavouring from the beverage onto the components of the brewing machine occurs and therefore no transfer of flavouring or deposits from a previous brew to a next brew occurs.

In the case of a rinsing step, the rinsing water is preferably introduced into the infusion chamber 21 via the openings 24 and/or 26 which can act as water inlets. If hot water is used for this optional rinsing, preferably the water is taken from the same boiler as the water in step c). In this case, flushing will be most effective if the water flow is directed around the wall 22 so as to spiral slowly downwards. Thus, the upper water intake 24 and/or 26 is arranged to direct water into the brewing chamber 1 in a substantially horizontal manner, so that the water travels along the wall 22 in a downward spiral, thus achieving flushing. Preferably, the angle between the opening and the wall is less than 30 degrees, more preferably less than 15 degrees, and most preferably the water inlet 24 and/or 26 is arranged substantially tangential to the wall 22. Flushing is even more effective when more than one upper inlet is used, and therefore the infusion chamber 21 preferably comprises two or more upper inlets 24 and 26, which may be in communication with the same or separate water sources.

In order to allow the incoming water to be directed around the wall 22 of the brew chamber 21, the beverage brewing machine preferably comprises a substantially cylindrical brew chamber 21 as described in the above embodiments. The infusion chamber 21, which is preferably cylindrical, has a cross-section of circular form, but other configurations can also be adopted. However, it is preferred that the inner surface of the infusion chamber 1 is substantially curved to allow water to flow around the inner surface, and therefore the preferred cross-section has an elliptical or circular form.

After brewing the beverage, the cartridge may be removed from the brewing chamber and discarded or cleaned. If cleaned, the cartridge may be filled with fresh infusible material to brew a second beverage before being reattached to the brew chamber. By removing the cartridge from the brew chamber and cleaning the cartridge or replacing it with another cartridge, no cross-flavor will occur between the brewed products.

A cartridge for use in a method according to the first aspect of the invention

wherein the first element 51 comprises a side wall 52 and a bottom wall 53,

wherein the bottom wall includes an opening 55,

wherein the opening includes a water permeable filter 56,

and wherein, the second member 71 comprises a bottom wall 72,

wherein the bottom wall 72 is made of a water-impermeable material,

wherein the bottom wall 72 comprises one or more ridges 74 capable of interlocking with the corresponding one or more recesses 60, and wherein the second element 71 is movable relative to the first element 51 around the corresponding recesses 60 and ridges 74.

A preferred embodiment of the cartridge is described with reference to figures 2 to 11. In this case, the cartridge is described as a disc-shaped cartridge having a circular periphery when viewed from above. However, the cartridge may have any other suitable shape, such as square or rectangular or oval, as long as the cartridge fits into the brewing chamber in the brewing apparatus.

Figure 2 shows a side view of a preferred non-limiting embodiment of a cartridge according to the second aspect of the present invention. The cartridge comprises a first member 51 and a second member 71. The first element comprises a side wall 52 and a bottom wall 53. The second member includes a bottom wall 72. A gap 75 is provided between the first and second elements. Optionally, the first element 51 is closed with a seal 58. The seal is preferably a peel seal.

Figure 3 shows a top view of the preferred non-limiting cartridge shown in figure 2. The first element 51 is closed with an optional seal 58.

Figure 4 shows a bottom view of the preferred non-limiting cartridge shown in figures 2 and 3. The cartridge comprises a first member 51 and a second member 71. The first element comprises the upper edge 59 of the side wall 52 and the ridge 54 in the bottom wall 53. The second member 71 includes a bottom wall 72, and the bottom wall 72 includes an opening 73. The opening 73 is interconnected with the bulge 54 such that the bulge 54 closes the opening 73.

Figure 5 shows a side view of a preferred non-limiting cartridge according to a second aspect of the invention, taken at line a-a indicated in figure 3. Figure 5 shows the cartridge closed such that the protuberance 54 of the first element 51 closes the opening 73 of the second element 71. Figure 6 shows the same preferred non-limiting cartridge, taken at line a-a indicated in figure 3. Figure 6 shows the cartridge open such that the protuberance 54 of the first element 51 does not close the opening 73 of the second element 71.

Referring to fig. 5 and 6, a preferred non-limiting cartridge will be described herein. The cartridge according to the second aspect of the invention is adapted to be connected to a brewing chamber and brew a beverage such as tea or any other beverage. The cartridge comprises a first element 51 and a second element 71, wherein the first element 51 comprises a side wall 52 and a bottom wall 53. The side walls preferably have an angle between 0 and 45 ° to the vertical. Since the cartridge is suitable for use in preparing beverages, the side wall 52 and the bottom wall 53 are made of a water impermeable material. The beverage to be prepared is preferably a hot beverage, and therefore preferably the material of the side wall 52 and the bottom wall 53 is capable of withstanding temperatures of about 100 ℃ or even higher during a time period of preferably at least 10 minutes, more preferably at least 5 minutes. The bottom wall of the first element comprises a ridge 54 directed outwardly of the first element 51. In the present non-limiting embodiment, the protuberance is surrounded by an opening 55 in the bottom wall 53, and the opening includes a water permeable filter 56. The filter 56 may be an integral part of the bottom wall 53. For example, if the first element of the cartridge is made of a plastics material and is moulded so as to provide it with the correct size and shape, the filter may be moulded as an integral part of the bottom wall 53. Alternatively, the filter may be secured to the first element 51 of the cartridge after it has been prepared, for example by gluing a woven cloth or film to the bottom wall 53 to cover the opening 55. If the filter is integrally moulded in the first element of the cartridge, it is preferred that the filter material is of the same construction as the bottom wall of the cartridge. In another preferred embodiment, the filter 56 is made of the same material as a conventional tea bag, such as cellulose with a PET/PP layer, or woven or non-woven PET.

The top of the first element 51 is optionally closed by a seal 58, which seal 58 may be attached to the upper edge 59 of the side wall 52. The seal may comprise any material as has been described hereinbefore and may be attached to the first element by any method as has been described hereinbefore. Preferably, the upper edge 59 of the side wall includes a flange that can be used to attach an optional seal to the first element 51 and can also serve to connect the cartridge to the brew chamber. The bottom wall 53 comprises one or more recesses 60 directed towards the inside of the first element 51. The recess 60 is present to receive a corresponding protuberance 74 of the second member 71 of the cartridge. Preferably, the recess is continuous and annular and follows the periphery of the bottom wall. Alternatively, there may be two or more notches 60 that are not annular and that are discontinuous along the perimeter of the bottom wall. For example, there may be 4, 6, 8, 10 or 12 or any other reasonable number of recesses in cylindrical form, such that the corresponding protuberances 74 are pins that fit into the recesses 60.

Fig. 7 shows a bottom view of a preferred non-limiting embodiment of the first element 51. In this particular embodiment, the cartridge has a circular periphery and the protuberance 54 is located in the middle of the bottom wall 53. The opening 55 includes a filter 56. The recess 60 has a continuous shape along the periphery of the bottom wall 53.

The second member 71 comprises a bottom wall 72, wherein the bottom wall 72 is made of a water-impermeable material. Since the beverage to be prepared is preferably a hot beverage, preferably the material of the bottom wall 72 is capable of withstanding temperatures of about 100 ℃ or even more during a time period of preferably at least 10 minutes, more preferably at least 5 minutes. The bottom wall 72 includes an opening 73 that can interlock with the protuberance 54 of the first member 51. A watertight connection is formed by this interlocking, which acts to close the opening 55 of the first element 51. The closed position is the normal position of the first and second elements 51, 71 when the cartridge is introduced into the brewing apparatus to brew a beverage.

The bottom wall 72 includes one or more ridges 74 capable of interlocking with corresponding one or more notches 60 of the first member 51. The second element 71 is movable relative to the first element 51 about the corresponding notch 60 and protuberance 74. The recess 60 and the protuberance 74 allow the second element 71 to be moved from the first element 51, as the protuberance 74 can slide inside the recess 60 to separate the protuberance 54 from the opening 73. The number and shape of the one or more protuberances 74 corresponds to the number and shape of the corresponding one or more indentations 60.

This movement of the second element 71 from the first element 51 will normally be performed inside the brewing apparatus when the cartridge has been connected to the brewing chamber. Movement of second member 71 from first member 51 will result in exposure of opening 55 and filter 56 to the atmosphere. After the bottom portion of the first element 51 is opened, the brewing process can begin by filling the brewing chamber with water and drawing gas, preferably air, from the headspace of the brewing chamber. Thus, gas, preferably air, will be drawn into the cartridge and the brew chamber through the openings 73 of the second element 71 and through the openings 55 of the first element 51 and the filter 56. Infusible material that would normally be present inside the cartridge when the cartridge is introduced into the brewing apparatus will mix with the water due to the water flow and bubbles rising from the filter 56.

When the beverage has reached its desired strength, the air pump is turned off and therefore no more air is drawn into the cartridge through the opening 55 and the filter 56. This causes the beverage to be expelled through the opening 55, the filter 56 (which retains the used infusible material) and through the opening 73 of the second element 71.

Fig. 8 shows a preferred embodiment of the ridge 74 of the second element and the notch 60 of the first element 51. The recess 60 preferably comprises two recesses 61 and 62 directed towards the inside of the first element 51. The two recesses 61 and 62 preferably follow the periphery of the recess 60 and the bottom wall 53. The corresponding ridges 76 may interlock with the notches 61 and 62. When the first element 51 is closed by the second element 71, the ridge 75 will then interlock with the notch 61. After the second element 71 is moved from the first element 51 and the opening 55 and filter 56 are exposed to the atmosphere, the ridge 76 will interlock with the recess 62. The latter interlock also results in directing the flow of brewed beverage into opening 73, as a water-tight connection is formed by the latter interlock. The distance between the notches 61 and 62 determines how far the second member 71 moves from the first member 51 when the first member 51 is opened.

Fig. 9 and 10 disclose a preferred method for preventing the second element 71 from moving relative to the first element 51 after the first element 51 is opened to close the first element 51 again. This is achieved by the ridge 77 being sandwiched between the ridge 74 and the inner wall of the recess 60 when the first element 51 is closed by the second element 71 (fig. 9). After opening the first member 51 by moving the second member 71 downward (fig. 10) and interlocking the protuberance 76 with the notch 62, the protuberance 77 will move outward and prevent the second member 71 from moving upward relative to the first member 51.

Alternative interlocking systems, such as the system shown in fig. 11, may be used in place of the preferred embodiments disclosed in fig. 8, 9 and 10. In this case, the recess 60 comprises recesses 63 and 64, the recesses 63 and 64 being directed slightly upwards and towards the inside of the first element. The recesses 63 and 64 may each comprise one, two (as shown in fig. 11) or more recesses. Corresponding ridges 78 on the ridges 74 interlock with these notches 63 and 64, respectively, when the second element 71 is moved. The ridges 78 lock the second element 71 relative to the first element 51 and they act as a watertight connection to direct the flow of beverage to the opening 73. The protuberances 78 additionally prevent the second element 71 from moving toward the first element 51 during operation of the brewing machine because the protuberances 78 act as barbs.

The thickness of the bottom wall 72 depends on the possibility of the bottom wall 72 locking the first element 51 and being able to direct the flow of brewed beverage to the opening 73. The thickness of the protuberance 54 is preferably equal to the thickness of the bottom wall 72 so that the bottom surface appears to be a continuous surface when the cartridge is in the closed position.

When used inside the brewing apparatus, the bottom wall 53 of the first element 51 and the filter 56, as well as the bottom wall 72 of the second element 71, may be substantially flat and/or horizontal. Alternatively, the surfaces may be inclined towards the centre of the bottom wall 53 and the bottom wall 72 so as to form a cone for directing the flow of brewed beverage firstly through the filter and secondly through the opening 73. Such a shape may also facilitate mixing and flow patterns inside the brewing chamber.

The size of the openings 55 and the holes in the filter 56 depend on the desired rate of discharge of the brewed beverage on the one hand, and the capacity of the air pump on the other hand, to draw air out of the head space and thus draw air, preferably air, into the cartridge and the brew chamber through the openings 73, the openings 55 and the filter 56. This pumping of gas into the brew chamber serves to retain the beverage inside the cartridge during the brewing process.

The dimensions of the cartridge and filter indicated in the context of the first aspect of the invention are applicable, mutatis mutandis, to the cartridge and filter of the second aspect of the invention.

Preferably, the first and second elements 51, 71 are both made of the same material, preferably a rigid plastic, preferably polypropylene. These elements are preferably prepared by injection molding. The thickness of the side walls 52, bottom wall 53 and bottom wall 72 is preferably between 0.1 and 2 millimeters, more preferably between 0.5 and 1.5 millimeters, and most preferably between 0.6 and 1.0 millimeters.

The pores of the filter pores preferably have a size between 0.1 and 1 mm. This may for example result in filter pores of between 0.25 and 0.35 mm, or between 0.4 and 0.9 mm, or between 0.5 and 0.7 mm, or between 0.8 and 1.0 mm, or any other dimension between 0.1 and 1 mm, inclusive. The shape of the holes in the filter may be square, rectangular, circular, octagonal or any other suitable shape. In this context, the size of the filter pores is understood to mean the largest cross-sectional dimension of the filter pores. For example, for a circular shape this represents the diameter, and for a rectangular shape this represents the length of the diagonal between two opposing corners.

Preferably, the cartridge according to the second aspect of the invention comprises infusible particulate material having a particle size greater than the pore size of the filter 56. The infusible material preferably comprises tea leaves and/or a herbal composition. As in the first aspect of the invention, preferably, the infusible material is cut and/or ground into pieces such that the infusible material has an average particle size of between 0.1 and 10 millimeters (which corresponds to a mesh size of about 150 to about 2.5). Preferably, the minimum size of the infusible material corresponds to the size of the filter pores. More preferably the infusible material has been cut to a size of between 1 and 8mm (about 16 and 3 mesh), most preferably between 1 and 5mm (about 16 and 4 mesh). However, the infusible material may comprise some very fine material or dust that will be able to pass through the filter.

All preferred embodiments of the cartridge described in the context of the first aspect of the invention may, mutatis mutandis, be preferred embodiments of the cartridge according to the second aspect of the invention.

Method for brewing a beverage using the cartridge of the second aspect of the invention

the method comprises the following steps:

a) optionally, the seal 58 is released from the cartridge,

Steps a) and b) may be performed first a) then b), or first b) then a) in either order. If the cartridge is a sealed new cartridge in step a), the seal 58 is typically peeled off the cartridge before the second member 71 is moved away from the first member 51 to open the first member 51. The optional seal may be manually removed by an operator of the brewing machine, or may be removed by the implement of a mechanical machine or manually when the cartridge has been placed in the brewing apparatus. Typically, prior to application of the cartridge to the brewing apparatus, the cartridge will be in the closed position, meaning that the second element 71 is positioned against the first element 51 and the opening 73 is closed by the protuberance 54. However, prior to application of the cartridge to the brewing apparatus, the second element 71 may be moved away from the first element 51 to open the first element 51. This means that step c) can be performed before step b) or step a).

If the cartridge is a reusable cartridge, the cartridge may not have a seal for closing the top portion. In this case, the cartridge may already be open, in the sense that the second element 71 may be moved away from the first element 51 to open the first element 51.

In steps b) and c), the top edge of the cartridge is connected to the lower edge of the infusion chamber, and the second element 71 is moved away from the first element 51 to open the first element 51 and expose the filter 56 to the atmosphere. These steps may be performed in any order or simultaneously. The attachment of the cartridge to the brew chamber may be performed manually by an operator using a clamp or any other suitable fastening means, or may be performed automatically by the brewing apparatus. Thus, the means for connecting the cartridge to the infusion chamber may be a mechanical device, such as a clamp, or may be a press for pushing the cartridge against the infusion chamber, or any other suitable mechanical element. Opening the cartridge by moving the second element 71 from the first element 51 may also be performed manually by an operator or may be performed automatically by the brewing apparatus.

After connecting the cartridge to the brewing chamber and opening the cartridge, the brewing process starts in steps d) and e). During these steps, the vacuum pump is turned on to draw gas out of the headspace of the brew chamber, which will cause gas to be drawn into the brew chamber through the opening 55 of the cartridge and the filter 56. At the same time, the infusion chamber is filled with water, preferably hot water, through the inlet 24 in step e). As gas is drawn through the filter 56, bubbles are formed that rise from the filter 56 to the headspace of the brew chamber while the infusible material is mixed with water. In this way, the beverage is effectively infused.

The introduction of water in step e) is at least partially simultaneous with the withdrawal of gas from the infusion chamber in step d). This means that the introduction of water in step e) can be started at the same time as the extraction of gas from the infusion chamber in step d) is started. Step e) may also be started later than step d). The addition of water to the brew chamber may be stopped earlier than and at the same time as the end of the extraction of gas from the headspace in step f). While the water is inside the brewing chamber, the brewing process starts in step e), as the infusible material is extracted by the water.

If the beverage has been sufficiently brewed, the extraction of gas from the head space and therefore the suction of gas into the brewing chamber through the filter 56 is also ended in step f), and the brewed beverage is discharged into the receptacle through the opening 55 and the filter 56.

In a third aspect, the invention provides an apparatus for brewing a beverage using a cartridge according to the second aspect of the invention, comprising a brewing chamber and means for connecting the cartridge to the brewing chamber such that a water-tight connection is formed, and means for moving the second element 71 of the cartridge relative to the first element 51 of the cartridge about the respective recess 60 and protuberance 74,

wherein the retainer is movable relative to the first member 51 to increase the width of the gap 75 between the first member 51 and the second member 71. The apparatus is particularly suitable for use in conjunction with the cartridge according to the second aspect of the invention.

In a preferred embodiment, the apparatus is provided with a drawer to receive the magazine according to the second aspect of the invention. The following preferred non-limiting modes of operation may be applied. The optional seal 58 is removed from the first member 51. This removal of the optional seal 58 may be done manually prior to placing the cartridge in the drawer, or may be done internally of the drawer or by a mechanism that is part of the brewing machine or manually after placing the cartridge in the drawer. A magazine in which the protuberance 54 is interconnected with the opening 73 to close the first element 51 is inserted into the drawer. The cartridge is positioned below the brew chamber when the drawer is closed. When the drawer is closed, the magazine can be opened by moving the second member 71 from the first member 51 and exposing the opening 55 and filter 56 to the atmosphere. The cartridge is then preferably tightly connected to the brew chamber by use of an optional flange 59. Connecting the cartridge to the infusion chamber and opening the cartridge by moving the second element 71 from the first element 51 may also be performed in other ways.

The infusion chamber of the apparatus according to the fourth aspect of the invention preferably comprises a transparent side wall. This has the advantage that the operator and consumer can observe the improved brewing process. This observation has the advantage that the consumer feels that the consumed beverage is more specific to him or her. This is in contrast to similar beverages which are provided to the consumer at the same time as their brewing process is not observed by the consumer, or which have been prepared in a conventional manner (e.g., tea using a tea bag). By perceiving the beverage more particularly, the perceived high quality and uniqueness of the beverage is enhanced. Moreover, by using transparent side walls, operators and consumers will be assured that the brew chamber is indeed clean after flushing before a new brew cycle will begin.

In a fourth aspect, the present invention provides a method for opening a cartridge according to the second aspect of the invention, wherein the protuberance 54 of the first element 51 of the cartridge is interconnected with the opening 73 of the second element 71 to close the bottom wall 53 of the first element 51, wherein the second element 71 moves from the first element 51 about the corresponding recess 60 and protuberance 74 to expose the filter 56 to the atmosphere. The method is particularly suitable for being carried out by an apparatus according to the third aspect of the invention in combination with a cartridge according to the second aspect of the invention.

The preferred aspects disclosed in connection with any of the first, second, third or fourth aspects of the invention are applicable to other aspects of the invention mutatis mutandis. The various features and embodiments of the invention recited in the various sections below are applicable to the other sections where appropriate with necessary modifications. Thus, features specified in one section may be combined with features specified in other sections as appropriate. All publications mentioned in this specification are herein incorporated by reference. Various modifications and variations of the described methods and products of the invention will be apparent to those skilled in the art without departing from the scope of the invention. While the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims.

Examples of the invention

The following non-limiting examples illustrate the invention.

Example 1: beverage brewing apparatus

Referring to non-limiting fig. 1-11, the beverage brewing apparatus is designed and assembled for brewing a beverage through the use of a removable cartridge containing tea leaves. The apparatus is provided with:

■ have a brew chamber with the following characteristics: cylindrical shape, height 135mm, outer diameter 60mm, inner diameter 54mm (total volume: about 300 ml), glass material (transparent);

■ a vacuum pump for drawing air from the headspace of the brew chamber, and tubing, connectors, and valves for connecting the air pump to the brew chamber;

■ an air pump for blowing air into the headspace of the brew chamber, and tubing, connectors and valves for connecting the vacuum pump to the brew chamber;

■ a boiler for heating water to a temperature of about 92 ℃;

■ a water pump for pumping water from the boiler to the brew chamber, and pipes, tubes, connectors and valves for connecting the boiler to the brew chamber;

■ are used to control the operation of the pumps and valves.

A cartridge according to a preferred embodiment disclosed in figures 2 to 7 is used. The cartridge has a disc shape and the first and second members 51, 71 of the cartridge are made of polypropylene, which has been injection moulded and has the correct shape and size. The side walls 52 and the bottom wall 53 of the first element 51 and the bottom wall of the second element 71 have a thickness of 0.8 mm. The inner diameter of the first element 51 between the flanges 59 is 54mm, the overall outer diameter of the second element 71 at the location of the bottom wall 72 is 46.5mm, and the overall height of the cartridge (in the closed position) is 20.25 mm. The width of the gap 75 is 1.5 mm. When the second part 71 is moved from the first part 51, the width of the gap 75 increases to 6 mm.

The filter 56 is moulded into the cartridge and forms an integral part of the base of the first element 51. The filter contained 450 pores, which were cylindrical in shape with a waist. The diameter of the filter pores was about 0.95 mm at the top side (inside the cartridge); the diameter of the waist is about 0.85 mm; and the diameter of the filter pores is about 0.95 mm at the bottom side of the cartridge (outside the cartridge). The total cross-sectional area of the filter pores is therefore about 2.5 square centimeters.

The bin was filled with 2.5 grams of black tea.

After the cartridge has been connected to the brew chamber and the second element 71 has been moved from the first element 51, a brew cycle may be commenced. One brewing cycle includes the following operations:

■ turning on the vacuum pump: from 0 seconds to 19 seconds; to draw air out of the headspace of the brew chamber and simultaneously draw air in through the opening 55 of the cartridge. During 0-2 seconds, the gas flow rate of the pump is about 4.5-5.5 liters/minute; and from 2 to 19 seconds, the gas flow rate is about 2.5 liters/minute.

■ turning on the water pump: from 0.5 seconds to 12 seconds, to fill the brewing chamber with hot water coming from the boiler, the hot water having a temperature of about 85 ℃; the maximum water flow during filling of the brewing chamber is about 975 ml/min.

■ the infusion of the beverage takes place whilst the vacuum pump is switched on and air is drawn through the openings 55 of the first element 51 of the cartridge, thus causing the formation of bubbles rising during the infusion process which mix the beverage with the tea leaves.

■ when the vacuum pump is turned off at 19 seconds: brewed beverage drains from the brew chamber through the opening 55 and the opening 73 of the cartridge into the cup. A valve in a conduit connected to the headspace of the brew chamber is opened to vent the brew chamber to atmosphere and to allow the brew chamber to discharge through the opening 55 and the opening 73 of the cartridge.

At 23 seconds, a burst of hot water is injected during 1 second in order to flush the contents of the infusion chamber. From 24 to 26 seconds, the air pump is turned on to blow air into the headspace of the brew chamber and subsequently push the beverage out of the brew chamber through the filter.

Similarly, at 26 seconds, a second burst of hot water is injected during 1 second in order to flush the contents of the brewing chamber. From 27 to 29 seconds, the air pump is turned on to blow air into the headspace of the brew chamber and subsequently push the beverage out of the brew chamber through the filter.

Example 2: comparison of the teas prepared by the method of the present invention

In order to determine whether the tea prepared by the apparatus and method according to the present invention is perceived by the consumer as having a particular quality, the following experiment was conducted.

A total of 474 consumers were divided into 3 groups (150, 166 and 158 individuals, respectively) and all were asked to give their evaluation of a cup of tea prepared with the apparatus described in example 1 with a transparent infusion chamber or a cup of normal tea prepared with a normal tea bag.

Group A: a fresh cup of tea was provided to 150 consumers and they were also presented with the apparatus described in example 1 for preparing the fresh cup of tea. These consumers not only enjoyed the cup of tea, but also experienced them how to prepare the cup of tea using the apparatus described in example 1.

Group B: 166 consumers were provided a similar cup of fresh tea with the same quality as the other 150 consumers in group a, but they were not shown the equipment used to prepare this cup of tea and therefore they did not experience the brewing process.

Group C: 158 consumers were provided with a common cup of tea prepared using twins tea bags.

The following table shows the results with respect to several aspects used as a measure of the perceived distinctiveness and uniqueness of the tea.

Table 1: comparison between three groups of consumers regarding their evaluation of the quality of tea or regular tea prepared with the device of the present invention; scores for ranks 1 to 5, 1 being "very disagreeable," 5 being "very consented".

*B or C indicates whether the measured difference was statistically significant (95% confidence level) for group B or group C or for both groups, respectively. These results show that consumers especially like the teas prepared with the apparatus of example 1 (groups a and B): in many attributes, the tea prepared using the method according to the invention scored higher than normal tea prepared using normal tea bags (group C). In addition, consumers in group a scored a cup of tea higher in many ways than in group B. Thus, consumers in group a rated tea as having a more specific quality and uniqueness than consumers who had tasted tea made by the same equipment and process but did not display the equipment to them.

These results show that the appearance of the apparatus with a transparent infusion chamber and demonstrating the way in which the tea is prepared provides an attractive experience for the consumer, resulting in the impression that the tea has a more particular quality than normal tea or similar tea prepared without demonstrating the infusion process.

Claims

1. A method for brewing a beverage in a brewing apparatus, wherein the apparatus comprises a brewing chamber (21), the brewing chamber (21) comprising a side wall (22), a bottom rim (25), a top wall (23) and an opening (24), comprising the steps of:

a) connecting a top rim (3) of a cartridge (1) containing infusible particulate material (2) to the bottom rim (25) of the brew chamber such that a water-tight connection is achieved;

wherein the cartridge (1) comprises a side wall (4) and a bottom wall (5) and is made of a water impermeable material, and wherein the bottom wall contains an opening (6) and a filter (7);

b) drawing gas out of the infusion chamber through the opening (24) and simultaneously sucking gas into the infusion chamber through the opening (6) of the bottom wall and the filter (7);

c) filling the brewing chamber with water through an inlet (26) at least partially simultaneously with step b) and brewing the beverage by mixing water and infusible particulate material (2) in the brewing chamber (21); and

d) the extraction of gas from the infusion chamber is ended and the infused beverage is discharged through the opening (6) and the filter (7).

2. The method of claim 1, wherein the infusible particulate matter comprises a herbal composition.

3. The method of claim 1, wherein the infusible particulate material comprises tea leaves.

4. A method according to any one of claims 1 to 3, wherein the pores of the filter (7) have a size of between 0.1 and 1 mm.

5. A method according to any one of claims 1 to 3, wherein the infusible particulate material has an average particle size of between 0.1 and 10 millimetres.

6. The method according to claim 4, wherein the infusible particulate matter has a particle size greater than the pore size of the filter (7).

7. The method of claim 1, wherein the brew chamber comprises a transparent sidewall (22).

8. A cartridge for connection to a brewing chamber for brewing a beverage, comprising a first element (51) and a second element (71),

wherein the first element (51) comprises a side wall (52) and a bottom wall (53),

wherein the side wall (52) and the bottom wall (53) are made of a water-impermeable material,

wherein the bottom wall (53) comprises a bulge (54) directed outwards of the first element (51),

wherein the bottom wall comprises an opening (55),

wherein the opening comprises a water permeable filter (56),

and wherein the bottom wall (53) comprises one or more notches (60) directed towards the inside of the first element (51),

and wherein the second element (71) comprises a bottom wall (72),

wherein the bottom wall (72) is made of a water-impermeable material,

wherein the bottom wall (72) comprises an opening (73), the opening (73) being interlockable with the bulge (54) for forming a watertight connection,

wherein the bottom wall (72) comprises one or more ridges (74) capable of interlocking with corresponding one or more recesses (60),

and wherein the second element (71) is movable relative to the first element (51) around the corresponding recess (60) and protuberance (74).

9. A cartridge as claimed in claim 8 wherein the first element is closable by a seal (58), the seal (58) being attached to an upper edge (59) of the side wall (52).

10. A cartridge as claimed in claim 9 wherein the side walls (51) and bottom wall (52) of the first element comprise polypropylene.

11. A cartridge as claimed in any of claims 9 to 10 wherein the apertures of the filter (56) have a size of between 0.1 and 1 mm.

12. The cartridge according to claim 11, wherein the cartridge contains infusible particulate material having a particle size greater than the pore size of the filter (56).

13. The cartridge of claim 12 wherein the infusible particulate matter comprises a herbal composition.

14. The cartridge of claim 12 wherein the infusible particulate material comprises tea leaves.

15. A method for brewing a beverage in a brewing apparatus using the cartridge according to any one of claims 12 to 14,

wherein the apparatus comprises: an infusion chamber (21) and means for connecting a cartridge to said infusion chamber, said infusion chamber (21) comprising a side wall (22), a bottom rim (25), a top wall (23) and an opening (24),

the method comprises the following steps:

a) -releasing a seal (58) from the cartridge with the cartridge sealed, wherein the bulge (54) of the first element (51) is interconnected with the opening (73) of the second element (71) to close the bottom wall (53) of the first element (51);

b) -placing the cartridge in the brewing apparatus and connecting the upper rim (59) of the first element of the cartridge to the bottom rim (25) of the brewing chamber, so that a water-tight connection is achieved;

c) prior to or simultaneously with step b), moving the second element (71) of the cartridge relative to the first element (51) of the cartridge such that the filter (56) is exposed to atmosphere;

d) drawing gas out of the brew chamber through an opening (24) or through an optional inlet (26) and simultaneously drawing gas into the brew chamber through an opening (55) of the cartridge and a filter (56);

e) filling the brewing chamber (21) with water at least partially simultaneously with step d) and brewing the beverage by mixing water with infusible particulate material in the brewing chamber (21); and

f) ending the extraction of gas from the infusion chamber and discharging the infused beverage through an opening (55).

16. An apparatus for brewing a beverage using the cartridge of any of claims 8 to 14 comprising a brewing chamber and means for connecting the cartridge to the brewing chamber such that a water-tight connection is formed, and

means for moving the second element (71) of the cartridge relative to the first element (51) of the cartridge about the corresponding recess (60) and protuberance (74),

wherein the device comprises a retainer which fits in a gap (75) between the first element (51) and the second element (71), and

wherein the retainer is movable relative to the first element (51) to increase the width of a gap (75) between the first element (51) and the second element (71).

17. The apparatus of claim 16, wherein the brew chamber comprises a transparent sidewall.

18. A method for opening a cartridge as claimed in any of claims 8 to 14 wherein the protuberance (54) of the first element (51) of the cartridge is interconnected with the opening (73) of the second element (71) to close the bottom wall (53) of the first element (51), wherein the second element (71) moves from the first element (51) around the corresponding recess (60) and protuberance (74) to expose the filter (56) to atmosphere.