Brewing unit, beverage preparation machine, system and method for beverage preparation

Abstract

The invention relates to a brewing unit (10) for a beverage preparation machine, comprising at least one first and one second brewing chamber half (11, 12) for forming a brewing chamber (13). The two brewing chamber halves (11, 12) can be moved relative to one another from an open position for inserting a beverage substance to a closed position for forming a closed brewing chamber (13) having a volume (14) and for extracting the beverage substance. At least one brewing chamber half (11, 12) has at least one spike (20) for piercing a casing surrounding the beverage substance. The first and / or second brewing chamber half (11, 12) is designed such that in the closed position, the volume (14) of the closed brewing chamber (13) can be changed. For changing the volume (14), a mechanically coupled motor (30) and / or a device which can be actuated by a hydraulic drive and / or by a user is provided.

Description

[0001] Brewing unit, beverage preparation machine, system and method for beverage preparation

[0002] The present invention relates to a brewing unit, a beverage preparation machine, a system and a method for beverage preparation according to the preambles of the independent claims.

[0003] Various brewing units for beverage preparation machines are known from the state of the art.

[0004] For example, WO 2023 / 036601 A1 discloses a brewing unit for a beverage preparation machine which receives capsules in a brewing chamber and in which, after the brewing chamber has been closed, the volume of the brewing chambers is reduced by a hydraulically actuated pressure piston.

[0005] WO 2020 / 233783 A1 discloses a brewing chamber for a brewing unit, wherein one brewing chamber half has a hydraulically displaceable slider in order to increase a contact pressure on a seal between the brewing chamber halves.

[0006] WO 2022 / 018242 A1 discloses a brewing chamber with a movable wall part for breaking up a beverage substance in solid dosage form for extraction.

[0007] The disadvantage of such brewing chambers is that the hydraulic movement cannot be precisely controlled. Furthermore, the hydraulic actuation carries the risk of calcification and requires a comparatively high amount of energy, especially when using heated brewing liquid. Furthermore, the hydraulic control requires a separate hydraulic volume, which either flows into the capsule during or after extraction or must be drained into a waste container.

[0008] The object of the invention is to overcome the disadvantages of the prior art. In particular, a brewing unit, a beverage preparation machine, a system, and a method for beverage preparation are to be provided that allow precise adjustment of the volume of the brewing chamber.

[0009] This object is achieved by the devices defined in the independent patent claims. Further embodiments emerge from the dependent patent claims.

[0010] In the following, a brewing chamber is understood to mean a chamber which contains a beverage substance loose in powder form and / or in the form of one or more pellets and / or pressed tablets, and / or enclosed in a shell and / or in a capsule, and through which a liquid can flow to prepare a beverage.

[0011] A beverage substance is understood to be a substance from which a beverage can be obtained by contact with a liquid. For example, a beverage substance can include tea herbs, coffee powder, dried soup, cocoa powder, etc. The beverage substance can be in loose powder form and / or in the form of one or more pellets and / or tablets, and / or enclosed in a shell and / or capsule.

[0012] Extraction is understood here to mean that a beverage is produced from a beverage substance under the action of a liquid. Various factors such as temperature, pressure or residence time of the liquid can influence the beverage to be produced. A brewing unit according to the invention for a beverage preparation machine comprises at least a first brewing chamber half and a second brewing chamber half for forming a brewing chamber. The first brewing chamber half and the second brewing chamber half can be moved relative to one another from an open position for inserting a beverage substance into a closed position for forming a closed brewing chamber with a volume and for extracting the beverage substance. The first and / or the second brewing chamber half has at least one piercing spike for piercing a casing enclosing the beverage substance.The first brewing chamber half and / or the second brewing chamber half are designed such that, in the closed position, the volume of the closed brewing chamber can be changed. A mechanically coupled motor and / or a hydraulic drive and / or a device operable by a user is provided for changing the volume.

[0013] An open position is understood here and below to mean that the brewing chamber halves are spaced apart from one another such that a beverage substance can be inserted. When the brewing chamber halves are in the open position, the brewing chamber is not suitable for extracting the beverage substance. Accordingly, a closed position is understood to mean that a previously inserted beverage substance is enclosed. When the brewing chamber halves are in the closed position, the brewing chamber is ready for extraction of the beverage substance.

[0014] The presence of piercing spikes means that a beverage substance enclosed in a casing can be used to prepare the beverage. On the one hand, this allows the user to dose the substance easily, and on the other hand, the brewing chamber is not contaminated by residues of the beverage substance. This significantly reduces the amount of cleaning required for the brewing chamber or the brewing chamber halves. A piercing spike can be designed as a hollow cannula, through the bore of which an extraction fluid is introduced into the casing or the prepared beverage is discharged from the casing. It is also conceivable, however, for the piercing spike to simply provide an opening in the casing, with the fluid being fed into the casing or discharged from the casing externally along the piercing spike.

[0015] The ability to change the volume of the brewing chamber means that the volume can be precisely adjusted to the size or volume of the beverage substance required for optimal extraction. For example, this makes it possible to expand a portion capsule. The volume of a portion capsule can also be reduced to ensure correct extraction, for example with a portion capsule containing a reduced amount of coffee powder. Likewise, a beverage substance that is in the form of one or more pellets can be broken up and / or loosened. Furthermore, by reducing the volume after extraction, the remaining beverage substance can be squeezed out, for example to prevent dripping. A change in volume does not explicitly mean a change that occurs solely as a result of plastic and / or elastic deformation of a sealing element.The volume of the closed brewing chamber can be varied by at least 3%, preferably by at least 5%, and particularly preferably by at least 7%, based on a preset extraction volume. The preset extraction volume is the volume typically intended for optimal extraction.

[0016] The use of a mechanically coupled motor and / or a hydraulic drive allows a direct reaction of a motor control to the volume of the brewing chamber and thus a precise adjustment of the desired volume.

[0017] The mechanically coupled motor can comprise an electric motor. The brewing unit is typically used in an electrically powered beverage preparation machine. Accordingly, the use of an electric motor simplifies volume adjustment. Furthermore, an electric motor allows precise control and controlled volume adjustment. Likewise, an electric motor can drive movement in both directions, with a change of direction possible at any time. The volume of the brewing chamber can be increased or decreased independently of the drive.

[0018] A separate pump can be provided for the volume change via a hydraulic drive. Likewise, the pump already provided for the extraction liquid can be used for the hydraulic drive by means of a suitable valve control.

[0019] If the volume change is achieved via a suitable device operable by the user, a mechanically coupled motor is not necessarily required. For example, the volume change can be made by the user via a lever and / or a gear. This gives the user the feeling of influencing the quality of the prepared beverage, as with a classic barista machine with manual pressure control.

[0020] The first brewing chamber half and / or the second brewing chamber half can be designed in two parts and have an outer part and an inner part, wherein the outer part and the inner part are movable relative to one another. By designing a brewing chamber half in this way, the volume of the closed brewing chamber can be easily changed. The brewing chamber can remain closed during such a volume change, so that no beverage substance and no liquid escapes from the brewing chamber. Likewise, the brewing chamber can also be easily opened, for example in order to be able to drain residual water from the brewing chamber. Such an opening of the brewing chamber can also take place during the brewing process, for example in order to drain rinsing water, in particular for conditioning the beverage substance, from the brewing chamber before the actual beverage preparation.The movement of the outer and inner parts of the brewing chamber half can occur independently of each other.

[0021] The outer part can have a passage, in particular with a hollow cylindrical region, in which the inner part is mounted so as to be movable in a sealing manner. A hollow cylindrical region is not just understood to mean a circular cylindrical region, but rather any region formed by a displacement of a closed, flat curve along a straight or curved path. The volume can be changed by displacing the inner part relative to the outer part. By sealingly mounting the inner part in the outer part, the pressure in the brewing chamber, for example, can be varied when the volume changes.

[0022] The motor with any gear ratio, the hydraulic drive and / or the device operable by the user can be designed in such a way that the inner part can be actuated with a force in the range of 0 . 1-3 . 0 N / mm 2 , preferably in the range of 0 . 4-2 . 0 N / mm 2 , preferably in the range of 0 . 8- 1 . 2 N / mm 2can be moved. The force can be dimensioned differently depending on the application. If, for example, the volume of a capsule, particularly an aluminum capsule, is to be reduced before or after its extraction, the force must be large enough that the capsule and in particular the shell or the capsule body can be deformed. Naturally, the force required for this does not only depend on the material of the capsule, but overall on the design of the capsule and the effective location of the force on the capsule. However, if the volume of the brewing chamber is only to be increased during extraction in order to provide more space for the beverage substance, the force for the volume change can be dimensioned smaller. The motor is preferably decoupled from the closing movement of the brewing chamber halves.Accordingly, the motor does not have to apply all of the power required to tightly close the brewing chamber. In addition, the motor’s travel can be kept short because the entire closing movement does not have to be performed by the motor. If the closing movement of the brewing chamber halves is carried out in the traditional way by operating a lever and only the change in volume is motor-driven, the user has the feeling of having direct influence on the brewing process. It is also conceivable for the user to carry out a large part of the closing movement when closing and only the final section is closed by a motor. This means that the final section of the closing movement and / or the first section of the opening movement can be motor-driven using the same motor drive. For example, a gap between the two brewing chamber halves can be deliberately left open or created in order to be able to drain residual or rinsing water from the brewing chamber.The hydraulic drive or the device actuable by the user can also be decoupled from the closing movement of the brewing chamber halves in the same way. The inner part can have an inlet into the brewing chamber for introducing an extraction liquid, in particular at least one piercing spike in the form of an injector, in particular for piercing a casing and introducing the extraction liquid into a capsule. By arranging the inlet on the inner part, not only can the volume be changed, but the distance of the inlet from a beverage substance arranged in the brewing chamber can also be changed. In particular, when the inlet is designed with one or more piercing spikes, the time of piercing a capsule and / or the removal of the piercing spikes or perforation needles from the capsule can be precisely controlled.

[0023] The volume of the closed brewing chamber can have a preset extraction volume in the range of 7 ' 000 mm 3 up to 94,000 mm 3 , preferably 10 ' 500 mm 3 up to 70,000 mm 3 , particularly preferably 14 ' 000 mm 3 up to 47,000 mm 3 , have. Based on this preset extraction volume, the volume of the closed brewing chamber can be adjusted in a range from 30% to 300%, preferably from 40% to 200%, particularly preferably from 50% to 150%, of the preset extraction volume. The preset extraction volume is the volume which is usually intended for optimum extraction. Accordingly, the preset extraction volume for the extraction of coffee is designed for an amount of coffee powder in the range 3 g to 40 g, preferably 4 g to 30 g, particularly preferably 5 g to 20 g.

[0024] The first brewing chamber half and / or the second brewing chamber half can have at least one injection nozzle for introducing a rinsing liquid for spraying and / or wetting the beverage substance and / or for rinsing the brewing chamber. Using an injection nozzle, for example, the volume of the brewing chamber can be rinsed before or after extraction for cleaning purposes. The brewing chamber can also be preheated before extraction so that a subsequent extraction of a beverage substance and the beverage prepared therefrom have the desired temperature right from the start. However, it is also possible to wet a beverage substance arranged in the brewing chamber in order to improve the quality of a subsequent extraction. The physical properties of a capsule shell can also be influenced by spraying and / or wetting.For example, plastic capsules can be softened by spraying them with hot water, allowing them to expand during subsequent extraction. Likewise, a shell surrounding the beverage substance can be softened by spraying, allowing, for example, a beverage substance pellet enclosed in the shell to be broken open and / or loosened upon a reduction in volume.

[0025] The rinsing liquid does not have to be different from the liquid used to extract the beverage substance. This has the advantage that a special tank for the rinsing liquid is not required in a beverage preparation machine. Of course, it is also conceivable for the rinsing liquid to be different from the extraction liquid and, for example, to be pumped from a different tank. In this case, it is preferable to ensure that the extraction liquid is not contaminated with the rinsing liquid.

[0026] An injection valve can be arranged in a supply line to the injection nozzle. Such an injection valve allows targeted opening so that the exact time of introduction of the flushing fluid can be controlled. Likewise, the amount of flushing fluid, for example, can be precisely determined. The injection valve can be formed between the inner and outer parts and can be controlled by the relative position between the inner and outer parts. This enables simple control of the valve by the motor, the hydraulics and / or the device actuated by the user. In particular, an expensive solenoid valve can be dispensed with.

[0027] The injection nozzle can be formed by the inlet to the brewing chamber. This allows for a simple construction.

[0028] The injection nozzle can be designed as a gap nozzle between the outer and inner parts. This eliminates the need for a separate nozzle. At the same time, a gap nozzle between the inner and outer parts prevents residues of the beverage substance from accumulating in the gap between the inner and outer parts.

[0029] The brewing chamber may have an outlet for discharging a beverage extracted from the beverage substance and an opening for discharging a residual liquid. The opening may be formed separately from the outlet.

[0030] Here and in the following, a residual liquid is understood to mean any liquid that is not intended as a beverage. For example, a liquid that is used to rinse the brewing chamber and / or to spray and / or wet the shell of the beverage substance. Likewise, a leakage liquid is also understood to be a residual liquid, i.e., a portion of the extraction liquid that, for example, escapes through the shell of the beverage substance or through a passage through the shell formed by a piercing spike.

[0031] By designing a separate opening, the residual liquid can be easily drained away without it flowing through the outlet. Contamination of the prepared beverage can be easily avoided. However, it is also conceivable for the opening to be formed by the outlet itself. Separation from the prepared beverage can then take place outside the brewing chamber, for example, through a separate outlet, particularly one with a valve. It is also conceivable that, instead of an explicitly designed opening, the two brewing chamber halves are moved into a position in which they do not engage with each other in a sealing manner. The residual liquid is then drained away through a gap between the brewing chamber halves.

[0032] When used as intended, the opening can be positioned near the lowest point of the brewing chamber. Such an arrangement allows for complete drainage of any residual liquid from the brewing chamber.

[0033] The opening can also be located in the upper area of ​​the brewing chamber, particularly at the highest point of the brewing chamber, even when used as intended. With such an arrangement, the opening can also serve to supply and / or exhaust air into / out of the brewing chamber. For example, such an opening makes it easier to separate the two brewing chamber halves because negative pressure can be avoided. On the other hand, such an arrangement also allows air to be removed from the brewing chamber, which could otherwise lead to uncontrolled extraction. The opening can be opened and / or closed as required by a solenoid valve. It is also conceivable, however, that the opening is closed by the capsule itself when the capsule expands or the brewing chamber volume reduces.If the capsule expands and / or the brewing chamber volume reduces, any residual liquid in the brewing chamber can escape through this opening or when the brewing chamber is opened. When a controllable valve is used, this opening can also be used to relieve increased pressure in the brewing chamber, which could, for example, press against a lock on the brewing chamber and block it. Opening the brewing chamber can therefore be made easier. It goes without saying that an opening can be arranged either in the lowest point of the brewing chamber or in the upper area of ​​the brewing chamber, whereby the aforementioned advantages are combined.

[0034] The brewing chamber can have a safety valve that opens in the event of excess pressure in the brewing chamber. This prevents uncontrolled escape of extraction, rinsing, and / or residual liquid in the event of excess pressure. The safety valve can be designed for a pressure between 20 bar and 25 bar. As soon as the pressure in the brewing chamber exceeds this pressure, the safety valve opens and allows the fluid responsible for the excess pressure to escape. The safety valve preferably opens in an area that is not accessible to the user.

[0035] The safety valve can be implemented by a seal between the two brewing chamber halves. Accordingly, no further component is required. Only the seal must be designed in such a way that it functions as a safety valve. For example, the seal has an inward-facing sealing lip which, when the preset pressure is exceeded, is turned outwards and opens up a gap between the two brewing chamber halves. It is conceivable that only one brewing chamber half has the at least one piercing spike, while the other brewing chamber half has at least one penetration means for piercing a casing enclosing the beverage substance and an ejector.With a suitable design of the penetration means, it can be determined, for example, that when the brewing chamber is opened, the remaining beverage substance remains on the penetration means and is released from at least one piercing spike. In order to release the used beverage substance from the penetration means, the ejector can be used. The ejector is preferably designed such that it is movable relative to the penetration means. The ejector can, for example, have openings through which the penetration means reaches into the brewing chamber. Pushing the ejector forward towards the brewing chamber then strips the beverage substance from the penetration means. The ejector, the penetration means, or both can be moved.

[0036] The ejector can be mounted so as to be displaceable relative to the penetration means between an ejection position and a retraction position, wherein in the ejection position, the at least one penetration means can be covered by the ejector, and in the retraction position, the at least one penetration means can be exposed. The ejector can remain in the ejection position even when the brewing chamber is open and the beverage substance is being introduced, thus preventing damage to the casing surrounding the beverage substance by the penetration means.

[0037] This also allows for pre-brewing of the beverage substance and pressure buildup within the shell before the ejector is moved into the retracted position. The creation of an outlet opening from the shell can thus be actively controlled.

[0038] It is also conceivable for only one half of the brewing chamber to have the at least one piercing spike, and for the other half of the brewing chamber to have a structure for cutting and / or breaking open the shell enclosing the beverage substance. The structure can be designed in such a way that cutting and / or breaking open the shell only occurs under a predetermined internal pressure in the shell or under a predetermined contact pressure of the shell on the structure. Extraction under pressure, in particular with sudden pressure reduction, is made possible. The sudden pressure reduction or the pre-brewing / humidification of the beverage substance under pressure results in an increase in the TDS (Total Dissolved Solids) compared to conventional piercing. The extraction rate can also be improved, in particular to approx. 20% to 24%. The extraction rate refers to the production of a 40 ml espresso from 6.0 g of ground coffee.This corresponds to an improvement in the extraction rate of at least 0.5%, preferably 1.0%, particularly preferably at least 2.0%, compared to piercing without internal pressure.

[0039] The structure for cutting and / or breaking open the casing enclosing the beverage substance can comprise a plurality of projections and / or depressions protruding from a surface. The surface can be flat or curved.

[0040] For example, the structure can be designed similarly to a known relief plate with projections, which, for example, have the shape of a cone or a pyramid, pointed or blunt, or a cylinder. The contact pressure or internal pressure required for cutting and / or breaking open the casing can be determined by the design of the edges and / or tips of the projections, as well as their number.

[0041] The structure can also consist of a surface with holes perforated or simply indentations. The pressure required for cutting and / or breaking can then be influenced by the design of the indentations, particularly their size and number, as well as by the design of the transition from the surface to the indentation.

[0042] A beverage preparation machine according to the invention comprises a brewing unit as described above.

[0043] A system for preparing beverages according to the invention comprises a capsule containing a beverage substance and a beverage preparation machine as described above, wherein a shape of the capsule can be changed, in particular when the volume of the brewing chamber changes.

[0044] A method according to the invention for preparing a beverage with a beverage preparation machine, in particular as described above, comprises at least the steps:

[0045] - Introducing a beverage substance enclosed in a shell into a brewing chamber,

[0046] - Closing the brewing chamber and forming a volume,

[0047] - Extracting a beverage from the beverage substance by piercing the shell enclosing the beverage substance and introducing an extraction liquid into the shell and draining the extraction liquid from the shell and from the brewing chamber, - Changing the volume of the sealed brewing chamber before and / or during and / or after extraction, wherein the change in volume is effected by a mechanically coupled motor and / or by a hydraulic drive and / or by a device operable by a user.

[0048] By changing the volume of the brewing chamber, the volume can be precisely adjusted to the size or volume of the beverage substance required for optimal extraction. For example, this can allow a portion capsule to expand. Likewise, the volume of a portion capsule can be reduced to ensure correct extraction, for example with a portion capsule that contains a reduced amount of coffee powder. Likewise, a beverage substance that is in the form of one or more pellets can be broken up and loosened. Furthermore, by reducing the volume after extraction, the remaining beverage substance can be squeezed out, for example to prevent dripping.

[0049] By enclosing the beverage substance in a casing, it is possible, on the one hand, to remove the entire beverage substance from the brewing chamber when opening the brewing chamber. This makes cleaning the brewing chamber much easier for the user. On the other hand, the beverage substance can be introduced in sealed portion packs. The beverage substance can be sealed in the casing in an oxygen-tight and / or aroma-tight manner, which allows for extended storage.

[0050] By piercing a shell, extraction can occur within the shell, which in turn reduces cleaning effort. The brewing chamber itself does not need to come into contact with the prepared beverage. This also reduces the risk of cross-contamination during successive extraction of different beverage substances. Furthermore, the beverage substance can be enclosed in an aroma- and / or oxygen-tight shell.

[0051] The use of a mechanically coupled motor and / or a hydraulic drive to change the volume allows a motor control or pump control to respond directly to the volume of the brewing chamber. This enables precise volume adjustment.

[0052] If the volume change is achieved via a suitable device operable by the user, a mechanically coupled motor is not necessarily required. For example, the volume change can be made by the user via a lever and / or a gear. This gives the user the feeling of influencing the quality of the prepared beverage, as with a classic barista machine with manual pressure control.

[0053] The volume of the closed brewing chamber can be reduced. This allows a beverage substance that is in the form of a pressed pellet to be broken up and mechanically loosened in order to enable improved extraction. It is also conceivable, however, that the volume of the closed brewing chamber is increased, for example to take account of the beverage substance swelling upon contact with the extraction fluid. It is also conceivable that the volume of the closed brewing chamber is first reduced and then increased. Likewise, the volume can first be expanded and then reduced. In addition, multiple reduction and expansion cycles can be run.

[0054] The volume of the closed brewing chamber can have a preset extraction volume in the range of 7 ' 000 mm 3 up to 94,000 mm 3 , preferably 10 ' 500 mm 3up to 70,000 mm 3 , particularly preferably 14 ' 000 mm 3 up to 47,000 mm 3 , have. Based on this preset extraction volume, the volume of the closed brewing chamber can be varied within a range of 30% to 300%, preferably from 40% to 200%, particularly preferably from 50% to 150%, of the preset extraction volume. The preset extraction volume is the volume which is usually intended for optimum extraction. Accordingly, the preset extraction volume for an extraction of coffee is designed for an amount of coffee powder in the range 3 g to 40 g, preferably 4 g to 30 g, particularly preferably 5 g to 20 g.

[0055] Before changing the volume of the closed brewing chamber, the shell of the beverage substance introduced into the brewing chamber can be sprayed and / or wetted with a rinsing liquid. For example, this can be used to preheat the brewing chamber to an operating temperature. The physical properties of the shell can also be influenced. For example, a plastic shell can be softened by heating so that it adapts to the volume of the brewing chamber during subsequent extraction. Likewise, the softened capsule shell can also be deformed more easily so that, for example, the capsule volume, i.e. the space in which the beverage substance is enclosed, can be easily reduced or expanded by internal pressure in the shell. Likewise, a shell made of a biodegradable material can be softened by spraying / wetting so that it becomes flexible and stretchable.Accordingly, if the volume is reduced, a pellet enclosed in the casing can be broken up, which is necessary for satisfactory beverage preparation.

[0056] The rinsing liquid used for spraying or wetting can be drained from the brewing chamber before the beverage substance is extracted, for example, through an opening as described above. Mixing of this liquid with the prepared beverage can be prevented.

[0057] The spraying and / or wetting can be carried out by an injection nozzle, in particular by a gap nozzle between an outer part and an inner part of a first and / or second brewing chamber half, which inner part is mounted so as to be relatively displaceable therein. Depending on the design of the nozzle, the injected rinsing liquid can be dispensed in the form of a fine atomizer or as a liquid jet. With a fine atomization, only a small amount of rinsing liquid is needed to spray and / or wet the casing. By designing the nozzle as a gap nozzle between two moving parts, calcification can be easily prevented. In addition, it can be ensured that dirt that accumulates between the parts is rinsed out.

[0058] For spraying and / or wetting, an injection valve can be controlled by the motor and / or the hydraulic drive. By controlling the injection valve by the motor and / or the hydraulic drive, a separate control system for the valve is not necessary. Furthermore, the valve can be designed as an inexpensive mechanical valve. A solenoid valve is also not required. This makes production inexpensive. The extraction liquid can be drained from the shell and from the brewing chamber once a preset pressure has been reached in the shell and / or a preset time has been reached and / or after a preset amount of extraction liquid has been introduced into the shell and / or at a preset volume flow rate. This enables pre-brewing and extraction of the beverage substance within the brewing chamber under pressure.This allows the quality to be optimized, particularly for coffee preparation, and the timing of the extraction can be controlled. It goes without saying that the extraction liquid can be extracted independently of any change in volume. In particular, the extraction liquid can also be extracted in a beverage preparation machine that does not have a drive for changing the volume of the closed brewing chamber and, in particular, in which no change in the volume of the closed brewing chamber occurs.

[0059] For example, an opening in the casing for draining the extraction liquid can be created only after a preset pressure has been reached in the casing and / or a preset time has elapsed and / or after a preset amount of extraction liquid has been introduced into the casing and / or at a preset volume flow. The opening can be created actively, for example, by the movement of a penetrating agent, or passively, triggered solely by the internal pressure in the casing.

[0060] To create the opening for draining off the extraction liquid, the casing can be pierced by at least one penetrating means and / or cut and / or broken open at a structure. The penetrating means can be actively moved or released. It is also conceivable for the casing to move towards the penetration element due to the expansion of the internal pressure prevailing in the casing and thus be passively pierced. It is also conceivable for the casing to press against a structure due to the expansion of the internal pressure prevailing in the casing and thus be cut and / or broken open purely passively. Of course, the structure can also be moved towards the casing when a preset pressure and / or a preset time is reached and / or after a preset amount of extraction liquid has been introduced and / or at a preset volume flow.

[0061] The invention is explained in more detail below with reference to figures which merely represent exemplary embodiments. They show:

[0062] Figure 1: a schematic representation of a beverage preparation machine according to the invention,

[0063] Figure 2: a schematic representation of a brewing unit according to the invention,

[0064] Figure 3: a schematic representation of a first brewing chamber half of a brewing unit according to the invention,

[0065] Figure 4 : a schematic representation of the brewing chamber half of Figure 3 with an inner part in a different position,

[0066] Figure 5: a schematic representation of a brewing unit according to the invention,

[0067] Figure 6a: a perspective view of a relief plate of a second brewing chamber half, Figure 6b: a cross section through the relief plate according to Figure 6a,

[0068] Figure 7a: a schematic representation of a brewing unit according to the invention in front of an outlet-side opening of a shell around a beverage substance,

[0069] Figure 7b: a schematic representation of the brewing unit according to Figure 7a with an outlet-side opening of a shell around a beverage substance under internal pressure.

[0070] Figure 1 shows a schematic representation of a beverage preparation machine 1 according to the invention with a first embodiment of a brewing unit 10. In a known manner, the beverage preparation machine 1 has a water tank 37, a flow meter 38, a pump 39, a thermoblock 40, and a residue container 36.

[0071] To prepare a beverage, a beverage substance with a shell enclosing the beverage substance, for example as a portion capsule, is introduced into a brewing chamber 13 which is formed by a first brewing chamber half 11 and a second brewing chamber half 12. For this purpose, the two brewing chamber halves 11, 12 are mounted so as to be displaceable relative to one another, so that they can be moved from an open position, in which the beverage substance can be introduced, into a closed position to form a closed brewing chamber 13. The brewing unit 10 is not completely closed in the illustration shown. A gap S (see Figure 2) can be seen between the two brewing chamber halves 11, 12. In the closed position, the shell of the beverage substance enclosed in the brewing chamber 13 is pierced by piercing spikes 20 of the first brewing chamber half 11 and by penetration means 41 of the second brewing chamber half 12.Water is pumped from the water tank 37 via an optional flow meter 38 by means of a pump 39 under pressure through a thermoblock 40 into the brewing chamber 13. The water, which has been heated or cooled in the thermoblock 40 to the temperature required to prepare the respective beverage, flows through the beverage substance in the brewing chamber 13 and is dispensed through an outlet 23, for example into a cup. Residual water or leakage water that is not carried through the beverage substance to the outlet 23 can be fed to a residual container 36 through a separate outlet, for example via a valve 35.

[0072] Figure 2 shows a schematic representation of a brewing unit 10 according to the invention. The brewing unit 10 in turn has a first and a second brewing chamber half 11, 12. The first brewing chamber half 11 has an outer part 15 and an inner part 16 slidably mounted therein. On the outer part 15, on its side facing the second brewing chamber half 12, a seal 26 is arranged, which enables a tight closure of the two brewing chamber halves 11, 12 and thus the formation of a closed brewing chamber 13 with a volume 14. In the representation shown, the brewing chamber 13 is not closed; despite the seal 26, a gap S is still formed between the two brewing chamber halves 11, 12. Of course, the seal 26 can also be arranged on the second brewing chamber half 12.When the brewing chamber 13 is closed, the seal 26 can also function as a safety valve due to its design with an inward-facing lip. As soon as the pressure within the brewing chamber 13 exceeds a predetermined value, typically between 20 bar and 25 bar, the lip of the seal is turned outward, allowing the excess pressure to escape from the brewing chamber 13.

[0073] The inner part 16 of the first brewing chamber half 11 is slidably mounted in a passage 17 of the outer part 15. For this purpose, the outer part 15 has a hollow cylindrical region 18 in the passage 17, in which the complementarily designed inner part 16 is arranged. The displacement between the outer and inner parts 15, 16 is effected by a motor, which is only shown in the illustration by an arrow 30. In order to prevent leakage between the outer and inner parts 15, 16, two seals 29, for example an O-ring each, are provided. It goes without saying that only one seal or more than two seals can be present. The inner part 16, which is arranged so as to be slidable relative to the outer part 15, has a supply line 28 for an extraction liquid, usually water at a predetermined temperature. The supply line 28 opens into an inlet 19 to the brewing chamber 13 .In the illustrated embodiment, the inlet 19 terminates in one or more piercing spikes 20, so that these simultaneously serve as injectors 21 for injecting the extraction liquid through the casing directly into the beverage substance. Likewise, the inlet 19 can also open into the brewing chamber 13 at the base of the piercing spike 20. The extraction liquid is then directed into the brewing chamber 13 and finds its way through the casing pierced by the piercing spike 20 along the piercing spike 20 into the beverage substance.

[0074] The second brewing chamber half 12 has one or more penetration means 41. These are again shown as hollow cannulas, so that they form an outlet 23 from the brewing chamber 13 for the prepared beverage. Furthermore, the second brewing chamber half 12 has an ejector 31, which pushes the beverage substance from the penetration means 41 after extraction has taken place and after the brewing chamber 13 has been opened. Depending on the type of beverage substance to be extracted and its surrounding shell, the second brewing chamber half 12 can also have a different outlet 23. For example, the second brewing chamber half 12 can have a relief plate which is provided with outlet openings 23. A relief plate can, for example, be used on a lid foil of a capsule under pressure to form a large number of cracks so that the prepared beverage can flow out of the capsule.In this case, the ejector 31 will also be designed differently.

[0075] To prepare a beverage, it may be necessary for the shell of the beverage substance to be conditioned before extraction. For example, when using a plastic capsule, the shell can be softened by heat. The shell and possibly also the beverage substance enclosed in the shell can then be deformed. This is particularly necessary when using a compacted beverage substance, for example in a pressed pellet, in order to be able to loosen the beverage substance. For this purpose, in the embodiment shown, the first brewing chamber half 11 has injection nozzles 22 on its piercing spikes 20. The beverage substance introduced into the brewing chamber 13 can thus be sprayed and / or wetted with a rinsing liquid, for example hot water, before the actual extraction process begins.Accordingly, in this configuration, the inner part 16 in the illustrated embodiment is moved to the left by the motor 30 so that the piercing spikes 20 do not yet penetrate the shell of the beverage substance. It goes without saying that the displacement to the left of the inner part 16 can already take place before or during the closing of the brewing chamber 13. Obviously, such a displacement of the inner part 16 can expose an opening 24 which drains the rinsing liquid to a residual container 36 (see Figures 3 and 4). Alternatively, the rinsing liquid can also be drained through the gap S between the two brewing chamber halves 11, 12.

[0076] Once the shell of the beverage substance has been softened, the inner part 16 can be moved back to the right (in the embodiment shown) by the motor drive 30 so that the shell can be pierced and, if necessary, a pellet can be loosened. The extraction of the beverage substance can then take place in the usual way. If necessary, the inner part 16 can be moved back to the left before, during or after the extraction, for example to take into account an expansion of the beverage substance due to contact with the extraction liquid. The shell of the beverage substance will adapt to the increased volume 14 of the brewing chamber 13 due to the internal pressure prevailing in the shell. It can thus be ensured that the extraction always takes place in an optimal extraction volume.

[0077] Figures 3 and 4 show a schematic representation of a further embodiment of a first brewing chamber half 11 of a brewing unit according to the invention. A beverage substance 6 enclosed in a shell 8, thus in the form of a capsule 5, is also shown. In this case, an inner part 16 in Figure 3 is arranged in a position in the outer part 15 where the opening 24 to the residual container 36 is closed and the piercing spikes 20 have pierced the shell 8 of the beverage substance 6. In Figure 4, the opening 24 to the residual container 36 is exposed by the inner part 16, the shell 6 of the capsule 5 is still undamaged. In this position in Figure 4, an injection nozzle 22 is formed between the inner part 16 and the outer part 15, through which the shell 8 of the beverage substance 6 can be sprayed and / or wetted. For this purpose, a supply line 28 is provided which leads to a channel 32 between the two seals 29 between the outer and inner parts 15, 16.Depending on the position of the inner part 16 relative to the outer part 15, the injection nozzle 22 is connected to the supply line 28 or not. Thus, an injection valve 27 is formed, which can be switched depending on the position of the inner part 16.

[0078] As already explained in relation to Figure 2, for the actual extraction, the inner part 16 is displaced with a force F in the illustration again to the right as shown in Figure 3, so that the injection valve 27 and the opening 24 to the residual container 36 are closed. During this displacement, the shell 8 of the beverage substance 6 is penetrated by the piercing spikes 20 or the injectors 21. The extraction can then take place. Of course, it is also conceivable for the opening 24 and / or the injection valve 27 to remain open during the extraction.

[0079] Figure 5 shows a schematic representation of a brewing unit 10 according to the invention with a first brewing chamber half 11 and a second brewing chamber half 12. As already disclosed in the preceding figures, the first brewing chamber half 11 has piercing spikes 20 for penetrating a shell enclosing a beverage substance. The piercing spikes are in turn designed as hollow cannulas, thus enabling the introduction of an extraction liquid into the beverage substance.

[0080] The second brewing chamber half 12 in turn has one or more penetration means 41, which are also shown as hollow cannulas and form the outlet from the brewing chamber. The penetration means are covered by an ejector 31 so that the shell of the beverage substance is not damaged on the outlet side. This enables pre-brewing of the beverage substance in the shell. For example, a certain amount of extraction liquid can be introduced into the shell before the ejector 31 releases the penetration means 41. Accordingly, the ejector 31 and the penetration means 41 are displaceable relative to one another. The ejector 31 and / or the penetration means 41 can be displaceably mounted in the brewing chamber half 12. The displacement can be triggered under a certain internal pressure in the shell or in the supply line to the injection spikes 20.It is also conceivable that the triggering could be controlled by timing or by the flow rate of the extraction liquid. Especially when preparing coffee, a pressure buildup in the beverage followed by an abrupt pressure release is crucial for the extraction of good coffee, ensuring optimal aroma extraction and flavor development. Furthermore, a sudden pressure drop promotes the formation of a crema.

[0081] Figures 6a and 6b show, in a perspective view and a cross-section, a relief plate such as can be arranged in a second brewing chamber half instead of penetration means. The relief plate has a surface 43 and a structure 42 protruding from this surface 43. In the case shown, the structure 42 is a plurality of projections 44 which protrude from the surface 43. At the base of some or all of the projections 44 there is an outlet 23 which allows the prepared beverage to escape. Depending on the design of the casing enclosing the beverage substance and of the projections 44, as well as their number, it can be precisely defined under which pressure or at which contact force on the projections 44 the casing breaks open. Accordingly, pre-brewing of the beverage substance in the casing under pressure with a sudden drop in pressure is again possible.In addition, there is no need for moving elements in the second half of the brewing chamber.

[0082] It goes without saying that an ejector, similar to Figure 5, can also be used in this case. The ejector serves to facilitate the ejection of the beverage substrate and / or to protect the casing when the beverage substrate is introduced into the brewing chamber.

[0083] Figures 7a and 7b show a schematic representation of a further embodiment of a brewing unit 10 according to the invention. The first brewing chamber half 11 is designed as already described above and has a plurality of piercing spikes 20. The second brewing chamber half 12 has a structure 42 which, similar to the relief plate in Figures 6a and 6b, has a surface 43 facing the brewing chamber. In contrast to the relief plate, however, the structure 42 has depressions 45 which promote the breaking open of the shell of the beverage substance.

[0084] After an initial deformation of the beverage substance, as shown in Figure 7a, the internal pressure in the shell can be increased by introducing an extraction liquid such that the shell expands and fills the entire brewing chamber. Accordingly, the shell is pressed onto the structure 42 with the force of the internal pressure so that the shell tears or bursts in the area of ​​the depressions 45. The pressure required to tear or burst the shell can be adjusted by the design of the shell, the edge in the transition from the surface 43 to the depression 45, as well as the number and size of the depressions. Again, no moving parts are necessary on the second brewing chamber half. Of course, an ejector is also conceivable in this configuration, although in this case the ejector is preferably assigned to the first brewing chamber half 11.

Claims

Patent claims 1. Brewing unit (10) for a beverage preparation machine (1) comprising at least a first brewing chamber half (11) and a second brewing chamber half (12) for forming a brewing chamber (13), wherein the first brewing chamber half (11) and the second brewing chamber half (12) are movable relative to one another from an open position for inserting a beverage substance (6) into a closed position for forming a closed brewing chamber (13) with a volume (14) and for extracting the beverage substance (6), wherein the first brewing chamber half (11) and / or the second brewing chamber half (12) have at least one piercing spike (20) for piercing a casing (8) enclosing the beverage substance (6), wherein the first brewing chamber half (11) and / or the second brewing chamber half (12) are designed such that in the closed position the volume (14) of the closed brewing chamber (13) is changeable,wherein a mechanically coupled motor (30) and / or a hydraulic drive and / or a device operable by a user is provided for changing the volume (14).

2. Brewing unit (10) according to claim 1, wherein the first brewing chamber half (11) and / or the second brewing chamber half (12) is designed in two parts and has an outer part (15) and an inner part (16), wherein the outer part (15) and the inner part (16) are displaceable relative to one another.

3. Brewing unit (10) according to claim 2, wherein the outer part (15) has a passage (17), in particular with a hollow cylindrical region (18), in which the inner part (16) is mounted in a sealingly displaceable manner.

4. Brewing unit (10) according to claim 2 or 3, wherein the motor (30) and / or the hydraulic drive and / or the device operable by the user, in particular with a transmission, is designed such that the inner part is actuated with a force (F) in the range of 0.1-3.0 N / mm 2 , preferably in the range of 0.4-2.0 N / mm 2 , preferably in the range of 0.8-1.2 N / mm 2 , can be moved.

5. Brewing unit (10) according to one of claims 2 to 4, wherein the inner part (16) has an inlet (19) into the brewing chamber (13) for introducing an extraction liquid, in particular at least one piercing spike (20) in the form of an injector (21) for piercing a shell (8) and for introducing the extraction liquid into a capsule (5).

6. Brewing unit (10) according to one of the preceding claims, wherein the volume (14) of the closed brewing chamber (13) is adjustable starting from a preset extraction volume in the range from 30% to 300%, preferably from 40% to 200%, particularly preferably from 50% to 150%.

7. Brewing unit (10) according to one of the preceding claims, wherein the first brewing chamber half (11) and / or the second brewing chamber half (12) has at least one injection nozzle (21) for introducing a rinsing liquid for spraying and / or wetting the beverage substance (6) and / or for rinsing the brewing chamber (13).

8. Brewing unit (10) according to claim 7, wherein an injection valve (27) is arranged in a supply line (28) to the injection nozzle (21).

9. Brewing unit (10) according to claim 2 and 8, wherein the injection valve (27) is formed between the inner part (16) and the outer part (15) and can be controlled by the relative position between the inner part (16) and the outer part (15).

10. Brewing unit (10) according to claim 2 and one of claims 7 to 9, wherein the injection nozzle (22) is designed as a gap nozzle between the outer part (15) and the inner part (16).

11. Brewing unit (10) according to one of the preceding claims, wherein the brewing chamber (13) has an outlet (23) for discharging a beverage and an opening (24) for discharging a residual liquid.

12. Brewing unit (10) according to one of the preceding claims, wherein only one brewing chamber half (11, 12) has the at least one piercing spike (20) and the other brewing chamber half (12, 11) has at least one penetration means (41) for piercing and an ejector (31).

13. Brewing unit (10) according to claim 12, wherein the ejector (31) is mounted displaceably relative to the penetration means (41) between an ejection position and a retraction position, wherein in the ejection position the at least one penetration means (41) is covered by the ejector (31) and in the retracted position, at least one penetration means (41) is exposed.

14. Brewing unit (10) according to one of claims 1 to 11, wherein only one brewing chamber half (11, 12) has the at least one piercing spike (20) and the other brewing chamber half (12, 11) has a structure (42) for cutting and / or breaking open the casing (8) enclosing the beverage substance (6).

15. Brewing unit (10) according to claim 14, wherein the structure (42) for cutting and / or breaking open the casing (8) enclosing the beverage substance (6) has a plurality of projections (44) and / or depressions (45) projecting from a surface (43).

16. Beverage preparation machine (1) comprising a brewing unit (10) according to one of the preceding claims.

17. A system for beverage preparation comprising a capsule (5) containing a beverage substance (6) and a beverage preparation machine (1) according to claim 15, wherein a shape of the capsule (5) is changeable, in particular upon a change in the volume (14) of the brewing chamber (10).

18. A method for preparing a beverage with a beverage preparation machine (1), in particular according to claim 16, comprising at least the steps, Introducing a beverage substance (6) enclosed by a shell (8) into a brewing chamber (13), closing the brewing chamber (13) and forming a volume (14), extracting a beverage from the beverage substance (6) by piercing the casing (8) enclosing the beverage substance (6) and introducing an extraction liquid into the casing (8) and draining the extraction liquid from the casing (8) and from the brewing chamber (13), Changing the volume (14) of the closed brewing chamber (10) before and / or during and / or after extraction, characterized in that the change in the volume (14) is carried out by a mechanically coupled motor (30) and / or by a hydraulic drive and / or by a device that can be actuated by a user.

19. The method according to claim 18, wherein the volume (14) of the closed brewing chamber (10) is reduced and / or increased.

20. Method according to claim 18 or 19, wherein before changing the volume (14) of the closed brewing chamber (10), the shell (8) of the beverage substance (6) introduced into the brewing chamber (10) is sprayed and / or wetted with a rinsing liquid.

21. The method according to claim 20, wherein the rinsing liquid used for spraying and / or wetting is removed from the brewing chamber before the extraction of the beverage substance.

22. Method according to claim 21, wherein, in order to drain the rinsing liquid, the two brewing chamber halves (11, 12) are moved apart in such a way that a gap (S) is formed between the two brewing chamber halves (11, 12).

23. Method according to one of claims 20 to 22, wherein the spraying and / or wetting is carried out by an injection nozzle (22), in particular by means of a gap nozzle between an outer part (15) and an inner part (16) of a first and / or second brewing chamber half (11, 12) which is mounted relatively displaceably therein.

24. Method according to one of claims 20 to 23, wherein an injection valve (27) is controlled by the motor (30) and / or the hydraulic drive for spraying and / or wetting.

25. Method according to one of claims 18 to 24, wherein the extraction liquid is drained from the casing (8) and from the brewing chamber (13) after reaching a preset pressure in the casing (8) and / or a preset time and / or after introducing a preset amount of the extraction liquid into the casing (8) and / or at a preset volume flow.

26. The method according to claim 25, wherein after reaching a preset pressure in the casing (8) and / or a preset time and / or after introducing a preset amount of the extraction liquid into the casing (8) and / or at a preset volume flow, an opening for discharging the extraction liquid from the casing (8) is created.

27. The method according to claim 26, wherein, to create the opening for discharging the extraction liquid, the casing (8) is pierced by at least one penetration means (41) and / or cut and / or broken open at a structure (42).

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