Blending unit, beverage preparation machine and beverage preparation system

Abstract

A brewing unit of a beverage preparation machine having a brewing chamber (10) and a brewing chamber surface (15), the brewing chamber (10) being designed to be substantially rotationally symmetrical with respect to an axis (16) directed from a first brewing chamber half (11) to a second brewing chamber half (12). The brewing chamber (10) has a maximum axial extension (17) in the direction of the axis (16) that is smaller than a maximum diameter (18) transverse to the axis (16). Furthermore, in the area of ​​the axis (16), the brewing chamber (10) has a thickness (19) equal to or smaller than the axial extension (17).

Description

[Technical field]

[0001] The present disclosure relates to a brewing unit, a beverage preparation machine and a beverage preparation system according to the subject matter of the independent claims. [Background technology]

[0002] Various capsule-based beverage preparation machines with brewing units and brewing chamber halves as well as various methods for capsule management and beverage preparation are known from the prior art. Summary of the Invention [Problem to be solved by the invention]

[0003] The object of the present invention is to overcome the drawbacks of the prior art. In particular, a system should be provided which allows simple operation by the user. [Means for solving the problem]

[0004] This problem is solved by an apparatus and a method as defined in the independent claims. Further embodiments result from the dependent patent claims.

[0005] In the following, a capsule is understood to be a capsule for preparing a beverage or liquid food. The capsule may comprise a capsule body filled with a substance for preparing a beverage. However, the capsule should also be understood as a beverage substance enclosed in a shell. For example, the beverage substance may be compressed into a preferably spherical shaped body and coated with a shell material or enclosed in a loose shell. However, the capsule may also contain a loose beverage substance in powder form enclosed in a casing.

[0006] A brewing unit for a beverage preparation machine disclosed herein comprises at least a first and a second brewing chamber half. The brewing chamber halves are arranged to be movable relative to each other from a closed position for forming a closed brewing chamber to an open position in which a capsule can be inserted into the brewing chamber. In this respect, the brewing unit has at least one, preferably two, holding means, which holds the capsule in an intermediate open position between the first and second brewing chamber halves when the capsule is inserted and releases it when the brewing chamber is closed. The first and second brewing chamber halves are spaced apart before the capsule is released by the holding means such that the brewing chamber halves cannot grip the capsule, so that the capsule would fall through between the brewing chamber halves if not held by the holding means.

[0007] This spacing of the two brewing chamber halves ensures that the capsule can be easily removed from the brewing unit once the intermediate position is reached. Only the retaining means need to be separated to release the capsule. Thus, if a capsule is accidentally inserted into the brewing chamber, it can be removed again and stored for later use.

[0008] The distance between the brewing chamber halves may be at least 10% greater than the largest dimension or diameter of a capsule for the preparation of a beverage in the brewing unit before and / or after its extraction.

[0009] Spherical or polygonal capsules for preparing coffee portions can have a maximum dimension or diameter of 21 to 52 mm, preferably 23 to 42 mm, particularly preferably 25 to 30 mm. However, depending on the amount of beverage substance required for beverage preparation, spherical or polygonal capsules with a maximum dimension or diameter of 50 mm ± 10%, 26 mm ± 10% or 23 mm ± 10% are also conceivable.

[0010] The capsule may be guided and held, prior to release, in the intermediate position by a holding means such that it is not in mechanical contact with the first brew chamber half and / or the second brew chamber half.

[0011] By avoiding mechanical or physical contact between the capsule and the brewing chamber halves, an easy insertion of the capsule can be achieved. It is likewise possible that the capsule can be removed again from the brewing unit after reaching an intermediate position without being damaged. Thus, if a capsule is inserted in the brewing chamber by mistake, it can be removed again and stored without restriction for later use.

[0012] The brewing unit may have control means which interact with the holding means such that they release the capsules when the brewing chamber is closed. The direct coupling of the movement of the brewing chamber with the holding means is easy to achieve, since the control means are directly connected to the brewing unit. Furthermore, the capsules do not have to be pushed out of the holding means, but the holding means automatically releases the capsules.

[0013] The holding means can be mounted such that it can pivot about an axis and / or be displaced axially. In order for the brewing chamber halves to move together, the holding means must be displaced away from the area between the brewing chamber halves. A simple moving away can be realized by pivoting about an axis and / or axial displacement. At the same time, the axis can define an axial direction for the displacement. However, it is also conceivable that the displacement occurs along an axial direction that runs at an angle to the axis of the pivoting movement. If the pivoting axis is horizontal, a movement of the holding means in at least one direction can occur due to its gravitational force.

[0014] The holding means may be spoon-shaped. In this context, spoon-shaped means that the holding means is concave on the side associated with the capsule in the intended application, so that the capsule can be at least partially gripped around and / or under it. The capsule can thus be gripped and held in a corresponding intermediate position with only slight engagement. It goes without saying that the concave design of the holding means must be adapted to the shape of the capsule to be used.

[0015] Conventional capsules are usually gripped by the holding means on a circumferential flange. In contrast to this gripping at the flange, the present holding means can be designed such that it can grip a capsule without a defined gripping point. For example, a capsule without a flange can be held in an intermediate position by the holding means. Spherical or cubic shaped capsules are particularly contemplated. Likewise, capsules with any polyhedral shape or even cylindrical capsules can be gripped by the holding means. Spherical, cubic or polyhedral shaped capsules have the advantage that they do not have to be held aligned in an intermediate position.

[0016] The holding means can laterally surround the capsule in the intermediate position. The holding means have a minimum distance from each other, which corresponds to a maximum of 90% of the capsule diameter measured in the perimeter area of ​​the capsule. This ensures that the capsule, when held in the intermediate position, cannot under any circumstances slide between the holding means and fall out of the intermediate position. The capsule diameter in the perimeter area is determined by a cross section through the capsule transverse to the direction of movement of the two brewing chamber halves relative to each other. The holding means preferably enclose the capsule to a range of at least 20° each. This ensures that the capsule can be reliably held in the intermediate position.

[0017] The holding means can be pretensioned against one another on the axis by a spring element. Using this pretension of the spring force, a capsule inserted by mistake in an intermediate position can be determined with a force with which it can be removed again from the intermediate position when not in use. It can happen, for example, that a user has inserted an espresso capsule by mistake, but wants to enjoy a long coffee. In conventional brewing units, the inserted capsule can only be removed from the brewing unit by closing the brewing chamber and reopening it. The user can therefore only prepare an espresso capsule with a larger amount of water, enjoy an espresso instead of a long coffee, or remove the pierced capsule from the brewing unit without extraction. However, if the holding means only hold the capsule in position by a slight pretension of the spring force against one another, the capsule can simply be pushed through the space between the brewing chambers. The capsule is not damaged or punctured during the process and can be reused.

[0018] Another aspect of the present disclosure relates to a method of inserting a capsule into a brewing unit of a beverage preparation machine. In this respect, the brewing unit comprises a first brewing chamber half and a second brewing chamber half displaceably arranged with respect to each other to form a brewing chamber. And the brewing unit has at least one, preferably two holding means for holding and positioning the capsule. During the process, the capsule is held in an intermediate position between the two brewing chamber halves by or with the holding means. When the brewing chamber halves are moved together, the holding means releases the capsule, which is gripped and aligned by one or both of the brewing chamber halves. The brewing chamber halves move together to form a closed brewing chamber. The first brewing chamber half and the second brewing chamber half move apart before release by the holding means, so that if the brewing chamber half is released prematurely by the holding means, the brewing chamber half cannot engage the capsule. If the capsule is released prematurely, it falls between the two brewing chamber halves.

[0019] A capsule can therefore be freely inserted into an intermediate position before the brewing chamber halves move together. An incorrectly inserted capsule can be removed again from the intermediate position, for example to prepare an espresso instead of a long coffee. To do this, only the retaining means need to be overcome, for example by pushing them apart.

[0020] The capsule may not be in mechanical contact with the first and / or second brew chamber halves before being released by the retaining means.

[0021] Thus, removal of an incorrectly inserted capsule from the intermediate position can be performed without damaging the capsule, and the user can therefore subsequently use the capsule thus "recovered" without restriction.

[0022] When the brewing chamber halves are moved together, the retaining means can be shifted axially on the axis, resulting in an increase in the distance between the retaining means. The axial displacement is easy to achieve and can be precisely controlled.

[0023] The holding means can be moved on the axis against the force of the spring element, so that the holding means are preloaded against each other, whereby a defined minimum distance between the holding means can be provided, and by overcoming the spring force, the capsule held by the holding means in an intermediate position can be removed.

[0024] When the capsules are released, the holding means may pivot about an axis. The axis may be the same axis along which the holding means move. Alternatively, it may be a different axis. The pivoting movement of the holding means simply removes them from the area between the brewing chamber halves so that the brewing chamber can be closed. The pivoting movement may be performed upwards or downwards about a horizontally arranged axis. It is likewise conceivable that the axis is aligned vertically and the holding means pivots laterally. The holding means may perform only a pivoting movement or only a sliding movement. A combination of movements is also possible.

[0025] When the brewing chamber halves are released, the holding means can pivot about an axis to return to a position between the brewing chamber halves. In doing so, the capsule adhering to the brewing chamber halves can be pushed away from the brewing chamber halves. Preferably, such return pivoting occurs downwards such that the capsule is pushed downwards away from the area between the brewing chamber halves by gravity. The moment of swinging back to a position between the brewing chamber halves can be delayed, for example, only after the brewing chamber halves have reached their open position.

[0026] Another aspect of the present disclosure relates to a beverage preparation machine having a brewing unit as described above. Another aspect of the present disclosure relates to a beverage preparation system comprising the capsule and a brewing unit described above.

[0027] Another aspect of the disclosure relates to a brewing chamber half for forming a brewing chamber together with a corresponding second brewing chamber half of a brewing unit of a beverage preparation machine. In this regard, the brewing chamber half comprises an inlet for introducing a brewing liquid for beverage preparation and / or an outlet for discharging the prepared beverage. Furthermore, the brewing chamber half has at least one further passage for the introduction and / or discharging of a rinsing liquid. Thereby, the further passage is preferably separate from the inlet and the outlet. In case of a single further passage, this preferably serves for introducing and discharging the rinsing liquid. In case of two or more further passages, the introduction and discharging can be performed via separate passages. The brewing unit can be designed as described above.

[0028] Such additional passages in the brewing chamber halves allow easy cleaning and / or rinsing of the brewing chamber without the inlet and / or outlet for preparing the beverage coming into contact with the rinsing liquid.

[0029] The further passage can have a filter element. By using a filter element, interfering particles can be prevented from being washed into the brewing chamber and subsequently affecting the beverage preparation there. It also prevents larger components of the beverage preparation, such as coffee particles, from escaping via the further passage and damaging, blocking or obstructing downstream valves.

[0030] The brewing chamber half may have an ejector for ejecting the capsule, designed to be movable relative to the brewing chamber half. This allows the capsule attached to the brewing chamber half to be ejected after the beverage has been prepared and after the brewing chamber has been opened. Such an ejector is particularly useful when the capsule is perforated by a perforation means attached to the brewing chamber half. Conventional capsules with flanges can be gripped at the flange and separated from the perforation means. In the case of capsules without a stable flange or without any flange at all, the perforated capsule adheres to the perforation means and can then be moved away from them or peeled off with the ejector. The ejector also serves to separate the capsule from the brewing chamber half or from the perforation means, for example in the case of capsules with a shell made of cellulose or alginate.

[0031] Further passages can be formed or opened between the ejector and the brew chamber halves. The movement of the ejector relative to the brew chamber halves ensures that the further passages are always self-cleaning.

[0032] The filter element can be designed as a gap, preferably an annular gap, between the ejector and the brewing chamber half. The gap is preferably dimensioned such that the beverage substance cannot penetrate into the gap. The aforementioned movement between the ejector and the brewing chamber half actively prevents particles of the beverage substance from clogging the gap.

[0033] The gap may have a typical width of 200 μm, in particular the width of the gap is between 50 μm and 500 μm, preferably between 100 μm and 350 μm, particularly preferably between 150 μm and 250 μm. This dimensioning in particular prevents the ingress of coffee particles which may occur during extraction of the coffee capsule.

[0034] The brewing chamber halves may have piercing means for piercing the inlet or outlet side of the capsule. The piercing means serve to pierce the capsule shell so that the extraction fluid can be introduced into or ejected from the capsule. The piercing means are preferably arranged movably relative to the brewing chamber halves. The movably arranged piercing means allows the timing of the puncturing of the capsule to be controlled purposefully independent of the closing of the brewing chamber. For example, it is possible to arrange the piercing means on the outlet side of the capsule so that the piercing means does not protrude into the brewing chamber. For example, the piercing means can be covered by an ejector on the outlet side. Thus, in a first extraction step, the capsule can be first pierced on the inlet side so that the beverage substrate to be extracted is wetted. Only in a subsequent step is the capsule opened, pierced or perforated on the outlet side. In this way, pressure can be built up in the capsule before the actual extraction. For example, this allows the coffee substance to be pre-extracted before the coffee beverage is prepared. However, it is also conceivable that the piercing means pierces the capsule simultaneously on the inlet side and on the outlet side, in which case the piercing means is exposed and not covered by the ejector.

[0035] The ejector may be arranged to be movable relative to the piercing means, which allows the capsule to be peeled off from the piercing means even though the piercing means is movable relative to the brewing chamber half.

[0036] The brewing chamber half may have at least one groove approximately in the middle, which extends from the ejector in the direction of the corresponding second brewing chamber half. Such a groove facilitates the detachment of the capsule from the surface of the brewing chamber or from the corresponding perforation means. Thus, a vacuum created between the brewing chamber wall and the capsule by retracting the perforation means or the injector plate and, if necessary, by opening the brewing chamber, may be particularly prevented. Beverage substance is not drawn from the capsule through the opening formed by the perforation means, which may contaminate the brewing chamber. This groove may absorb any residual water during extraction, which, in turn, supports the capsule in the area of ​​the groove.

[0037] The groove may have a width of 0.2 mm to 3.0 mm, preferably 1.0 mm, and a depth of 0.2 mm to 3.0 mm, preferably 1.0 mm. These dimensions have been found to be optimal for separating the capsule from the brewing chamber without adversely affecting the behavior of the capsule in the brewing chamber during extraction.

[0038] Another aspect of the present disclosure relates to a brewing unit of a beverage preparation machine. The brewing unit comprises two corresponding brewing chamber halves. The brewing chamber halves are configured to be movable relative to each other to be moved from an open position for feeding and inserting a capsule to a closed position for forming a brewing chamber and for sealing and extracting the capsule. In this regard, at least one of the brewing chamber halves has an inlet for introducing an extracting liquid for preparing a beverage, and at least one brewing chamber half has an outlet for discharging the prepared beverage. Furthermore, at least one brewing chamber half has at least one further inlet for introducing and / or discharging a rinsing liquid. The brewing unit can be designed as described above.

[0039] Such additional passages in the brewing chamber halves allow easy cleaning and / or rinsing of the brewing chamber without the rinsing liquid entering the inlet and / or outlet. The inlet and outlet can be located in the same half of the brewing chamber or in different halves of the brewing chamber. Similarly, the additional passage may be located in one half of the brewing chamber together with the inlet or outlet, or the additional passage is located in the same half of the brewing chamber together with the inlet and outlet. Furthermore, the additional passage can be located in one half of the brewing chamber and the inlet and outlet are located in the other half of the brewing chamber. If there are several additional passage points, these can be located in both brewing chamber halves.

[0040] At least one of the brewing chamber halves may have a piercing means for piercing the inlet or outlet side of the capsule and an ejector for ejecting and peeling the capsule from the piercing means. In this case, the ejector is arranged movably relative to the brewing chamber halves and / or the piercing means. In the open position, the ejector covers the piercing means such that the piercing means protrudes at most slightly. Here and below, "protrudes at most slightly" means that the piercing means does not interfere with or damage the capsule during insertion and / or ejection from the brewing chamber.

[0041] Another aspect of the disclosure relates to a method for ejecting a capsule from a brewing unit as mentioned above of a beverage preparation machine. In a first step, the brewing chamber halves move away from each other when the brewing chamber halves move relative to each other from a closed position forming the brewing chamber and for enclosing and extracting the capsule to an open position for feeding and inserting the capsule. In an at least partially simultaneous or subsequent further step, the perforation means moves relative to the ejector until it protrudes at most slightly or no longer. The relative movement between the ejector and the perforation means can determine in which half of the brewing chamber the capsule stays only when the brewing chamber is open and is released only afterwards. Furthermore, the perforation means can be designed such that the capsule remains intentionally stuck on the perforation means. For example, a barb can be provided or the perforation means has a neck that is thinner than the tip. This detachment from the perforation means must therefore be intentionally assisted, for example by an ejector.

[0042] The ejector can be moved relative to the brew chamber half so as to protrude from a surface of the brew chamber half, which has the advantage that the capsule does not only detach from the piercing means but also detaches from the brew chamber half and is simultaneously displaced.

[0043] The ejector can only move relative to the brew chamber halves when they are already in the open position or just before they reach the open position, allowing the capsule to exit the area between the brew chamber halves directly without further contact with the brew chamber halves, which prevents the capsule from sticking again and the brew chamber halves from becoming soiled.

[0044] The ejector can be moved relative to the brew chamber halves so that it does not protrude from the brew chamber halves, so that a new capsule can be inserted unhindered.

[0045] Another aspect of the present disclosure relates to a beverage preparation machine having a brewing unit as described above. Another aspect of the present disclosure relates to a beverage preparation system comprising the capsule and a brewing unit described above.

[0046] Another aspect of the disclosure relates to a beverage preparation machine comprising a brewing unit, in particular as described above, a pump, first and second fluid conduits, and a controller. The brewing unit comprises two corresponding brewing chamber halves arranged to be movable relative to each other. The brewing chamber halves can be moved from an open position for feeding and inserting the capsule to a closed position for forming the brewing chamber and for sealing and extracting the capsule. In this case, the brewing chamber has an inlet for introducing an extract, an outlet for discharging the prepared beverage, and at least one further passage for rinsing the brewing chamber. The further passage is separate from the inlet and the outlet. A pump is used to deliver the extract or the rinsing liquid. A first fluid line is arranged between the pump and the inlet and has a first valve for opening and closing the first fluid line. A second fluid line is arranged between the pump and the at least one further inlet and is provided with a second valve for opening and closing the second fluid line. At least one of the valves and / or the pump is controllable by the control device.

[0047] The further passages in the brewing chamber allow for easy cleaning and / or rinsing of the brewing chamber without the need to supply rinsing liquid to and / or expel it from the brewing chamber through an inlet and / or an outlet.

[0048] The beverage preparation machine may comprise a third fluid conduit between the at least one further passageway and the collection vessel having a third valve for opening and closing the third fluid conduit. Such a third fluid line with a corresponding valve allows the rinsing liquid to be dispensed from the brewing chamber to the collection vessel. Thus, the rinsing fluid does not have to exit via the outlet of the brewing chamber.

[0049] The first and / or second and / or third valves can be actively controlled by the control unit. For this purpose, solenoid valves or motor valves are conceivable. Thus, for example, when filling the preparation chamber with rinsing liquid, the second valve can be opened while the third valve remains closed. After a reaction time, the second valve can be closed and the third valve opened to drain the rinsing liquid.

[0050] The first valve can be designed as a self-opening pressure valve, which can ensure that the rinsing liquid does not enter the first fluid line and the capsule inserted in the preparation chamber. Thus, via at least one further passage, the rinsing liquid can be injected under pressure into the preparation chamber as long as the pressure remains lower than the pressure required to open the first valve.

[0051] The first valve can have a hysteresis and open in particular at a pressure between 3 bar and 14 bar, preferably between 5 bar and 12 bar, particularly preferably between 7 bar and 9 bar, and close in particular at a pressure between 0.5 bar and 5.0 bar, preferably at 2 bar. There should be a pressure gradient of at least 1 bar between the opening pressure and the closing pressure. Such a hysteresis ensures that the extraction only starts at a certain pressure and stops again at a lower pressure. It can be avoided that the extract drips into the brewing chamber. Of course, such a hysteresis can also be formed via a control system with an actuated first valve. The controlled valve allows the switching points to be defined independently of the applied pressure. The process sequence can thus be freely designed. Furthermore, defined intermediate positions can also be realized.

[0052] The beverage preparation machine may have a fourth valve for opening and closing the beverage outlet. The beverage outlet is understood to be a fluid line extending from the outlet of the brewing chamber to the supply opening of the beverage preparation machine. For example, the fourth valve can be an automatic opening pressure valve, which opens in particular at a pressure between 1 bar and 12 bar, preferably between 3 bar and 10 bar, particularly preferably between 6 bar and 9 bar. Such a valve allows beverage extraction only from a pre-set pressure. For example, for the preparation of coffee, it is important that the extraction takes place under a certain pressure. Otherwise the quality of the coffee will be significantly reduced. It also prevents the rinsing liquid from flowing from the beverage outlet to the supply opening and thus into the cup offered by the user. This valve also allows a certain amount of air trapped in the brewing chamber to be compressed so that the closed brewing chamber can be filled with rinsing liquid and emptied again. The fourth valve can also be a valve that is actively controlled by the control unit.

[0053] The beverage preparation machine may comprise a hydraulic piston with an injector plate, the injector plate being part of the brewing chamber half. This pressure piston is arranged between the pump and the first valve, the pressure piston displacing the injector plate and thus part of the brewing chamber half. This reduces the volume of the brewing chamber before the first valve opens. The capsule enclosed in the brewing chamber is deformed. In particular, in the case of capsules containing a moulding, the deformation of the capsule is necessary so that the beverage substance compressed in the moulding can be broken. Only in this way can a uniform extraction of the beverage substance be performed. The hydraulic pressure of the plunger can be determined by the effective diameter of the plunger and the pressure required to open the first valve. The shape and movement of the injector plate can be adapted to the capsule contained in the brewing chamber, such that the breakup of the beverage substrate of the capsule is achieved. This may involve introducing a crack structure or other, e.g. perforations, in part of the shell or surface material of the capsule. At the same time or alternatively, the injector plate may also serve to compress the beverage substrate so that it has a uniform density suitable for extraction.

[0054] The contact pressure piston allows to increase the contact pressure of the two brewing chamber halves against each other. Thus, less force can be used to close the brewing chamber while maintaining the sealing effect. The movement of the brewing chamber halves is significantly dampened.

[0055] Another aspect of the disclosure relates to a method of preparing a beverage, in particular using a beverage preparation machine as described above, comprising: a) inserting a capsule into a blending chamber; b) closing the blending chamber; and c) filling the preparation chamber with a rinse liquid through a further passage; d) draining the rinse solution from the blend chamber into a collection container; e) introducing the extract into the preparation chamber through an inlet different from the further passageway so that it flows into the capsule; Includes.

[0056] Such a process can be used to wet the capsules in the brewing chamber without the rinse liquid coming into contact with the prepared beverage. For example, the capsule shell, which is particularly hygroscopic, can be wetted. At most, the physical properties of the capsule shell may be affected. For example, the capsule may be more easily punctured by contact with the rinse liquid. It is also conceivable that the elasticity or extensibility of the capsule shell increases, especially when rinsing with a hot rinse liquid.

[0057] Steps c) and d) can be repeated once, twice, three times or several times. Depending on the material of the capsule shell and the effect to be achieved, several iterations can be performed.

[0058] Steps d) and e) can be performed at least partially simultaneously. In particular, in the case of a flexible capsule shell, when the extract is injected into the capsule, the evacuation of the rinsing liquid from the brewing chamber is assisted by the expansion of the capsule volume.

[0059] Before the extraction liquid is introduced into the capsule, the size of the brewing chamber is reduced, allowing the capsule to deform. For this purpose, it is advantageous for the capsule shell to be designed to be flexible and stretchable, so that the shell does not break open and the beverage substance is not released. In particular, if the capsule comprises a moulded body, by reducing the volume of the brewing chamber, the moulded body can be broken down, after which a uniform extraction can be performed. The size and shape of the brewing chamber can be adapted to the capsule contained in the brewing chamber, so that separation of the beverage matrix of the capsule is achieved. This can include introducing a crack structure or other, e.g. perforations, into a part of the shell or surface material of the capsule. At the same time or alternatively, the reduction of the brewing chamber volume may also serve to compress the beverage matrix so that it has a uniform density suitable for extraction.

[0060] During the introduction of the extract into the capsule through the inlet, the capsule's volume can expand. The reduction in size of the brewing chamber already allows the capsule to fit into its volume. However, when the extract is introduced, this adaptation of the capsule's volume to the volume of the brewing chamber is further increased. The capsule is pressed against the walls of the brewing chamber by the pressure prevailing inside the capsule.

[0061] Another aspect of the present disclosure relates to a beverage preparation system comprising a capsule and a beverage preparation machine as described above.

[0062] Another aspect of the disclosure relates to a brewing unit of a beverage preparation machine, in particular as mentioned above, having a brewing chamber and a brewing chamber surface. The brewing chamber is formed substantially rotationally symmetrical with respect to an axis directed from a first brewing chamber half to a second brewing chamber half. In the direction of the axis, the brewing chamber has a maximum axial extension that is smaller than a maximum diameter of the brewing chamber transverse to the axis. In the area of ​​the axis, the brewing chamber has a thickness that is equal to or smaller than its axial extent.

[0063] Such a shape of the brewing chamber has been found to be advantageous for uniform extraction of the beverage substance.

[0064] The brewing chamber surface is understood here and below to be the outer surface of the space enclosed by the brewing chamber, except for recesses for the piercing means for piercing the capsule or small recesses or grooves having a width of up to 3 mm.

[0065] The brewing chamber can be thinned on both sides in the area of ​​the axis, the brewing quality being further improved by the reduced thickness on both sides.

[0066] The brewing unit of the beverage preparation machine disclosed herein, in particular having a brewing chamber and a brewing chamber surface as described above, is designed to be essentially rotationally symmetrical with respect to an axis directed from the first brewing chamber half to the second brewing chamber half, in the region of the axis the brewing chamber surface has a concave depression on at least one side, preferably on both sides, and is convex in the region transverse to the axis.

[0067] The concave-convex design of the brewing chamber ensures optimal extraction of capsules of corresponding shape. The brewing chamber surface can have a stable curvature. By avoiding sharp changes in direction and edges, a uniform extraction can be guaranteed. Furthermore, the capsules contained within the brewing chamber can safely deform and adapt to the shape of the brewing chamber.

[0068] The brewing chamber surface may have a minimum radius of curvature of 3 mm. Again, this avoids abrupt changes in direction and edges.

[0069] Less than 50%, preferably less than 30%, particularly preferably less than 20% of the brewing chamber surface can be formed as a flat surface. Such flat surfaces are conceivable, the aim being to achieve a "circular" surface as far as possible so that extraction can be optimally performed. Of course, a "circular" surface can also be achieved from a number of polygons. However, in this case, a minimum angle between two contact polygonal surfaces of 150°, preferably 160°, particularly preferably 170° must be observed.

[0070] The brewing unit may have two corresponding brewing chamber halves movable relative to each other to move from an open position for feeding and inserting the capsule to a closed position for forming the brewing chamber and for encapsulating and extracting the capsule. In this regard, both the first and the second brewing chamber may be movably arranged. It is equally conceivable that both brewing chamber halves are movably arranged.

[0071] The brewing chamber may have a maximum axial extension in the axial direction ranging from 15 mm to 42 mm, preferably from 18 mm to 32 mm, particularly preferably from 20 mm to 26 mm. Typically, the maximum extension is 22 mm.

[0072] The brew chamber may have a maximum diameter of the brew chamber transverse to the axis in the range of 25mm to 65mm, preferably 28mm to 50mm, more preferably 30mm to 35mm. Typically the maximum diameter is 32mm.

[0073] The brewing chamber may have a reduced thickness in the region of its axis ranging from 12 mm to 40 mm, preferably from 14 mm to 32 mm, more preferably from 15 mm to 20 mm. Typically, the reduced thickness is 17 mm.

[0074] These dimensions may also vary, however, it has been shown that for optimal extraction, the axial dimension should be less than the maximum diameter and the thickness should be less than the axial dimension.

[0075] Another aspect of the present disclosure relates to a beverage preparation machine having a brewing unit as described above. Another aspect of the present disclosure relates to a beverage preparation system comprising the capsule and a brewing unit described above.

[0076] The disclosed invention is explained in more detail below with reference to the figures, which are merely examples of embodiments, in which: [Brief description of the drawings]

[0077] [Figure 1] FIG. 2 is a perspective view from above of a brewing unit having a closed brewing chamber; [Diagram 2] FIG. 2 is a cross-sectional view through the brewing unit according to FIG. 1. [Diagram 3] FIG. 2 is a perspective view from above of a brewing unit with an open brewing chamber; [Figure 4] FIG. 4 is a cross-sectional view through the brewing chamber according to FIG. [Diagram 5] FIG. 2 is a schematic diagram of the capsule in an intermediate position. [Figure 6] FIG. 5 is a longitudinal section through the brewing unit of FIG. 4, with the brewing chamber no longer fully open. [Figure 7] FIG. 5 is a longitudinal section through the brewing unit of FIG. 4, with the brewing chamber open. [Figure 8] FIG. 2 is a perspective view of a brewing chamber half with an ejector and piercing means. [Figure 9] FIG. 13 is a hydraulic diagram of the blending unit. [Figure 10] FIG. 2 is a cross-sectional view through a closed brewing chamber of the brewing unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0078] Figure 1 shows a perspective view of an embodiment of a brewing unit 3 for a beverage preparation machine, whereby the brewing chamber of the brewing unit 3 is closed. On the upper side of the brewing unit 3 an insertion shaft 40 is visible, bounded on both sides by a retaining means 38. When the brewing chamber is open, a capsule 60 (see Figure 3) can be inserted into this insertion shaft 40.

[0079] Figure 2 shows a longitudinal section of the brewing unit 3 of figure 1. Here again the feed chute 40 and the retaining means 38 that laterally limit the feed chute 40 are visible. The brewing chamber 10 is arranged below the feed chute 40 and is closed in the example shown. The brewing chamber 10 comprises a first brewing chamber half 11 and a second brewing chamber half 12 that are movable relative to each other from an open position, in which a capsule 60 (see figure 3) can be inserted between the brewing chamber halves 11 and 12, to the closed position shown. It is immaterial which of the two brewing chamber halves 11, 12 is moved. Likewise, both brewing chamber halves 11, 12 can be designed to be movable. The movement of the brewing chamber halves 11, 12 relative to each other defines an axis 16 that runs from the first brewing chamber 11 to the second brewing chamber 12.

[0080] The brewing chamber 10 has an inlet 23 in the first brewing chamber half 11 to allow the introduction of an extraction fluid into the brewing chamber 10 and into the capsule 60 (see FIG. 3). The inlet 23 opens into the tip of the respective perforation means 32a of the injector plate 58. Furthermore, the brewing chamber 10 has an outlet 24 in the second brewing chamber half 12 to allow the prepared beverage to be ejected from the brewing chamber 10. The outlet 24 is formed in the second brewing chamber half 12 by an opening into the hollow perforation means 32b. A further passage 25 opens into the brewing chamber 10, through which the rinsing liquid can be introduced into the brewing chamber 10 and removed therefrom. This further passage 25 is formed as an annular gap 27 (see FIG. 8) between the ejector 30 and the fixed part of the second brewing chamber half 12. The annular gap 27 is dimensioned to act as a filter element 26 (see FIG. 8) to prevent residues from exiting the brewing chamber 10 through the further passage 25. The width of the annular gap is 200 μm. A sealing element 22 is arranged between the two brewing chamber halves 11 and 12 and facilitates a tight closing of the brewing chamber 10.

[0081] 3 and 4 show the brewing unit 3 with the brewing chamber 10 in an open position, the spherical capsule 60 being held in an intermediate position between the brewing chamber halves 11 and 12 by the holding means 38.

[0082] FIG. 5 shows diagrammatically two holding means 38 for holding a capsule 60. In the intermediate position, the capsule 60 is not in contact with the brewing chamber halves 11 and 12, but is free to lie in this intermediate position away from the holding means 38. The holding means 38 are spoon-shaped and each surround the capsule 60 with an angular extent of 28°. The minimum distance 39 between the holding means 38 is therefore 16% smaller than the capsule diameter 61. The capsule 60 cannot therefore slip between the holding means 38. When the brewing chamber 10 is open, the holding means 38 are pretensioned relative to each other by at least one spring element 41, as can be seen diagrammatically in FIG. 5.

[0083] As soon as the brewing chamber halves 11 and 12 move relative to each other and are only at a distance from each other that is smaller than the dimensions of the capsule 60, in this case a spherical capsule, i.e. smaller than its diameter 61 (see FIG. 5), the holding means 38 move away from each other against the spring force of the spring element 41 so that the capsule 60 falls. This moving away of the holding means 38 is performed by the control means 44 (see FIG. 1), which presses itself in a wedge shape between the holding means 38, thus increasing their distance. The holding means 38 can also pivot around an axis 42 shown in FIGS. 3 and 4. The spring element 41 is preferably also arranged on this axis 42 so that a spring force acts along this axis 42. The pivoting movement takes the holding means 38 completely out of the area between the brewing chamber halves 11, 12. The brewing chamber halves 11 and 12 moving together are therefore not impeded by the holding means 38. At the same time, the brewing chamber halves 11 and 12 capture the capsule 60 (see FIG. 6) and align it so that it is located between the two brewing chamber halves 11 and 12 when the brewing chamber 10 is closed (see FIG. 7).

[0084] While the brew chamber halves 11 and 12 are moving together, the injector plate 58 in the first brew chamber half 11 is retracted so that the capsule 60 has sufficient clearance between the brew chamber halves 11 and 12. The piercing means 32b of the second brew chamber half 12 are covered by the protruding ejectors 30 so that the capsule 60 is not hindered in its movement by these.

[0085] 7, when the brew chamber 10 is closed, the ejector 30 of the second brew chamber half 12 is retracted again such that the piercing means 32b protrudes from the ejector 30 and contacts the capsule 60. The injector plate 58 of the first brew chamber half 11 is still recessed such that the corresponding piercing mandrel of the injector plate 58 only contacts the capsule 60.

[0086] FIG. 8 shows an enlarged view of the second brewing chamber half 12 with the circumferential sealing element 22. The ejector 30, movably mounted in the brewing chamber half 12, is clearly visible. The piercing means 32b protruding from the ejector 30 is also visible. The piercing means 32b is designed as a hollow cannula and has an inlet opening forming the outlet 24 of the brewing chamber. Between the ejector 30 and the second brewing chamber half 12 an annular gap 27 is formed, which extends around the ejector 30. On the one hand, this annular gap 27 forms a further passage 25 to the brewing chamber to be able to pressurize it with a rinsing liquid. By suitable dimensioning of the gap 27, it also serves as a filter element 26 to prevent the unintentional introduction of foreign bodies into the brewing chamber as well as the escape of residual substances from the brewing chamber. In the illustrated embodiment, the annular gap 27 has a width of 200 μm.

[0087] Figure 9 shows a diagram of the hydraulic system of a beverage preparation machine 1 with a brewing unit 3 as described above. In addition to the brewing unit 3, the beverage preparation machine 1 also has a tank 8 or a fresh water connection. Both the brewing liquid and the rinsing liquid are supplied from this tank 8 or fresh water connection. A pump 4 is used to pump the brewing liquid and the rinsing liquid. A heating element 9 heats the water to the temperature required for the extraction of the desired beverage.

[0088] A first fluid line 49 leads from the pump 4 or heating element 9 to the inlet 23 of the brewing chamber 10. A first valve 50 is arranged between the pump 4 and the inlet 23. This valve 50 is designed as a pressure valve and ensures that the extraction fluid can only pass through the first valve 50 after exceeding a pre-set pressure. It also ensures that the hydraulic piston 57 (see FIG. 2) generates a sufficiently large force with its effective diameter to allow the hydraulic piston 57 to move. Furthermore, this pressure valve prevents the liquid from flowing back from the brewing chamber 10 to the heating element 9 or the pump 4.

[0089] A second fluid line 51 leads from the pump 4 or the heating element 9 to the further passage 25 of the brewing chamber. A second valve 52 is arranged between the pump 4 and the further passage 25. Via this second valve 52, the further passage 25 and the brewing chamber 10 can be provided with a rinsing liquid, for example for wetting a capsule 60 inserted in the brewing chamber (see FIG. 7). At the same time, the second valve 52 ensures that the rinsing liquid does not flow back into the heating element 9 or the pump 4 when the pump 4 is switched off.

[0090] A third fluid line 53 connects the further passage 25 of the brewing chamber 10 with the collection container 6. The third fluid line comprises a third valve, which ensures that the rinsing fluid is first supplied to the brewing chamber 10 before being drained into the collection container 6 after closing the second valve 52 and opening the third valve 54.

[0091] Starting from the outlet 24 (see FIG. 8 ), another fluid line leads to the supply opening 7 of the beverage preparation machine as a beverage outlet 55. In the illustrated embodiment, a fourth valve 56 is arranged at this beverage outlet 55, which is further designed as a pressure valve. The fourth valve prevents the rinsing liquid, which is supplied under pressure to the brewing chamber 10, from flowing through the beverage outlet into the cup 2 for holding the beverage desired by the user. Since, in addition to the capsule 60, a certain amount of ambient air is also enclosed in the closed brewing chamber 10 before rinsing, the fourth valve 56 allows the compression of this air volume, thus improving the wetting of the capsule 60. Furthermore, this fourth valve 56 can ensure that the preparation of the beverage is only performed from a preset pressure, which contributes greatly to the quality, especially when preparing coffee.

[0092] The beverage preparation machine 1 also has a controller 5 which controls the pump 4, the heating element 9 and the second and third valves 52, 54. Of course, the controller 5 can also be connected to sensors, e.g. flow meters, temperature sensors, etc., whose signals contribute to the controller. Also, for example, the movement of the brewing chamber halves 11, 12 can be monitored by the controller 5 or even triggered by suitable drives.

[0093] To prepare the beverage, after the capsule 60 has been inserted into the insertion chute 40, the brewing chamber 10 is closed. This is done by relative movement of the two brewing chamber halves 11 and 12. In the illustrated embodiment, the first brewing chamber half 11 moves from an open position as shown in Fig. 3 and Fig. 4, via a half-open or half-closed position according to Fig. 6, to a closed position according to Fig. 7. The capsule 60 is initially held by the two holding means 38 in an intermediate position between the two spaced apart brewing chamber halves 11 and 12 on the axis 16, directed from the first to the second brewing chamber halves 11 and 12. As soon as the brewing chamber halves 11 and 12 approach each other, the two holding means 38 are pushed apart by the control means 44 against the spring force of the spring element 41. The capsule 60 falls onto the lower edges of the brewing chamber halves 11 and 12, which have already moved somewhat together. When the brewing chamber halves 11 and 12 move further together, the capsule is again aligned with the axis 16. Now the brewing chamber 3 can be closed. With the help of the sealing element 22, the two brewing chamber halves 11 and 12 form a closed, sealed brewing chamber 3. In the first brewing chamber half 11, the injector plate 58 with the piercing means 32a is retracted so that it only contacts the capsule 60 and does not yet puncture it. In the second brewing chamber half 12, the ejector 30 is in the retracted position and releases the piercing means 32b. On this side too, the capsule 60 is only contacted by the piercing means 32b but is not yet pierced.

[0094] The control device 5 switches on the heating element 9, opens the second valve 52 and releases the pump 4 to deliver about 10 ml of water. The first valve 50 opens only at a preset pressure, so that the water can only flow through the open second fluid line 51 to the further passage 25 and the brewing chamber 3. The water rinses the brewing chamber 3 and wets the capsule 60 enclosed therein. The second valve 52 is closed and the third valve 54 is opened. This opens the third fluid line 53. The rinsing water can again escape from the brewing chamber 3. The escape of the rinsing water is facilitated, since a certain amount of compressed air is enclosed in the brewing chamber 3 in addition to the capsule. After about one second, the third valve 54 is closed again, thus closing the passage to the collection container 6. The second valve 52 is opened again, injecting a further amount of rinsing water into the brewing chamber 3. The brewing chamber 3 is again flooded and the capsule 60 is again wetted. After an action time of about 2 seconds, the second valve 52 closes and shortly thereafter the third valve 54 opens. A portion of the rinsing water may be discharged into the collection container 6 again.

[0095] The pump is actuated when the second valve 52 is closed and delivers water. It can only extend in the first fluid line 49 up to the first valve 50. The water flows into the antechamber 59 of the hydraulic piston 57, which is connected to the injector plate 58. The hydraulic piston 57 is part of the first brewing chamber half 11. Since the first valve only opens from a preset pressure, 7 bar in the example of the illustrated embodiment, the water delivered by the pump 4 first drives the pressure piston 57 and thus the injector plate 58. This, however, reduces the volume of the brewing chamber 3, and the capsule 60 is deformed and is perforated by the perforation means 32a and 32b of the first and second brewing chamber halves 11 and 12. This deformation of the capsule 60 is particularly important if the capsule 60 contains a moulded body as beverage substance. The deformation not only deforms the pressed product, but also breaks it open. This allows the beverage substance to be extracted evenly. If the capsule contains loose beverage material, the injector plate also deforms the capsule, which compresses the loose beverage material. The capsule 60 is wetted with preferably hot rinsing water before its deformation, so that the capsule shell is softened and can easily undergo deformation. The capsule 60 adapts its shape to that of the brewing chamber 3 by hydraulic pressure and expansion by the injected brewing liquid. Until the capsule 60 is completely deformed, i.e. until the capsule shape adapts to the shape of the brewing chamber 3, the third valve 54 is still open, so that the rinsing water is displaced from the brewing chamber 3 and is supplied to the collection container 6 through the further passage 25 and the third fluid line 53.

[0096] The pump 4 continues to deliver water even when the capsule 60 is completely deformed and the hydraulic piston 57 reaches its end position. As a result, the pressure in the antechamber 59 rises further. As soon as a preset pressure is reached, which in the illustrated embodiment is 7 bar, the first valve 50 opens and the first fluid line 49 is released to the inlet 23. The perforation means 32a of the injector plate 30 is already perforated in the capsule 60 so that water or the extraction fluid is injected under high pressure into the capsule 60. The extraction liquid enters the capsule 60, fills it and expands it until it fills the brewing chamber 3. The pressure in the capsule 60 rises until the fourth valve 56 in the beverage outlet 55 opens. At the latest at this point, the third valve 54 is closed. The extraction liquid passes through the capsule 60 from its inlet side to the opposite outlet side, where it is expelled from the brewing chamber as a prepared beverage through the outlet of the perforation means 32b. The beverage flows through the beverage outlet 55 to the dispensing opening 7 where it is dispensed into the cup 2. The fourth valve 56 opens only when a preset pressure is reached, which results in a good quality extraction, especially when preparing coffee.

[0097] The pump 4 stops after delivering the amount of water required for the desired beverage. The heating power of the heating element 9 is also switched off. Now the third valve 54 is first opened. Any pressure in the third fluid line 53 from the further passage 25 can be discharged into the collection container 6. Then the second valve 52 is opened. Thus, the built-up pressure in the first fluid line 49, in particular in the hydraulic piston 57, is discharged via the second valve 52 and the third valve 54 into the collection container 6. Since the first valve 50 is designed as a pressure valve, it closes immediately after the sudden drop of the excess pressure. Thus, residues from the brewing chamber 3 cannot be flushed into the second and third valves 52 and 54. As soon as the pressure in the antechamber 59 of the hydraulic piston 57 decreases and the brewing chamber 3 opens, the latter returns to its original position by the return spring 46, thereby pulling the injector plate 58 with its piercing means 32a away from the capsule 60.

[0098] As soon as the pressure in the beverage preparation machine is released, the movement of the brewing chamber halves 11 and 12 can be released again. Upon opening of the brewing chamber 3, which can be done automatically or manually, the first brewing chamber half 11 moves from the closed position to the open position. The deformed and extracted capsule remains attached to the piercing means 32b of the second brewing chamber half 12. At the last moment of the opening movement, the ejector 30 moves forward, i.e. towards the first brewing chamber half 11, thereby peeling off the capsule 60 from the piercing means 32b. Simultaneously with the ejector 30, the holding means 38 also moves downwards again, peeling off the capsule 60 adhering to the ejector 30.

[0099] Figure 10 shows a cross section through the closed brewing chamber 10 of the brewing unit 3 along the axis 16 from the first brewing chamber half 11 to the second brewing chamber half 12. The brewing chamber 3 has a brewing chamber surface 15 which, apart from the perforation means 32a and 32b and possible grooves, has no sharp edges or abrupt changes of direction. The brewing chamber surface 15 has a continuous curvature, with a minimum radius of curvature of 3 mm. In the illustrated embodiment, the brewing chamber surface 15 does not have a flat surface.

[0100] The brewing chamber 15 is essentially rotationally symmetrical about the axis 16. The diameter across the axis 16 is 32 mm. The brewing chamber 3 has a maximum extension 17 in the axial direction of 21.3 mm. In the central area, i.e. in the area of ​​the axis 16, the brewing chamber 3 has a concave recess 20, so that the brewing chamber has there a reduced thickness 19 of only 17 mm. This shape of the brewing chamber 3 has been shown to enable the spherical capsule 60 bodies to be optimally broken down and extracted.

Claims

1. 1. A brewing unit (3) for a beverage preparation machine, comprising a brewing chamber (10) and a brewing chamber surface (15), wherein the brewing chamber (10) is designed to be essentially rotationally symmetrical about an axis (16) directed from a first brewing chamber half (11) to a second brewing chamber half (12), the brewing chamber (10) having a maximum axial extent (17) in the direction of the axis (16) that is smaller than a maximum diameter (18) transverse to the axis (16), and the brewing chamber (10) has a thickness (19) in the region of the axis (16) that is equal to or smaller than the maximum axial extent (17).

2. 2. The brewing unit (3) according to claim 1, wherein the brewing chamber (10) has a reduced thickness (19) on both sides of the region of the axis (16).

3. 3. A brewing unit (3) for a beverage preparation machine having a brewing chamber (10) and a brewing chamber surface (15) according to claim 1 or 2, wherein the brewing chamber (10) is rotationally symmetrical about an axis (16) directed from the first brewing chamber half (11) to the second brewing chamber half (12), and the brewing chamber surface (15) has a concave depression (20) on at least one side in the region of the axis (16) and is convex in a region transverse to the axis (16).

4. 3. The brewing unit (3) according to claim 1 or 2, wherein the brewing chamber surface (15) has a continuous curvature.

5. 3. The brewing unit (3) according to claim 1 or 2, wherein the brewing chamber surface (15) has a minimum radius of curvature of 3 mm.

6. 3. The brewing unit (3) according to claim 1 or 2, wherein less than 50% of the brewing chamber surface (15) is formed as a flat surface.

7. 3. The brewing unit (3) according to claim 1 or 2, comprising two corresponding brewing chamber halves (11, 12) movably arranged relative to each other so as to be brought from an open position for feeding and inserting a capsule (60) to a closed position for forming the brewing chamber (10) and for enclosing and extracting the capsule (60).

8. A beverage preparation machine (1) comprising a blending unit (3) as described in claim 1 or 2.

9. A beverage preparation system comprising a capsule (60) and a brewing unit (3) according to claim 1 or 2.

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