BREWING UNIT, BEVERAGE PREPARATION MACHINE AND BEVERAGE PREPARATION SYSTEM

Abstract

Brewing unit of a beverage preparation machine with a brewing chamber (10) and a brewing chamber surface (15), wherein the brewing chamber (10) is 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), which is smaller than the largest diameter (18) transverse to the axis (16). Furthermore, the brewing chamber (10) has a thickness (19) in the area of the axis (16) which is equal to or smaller than the axial expansion (17).

Claims

1.-9. (canceled)

10. A brewing unit of a beverage preparation machine having a brewing chamber and a brewing chamber surface, the brewing chamber being designed to be essentially rotationally symmetrical with respect to an axis directed from a first brewing chamber half to a second brewing chamber half, wherein the brewing chamber has a maximum axial extent in the direction of the axis which is smaller than the largest diameter transverse to the axis, wherein the brewing chamber has a thickness in the region of the axis which is equal to or smaller than the axial extent.

11. The brewing unit according to claim 10, wherein the brewing chamber has a reduced thickness on two sides in the region of the axis.

12. The brewing unit according to claim 10, wherein the brewing chamber is substantially rotationally symmetrical with respect to an axis directed from a first brewing chamber half to a second brewing chamber half, wherein the brewing chamber surface has a concave recess in the region of the axis on at least one side and is convex in the region transverse to the axis.

13. The brewing unit according to claim 10, wherein the brewing chamber surface has a continuous curvature.

14. The brewing unit according to claim 10, wherein the brewing chamber surface has a minimum radius of curvature of 3 mm.

15. The brewing unit according to claim 10, wherein less than 50% of the brewing chamber surface is formed as a flat surface.

16. The brewing unit according to claim 10, wherein the brewing unit comprises two corresponding brewing chamber halves which are movably arranged relative to each other to be brought from an open position for dispensing and inserting a capsule to a closed position for forming the brewing chamber and enclosing and extracting the capsule.

17. A brewing unit of a beverage preparation machine with a brewing chamber and a brewing chamber surface, wherein the brewing chamber is substantially rotationally symmetrical with respect to an axis directed from a first brewing chamber half to a second brewing chamber half, wherein the brewing chamber surface has a concave recess in a region of the axis on at least one side and is convex in a region transverse to the axis.

18. The brewing unit according to claim 17, wherein the brewing chamber surface has a continuous curvature.

19. The brewing unit according to claim 17, wherein the brewing chamber surface has a minimum radius of curvature of 3 mm.

20. The brewing unit according to claim 17, wherein less than 50% of the brewing chamber surface is formed as a flat surface.

21. The brewing unit according to claim 17, wherein the brewing unit comprises two corresponding brewing chamber halves which are movably arranged relative to each other to be brought from an open position for dispensing and inserting a capsule to a closed position for forming the brewing chamber and enclosing and extracting the capsule.

22. A beverage preparation machine comprising a brewing unit according to claim 10.

23. A beverage preparation machine comprising a brewing unit according to claim 17.

24. The beverage preparation system comprising a capsule and a brewing unit according to claim 10.

25. A beverage preparation system comprising a capsule and a brewing unit according to claim 17.

Description

[0097] FIG. 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. An insertion shaft 40 can be seen on the upper side of the brewing unit 3, which is delimited on both sides by a holding means 38. A capsule 60 (see FIG. 3) can be inserted into this insertion shaft 40 when the brewing chamber is open.

[0098] FIG. 2 shows a longitudinal section of the brewing unit 3 from FIG. 1. Again, the feed chute 40 and a holding means 38, which laterally limits the feed chute 40, can be seen. A brewing chamber 10 is arranged below the feed chute 40, which is closed in the illustration shown. The brewing chamber 10 comprises a first brewing chamber 11 and second brewing chamber half 12, which are movable relative to each other from an open position, in which the capsule 60 (see FIG. 3) can be inserted between the brewing chamber halves 11 and 12, to the closed position shown. It is irrelevant which of the two brewing chamber halves 11, 12 moves. 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 define an axis 16, which is directed from the first brewing chamber 11 to the second brewing chamber 12.

[0099] The brewing chamber 10 has an inlet 23 in the first brewing chamber half 11 to allow an extraction fluid to be introduced into the brewing chamber 10 and into the capsule 60 (see FIG. 3). The inlet 23 opens into the tips of individual perforation means 32a of an injector plate 58. In addition, the brewing chamber 10 has an outlet 24 in the second brewing chamber half 12 to allow a prepared beverage to be discharged from the brewing chamber 10. The outlet 24 is formed in the second brewing chamber half 12 by openings to the hollow perforation means 32b. A further access 25 opens into the brewing chamber 10, through which a rinsing liquid can be introduced into the brewing chamber 10 and removed therefrom. This further access 25 is formed between the ejector 30 and the fixed part of the second brewing chamber half 12 as an annular gap 27 (see FIG. 8). The annular gap 27 is dimensioned in such a way that it serves as a filter element 26 (see FIG. 8) to prevent residues from being flushed out of the brewing chamber 10 through the further access 25. The annular gap has a width of 200 m. A sealing element 22 is arranged between the two halves of the brewing chamber 11 and 12, which facilitates a tight closure of the brewing chamber 10.

[0100] FIGS. 3 and 4 show the brewing unit 3 with the brewing chamber 10 in the open position, a spherical capsule 60 being held in an intermediate position between the brewing chamber halves 11 and 12 by the holding means 38.

[0101] FIG. 5 shows schematically the two holding means 38 which hold the capsule 60. In the intermediate position, the capsule 60 is not in contact with the brewing chamber halves 11 and 12 but lies freely in this intermediate position apart from the holding means 38. The holding means 38 are spoon-shaped and enclose the capsule 60 in an angular range of 28 each. Accordingly, the smallest distance 39 between the holding means 38 is 16% smaller than the capsule diameter 61. Thus, the capsule 60 cannot slip between the holding means 38. When the brewing chamber 10 is open, the holding means 38 are relatively pretensioned against each other by at least one spring element 41, as can be seen schematically in FIG. 5.

[0102] As soon as the brewing chamber halves 11 and 12 move relative to each other and are only at a distance from each other which is less than the dimensions of the capsule 60, in this case a spherical capsule, i.e. less than its diameter 61 (see FIG. 5), the holding means 38 are moved apart relative to each other against the spring force of the spring element 41 so that the capsule 60 is dropped. This movement of the holding means 38 apart is effected by a control means 44 (see FIG. 1), which pushes itself wedge-shaped between the holding means 38 and thus increases their distance. The holding means 38 can also swivel around an axis 42, which is shown in FIGS. 3 and 4. The spring element 41 is preferably also arranged on this axis 42, so that the spring force acts along this axis 42. The pivoting movement completely removes the holding means 38 from the area between the brewing chamber halves 11, 12. The brewing chamber halves 11 and 12 moving together are accordingly not hindered by the holding means 38. At the same time, the brewing chamber halves 11 and 12 catch the capsule 60 (see FIG. 6) and align it so that it lies between the two brewing chamber halves 11 and 12 when the brewing chamber 10 is closed (see FIG. 7).

[0103] While the brewing chamber halves 11 and 12 are moving together, the injector plate 58 in the first brewing chamber half 11 is set back so that the capsule 60 has sufficient clearance between the brewing chamber halves 11 and 12. The perforation means 32b of the second brewing chamber half 12 are covered by the projecting ejector 30 so that the capsule 60 is not hindered in its movement by these.

[0104] As can be seen in FIG. 7, when the brewing chamber 10 is closed, the ejector 30 of the second brewing chamber half 12 is retracted again so that the perforation means 32b protrude from the ejector 30 and contact the capsule 60. The injector plate 58 of the first brewing chamber half 11 is still recessed, the corresponding piercing mandrels of the injector plate 58 merely touch the capsule 60.

[0105] FIG. 8 shows an enlarged view of the second half of the brewing chamber 12 with the circumferential sealing element 22. The ejector 30, which is movably mounted in the brewing chamber half 12, is clearly visible. Also visible are the perforation means 32b, which protrude from the ejector 30. The perforation means 32b are designed as a hollow cannula and have inlet openings which form the outlet 24 of the brewing chamber. An annular gap 27 is formed between the ejector 30 and the second brewing chamber half 12, which extends around the ejector 30. On the one hand, this annular gap 27 forms the further access 25 to the brewing chamber to be able to pressurise it with a rinsing liquid. By means of a suitable dimensioning of the gap 27, it also serves as a filter element 26 to prevent an unintentional introduction of foreign bodies into the brewing chamber as well as a flushing out of residual substances from the brewing chamber. In the embodiment shown, the annular gap 27 has a width of 200 m.

[0106] FIG. 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 extraction liquid and the rinsing liquid are provided from this tank 8 or fresh water connection. A pump 4 is used to deliver the extraction liquid and the rinsing liquid. A heating element 9 heats the water to the temperature required for the extraction of the desired beverage.

[0107] A first fluid line 49 leads from the pump 4 or the 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 a preset pressure has been exceeded. It also ensures that a hydraulic pressure piston 57 (see FIG. 2) generates a sufficiently large force with its effective diameter so that the hydraulic pressure piston 57 can move. Furthermore, this pressure valve prevents a liquid from flowing back from the brewing chamber 10 into the heating element 9 or the pump 4.

[0108] A second fluid line 51 leads from the pump 4 or the heating element 9 to the further access 25 of the brewing chamber. A second valve 52 is arranged between the pump 4 and the further access 25. Through this second valve 52, the further access 25 and the brewing chamber 10 can be provided with a rinsing liquid, for example to wet a capsule 60 inserted in the brewing chamber (see FIG. 7). At the same time, the second valve 52 ensures that no rinsing liquid can flow back into the heating element 9 or the pump 4 when the pump 4 is switched off.

[0109] A third fluid line 53 connects the further access 25 of the brewing chamber 10 with a collection container 6. The third fluid line has a third valve. This ensures that the rinsing fluid is first fed into the brewing chamber 10 before it is expelled into the collection container 6 after closing the second valve 52 and opening the third valve 54.

[0110] Starting from the outlet 24 (see FIG. 8), another fluid line leads as a beverage outlet 55 to a dispensing opening 7 of the beverage preparation machine. In the embodiment shown, a fourth valve 56 is arranged in this beverage outlet 55, which in turn is 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 a cup 2 for holding a beverage desired by a user. Since a certain volume of ambient air is also enclosed in the closed brewing chamber 10 prior to rinsing, in addition to the capsule 60, the fourth valve 56 enables compression of this air volume and thus improved wetting of the capsule 60. Furthermore, this fourth valve 56 can ensure that the preparation of the beverage only takes place from a preset pressure, which contributes significantly to the quality, particularly when preparing coffee.

[0111] The beverage preparation machine 1 also has a control 5 which controls the pump 4, the heating element 9 and the second and third valves 52, 54. Of course, the control 5 can also be connected to sensors, for example a flow meter, a temperature sensor, etc., whose signals contribute to the control. Also, for example, the movement of the brewing chamber halves 11, 12 can be monitored by the control 5 or even triggered by means of suitable drives.

[0112] To prepare a beverage, the brewing chamber 10 is closed after the capsule 60 has been inserted into the insertion chute 40. This is done by a relative movement of the two brewing chamber halves 11 and 12. In the embodiment shown, the first brewing chamber half 11 moves from the open position, as shown in Figures 3 and 4, via the half-open or half-closed position according to FIG. 6 to the closed position according to FIG. 7. The capsule 60 is first held by the two holding means 38 in the intermediate position between the two spaced brewing chamber halves 11 and 12 on the axis 16, directed from the first to the second brewing chamber half 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 a lower edge of the brewing chamber halves 11 and 12, which have already moved together somewhat. As the brewing chamber halves 11 and 12 move together further, the capsule is again aligned with the axis 16. The brewing chamber 3 can now be closed. With the aid of the sealing element 22, the two brewing chamber halves 11 and 12 form a closed and tight brewing chamber 3. In the first brewing chamber half 11, the injector plate 58 with its perforation means 32a is set back so far that they merely touch the capsule 60 but do not yet pierce it. In the second half of the brewing chamber 12, the ejector 30 is in a retracted position and releases the perforation means 32b. Also on this side, the capsule 60 is only touched by the perforation means 32b, but not yet perforated.

[0113] The control 5 switches on the heating element 9, opens the second valve 52 and releases the pump 4 to deliver approx. 10 ml of water. Since the first valve 50 only opens at a preset pressure, the water can thus only flow through the open second fluid line 51 to the further access 25 and into the brewing chamber 3. The water rinses the brewing chamber 3 and the capsule 60 enclosed in it is wetted. The second valve 52 is closed and the third valve 54 is opened. This opens the third fluid line 53. The rinsing water can escape from the brewing chamber 3 again. Since a certain volume of compressed air has been enclosed in the brewing chamber 3 in addition to the capsule, the escape of the rinsing water is facilitated. After approx. 1 s the third valve 54 is closed again, the access to the collection container 6 is thus closed. The second valve 52 is opened again to inject a further quantity of rinsing water into the brewing chamber 3. The brewing chamber 3 is flooded again and the capsule 60 is wetted again. After an action time of approx. 2 s, the second valve 52 closes and shortly afterwards the third valve 54 opens. Part of the rinsing water can again be discharged into the collection container 6.

[0114] The pump is activated when the second valve 52 is closed and delivers water. This can only spread in the first fluid line 49 up to the first valve 50. The water flows into an antechamber 59 of a hydraulic pressure piston 57, which is connected to the injector plate 58. The hydraulic pressure piston 57 is part of the first brewing chamber half 11. Since the first valve only opens from a preset pressure, in the shown embodiment example from 7 bar, the water delivered by the pump 4 will first drive the pressure piston 57 and thus the injector plate 58. However, this reduces the volume of the brewing chamber 3, the capsule 60 is deformed and pierced 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 when the capsule 60 comprises a compact as a beverage substance. The deformation not only deforms the pressed product, but also breaks it open. The beverage substance can thus be extracted evenly. If the capsule contains a loose beverage substance, the injector plate also deforms the capsule. This compresses the loose beverage substance. Since the capsule 60 has been wetted with the preferably hot rinsing water prior to its deformation, the capsule shell has softened and can easily undergo the deformation. The capsule 60 adapts its shape to the shape of the brewing chamber 3 through the hydraulic pressing and expansion by the injected extraction liquid. Since the third valve 54 is still open until the capsule 60 is completely deformed, i.e. until the capsule shape is adapted to the shape of the brewing chamber 3, the rinsing water is displaced from the brewing chamber 3 and fed to the collection container 6 through the further access 25 and the third fluid line 53.

[0115] The pump 4 continues to deliver water even when the capsule 60 is completely deformed and the hydraulic pressure piston 57 has reached its end position. The pressure in the antechamber 59 increases further as a result. As soon as the preset pressure, in the shown embodiment example 7 bar, is reached, the first valve 50 opens and the first fluid line 49 is released up to the inlet 23. The perforation means 32a of the injector plate 30 are already pierced into the capsule 60, so that the water or extraction fluid is injected into the capsule 60 under high pressure. The extraction fluid enters the capsule 60, fills it and inflates it until the capsule 60 fills the brewing chamber 3. The pressure in the capsule 60 increases until the fourth valve 56 in the beverage outlet 55 opens. At this moment at the latest, 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 discharged from the brewing chamber as a prepared beverage through the outlet in 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 only opens when a preset pressure is reached, which results in good quality extraction, especially when preparing a coffee.

[0116] After the pump 4 has delivered the amount of water required for the desired drink, it stops. The heating power of the heating element 9 is also switched off. Now the third valve 54 is opened first. Any pressure in the third fluid line 53 from the further access 25 can be discharged into the collection container 6. Then the second valve 52 is opened. The built-up pressure in the first fluid line 49, in particular in the hydraulic pressure piston 57, is thus discharged via the second valve 52 and the third valve 54 to the collection container 6. Since the first valve 50 is designed as a pressure valve, it will close immediately after the collapse of the excess pressure. Accordingly, no residue from the brewing chamber 3 can be washed into the second and third valves 52 and 54. As soon as the pressure in the antechamber 59 of the hydraulic pressure piston 57 decreases and the brewing chamber 3 is open, the latter moves back to its original position due to a return spring 46 and thereby pulls the injector plate 58 with its perforation means 32a away from the capsule 60.

[0117] 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. When opening 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 perforation means 32b of the second brewing chamber half 12. At the last moment of the opening movement, the ejector 30 is moved forward, i.e. towards the first brewing chamber half 11, so that it strips the capsule 60 from the perforation means 32b. At the same time as the ejector 30, the holding means 38 also move downwards again, so that a capsule 60 adhering to the ejector 30 is stripped off.

[0118] FIG. 10 shows a section through the closed brewing chamber 10 of the brewing unit 3 along the axis 16 from the first to the second brewing chamber half 11 and 12. The brewing chamber 3 has a brewing chamber surface 15 which, apart from the perforation means 32a and 32b and a possible groove, has no sharp edges or abrupt changes of direction. The brewing chamber surface 15 has a continuous curvature, the minimum radius of curvature being 3 mm. In the embodiment shown, the brewing chamber surface 15 has no flat surfaces.

[0119] The brewing chamber 15 is essentially rotationally symmetrical with the axis 16 as the axis of symmetry. The diameter transverse to the axis 16 is 32 mm. The brewing chamber 3 has a maximum extension 17 of 21.3 mm in the axial direction. In a 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 a reduced thickness 19 of only 17 mm there. It has been shown that this shape of the brewing chamber 3 allows a compact of a spherical capsule 60 to be optimally broken up and extracted.