Coffee machine comprising a centrifugal brewing unit

Abstract

The invention concerns a coffee machine (1) provided with a centrifugal brewing unit (10), wherein a control unit is able to set a desired brewing volume of a brewing chamber (100) of the centrifugal brewing unit (10) among different predefined brewing volumes and is able to operate at least part of a spinning assembly of the centrifugal brewing unit (10) to rotate around a spinning axis (Y) to create a coffee donut with the ground coffee inside the brewing chamber (100) having the desired brewing volume before or during the water injection by the water injection device (410).

Description

[0001] 19794-EP-EPA

[0002] COFFEE MACHINE COMPRISING A CENTRIFUGAL BREWING UNIT

[0003] Field of the invention

[0004] The present invention relates to the field of dispensing beverages, in particular coffee beverages.

[0005] More particularly, the present invention relates to coffee machine provided with brewing units having a centrifugal extraction of the coffee.

[0006] Background of the invention

[0007] Machines for dispensing beverages are known, in particular for coffee and beverages of the same kind, having a dispensing apparatus for preparing coffee, where ground coffee is measured and inserted, by gravity, into an infusion chamber and then compressed by one or more movable walls, usually one or more pistons. An infusion liquid, usually water, is then forced through the coffee tablet compressed into the infusion chamber, so that the substances of the ground product are extracted, and the beverage is obtained.

[0008] Traditional roast and ground coffee extractions are based on conventional pressurized brewing units and related processes for preparing a beverage by operating such pressurized brewing units.

[0009] The amount of ground coffee to be dispensed inside the brewing chamber depends on the type of desired beverage: for example, for an espresso may be necessary an amount of ground coffee much lower than the coffee amount necessary for a so-called “American” coffee. The ground coffee is fed into the brewing chamber and tends to settle inside it randomly. The ground coffee poured into the brewing chamber is thus compressed in a coffee tablet, by one or more movable walls, usually one or more pistons. An infusion liquid, usually water, is then forced through the coffee tablet compressed into the brewing chamber, so that the substances of the ground coffee are extracted and the beverage (i.e., the coffee) is obtained.

[0010] The conventional pressurized technology relies heavily on the coffee itself and its fluidic resistance for extraction.

[0011] In case of small coffee amount, little brewing chambers have to be adopted in order to obtain beverages having acceptable qualities. For this reason, dispensing machines (or coffee machines) are known having two brewing chambers, to be used based on the coffee amount to be used, such as one brewing chamber with greater dimensions for greater amounts of ground coffee and the other with smaller dimensions for beverages needing less ground coffee in the brewing chamber, such as for example the “ristretto” and “espresso ’’coffee. However, such a solution is expensive to manufacture and needs an additional space in the dispensing machine. Furthermore, the presence of two brewing chambers increases the maintenance machine costs considerably. 19794-EP-EPA

[0012] To avoid this inconvenience, coffee machines are known having a single brewing chamber formed by a brewing cylinder, an upper piston and a lower piston. The brewing cylinder and the pistons are held in a frame and movable with respect to the same. Coffee powder is fed in the brewing chamber by means of a swivel-type funnel which can be moved into a swiveled- away position and locked in such position to facilitate clearing of the upper piston. The movement of the parts of the brewing chamber can define different volumes to contain different amounts of ground coffee.

[0013] Despite the simplification with a single brewing chamber, the yield of extraction can wide vary among the different coffee weights to be used, and the same uncontrollable variation can be in the distribution of the ground coffee inside the brewing chamber.

[0014] In view of the aforementioned problems, a negative impact is particularly noticeable in the body of the coffee beverage when using a low coffee weight. In turn, this leads to a use of a greater amount of ground coffee per single cup to compensate for the drawbacks, with a consequence of having an increase of cost for each cup serving.

[0015] Moreover, a non-homogeneous distribution of the ground coffee inside the brewing chamber can provide an inaccurate reading of pressure exercised during the ground coffee pressing. Additionally, the non-homogeneous distribution of the ground coffee can further be a greater wear of piston which compresses the coffee powder, with a consequent friction increase that could lead not only to a wrong reading of the forming pressure of a ground coffee tablet, but also to damages of the piston itself. The non homogeneity of the coffee puck leads to an underperforming extraction yields or preferential fluidic paths in the coffee bed affecting then the sensorial profile.

[0016] Additional known problems of the known coffee machines refer to the repeatability of the beverage quality for all extractions and the reduced flexibility in the consumer personalization which is currently a popular trend among coffee lovers. The current coffee machines typically offer a two-size variation of the brewing chamber, for example capable of processing 6g and 9g of ground coffee in weights respectively. However, the existence of other variants beyond these specifications could potentially impact the economy of scale of a business, targeting specific market segments based on consumer preferences and preferences for different coffee strengths.

[0017] Some of the know coffee machines also allows the brewing chamber to have size to fit for up to 12 g of ground coffee in weight but, when decreasing the brewing chamber size for a smaller weight, this leads to a low extraction yield and a change in the sensorial profile making coffees more watery with low consistency and also affecting the crema quality.

[0018] Summary of the invention

[0019] The object of the present invention is to provide a coffee machine able to minimize the 19794-EP-EPA aforementioned drawbacks.

[0020] In particular, the object of the present invention is to provide a coffee machine able to flexible define the amount of ground coffee to be used according to the type of beverage to prepare while maintaining high quality of extraction and repeatability of the same.

[0021] The aforementioned objects are achieved, in a first aspect of the invention, by a coffee machine provided with a centrifugal brewing unit and with a control unit, operatively connected to the centrifugal brewing unit, wherein the centrifugal brewing unit comprises a spinning assembly, which is rotatable around a spinning axis, the spinning assembly is provided with a plurality of parts able to define a brewing chamber with a variable volume for containing ground coffee, wherein the centrifugal brewing unit also comprises a water injection device to inject water into the brewing chamber, wherein one or more of the parts of the spinning assembly are movable along a direction parallel to the spinning axis in a plurality of predefined brewing positions defining different brewing volumes of the brewing chamber provided with different heights over the same diameter, wherein the control unit is able to set the desired brewing volume among the different predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types, by the movement of one or more of the parts of the spinning assembly along a direction parallel to the spinning axis, and wherein the control unit is able to operate at least part of the spinning assembly to rotate around a spinning axis to create a coffee donut with the ground coffee inside the brewing chamber having the desired brewing volume before or during the water injection by the water injection device, wherein the shape of the coffee donut is defined in the defined brewing volume according to the desired brewing volume set.

[0022] By leveraging the variable brewing volume and the spinning technology to shape the coffee donut, the coffee machine according to the present invention offers enhanced control and efficiency in the extraction process.

[0023] In an embodiment, the coffee machine further comprises a feeding device to feed the ground coffee in the brewing chamber, and wherein the control unit is able to operate one or more of the parts of the spinning assembly to rotate around a spinning axis while the ground coffee is fed in the brewing chamber.

[0024] The rotation operated while the ground coffee is fed allows a uniform distribution of the dose inside the brewing chamber.

[0025] In an embodiment, the control unit is able to operate one or more of the parts of the spinning assembly along a direction parallel to the spinning axis to compress the ground coffee in the brewing chamber. 19794-EP-EPA

[0026] In an embodiment, the centrifugal brewing unit further comprises: a spinning motor, operatively connected to one or more of the parts of the spinning assembly for the rotation around the spinning axis; a vertical displacement motor, separate from the spinning motor and operatively connected to one or more of the parts of the spinning assembly for a movement along a direction parallel to the spinning axis.

[0027] Therefore, the two drives, the spinning motor and the vertical displacement motor, are independent from each other and they can operate on the same or different parts of the spinning assembly.

[0028] In an embodiment, the control unit is able to operate the spinning motor so that one or more of the parts of the spinning assembly rotates around the spinning axis while the ground coffee is fed in the brewing chamber.

[0029] This allows to create a uniform distribution of the ground coffee in the brewing chamber.

[0030] In an embodiment, wherein the rotation of at least part of the spinning assembly while the ground coffee is fed in the brewing chamber is in a range of 100-400 revolutions per minute (RPM), preferably in a range of 150-300 revolutions per minute (RPM).

[0031] The aforementioned range is considered to fit the need of uniform distribution without compromising other feature of the coffee bed in the brewing chamber.

[0032] In an embodiment, the control unit is able to operate the vertical displacement motor so that one or more of the parts of the spinning assembly moves along the direction parallel to the spinning axis to compress the ground coffee in the brewing chamber.

[0033] The compression can improve the compaction of the ground coffee in the brewing chamber, as well as it can help to dry a wet coffee donut after the extraction.

[0034] In an embodiment, the control unit operates the vertical displacement motor up to a maximum electrical current limit set for the compression of the ground coffee in the brewing chamber.

[0035] In an embodiment, the rotation of at least part of the spinning assembly to create a dried coffee donut with the ground coffee inside the brewing chamber has an acceleration in a range of 300-2500 m / s2, preferably in a range of 500-2000 m / s2.

[0036] In an embodiment, the brewing chamber comprises: a cylindrical chamber element, extending along the spinning axis; a bottom wall of the cylindrical chamber element, arranged perpendicularly to the spinning axis; and a top wall of the cylindrical chamber element, arranged perpendicularly to the spinning axis parallel to the bottom wall; wherein one or more of the parts of the spinning assembly are movable along the direction parallel to the spinning axis from at least a first of the predetermined different brewing positions, wherein the cylindrical chamber element is in contact with the top wall so that the 19794-EP-EPA top wall is arranged inside the cylindrical chamber element at a first distance from the bottom wall defining a first volume of the brewing chamber, to at least a second of the predetermined different brewing positions, wherein the cylindrical chamber element is in contact with the top wall so that the top wall is arranged inside the cylindrical chamber element at a second distance from the bottom wall defining a second height of the brewing chamber which is lower than the first height.

[0037] The definition of different heights of the brewing chamber affects consequently the height of the coffee donut and, in turn, the properties of the extracted beverage.

[0038] In an embodiment, the cylindrical chamber element is movable together with the bottom wall with respect to the top wall along a direction parallel to the spinning axis from at least the first of the predetermined different brewing positions to at least the second of the predetermined different brewing positions.

[0039] This allows to drive one single part, such as the cylindrical chamber element, to define the desired heights or volumes of the brewing chamber, reducing costs and complexity of the centrifugal brewing unit.

[0040] In an embodiment, the top wall only is provided with coffee extraction nozzles.

[0041] This allows a better channelling of the water through the coffee bed defined by the coffee donut during the extraction of the beverage.

[0042] In an embodiment, the bottom wall is arranged in a fixed position with respect to the cylindrical chamber element in all the plurality of predetermined different brewing positions.

[0043] Therefore, the single movement of one of the two parts, in turn the cylindrical chamber or the bottom wall, also defines the movement for the other part.

[0044] In a further aspect, the aforementioned objects are achieved by a method for preparing a beverage by way of operating a coffee machine provided with a centrifugal brewing unit and with a control unit, operatively connected to the centrifugal brewing unit, comprising: setting, by the control unit, a desired brewing volume of a brewing chamber defined by a spinning assembly of the centrifugal brewing unit, wherein the desired brewing volume is set among a plurality of predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types; moving one or more parts of the spinning assembly along a direction parallel to a spinning axis, around which the spin assembly is rotatable, to define the desired brewing volume of the brewing chamber; operating, by the control unit, one or more parts of the spinning assembly to rotate around the spinning axis to create a coffee donut with the ground coffee inside the brewing chamber having the desired brewing volume before or during the water injection a water 19794-EP-EPA injection device of the centrifugal brewing unit, wherein the shape of the coffee donut is defined in the brewing chamber according to the defined brewing volume set. injecting water into the brewing chamber while the one or more parts of the spinning assembly rotate around the spinning axis.

[0045] By leveraging the variable brewing volume and the spinning to shape the coffee donut, the method for preparing a beverage according to the present invention offers enhanced control and efficiency in the extraction process.

[0046] In an embodiment, the method for preparing a beverage is by way of operating the coffee machine according to the present invention.

[0047] Brief description of the drawings

[0048] These and further features and advantages of the present invention will become apparent from the disclosure of the preferred embodiment, illustrated by way of a non-limiting example in the accompanying figures, wherein:

[0049] - Figure 1 is a schematic view of a coffee machine according to the present invention;

[0050] - Figure 2 is a front perspective view of the centrifugal brewing unit of the coffee machine of Figure 1 , wherein the top wall is open for entering the ground coffee;

[0051] - Figure 3 is a front planar cross-section view of the centrifugal brewing unit of Figure 2, wherein the brewing chamber is closed for pressing the ground coffee;

[0052] - Figure 4 is a front planar cross-section view of the centrifugal brewing unit of Figure 2, wherein the brewing chamber is closed creating a head space from the pressed coffee puck;

[0053] - Figure 5 is a front perspective cross-section view of the centrifugal brewing unit of Figure 2, after a centrifugation of the coffee puck;

[0054] - Figure 6A is a front perspective view of a coffee donut according to a first shape;

[0055] - Figure 6B is a front perspective view of a coffee donut according to a second shape;

[0056] - Figure 7 is a front perspective view of the centrifugal brewing unit of Figure 2, wherein the brewing chamber is open after drying the coffee donut;

[0057] - Figure 8 is a front perspective cross-section view of the centrifugal brewing unit of Figure 7;

[0058] - Figure 9 is a front perspective view of the centrifugal brewing unit of Figure 2, wherein the brewing chamber is open to expel the coffee donut;

[0059] - Figure 10 is a front perspective cross-section view of the centrifugal brewing unit of Figure 2, wherein the bottom wall is repositioned inside the brewing chamber.

[0060] Detailed description of exemplary embodiments

[0061] Figure 1 schematically illustrates a preferred embodiment of the coffee machine 1 according 19794-EP-EPA to the present invention. The coffee machine 1 is provided with a brewing unit 10, especially of a centrifugal type, and with a control unit 11 , operatively connected to the centrifugal brewing unit 10.

[0062] The centrifugal brewing unit 10 comprises a spinning assembly, which is rotatable around a spinning axis Y, better illustrated in the cross-section views of Figures 3-5.

[0063] The spinning assembly is provided with a plurality of parts able to define a brewing chamber 100, better illustrated in the same Figures 3-5, which when closed can allow the brewing of a beverage using ground coffee, as will be better explained below.

[0064] The brewing chamber 100 is designed such that it has a variable volume for containing, for example, ground coffee portions having different weights. Such a variable volume can then be used before the dosing of the ground coffee, defining different dosing volumes, after the dosing of the same ground coffee, defining a pressing volume, or for the brewing of the ground coffee in a beverage, defining predefined brewing volumes.

[0065] In the preferred embodiment illustrated in the attached Figures, the brewing chamber 100 comprises a cylindrical chamber element 1 10, extending along the spinning axis Y. The latter is defined by a sleeve, thus having two opposite openings, but according to further embodiments (not illustrated) different arrangements can be provided.

[0066] The same embodiment also illustrates the brewing chamber 100 comprising a bottom wall 210 and a top wall 310 of the cylindrical chamber element 110 designed to close the same, in particular with respect to the opposite openings of the sleeve. Thus, both the bottom wall 210 and the top wall 310 are arranged perpendicularly to the spinning axis Y and colinear to each other.

[0067] Other arrangements of the brewing chamber are possible according to different embodiments (not shown).

[0068] As illustrated in Figures 3-5 and 10, in the preferred embodiment the bottom wall 210 is arranged within the cylindrical chamber element 110. Preferably, also the top wall 310 can be arranged inside the cylindrical chamber element 110 or, according to the same preferred embodiment herewith illustrated, at least part of the same can be introduced inside the cylindrical chamber element to define the brewing chamber 100 when closed. This allows a better control of the tightness of the brewing chamber 100 itself, as well as a better control of the brewing chamber’s volume.

[0069] In the preferred embodiment, being fixed the diameter of the cylindrical chamber element 110, the different volumes of the brewing chamber 100, such as dosing volumes or pressing volumes or brewing volumes, can be defined by a difference distances between the bottom wall 210 and the top wall 310, and / or by the different positions of the bottom wall 210 or the top wall 310 inside the cylindrical chamber element 1 10.

[0070] Thus, one or more parts of the spinning assembly can move perpendicularly to the spinning 19794-EP-EPA axis Y, such as the cylindrical chamber element 110, the bottom wall 210 or the top wall 310, or combination of the same. In the preferred embodiment, herewith illustrated, the cylindrical chamber element 110 and the bottom wall 210 are movable perpendicularly to the spinning axis Y while the top wall 310 remains fixed in the same position, thus defining a referencing position. Another referencing position can also be defined by a bottom portion of a frame, as will be discussed in the following.

[0071] In particular, the one or more of the parts of the spinning assembly are movable along a direction parallel to the spinning axis Y in a plurality of predefined brewing positions defining different brewing volumes of the brewing chamber 100 provided with different heights over the same diameter.

[0072] The movement perpendicularly to the spinning axis Y is preferably along multiple predefined brewing positions that vary the brewing chamber’s volume by changing its height, wherein the latter is defined, as above described, as the distance between the bottom wall 210 and the top wall 310, and / or by position of the bottom wall 210 or the top wall 310 inside the cylindrical chamber element 1 10.

[0073] As an example, one or more of the parts of the spinning assembly are movable along a direction parallel to the spinning axis Y from at least a first of the predetermined different brewing positions, wherein the cylindrical chamber element 110 is in contact with the top wall 310 so that the latter is arranged inside the cylindrical chamber element 110 at a first distance from the bottom wall 210 defining a first height of the brewing chamber 100, corresponding a first volume, to at least a second of the predetermined different brewing positions, wherein the cylindrical chamber element 1 10 is in contact with the top wall 310 so that the latter is arranged inside the cylindrical chamber element 1 10 at a second distance from the bottom wall 210 defining a second height of the brewing chamber 100 which is lower than the first height, corresponding to a second volume which is smaller than the first volume.

[0074] In the preferred embodiment herewith illustrated, the cylindrical chamber element 1 10 is movable together with the bottom wall 210 with respect to the top wall 310 along a direction parallel to the spinning axis Y from at least the first of the predetermined different brewing positions to at least the second of the predetermined different brewing positions. More positions can be used according to the necessary volumes needed for different dosing volumes or different pressing volumes or different brewing volumes.

[0075] This allows to drive one single part, such as the cylindrical chamber element 110, to define the desired heights or volumes of the brewing chamber 100, reducing costs and complexity of the centrifugal brewing unit 10.

[0076] The centrifugal brewing unit is preferably provided with a frame 200 to sustain the spinning assembly and, in particular, the brewing chamber 100, as illustrated in the example of the present embodiment. The frame 200 also allows the one or more parts of the spinning 19794-EP-EPA assembly to move perpendicularly to the spinning axis Y defining a mobile platform. The mobile platform operates with a single displacement direction, allowing for seamless transitions from the bottom to the top and vice versa. This design facilitates the sequential steps involved in coffee beverage preparation, as described in greater details below. By leveraging the mobile platform, the centrifugal brewing unit according to the present invention offers enhanced control and efficiency in the extraction process.

[0077] The mobile platform is preferably defined by the cylindrical chamber element 110 and the bottom wall 210, which are movable with respect to the fixed top wall 310, but different arrangements can be used according to other embodiments (not shown). The spinning motor

[0078] 101 can also be considered part of the mobile platform, moving together with the rest of the part perpendicularly to the spinning axis Y, but it can also be fixed compared to the mobile platform.

[0079] Preferably, the bottom wall 210 is arranged in a fixed position with respect to the cylindrical chamber element 1 10 in all the plurality of predetermined different brewing positions.

[0080] Therefore, the single movement of one of the two parts, in turn the cylindrical chamber 110 or the bottom wall 210, also defines the movement for the other part.

[0081] In the preferred embodiment, the frame 200 comprises a supporting shaft 201 and a driving shaft 202, the latter allowing also the perpendicular movement with respect to the spinning axis Y of one or more parts of the spinning assembly. In the present embodiment, the driving shaft 202 defines a screwed element which the mobile platform can use to move up and down with the help of the vertical displacement motor 102. Therefore, the screw counterclockwise rotation makes the mobile platform to move down, while the screw clockwise rotation makes the mobile platform to move up.

[0082] The centrifugal brewing unit according to the present invention can thus comprise one or more drives to define the one or both of the movement of one or more of the parts of the spinning assembly perpendicularly to the spinning axis Y and around the spinning axis Y. In this regard, the preferred embodiment comprises a spinning motor 101 and a vertical displacement motor 102. The spinning motor 101 is operatively connected to one or more of the parts of the spinning assembly for the rotation around the spinning axis Y. The vertical displacement motor

[0083] 102 is also connected to one or more of the parts of the spinning assembly for a movement along a direction parallel to the spinning axis Y (up-down movement). In particular, the latter is separated from the spinning motor 101 .

[0084] Therefore, the two drives, the spinning motor 101 and the vertical displacement motor 102, are independent from each other and they can operate on the same or different parts of the spinning assembly.

[0085] As designed in the preferred embodiment, the spinning motor 102 is movable along the direction parallel to the spinning axis Y together with the one or more of the parts of the 19794-EP-EPA spinning assembly which are movable along the same direction parallel to the spinning axis Y. This design allows for enhanced control and efficiency in the extraction process by reducing the number of parts directly connected to the spinning motor, thereby simplifying the system and reducing costs. In particular, in the present embodiment, some of the parts of the spinning assembly define a driving portion, rotatable around the spinning axis Y due to a mechanical connection with the spinning motor 102, and some other parts of the spinning assembly define a chasing portion, freely rotatable around the spinning axis Y. In particular, the friction created between the driving portion and the chasing portion in the brewing chamber 110 while the driving portion is rotating transfers the rotation movement to the chasing portion. For example, the top wall 310 when inserted in the in the cylindrical chamber element 110 (especially with its own O-ring) ensures that both parts the driving portion (especially the cylindrical chamber element 110) and the chasing portion (such as the top wall 310 together with the bottom wall 210) are together rotating with the driving portion.This allows to reduce the number of parts directly connected to the spinning motor 102, reducing complexity and cost of the centrifugal brewing unit 10 and of the related coffee machine.

[0086] The centrifugal brewing unit 10 also comprises a water injection device 410 to inject water into the brewing chamber 100. According to the present embodiment, the design of the centrifugal brewing unit 10 is such that the needed water is injected from the top in the brewing chamber 100, but different design can be adopted according to different embodiment (not illustrated). Moreover, the same centrifugal brewing unit 10 is also provided with a beverage outlet 420 to extract the beverage from the brewing chamber 100. According to the present embodiment, the specific design of the centrifugal brewing unit 10 is such that also the (coffee) beverage is delivered from the top as well, the beverage outlet 420 being positioned above the top wall 310, but different design can be adopted according to different embodiment (not illustrated). Both the injection of water and the extraction of the beverage from the top of the brewing chamber 100 ensures efficient and controlled extraction processes.

[0087] One or more of the parts of the spinning assembly are also rotatable around the spinning axis Y so that it is possible to create a coffee donut 2A, 2B with the ground coffee inside the brewing chamber 100 having the desired brewing volume, as it will be described in greater details below. In particular, before or during the water injection by the water injection device 410, the coffee donut 2A, 2B can be formed, wherein the shape of the coffee donut is defined in the brewing chamber 100 according to the desired brewing volume set, as simplified in Figures 6A, 6B. In particular, the different coffee donuts 2A, 2B are defined by a donut wall having different dimensions, such as the donut wall heights 21 A, 21 B and the donut wall thicknesses 31A, 31 B.

[0088] By leveraging the variable brewing volume and the spinning action to shape the coffee donut, the centrifugal brewing unit according to the present invention offers enhanced control and 19794-EP-EPA efficiency in the extraction process.

[0089] In particular, the control unit 1 1 is able to set the desired brewing volume among the different predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types. The definition of the desired brewing volume is obtained by the movement of one or more of the parts of the spinning assembly along a direction parallel to the spinning axis Y. Moreover, the control unit 11 is able to operate at least part of the spinning assembly to rotate around a spinning axis Y to create a coffee donut (as in Figures 6A and 6B) with the ground coffee inside the brewing chamber 100 having the desired brewing volume before or during the water injection by the water injection device 410, wherein the shape of the coffee donut 2A, 2B is defined in the defined brewing volume according to the desired brewing volume set.

[0090] By leveraging the variable brewing volume and the spinning action to shape the coffee donut, the coffee machine 1 according to the present invention offers enhanced control and efficiency in the extraction process.

[0091] The definition of different heights of the brewing chamber 100 affects consequently the height of the coffee donut 2A, 2B (donut wall heights 21 A, 21 B) as well as the thickness of the same (donut wall thicknesses 31 A, 31 B) and, in turn, the properties of the extracted beverage. It result evident that coffee donut 2A in Figure 6A has a lower height compared to coffee donut 2B in Figure 6B. This difference is due to the varying height and volume of the brewing chamber 100, such as the difference in position of the top wall 310 inside the cylindrical chamber element 1 10 or the different positioning of the latter (and the related bottom wall 210) compared to the fixed top wall 310 or the different relative position of bottom wall 210 and top wall 310, or combination of the same.

[0092] Preferably, the plurality of predefined brewing positions defines different brewing volumes for different ground coffee weights, or for different types of coffee. Moreover, the shape of the coffee donut 2A, 2B can be defined in the brewing chamber 100 according to the desired brewing volume set so that the donut wall thickness 31 A, 31 B of the coffee donut 2A, 2B is substantially constant over the different brewing volumes.

[0093] The thickness of the coffee donut affects the sensorial profile of the final beverage, such as the coffee. When the coffee donut has a too thin donut wall thickness it affects the yield of extraction, cause substantially no coffee bed is defined. When the donut has a too thick donut wall thickness it increases the pressure of extraction with not extraction and wet coffee donut. Therefore, by maintaining it constant over the different brewing volumes it is possible to ensure a good sensorial profile across a wide range of beverages.

[0094] In the present embodiment, the top wall 310 only is provided with coffee extraction nozzles, but different arrangements can be used according to different embodiments (not shown). In 19794-EP-EPA turn, the extraction nozzle are fluidly connected to fluid channels 312 to drive the beverage to the beverage outlet 420, the latter in turn fluidly connected to the fluid channels 312. This allows a better channelling of the water through the coffee bed defined by the coffee donut 2A, 2B during the extraction of the beverage.

[0095] In particular, the coffee extraction nozzles are preferably arranged along the periphery of the top wall 310. In this way, the extraction nozzles are only provided at a position to cover the coffee donuts 2A, 2B to be extracted. These dispensing nozzles typically have a diameter ranging from 0.3 to 0.6 mm.

[0096] Moreover, the number of fluid channels 312 can vary across different embodiments, being preferably equal to three or equal to six as in the preferred one. The fluid channels 312 are also preferably evenly distributed around the diameter of the top wall 310.

[0097] Figures 1 -2 and 7-9 also illustrates a feeding device 430 for feeding ground coffee into the brewing chamber 100. In the preferred embodiment herewith described, the feeding device 430 comprises a toboggan element 431 which directs the ground coffee into the brewing chamber 100 when the latter is in the open position (the top wall 310 is open for entering the ground coffee) from a funnel element 432 bearing a reserve of ground coffee. While in Figure 2 the feeding device 430 is in the operative mode, meaning ready to feed the ground coffee in the brewing chamber 100, the other Figures 1 , 7-9 only illustrate the elements when not in an operative status.

[0098] The control unit 11 is able to operate one or more of the parts of the spinning assembly to rotate around a spinning axis while the ground coffee is fed, i.e. by the feeding device 430, in the brewing chamber 100. The rotation operated while the ground coffee is fed allows a uniform distribution of the dose inside the brewing chamber 100.

[0099] The rotation of at least part of the spinning assembly while the ground coffee is fed in the brewing chamber 100 is in a range of 100-400 revolutions per minute (RPM), preferably in a range of 150-300 revolutions per minute (RPM). The aforementioned range is considered to fit the need of uniform distribution without compromising other feature of the coffee bed in the brewing chamber 100.

[0100] A grinder (not illustrated) can be also provided upstream the funnel element, so that the coffee beans are ground in a batch or freshly ground in a single dose when requested.

[0101] Furthermore, the brewing chamber 100 can be also provided with an ejector device 440 as better illustrated in Figures 1 -2 and 7-9. The latter can be round shaped so as to copy the shape of a dried coffee donuts (a coffee donut which is dried, or almost dried, after the beverage extraction) to remove the same for the brewing chamber. While in Figure 9 the ejector device 440 is in the operative mode, meaning ready to remove the dried coffee donut from the brewing chamber 100, the other Figures 1 -2, and 7 only illustrate the same when not in an operative status (non-operative mode). The ejector device 440 can be operated from the 19794-EP-EPA operative mode to the non-operative mode, and vice versa, by rotating around a shaft of the frame 200. In particular, in the present invention the frame 200 is provided with an ejector shaft 203, separate from the others, which allows such movement of the ejector device 440.

[0102] The centrifugal brewing unit according to the present invention can be also integrated in a coffee machine to achieve the aforementioned technical benefits. The coffee machine can be provided with a control unit operatively connected to the centrifugal brewing unit, wherein the control unit is able to set the desired brewing volume of the brewing chamber according to a selection of a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types.

[0103] The present invention also relates to a method for preparing a beverage by way of operating a coffee machine provided with a centrifugal brewing unit and a control unit operatively connected to the centrifugal brewing unit. The centrifugal brewing unit can comprise a spinning assembly, which is rotatable around a spinning axis, wherein the spinning assembly is able to define a brewing chamber having a variable volume for containing ground coffee.

[0104] Preferably, the method for preparing a beverage is by way of operating the coffee machine 1 according to the present invention, to which reference is made in the following.

[0105] Taking into account the preparation of a beverage from ground coffee the preparation sequence is herewith described.

[0106] The ground coffee is fed into the brewing chamber 100.

[0107] In the example of present embodiment, the cylindrical chamber element 1 10 together with the bottom wall 210 are arranged close to the top wall 1 10, in a position such that to have a gap from the latter which allows the opening of the brewing chamber 100 for the introduction of the ground coffee. The movement of the cylindrical chamber element 1 10, and of the related bottom wall 210, can be operated by the vertical displacement motor 102, by moving the same from the rest position illustrated in Figure 1 to the feeding position illustrated in Figure 2.

[0108] If present, a grinder (not illustrated) can be simultaneously activated for a specific duration to provide the precise amount of ground coffee required for the beverage.

[0109] The (freshly) ground coffee cascades through the feeding device 430 from the funnel element 432 to the toboggan element 431 which directs the ground coffee into the brewing chamber 100, the latter being in the open position as illustrated in Figure 2.

[0110] During the ground coffee feeding, the brewing chamber 100, at least part of the same relating to the cylindrical chamber element 1 10 and the bottom wall 210, starts to rotate around the spinning axis Y, for example with a spinning action defined by the spinning motor 101. The rotation is preferably made at a low speed, typically ranging from 100 to 400 revolutions per minute (rpm), preferable from 150 to 300 rpm. This controlled flow of ground coffee together with the rotation ensures that the ground coffee is efficiently and accurately delivered into the brewing chamber 100, thus ensuring a homogeneous distribution of the ground coffee inside 19794-EP-EPA the same. In particular, the brewing chamber 100 rotation during the delivery of ground coffee plays a crucial role in ensuring the formation of a homogeneous coffee puck. As the ground coffee particles are dispensed into the brewing chamber 100, the rotation helps to distribute them evenly, resulting in a uniform and consistent coffee bed. This attention to detail in the distribution of ground coffee particles is a key factor in delivering a consistent coffee cup.

[0111] Optionally, the ground coffee is compacted into the brewing chamber 100, as illustrated in Figure 3.

[0112] After the targeted weight of ground coffee has been delivered, the rotation of the brewing chamber 100 comes to a halt. At this point, the control unit 1 1 is able to operate one or more of the parts of the spinning assembly along a direction parallel to the spinning axis Y to compress the ground coffee in the brewing chamber 100. Preferably, the control unit 1 1 is able to operate the vertical displacement motor 102 so that one or more of the parts of the spinning assembly moves along the direction parallel to the spinning axis Y to compress the ground coffee in the brewing chamber. In particular, the mobile platform (the cylindrical chamber element 110 and the bottom wall 210) can be displaced upwards (toward the top wall 310) to a predetermined position or up to the maximum electrical current limit set for the vertical displacement motor 102. In a first scenario, wherein the chamber platform is positioned at a determined position, the ground coffee remains uncompressed. This allows for a looser coffee bed and extraction process. In a second scenario, when the chamber platform reaches the maximum electrical current limit, the grind coffee is compressed with a force that is directly proportional to the defined maximum current of the vertical displacement motor 102. This compression results in a more compact and denser coffee bed, influencing the extraction process accordingly.

[0113] Thus, the method for preparing a beverage comprises defining a desired brewing volume of the brewing chamber 100 among a plurality of different brewing volumes provided with different heights over the same diameter. In particular, the method according to the present invention comprises setting, by the control unit 11 , a desired brewing volume of a brewing chamber 100 defined by a spinning assembly of the centrifugal brewing unit 10, wherein the desired brewing volume is set among a plurality of predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types.

[0114] Moreover, the method further comprises moving one or more parts of the spinning assembly, such as the cylindrical chamber element 110 and the bottom wall 210, along a direction parallel to the spinning axis Y to define the desired brewing volume of the brewing chamber, such as according to a plurality of predefined brewing positions defining different brewing volumes of the brewing chamber to define the desired brewing volume of the brewing chamber, as illustrated in Figure 4. 19794-EP-EPA

[0115] This allows the creation of a head space, which is an empty space in the brewing chamber 100 after the formation of the coffee puck. The mobile platform is then moved downward. This movement creates a defined distance from the top wall 310, leaving an empty space defined "head space". The head space is a critical element in the preparation of a high-quality coffee beverage. Its size is determined by two main factors: the desired sensorial profile of the coffee beverage and the weight of the ground coffee that has been fed into the brewing chamber 100. By carefully determining the size of the head space based on the specific coffee weight and desired sensorial profile, the centrifugal brewing unit 10 can consistently deliver a qualitative and customized coffee beverage.

[0116] As illustrated in Figure 5, the method further comprises operating, by the control unit 11 , one or more parts of the spinning assembly to rotate around the spinning axis Y to create a coffee donut with the ground coffee inside the brewing chamber 100 having the desired brewing volume before or during the water injection by the water injection device 410 of the centrifugal brewing unit 100, wherein the shape of the coffee donut 2A, 2B is defined in the brewing chamber 100 according to the defined brewing volume set, as illustrated in the different shapes of Figures 6A and 6B.

[0117] Once the mobile platform reaches its final position at the defined head space, the spinning motor 101 is activated, initiating a ramp of acceleration and targeting a specific speed. The acceleration phase is responsible for forming a coffee donut shape 2A, 2B, with the thickness of the coffee donut’s walls determined by the defined head space, according to the desired brewing volume. When the mobile platform comes into contact with the top wall 310 a mechanical friction is created. This friction allows the entire brewing chamber 100 to rotate as a result. The contact between the mobile platform and the top wall 310 enables the transfer of rotational motion from the spinning motor 101 to the whole brewing chamber. This mechanical friction ensures that the spinning motion is effectively transmitted throughout the centrifugal brewing unit 10, thus from the cylindrical chamber element 1 10 to the bottom wall 210 and in turn to the top wall 310 (the respective O-ring of the bottom wall 210 engages the cylindrical chamber element 1 10 to receive the rotation motion from the same, and the respective O-ring of the top wall 310 engages the cylindrical chamber element 110 to receive the rotation motion from the same). By utilizing this friction-based rotation mechanism, the centrifugal brewing unit 10 can maintain a consistent and controlled spinning motion around the spinning axis Y.

[0118] The head space distance plays a crucial role in shaping the coffee donut. As illustrated, the head space directly impacts the height of the coffee donut 2A, 2B, while inversely influencing the thickness of its walls. A larger head space distance results in a taller coffee donut 2B with thinner walls, while a smaller head space distance leads to a shorter coffee donut 2A with thicker walls. This visual representation highlights the direct and inverse proportional 19794-EP-EPA relationship between the head space distance and the height and thickness of the coffee donut, respectively.

[0119] By carefully adjusting the head space, according to a desired brewing volume of the brewing chamber 100 among a plurality of different brewing volumes, the centrifugal brewing unit 10 according to the present invention can precisely control the shape and characteristics of the coffee donut 2A, 2B, ultimately impacting the flavor, the yield and overall sensorial experience of the final coffee beverage.

[0120] The acceleration needed to form the coffee donut can range from 2000 to 4000 rpm / s, preferably from 3000 to 4000 rpm / s. This acceleration is an important factor in shaping the coffee donut. Regardless of the type of coffee beverage being prepared, it is important to maximize the final spinning velocity, in a range preferably from 2000 to 4000 rpm, more preferably from 3000 to 4000 rpm. This high spinning velocity is important for achieving an even and homogeneous tightening between the coffee grains within the coffee donut. By maximizing the spinning velocity, the centrifugal force exerted on the coffee grains is increased, resulting in a tighter and more uniform coffee bed in the coffee donut. This tightness ensures optimal water flow and extraction throughout the brewing process, leading to a well- extracted and flavorful coffee beverage. During this operation the maximum spinning velocity is preferably maintained during a defined period of time before moving to the next step of operation.

[0121] Thus, the method according to the present invention comprises injecting water into the brewing chamber 100 while the one or more parts of the spinning assembly rotate around the spinning axis Y. By leveraging the variable brewing volume and the spinning to shape the coffee donut, the method for preparing a beverage according to the present invention offers enhanced control and efficiency in the extraction process.

[0122] In particular, once the coffee donut has been formed and stabilized, the spinning velocity can be adjusted based on the specific type of coffee beverage being prepared. The level of spinning velocity is carefully determined to optimize the extraction process and achieve the desired characteristics of the final beverage. For espresso, Lungo, and Americano coffee beverages, the spinning velocity typically ranges from 2500 to 3800 rpm. This higher spinning velocity is necessary to ensure efficient extraction and the development of rich flavors and aromas. However, for filter-style coffee beverages, the spinning velocity is reduced to a range of 500 to 1000 rpm. This lower spinning velocity helps to prevent the formation of foam during the extraction process, ensuring a smoother and cleaner cup of coffee. By adjusting the spinning velocity according to the specific coffee beverage type, the centrifugal brewing unit 10 can tailor the extraction process to achieve optimal results. This attention to detail in controlling the spinning velocity contributes to the overall quality and taste of the final coffee beverage. 19794-EP-EPA

[0123] Once the desired spinning velocity is achieved, the water injection device 410 injects water into the center of the brewing chamber 100, particularly in the hole of the coffee donut created, at a defined flow rate (ml / s). As the water is expelled towards the periphery of the brewing chamber 100 thanks to the spinning, it effectively wets the entire coffee donut, ensuring thorough saturation of the ground coffee.

[0124] The spinning velocity of the brewing chamber 100 generates centrifugal pressure, which is directly proportional to both the spinning velocity and the combined mass of the ground coffee and water within the brewing chamber 100. This centrifugal pressure plays an important role in compacting and tightening the coffee grains of the coffee donut, ultimately enhancing the extraction process. By increasing the spinning velocity, the centrifugal pressure intensifies, leading to a tighter and more compact coffee bed of the coffee donut. This tighter arrangement of coffee grains is specifically adapted to the characteristics of the coffee blend or coffee types being used. Different coffee blends or coffee types may require different levels of compactness to achieve optimal extraction and flavor profiles.

[0125] The centrifugation pressure can be calculated as follow:

[0126] F ma)2r P = - = -

[0127] A 2nrh wherein:

[0128] • m is the mass of the ground coffee contained in the brewing chamber 100, and eventually the mass of the water contained in the same brewing chamber 100.

[0129] • co is the spinning velocity in rad / s.

[0130] • r the radius of the rotation.

[0131] • h being the overall height of the coffee donut.

[0132] A prewetting sequence can be implemented before the actual delivery of the coffee beverage. This prewetting sequence involves injecting a specific volume of water at a defined flow rate, followed by a waiting time. The purpose of the prewetting sequence is to ensure that the coffee grounds are properly saturated and prepared for extraction. By introducing water prior to the delivery of the coffee beverage, the prewetting sequence helps to initiate the extraction process and enhance the overall extraction efficiency.

[0133] Once the brewing chamber 100 is fed with water and the water is dispersed to the periphery of the same due to the centrifugal force, the coffee is expelled in an upward direction through the plurality of dispensing nozzle provided in the periphery of the top wall 310 and then through the fluid channels 312 located above the same dispensing nozzle. This expulsion mechanism ensures that the extracted coffee is directed towards the desired beverage outlet 420 for collection or further processing.

[0134] As the water passes through the thickness of the coffee donut wall, it becomes charged with soluble coffee material, resulting in the formation of the coffee beverage. The combination of 19794-EP-EPA the directed water flow and the pressure applied against the internal wall of the coffee donut helps to extract the soluble coffee compounds from the coffee grounds. This process results in the formation of the coffee beverage. The coffee beverage is directed towards the plurality of dispensing nozzle located on the top of the coffee donut, which help to retain the ground coffee and the fines and distribute the beverage evenly. After passing through the dispensing nozzle network, the coffee beverage is drained towards the fluid channels 312. These fluid channels 312 ensure a homogeneous flow of the coffee beverage. On top of these fluidic channels 312, further fluidic elements can be provided to control the extraction of the beverage or to control the amount and quality of the cream, if any.

[0135] In particular, in the present embodiment part of the fluidics elements are three silicone membranes that restrict the flow of the beverage. These membranes are attached to cantilevers that swing proportionally to the rotation speed and the force of the retainer spring. The retainer spring is designed to close the valve proportionally to the rotation speed. For example, the valve is fully closed at a rotation speed of 4000 rpm. The closure of the valve restricts the flow and increases the flow velocity in a valve chamber. This leads to the stretching of proteins present in the coffee beverage and an increase in the internal pressure of the coffee chamber. The stretching of proteins contributes to the formation of foam, with the quantity of foam being influenced by the rotation speed and the defined water flow rate. The increase in pressure also causes the ground coffee to be squeezed, resulting in the expulsion of other flavoring molecules.

[0136] Moreover, in the present embodiment part of the fluidics elements is also a fixed crown. After passing through the valve body, the coffee beverage and foam are sprayed against a fixed crown. This spray effect rapidly cools down the beverage. To maintain an acceptable cup temperature, the crown can be heated. The coffee beverage and foam are then collected in a circular cavity and evacuated through the beverage outlet 420.

[0137] In a further embodiment, especially when six channels are used, no restrictions and thus valves can be present. Stretching of the proteins is achieved by a rotating crown and the fixed crown distance. When the coffee beverage is in between the rotating crown and the fixed crown, the friction generated by the rotation stretches the proteins which combines with the Nitrogen present in the air and form a foam or macro emulsion. The shear stress is proportional to the velocity gradient and the form of the rotating crown as well as the distance between the rotating one and the fixed one.

[0138] After the coffee extraction process is complete, it is important to dry the coffee donut thoroughly. This drying step helps to remove any remaining moisture from the ground coffee, making them easier to remove from the brewing chamber 100. By effectively drying the coffee donut, the centrifugal brewing unit 10 ensures that no residual ground coffee is left behind, 19794-EP-EPA preventing any cross-contamination or interference with the next coffee beverage preparation. This helps to maintain the integrity and quality of each individual coffee beverage prepared. Depending on the type of coffee beverage prepared and the coffee type or blend used different drying methods can be used. For short cup coffees such as Lungo and Americano, one method is to directly increase the spinning velocity to its maximum and maintain it for a specific period of time. To obtain the effect, in the preferred embodiment, the rotation of at least part of the spinning assembly is operated to create a coffee donut (preferably a dried coffee donut) with the ground coffee inside the brewing chamber 100 with an acceleration in a range of 300-2500 rpm / s, preferably in a range of 500-2000 rpm / s. This high spinning velocity, preferably in a range from 2000 to 4000 rpm and more preferably from 3000 to 4000 rpm, helps to drain the remaining water from the coffee donut, effectively drying it. Preferably, the high spinning velocity is maintained in a range of 4-10 second or even up to 20 second, according to the weight of the ground coffee and other features of the same such as the freshness. By maintaining the maximum spinning velocity, any excess moisture is expelled towards the beverage outlet 420, leaving the coffee donut dry and the brewing chamber 100 ready for the next brewing cycle.

[0139] For filter-like coffees and highly hygroscopic coffee blends, a different method is required to ensure the drying of the coffee donut. In this case, the spinning motion is first stopped, and the mobile platform is moved up to compress the coffee donut. This compression helps to remove any excess moisture from the ground coffee ground and aids in the drying process. After the coffee donut has been compressed, the spinning motion is restarted with a high acceleration. The spinning velocity is maximized and maintained for a specific period of time, which is dependent on the coffee blend or type being used. This period allows for the remaining moisture to be expelled from the coffee donut, ensuring its dryness.

[0140] Once the coffee donut has dried, the spinning motion is halted. The mobile platform is then lowered to its lowest possible position, as illustrated in Figure 7 wherein the cylindrical chamber element 1 10 and the bottom wall 210 are brought to the lower level possible. In this embodiment, the bottom wall 210, which is movable within the cylindrical chamber element 1 10, comes into contact with the bottom part of the frame 200. As a result of this mechanical contact and the downward movement of the mobile platform, the bottom wall 210 moves upward inside the cylindrical chamber element 1 10, as illustrated in Figure 8.

[0141] Once the mobile platform has reached its final lowest position, it is then raised again. This upward movement, facilitated by the cam located in the frame 200, causes the ejector device 440 to rotate around its pivot axis defined by the ejector shaft 203, as illustrated in Figure 9. As a result, the coffee donut is expelled and directed towards the ground coffee bin (not illustrated). 19794-EP-EPA

[0142] After the coffee donut is ejected, the brewing unit 100 undergoes reconfiguration to ready itself for the subsequent coffee beverage preparation. To achieve this, the mobile platform (herewith defined by the cylindrical brewing element 110 and the bottom wall 210) is moved up to its maximum top position thanks to the vertical displacement motor 102. During this displacement, the top wall 310 comes into contact with the bottom wall 210, causing the latter to move down within the cylindrical chamber element 110, as illustrated in Figure 10. When the bottom wall 210 is pushed in the lowermost position, corresponding to the uppermost position of the mobile platform, the latter is then moved down to prepare for receiving the ground coffee. Thus, the toboggan element 431 can swing when the mobile platform moves to place itself in the right position for a new loading of the ground coffee.

[0143] According to another embodiment, it is also possible to keep the brewing chamber 100 closed after the bottom wall 210 is pushed in the lowermost position, corresponding to the uppermost position of the mobile platform. This can prevent the brewing chamber 100 from cooling down. In this case, when a new beverage preparation is required, the mobile platform simply moves down to its designated coffee load position near the toboggan 431 as described above.

[0144] Variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.

[0145] As used in this specification, the words "comprises", "comprising", and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean "including, but not limited to".

[0146] The coffee machine according to the present invention leverages centrifugal force to offer a more efficient and innovative extraction of coffee, which allows a better extraction efficiency in terms of yield, flavors and overall brewing performance. One of its key features is the ability to adjust the coffee chamber volume based on the weight of the coffee being used, as well as the desired sensorial profile of the coffee beverage. It also ensures high-performance extraction of the roast & ground coffee while also effectively ejecting the dried coffee donut (or formed coffee puck).

[0147] The coffee machine according to the present invention introduces a new approach to coffee extraction, where the spinning technology takes complete control. In contrast, the conventional pressurized technology relies heavily on the coffee itself and its fluidic resistance for extraction. The known coffee machines typically offer only two different sizes of extraction capabilities, for example capable of processing 6g and 9g coffee weights respectively. However, the coffee machine according to the present invention is able to extends beyond these specifications, inbetween as well as far away from the two ending points, potentially positive impacting the choice for consumers. In particular, the present invention enables the preparation of short cup coffees using a low coffee weight of 5g, all the way up to larger coffee weights of 12g for short 19794-EP-EPA cup coffee beverages, utilizing the same brewing unit. Importantly, the Yield of extraction remains constant in the coffee weight range considered. The impact is particularly noticeable in the body of the coffee beverage when using a low coffee weight. This allows to match consumer preferences and preferences for different coffee strengths while reducing the complexity and the number of brewing unit involved.

[0148] The coffee machine according to the present invention also allows to modify the sensorial profile of a coffee beverage by simply changing the volume of the brewing chamber and consequently shaping the coffee donut differently.

[0149] 19794-EP-EPA

[0150] List of references in the drawings:

[0151] Coffee machine

[0152] Centrifugal brewing unit

[0153] 100 Brewing chamber

[0154] 110 Cylindrical chamber element

[0155] 210 Bottom wall

[0156] 310 Top wall

[0157] 312 Fluid channels

[0158] 101 Spinning motor

[0159] 102 Vertical displacement motor

[0160] 200 Frame

[0161] 201 Supporting shaft

[0162] 202 Driving shaft

[0163] 203 Ejector shaft

[0164] 410 Water injection device

[0165] 420 Beverage outlet

[0166] 430 Feeding device

[0167] 431 Toboggan element

[0168] 432 Funnel element

[0169] 440 Ejector device

[0170] Y Spinning axis

[0171] 11 Control unit

[0172] 2A Coffee donut

[0173] 21A Donut wall height

[0174] 31A Donut wall thickness

[0175] 2B Coffee donut

[0176] 21 B Donut wall height

[0177] 31 B Donut wall thickness

Claims

19794-EP-EPACLAIMS1 . A coffee machine (1 ) provided with a centrifugal brewing unit (10) and with a control unit (1 1 ), operatively connected to the centrifugal brewing unit (10), wherein the centrifugal brewing unit (10) comprises a spinning assembly, which is rotatable around a spinning axis (Y), the spinning assembly is provided with a plurality of parts able to define a brewing chamber (100) with a variable volume for containing ground coffee, wherein the centrifugal brewing unit (10) also comprises a water injection device (410) to inject water into the brewing chamber (100), wherein one or more of the parts of the spinning assembly are movable along a direction parallel to the spinning axis (Y) in a plurality of predefined brewing positions defining different brewing volumes of the brewing chamber (100) provided with different heights over the same diameter, and wherein the control unit (11 ) is able to set the desired brewing volume among the different predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types, by the movement of one or more of the parts of the spinning assembly along a direction parallel to the spinning axis (Y), and wherein the control unit (1 1 ) is able to operate at least part of the spinning assembly to rotate around a spinning axis (Y) to create a coffee donut (2A, 2B) with the ground coffee inside the brewing chamber (100) having the desired brewing volume before or during the water injection by the water injection device (410), wherein the shape of the coffee donut (2A, 2B) is defined in the defined brewing volume according to the desired brewing volume set.

2. The coffee machine (1 ) according to claim 1 , wherein it further comprises a feeding device (430) to feed the ground coffee in the brewing chamber (100), and wherein the control unit (1 1 ) is able to operate one or more of the parts of the spinning assembly to rotate around a spinning axis (Y) while the ground coffee is fed in the brewing chamber (100).

3. The coffee machine (1 ) according to claim 1 or 2, wherein the control unit (1 1 ) is able to operate one or more of the parts of the spinning assembly along a direction parallel to the spinning axis (Y) to compress the ground coffee in the brewing chamber (100).

4. The coffee machine (1 ) according to one of claims 1 -3, wherein the centrifugal brewing unit (10) further comprises: a spinning motor (101 ), operatively connected to one or more of the parts of the spinning assembly for the rotation around the spinning axis (Y);2319794-EP-EPA a vertical displacement motor (102), separate from the spinning motor (101 ) and operatively connected to one or more of the parts of the spinning assembly for a movement along a direction parallel to the spinning axis (Y).

5. The coffee machine (1 ) according to claims 2 and 4, wherein the control unit (11 ) is able to operate the spinning motor (101 ) so that one or more of the parts of the spinning assembly rotates around the spinning axis (Y) while the ground coffee is fed in the brewing chamber (100).

6. The coffee machine (1 ) according to claim 2 or 5, wherein the rotation of at least part of the spinning assembly while the ground coffee is fed in the brewing chamber (100) is in a range of 100-400 revolutions per minute (rpm), preferably in a range of 150-300 revolutions per minute (rpm).

7. The coffee machine (1 ) according to claims 3 and 4, wherein the control unit (11 ) is able to operate the vertical displacement motor (102) so that one or more of the parts of the spinning assembly moves along the direction parallel to the spinning axis (Y) to compress the ground coffee in the brewing chamber (100).

8. The coffee machine (1 ) according to claim 7, wherein the control unit (1 1 ) operates the vertical displacement motor (102) up to a maximum electrical current limit set for the compression of the ground coffee in the brewing chamber (100).

9. The coffee machine (1 ) according to one of claims 1 -8, wherein the rotation of at least part of the spinning assembly to create a dried coffee donut with the ground coffee inside the brewing chamber (100) has an acceleration in a range of 300-2500 rpm / s, preferably in a range of 500-2000 rpm / s.

10. The coffee machine (1 ) according to one of claims 1 -9, wherein the brewing chamber (100) comprises: a cylindrical chamber element (110), extending along the spinning axis (Y); a bottom wall (210) of the cylindrical chamber element (1 10), arranged perpendicularly to the spinning axis (Y); and a top wall (310) of the cylindrical chamber element (1 10), arranged perpendicularly to the spinning axis (Y) parallel to the bottom wall (210); wherein one or more of the parts of the spinning assembly are movable along the direction parallel to the spinning axis (Y) from at least a first of the predetermined different brewing positions, wherein the cylindrical chamber element (1 10) is in contact with the top wall (310) so that the top wall (310) is arranged inside the cylindrical chamber element (110) at a first distance from the bottom wall (210) defining a first volume of the brewing chamber, to at least a second of the predetermined different brewing positions, wherein the cylindrical chamber element (110) is in contact with the top wall (310) so that the top wall (310) is arranged inside the cylindrical chamber19794-EP-EPA element (110) at a second distance from the bottom wall (210) defining a second height of the brewing chamber which is lower than the first height.1 1 . The coffee machine (1 ) according to claim 10, wherein the cylindrical chamber element (1 10) is movable together with the bottom wall (210) with respect to the top wall (310) along a direction parallel to the spinning axis (Y) from at least the first of the predetermined different brewing positions to at least the second of the predetermined different brewing positions.

12. The coffee machine (1 ) according to claim 10 or 11 , wherein, wherein the top wall (310) only is provided with coffee extraction nozzles.

13. The coffee machine (1 ) according to one of claims 10-12, wherein the bottom wall (210) is arranged in a fixed position with respect to the cylindrical chamber element (110) in all the plurality of predetermined different brewing positions.

14. A method for preparing a beverage by way of operating a coffee machine (1 ) provided with a centrifugal brewing unit (10) and with a control unit (11 ), operatively connected to the centrifugal brewing unit (10), comprising: setting, by the control unit (11 ), a desired brewing volume of a brewing chamber (100) defined by a spinning assembly of the centrifugal brewing unit (10), wherein the desired brewing volume is set among a plurality of predefined brewing volumes according to a beverage to be prepared among a plurality of predefined beverages and / or according to a coffee type to be used among a pluralities of predefined coffee types; moving one or more parts of the spinning assembly along a direction parallel to a spinning axis (Y), around which the spin assembly is rotatable, to define the desired brewing volume of the brewing chamber (100); operating, by the control unit (1 1 ), one or more parts of the spinning assembly to rotate around the spinning axis (Y) to create a coffee donut (2A, 2B) with the ground coffee inside the brewing chamber (100) having the desired brewing volume before or during the water injection a water injection device (410) of the centrifugal brewing unit (10), wherein the shape of the coffee donut (2A, 2B) is defined in the defined brewing chamber (100) according to the brewing volume set. injecting water into the brewing chamber (100) while the one or more parts of the spinning assembly rotate around the spinning axis (Y).

15. The method for preparing a beverage according to claim 14, wherein the method for preparing a beverage is by way of operating the coffee machine (1 ) according to one of claims 1 -13.

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