Brewing unit for brewing coffee, coffee machine and use thereof, and method for brewing coffee

Abstract

The invention relates to a brewing unit for brewing coffee, to a coffee machine, to a use thereof, and to a method for brewing coffee. The brewing unit for brewing coffee contains: a brewing chamber; a brewing plunger having a brewing screen; a water distribution plunger having a water distribution screen; a first fluidic line which is configured to discharge coffee from the brewing chamber via the brewing screen; and a second fluidic line which is configured to supply water to the brewing chamber through the water distribution screen in a direction parallel to a longitudinal axis of the brewing chamber; an actuator; and a movable structural element, wherein at least part of the movable structural element can be moved in the brewing chamber by means of the action of force of the actuator and is suitable for influencing a flow direction of water in the brewing chamber by means of said movement. As a result, a coffee can be brewed with high extraction efficiency and provided in the best possible quality.

Description

[0001] Brewing unit for brewing coffee, coffee machine and use thereof, as well as method for brewing coffee

[0002] A brewing unit for brewing coffee, a coffee machine, a use thereof, and a method for brewing coffee are provided. The brewing unit for brewing coffee contains a brewing chamber, a brewing piston with a brewing sieve, a water distribution piston with a water distribution sieve, a first fluidic line configured to discharge coffee from the brewing chamber via the brewing sieve, a second fluidic line configured to supply water to the brewing chamber through the water distribution sieve in a direction parallel to a longitudinal axis of the brewing chamber, an actuator, and a movable structural element, wherein at least a portion of the movable structural element is movable in the brewing chamber via the action of force from the actuator and is suitable for influencing a flow direction of water in the brewing chamber through this movement.

[0003] This allows coffee to be brewed with high extraction efficiency and delivered in the best possible quality. The price of coffee on the global market has been rising steadily for several years. There are various reasons for this.

[0004] On the one hand, coffee consumption is increasing worldwide, creating greater demand. This is particularly due to the fact that countries and regions where tea was traditionally consumed are now increasingly switching to coffee consumption. Furthermore, due to the growing prosperity of the populations of emerging markets, coffee consumption is becoming more and more common in these countries.

[0005] Secondly, the coffee plant only grows under specific climatic conditions, which means that the area under coffee cultivation cannot be expanded indefinitely. Furthermore, climate change and the associated extreme weather conditions are leading to more frequent harvests with reduced yields or even complete crop failures.

[0006] Not only the rising prices for green coffee, but also the growing understanding of sustainability and resource-saving use of agricultural products are calling for more efficient brewing units that produce the best possible brewing results with a correspondingly low input of goods.

[0007] The efficiency of brewing units, especially when brewing small volumes of coffee, can be increased by using a variably adjustable brewing sieve or by adjusting the effective brewing sieve area of ​​piston brewing systems.

[0008] The brewing units used in fully automatic coffee machines today are arranged in different ways. They can be upright, horizontal, or pivoting. The coffee bed through which the coffee is brewed (i.e., extracted with hot water) is generally pressed into a substantially cylindrical shape, with brewing taking place from one substantially planar base surface of the coffee bed to the other substantially planar base surface of the coffee bed (axial brewing). "Substantially planar" means that at least one of the two base surfaces has a slightly spherical shape, i.e., the base surface is slightly convex or slightly concave. The brewing sieve surface often remains unchanged in existing brewing units. This means that when brewing small amounts of coffee, the height of the coffee bed is very low, which can result in the contact time between the coffee powder and the hot water being too short (i.e.,under-extraction of the coffee powder occurs) and through a locally increased passage of hot water through the coffee bed (so-called "channeling"), a local over-extraction of the coffee bed at the said passage point and a local under-extraction of the coffee bed away from the said passage point. The disadvantage is that the brewed coffee cannot achieve its best possible coffee quality (e.g. its best possible aroma). Very small quantities of coffee cannot therefore be brewed with a satisfactory result.

[0009] EP 3 248 517 A1 discloses an automatic brewing unit for brewing coffee in a fully automatic coffee machine. The unit includes a tubular housing, at least one brewing piston, and an adjustment device. The adjustment device is configured to variably change the diameter of a brewing chamber of the brewing unit in order to brew even smaller quantities of coffee with acceptable quality. The disadvantage of this brewing unit, however, is that its structure is complex and the brewing unit cannot be designed very compactly. This makes the provision of the brewing unit time-consuming and costly and requires a large amount of free space when installed in a coffee machine.Furthermore, the brewing unit requires large sealing surfaces, which can at least locally lose their sealing properties over time, thereby reducing the long-term stability of the brewing unit and increasing the risk of downtime during which no brewed coffee can be provided by the brewing unit.

[0010] Proceeding from this, it was the object of the present invention to provide a brewing unit for brewing coffee, a coffee machine and a use thereof, as well as a method, wherein at least one disadvantage known in the prior art should be overcome. In particular, the brewing unit, the coffee machine, the use thereof and / or the method should make it possible to brew coffee with high extraction efficiency and to provide it in the best possible quality in a simple and cost-effective manner. This object is achieved by the brewing unit having the features of claim 1, the coffee machine having the features of claim 11, the use having the features of claim 15 and the method having the features of claim 16. The dependent claims show advantageous developments.

[0011] According to the invention, a brewing unit for brewing coffee is provided, comprising or consisting of a) a brewing chamber; b) a brewing piston configured to be arranged in the brewing chamber, wherein the brewing piston contains a brewing sieve; c) a first fluidic line arranged at least partially within the brewing piston, wherein the first fluidic line is configured to discharge coffee from the brewing chamber via the brewing sieve; d) a water distribution piston configured to be arranged in the brewing chamber, wherein the water distribution piston contains a water distribution sieve; e) a second fluidic line arranged at least partially within the water distribution piston, wherein the second fluidic line is configured to supply water to the brewing chamber through the water distribution sieve in a direction parallel to a longitudinal axis of the brewing chamber;characterized in that the brewing unit contains an actuator and a movable structural element, wherein at least a part of the movable structural element is movable in the brewing chamber via the action of force from the actuator and is suitable for influencing a flow direction of water in the brewing chamber by this movement (in particular from an at least partially axial flow direction to an at least partially radial flow direction and vice versa).

[0012] The brewing unit makes it possible to brew coffee with high extraction efficiency and the best possible quality in a simple and cost-effective way.

[0013] This is achieved by the actuator and the movable structural element, which can be moved in the brewing chamber by the force applied by the actuator and is suitable for influencing the direction of water flow in the brewing chamber through its movement. This allows water to be supplied to the brewing chamber not only axially but also radially, i.e. a cylindrical coffee bed present in the brewing chamber can also be flowed through radially (i.e. not only axially) with water, i.e. in a direction from the outer surface of the cylindrical coffee bed towards a central cylinder axis of the cylindrical coffee bed. As a result, the extraction path that water has to travel on its way to the first fluidic line of the brewing piston is defined not only by the height of the cylindrical coffee bed (i.e. its extension in a direction parallel to its central cylinder axis or parallel to its outer surface), but also by its width (i.e.Its extension in a direction perpendicular to its central cylindrical axis or perpendicular to its lateral surface. This allows for greater extraction efficiency and the provision of coffee of the highest possible quality. This advantage is achieved in a very simple and cost-effective manner.

[0014] A radial flow through the coffee bed is particularly (but not exclusively) advantageous when the coffee bed is shallow (due to a low amount of coffee powder), as the width of the coffee bed (i.e., its diameter) is then large compared to its height, thereby lengthening the flow path for the water. In other words, with radial extraction of the coffee bed, the water flows through a longer path on its way to the first fluidic line in the radial flow than with axial flow. This increases the efficiency of the extraction process, and coffee of the highest possible quality can be brewed (even with small amounts of coffee).

[0015] The actuator can be selected from the group consisting of electric actuators, pneumatic actuators, hydraulic actuators, and combinations thereof. The actuator is preferably an electric motor.

[0016] The movable structural element can have a first wall which is substantially perpendicular to the longitudinal axis of the brewing chamber. The first wall can have a through-opening. Preferably, an opening of the first fluidic line into the brewing chamber is arranged in the region of the through-opening of the movable structural element, i.e. the opening of the first fluidic line into the brewing chamber can be surrounded by the through-opening of the movable structural element. In this case, the movable structural element can be designed, at least in regions, as a hollow cylinder, very particularly preferably as a circular ring. The opening of the hollow cylinder, preferably the circular ring, represents the through-opening of the movable structural element. The through-opening allows water to flow through the through-opening. The brewing chamber-side wall of the hollow cylinder (i.e.the wall on its base surface and not on its lateral surface), preferably of the circular ring, represents the wall of the movable structural element, which is arranged substantially perpendicular to the longitudinal axis of the brewing chamber.

[0017] The movable structural element can also be viewed as an outer segment of a support structure of the brewing sieve. The support structure of the brewing sieve has an inner (circular) region in which the opening (i.e. a connection) of the first fluidic line (i.e. the coffee line) is located and has an outer region in which the movable structural element (e.g. in the form of a hollow cylinder, preferably a circular ring) can be arranged. If the surface area is considered, the area of ​​the inner region (i.e. the area of ​​the opening of the first fluidic line) is significantly smaller than that of the outer region. By means of the actuator, the two regions can be completely or partially separated from one another, i.e. the movable structural element can be arranged within the support structure of the brewing sieve.

[0018] The actuator can be suitable for causing the movable structural element to move in a direction into the brewing chamber and in a direction out of the brewing chamber. This can influence the flow direction of water in the brewing chamber, i.e., convert it from an axial flow direction into a radial flow direction, at least in some regions. The actuator can be suitable for causing the movable structural element to move into an intermediate space in the brewing chamber, the intermediate space being located between the brewing sieve of the brewing piston and a first opening of the first fluidic line located within the brewing piston, particularly preferably up to a point where the movable structural element comes into contact with the brewing sieve.The advantage of this is that the wall of the movable structural element, which has the through-opening of the movable structural element, can be moved towards the brewing chamber and there can influence the flow direction of water within the brewing chamber. In particular, the wall, which is arranged essentially perpendicular to the longitudinal axis of the brewing chamber, has the advantage that it forces a radial flow direction on the radially flowing water and thus prevents water flowing radially into the brewing chamber from being deflected in an axial direction before reaching a center of the coffee bed and flowing prematurely to the first opening of the first fluid line (coffee line). Through this movement of the movable structural element, an axial flow direction can be forced on the water flow within the brewing chamber, at least in some areas, thereby improving extraction efficiency.

[0019] Furthermore, the actuator can be suitable for causing the movable structural element to move out of an intermediate space between the brewing chambers, the intermediate space being arranged between the brewing sieve of the brewing piston and a first opening of the first fluidic line located within the brewing piston, particularly preferably completely out of the intermediate space. The resulting enlargement of the intermediate space increases the extraction efficiency with an axial flow onto the coffee bed. The larger the intermediate space, i.e. the longer its extension in the direction of the longitudinal axis of the brewing chamber, the more advantageous the extraction efficiency with an axial flow onto the coffee bed. This movement of the movable structural element can thus force the water flow within the brewing chamber to follow an axial flow direction, at least in some areas, and the extraction efficiency can be improved.

[0020] In addition, the movable structural element can have a second wall that is substantially parallel to the longitudinal axis of the brewing chamber, wherein the second wall has a through-opening, and the actuator is suitable for causing a movement of the through-opening of the movable structural element. In this case, the movable structural element can be configured, at least in some regions, as a pin with an opening, a needle valve, or a ball valve. In this case, the movable structural element is preferably moved into an intermediate space located between a first opening of the first fluidic line and the brewing sieve of the brewing piston, particularly preferably until it comes into contact with the brewing sieve.

[0021] The actuator can be adapted to cause a movement of the through-opening of the movable structural element in such a way that a flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through-opening of the movable structural element. This movement of the movable structural element can lengthen the flow path of water through the coffee bed in the case of an axial flow (extension into the gap), thereby improving extraction efficiency.

[0022] Furthermore, the actuator can be suitable for causing a movement of the movable structural element about its longitudinal axis in such a way that no flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through-opening of the movable structural element. This movement of the movable structural element can thus force the water flow within the brewing chamber to flow in a radial direction through the coffee bed, at least in some areas, thereby improving extraction efficiency. In other words, a radial flow of water through an intermediate space located between a first opening of the first fluidic line and the brewing sieve of the brewing piston, and thus bypassing the coffee bed, can be blocked, thereby increasing extraction efficiency.

[0023] The movable structural element can have a through-opening with a diameter in the range of 0.1 to 2 cm, preferably 0.2 to 1.5 cm, particularly preferably 0.5 to 1 cm, in a first wall of the movable structural element (i.e. in a wall in the direction of the longitudinal axis of the brewing chamber). The smaller the opening of the first wall, the longer the radial flow path along the first wall of the movable structural element that is forced upon the water in the event of a radial flow towards the brewing chamber, i.e. the better it can be ensured that coffee of the best possible quality is brewed. The diameter of the through-opening of the movable structural element can essentially correspond to a diameter of a first opening in the first fluid line (coffee line).

[0024] Furthermore, the movable structural element can have a continuous opening with a diameter in the range of 0.1 to 2 cm, preferably 0.2 to 1.5 cm, particularly preferably 0.5 to 1 cm, in a second wall of the movable structural element (i.e., in a wall perpendicular to the longitudinal axis of the brewing chamber). The larger the opening in the second wall, the more strongly the water flowing in the brewing chamber is forced into a radial flow direction, i.e., the better it can be ensured that coffee of the best possible quality is brewed.

[0025] Apart from that, the movable structural element may contain or consist of a material selected from the group consisting of metal, metal alloy, plastic and combinations thereof.

[0026] The first fluidic line may have a first opening located downstream of the brewing sieve and downstream of a gap in the brewing piston located between the first opening and the brewing sieve. Coffee brewed in the brewing chamber (i.e., extracted coffee) can be removed from the brewing chamber via the first opening of the first fluidic line and directed to an outlet for dispensing coffee (e.g., a dispensing unit of a coffee machine).

[0027] Furthermore, the first fluidic line may have a second opening which is fluidly connected to an outlet for dispensing coffee.

[0028] The second fluidic line may have a first opening arranged within the water distribution piston, preferably arranged upstream of the water distribution sieve, wherein the first opening is suitable for supplying water to the brewing chamber through the water distribution sieve in a direction parallel to the longitudinal axis of the brewing chamber.

[0029] Furthermore, the second fluidic line can have a second opening that is fluidically connected to a boiler and / or a continuous-flow heater. Hot water can be supplied to the brewing chamber via the second opening of the second fluidic line.

[0030] Furthermore, the second fluidic line can contain a second valve, wherein the second valve is preferably arranged between a first opening and a second opening of the second fluidic line, particularly preferably arranged within the water distribution piston. The second valve makes it possible to switch a water flow into the second fluidic line and thus switch an axial flow to the brewing chamber. Optionally, the second valve is identical to a third valve of the third fluidic line, in particular a 3-way valve.

[0031] In a preferred embodiment, the brewing unit contains a third fluidic line, which is arranged at least partially within the water distribution piston. The third valve makes it possible to switch a water flow into the third fluidic line and thus switch a radial flow to the brewing chamber.

[0032] The third fluidic line can be configured to supply water to the brewing chamber past the water distribution sieve in at least one direction radial to the longitudinal axis of the brewing chamber, preferably on a side of the water distribution sieve facing the brewing chamber. Furthermore, the third fluidic line can be configured to supply water to the brewing chamber within the water distribution sieve in at least one direction radial to the longitudinal axis of the brewing chamber. The advantage is that water can be supplied radially to the brewing chamber at multiple points around the water distribution sieve, thus further improving extraction efficiency and ensuring even better that coffee of the best possible quality is brewed.

[0033] The third fluidic line may have a first opening arranged in the water distribution sieve or arranged around the water distribution sieve, wherein the first opening is suitable for supplying water to the brewing chamber in at least one direction radial to the longitudinal axis of the brewing chamber.

[0034] Furthermore, the third fluidic line can have a second opening that is fluidically connected to a boiler and / or a flow heater, optionally via a 3-way valve. Hot water can be supplied radially to the brewing chamber via the second opening of the third fluidic line.

[0035] Furthermore, the third fluidic line may contain a third valve, wherein the third valve is preferably arranged between a first opening and a second opening of the third fluidic line or is arranged at a second opening of the third fluidic line, wherein the third valve is particularly preferably arranged within the water distribution piston. Optionally, the third valve is identical to a second valve of the second fluidic line and is in particular a 3-way valve.

[0036] The brewing unit can include a water distribution ring arranged around the water distribution sieve. The advantage of the water distribution ring is that, in the case of a radial flow to the brewing chamber, water can flow more evenly in a radial direction through the brewing chamber.

[0037] The water distribution ring can be fluidically connected to a first opening of a third fluidic line of the brewing unit.

[0038] Furthermore, the water distribution ring can be designed to redirect water flowing through the third fluidic line into a radial flow direction. This has the advantage that water can initially flow axially past the water distribution screen and only then is directed into a radial flow direction by the water distribution ring. This allows the brewing unit to be designed very compactly, since the third fluidic line does not have to discharge radially into the brewing chamber, which would increase the required width of the brewing unit.

[0039] The water distribution ring can have at least one opening, in particular at least two openings, more preferably at least four openings, most preferably at least six openings, in particular at least eight openings, optionally at least ten openings, which are fluidically connected to the third fluidic line. The water distribution ring is preferably configured to supply water in the third fluidic line to the brewing chamber via its opening(s) in a radial direction to a longitudinal axis of the brewing chamber. The more openings the water distribution ring has, the more points water is supplied to the brewing chamber and thus to the coffee bed in a radial direction, and the higher the extraction efficiency can be. With more openings, it can therefore be even better ensured that coffee of the best possible quality is brewed.

[0040] The brewing piston and / or the water distribution piston can each have a sealing ring. The sealing ring is preferably an O-ring. The third fluid line can open into an interior space of the brewing chamber, which is located between the sealing ring of the brewing piston and the sealing ring of the water distribution piston.

[0041] According to the invention, a coffee machine is further provided which contains a brewing unit according to the invention and a control unit.

[0042] The control unit of the coffee machine can be configured to cause the actuator of the brewing unit, preferably when the control unit receives a signal to brew a medium or low amount of coffee, i) to move a movable structural element of the brewing unit with a through-opening, which is preferably designed at least in regions as a hollow cylinder, most preferably as a circular ring, into an intermediate space located between a first opening of the first fluidic line and the brewing sieve of the brewing piston, preferably until it comes into contact with the brewing sieve; and / or ii) to move a through-opening of a movable structural element of the brewing unit, which is preferably designed at least in regions as a pin with an opening, needle valve, or ball valve, so that a flow of water in the direction of the longitudinal axis of the brewing chamber and past a coffee bed is blocked by the movable structural element.

[0043] A medium or low coffee quantity is particularly preferably understood to mean a quantity of coffee that forms a cylindrical coffee bed in the brewing chamber with a ratio between an extension along the longitudinal axis of the brewing chamber and an extension perpendicular to the longitudinal axis of the brewing chamber of <0.4, preferably <0.3, particularly preferably <0.2. The coffee quantity can, for example, be <7 g.

[0044] Furthermore, the control unit can be configured to cause the actuator of the brewing unit, preferably when the control unit receives a signal to brew a large quantity of coffee, i) to move a movable structural element of the brewing unit with a through-opening, which is preferably designed at least in part as a hollow cylinder, most preferably as a circular ring, out of an intermediate space located between a first opening of the first fluidic line and the brewing sieve of the brewing piston, preferably until the movable structural element has been completely moved out of the intermediate space; and / or ii) to move a through-opening of a movable structural element of the brewing unit, which is preferably designed at least in part as a pin with an opening, needle valve, or ball valve, so that a flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through-opening of the movable structural element.

[0045] A high coffee quantity is particularly preferably understood to mean a quantity of coffee that forms a cylindrical coffee bed in the brewing chamber with a ratio between an extension along the longitudinal axis of the brewing chamber and an extension perpendicular to the longitudinal axis of the brewing chamber of > 0.4, preferably > 0.3, particularly preferably > 0.2. The coffee quantity can be, for example, > 7 g.

[0046] Apart from that, the control unit can be configured to open a water flow through the third fluidic line i) when the control unit receives a signal from the coffee machine or a user of the coffee machine that a low or medium amount of coffee is to be brewed, wherein a medium or low amount of coffee is particularly preferably understood to mean an amount of coffee that forms a cylindrical coffee bed in the brewing chamber, which has a ratio between an extension along the longitudinal axis of the brewing chamber to an extension perpendicular to the longitudinal axis of the brewing chamber of < 0.4, preferably < 0.3, particularly preferably < 0.2 (e.g.a quantity of coffee of < 7 g); and / or ii) to close when the control unit receives a signal from the coffee machine or a user of the coffee machine that a large quantity of coffee is to be brewed, wherein a large quantity of coffee is particularly preferably understood to mean a quantity of coffee which forms a cylindrical coffee bed in the brewing chamber which has a ratio between an extent along the longitudinal axis of the brewing chamber to an extent perpendicular to the longitudinal axis of the brewing chamber of > 0.4, preferably of > 0.3, particularly preferably of > 0.2 (e.g. a quantity of coffee of > 7 g).

[0047] Furthermore, the use of a brewing unit according to the invention or a coffee machine according to the invention for brewing coffee is proposed.

[0048] In addition, a method for brewing coffee is provided, comprising or consisting of the following steps: a) conducting hot water in at least one radial direction through a cylindrical coffee bed in a brewing chamber of a brewing unit of a coffee machine, wherein the at least one radial direction is preferably understood to mean at least one direction that is substantially perpendicular to a lateral surface of the cylindrical coffee bed, wherein the conducting of hot water in at least one radial direction through the cylindrical coffee bed is particularly preferably carried out when a low or medium amount of coffee is to be brewed, wherein a medium or low amount of coffee is very particularly preferably understood to mean an amount of coffee that forms a cylindrical coffee bed in the brewing chamber that has a ratio between an extension along a longitudinal axis of the brewing chamber to an extension perpendicular to the longitudinal axis of the brewing chamber of < 0.4,preferably of < 0.3, particularly preferably of < 0.2; b) optionally: simultaneous or time-delayed conducting of hot water in an axial direction through the cylindrical coffee bed, wherein the axial direction is preferably understood to be a direction that is substantially perpendicular to at least one planar circular surface of the cylindrical coffee bed, wherein the conducting of hot water in an axial direction through the cylindrical coffee bed is particularly preferably carried out when a large amount of coffee is to be brewed, wherein a large amount of coffee is very particularly preferably understood to be an amount of coffee that forms a cylindrical coffee bed in the brewing chamber that has a ratio between an extent along the longitudinal axis of the brewing chamber to an extent perpendicular to the longitudinal axis of the brewing chamber of > 0.4, preferably of > 0.3, particularly preferably of > 0.2.

[0049] The method according to the invention is preferably carried out with a brewing unit according to the invention or with a coffee machine according to the invention.

[0050] The subject matter of the invention will be explained in more detail with reference to the following figures and the following example, without wishing to restrict it to the specific embodiments shown here.

[0051] Figure 1 schematically shows a brewing unit according to the invention with a radial flow 25 of the coffee bed 27. The brewing unit contains a brewing chamber 1, a brewing piston 2, which is configured to be arranged in the brewing chamber 1 and which contains a brewing sieve 3, a first fluidic line 4 (coffee discharge line), which is arranged at least partially within the brewing piston 2 and is configured to discharge coffee from the brewing chamber 1 via the brewing sieve 3, a water distribution piston 5, which is configured to be arranged in the brewing chamber 1 and which contains a water distribution sieve 6, a second fluidic line 7 (axial hot water supply line), which is arranged at least partially within the water distribution piston 5 and is configured to supply water to the brewing chamber 1 through the water distribution sieve 6 in a direction parallel to a longitudinal axis of the brewing chamber 1, and a third fluidic line 8 (radial hot water supply line).which is arranged at least partially within the water distribution piston 5 and is configured to supply water to the brewing chamber 1 past the water distribution sieve 6 in at least one direction radial to a longitudinal axis L of the brewing chamber 1. Furthermore, the brewing unit (more precisely: the brewing piston 2) here contains an actuator 9 (e.g., an electric motor) and a movable structural element 10 (here: a pin with a hole). The movable structural element 10 has a first wall 11, which is arranged substantially perpendicular to the longitudinal axis L of the brewing chamber 1, and has a second wall 11', which is arranged substantially in the direction of the longitudinal axis L of the brewing chamber 1. In this case, the second wall 11' has a through-opening 12', which allows water to flow through the through-opening 12' in the radial direction, i.e., toward the longitudinal axis L of the brewing chamber 1.and past the coffee bed 27 (i.e., through the intermediate space 13 instead of through the coffee bed), at least partially blocked. The brewing piston 2 and / or the water distribution piston 5 each have a sealing ring 23, 24. The first fluidic line 4 contains a first opening 14, a second opening (not shown), and a first valve (not shown), the second fluidic line 7 contains a first opening 19, a second opening 20, and a second valve 16, and the third fluidic line 8 contains a first opening 17,a second opening 18 and a third valve 15. The second opening 20 of the second fluidic line 7 and the second opening 18 of the third fluidic line 8 are each connected to a boiler 21. In the radial flow of the coffee bed 27 shown here, the movable structural element 10 (ie the pin with hole) is moved into a space 13 between the first opening 14 of the first fluidic line 4 and the brewing sieve 3 of the brewing piston 2 until it comes into contact with the brewing sieve 3. The movable structural element 10 is rotated about its own longitudinal axis by the actuator 9 in such a way that its through opening 12' is not aligned in the direction of the longitudinal axis L of the brewing chamber (but is rotated away from it) and thus (after opening of the third valve 15 of the third fluidic line 8) blocks at least a partial flow of hot water from the boiler 21 past the coffee bed 27 in the radial direction 26 through the brewing chamber 1,This means that the water is forced to flow radially through the coffee bed 27, at least in some areas. The second valve 16 of the second fluid line 7 is closed.

[0052] Figure 2 schematically shows a brewing unit according to the invention with an axial flow 26 of the coffee bed 27. The brewing unit has the same structural features as the brewing unit shown in Figure 1. With the axial flow 26 of the coffee bed 27 shown here, the movable structural element 10 (i.e., the pin with a hole) is rotated by the actuator 9 in such a way that it allows water to flow through the through-opening 12' in a radial direction, i.e., toward the longitudinal axis L of the brewing chamber 1, and past the coffee bed 27, thus extending the axial flow path of water through the coffee bed 27 (i.e., water can first flow into the intermediate space 13 and then through the first opening 14), which increases extraction efficiency. The second valve 16 of the second fluidic line 7 is open, thus allowing hot water to flow from the boiler 21 in the axial direction 26 into the brewing chamber 1.The third valve 15 of the third fluid line 8 is closed.

[0053] Figure 3 shows a first embodiment of the movable structural element. In this embodiment, the movable structural element is designed, at least in part, as a pin, the second wall 11' of which has a through-opening 12'. The through-opening 12' of the movable structural element (i.e., the pin) can be moved (here: rotated about its own axis) by rotating the movable structural element through the actuator (not shown) (see arrow directions). In a first position (left illustration), a flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through-opening 12' of the movable structural element. In the second position (right illustration), no flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through-opening 12' of the movable structural element, i.e.no water can flow through the through-opening 11' in a direction towards the longitudinal axis of the brewing chamber (radial direction). Nevertheless, the first wall 11 of the movable structural element contributes at least in part to the water flow within the brewing chamber being radial, at least in some areas (i.e. along the first wall 11). Depending on the amount of coffee in the coffee bed, the extraction time can be optimized and the best possible coffee can be provided by selecting the degree of movement of the movable structural element (i.e. the degree of rotation of the movable structural element about its own axis). Figure 4 shows a second embodiment of the movable structural element 10. In this embodiment, the movable structural element is designed, at least in some areas, as a pin, the second wall 11' of which has a through-opening 12', wherein the through-opening 12' is part of a sphere (ball valve).The through opening 12' of the movable structural element (i.e. the pin) can be moved by rotating the ball of the movable structural element by the actuator (not shown) (here: rotating or tilting the ball) (see arrow directions). In a first position (left illustration), a flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through opening 12' of the movable structural element. In the second position (right illustration), no flow of water is permitted in the direction of the longitudinal axis of the brewing chamber and through the through opening 12' of the movable structural element, i.e. no flow of water can occur through the through opening 11' in a direction towards the longitudinal axis of the brewing chamber (radial direction).Nevertheless, the first wall 11 of the movable structural element contributes at least in part to ensuring that the water flow within the brewing chamber is radial, at least in some areas (i.e., along the first wall 11). Depending on the amount of coffee in the coffee bed, the extraction time can be optimized and the best possible coffee can be provided by selecting the degree of movement of the movable structural element (i.e., the degree of rotation or tilt of the ball of the movable structural element).

[0054] Figure 5 shows a third embodiment of the movable structural element 10. In this embodiment, the movable structural element is designed, at least in part, as a hollow cylinder or as a circular ring, the first wall 11 of which has a through-opening 12. The movable structural element can be moved by the actuator (not shown) in one direction into the brewing chamber and in one direction out of the brewing chamber (see arrow directions). When the movable structural element is moved into the brewing chamber, a flow of water is promoted, first along the first wall 11 of the movable structural element and then through the through-opening 12 (i.e., a radial flow) (i.e., an axial flow direction is more strongly imposed on the water flow within the brewing chamber), and an axial flow of water is inhibited (i.e., the path for an axial water flow is shortened).When the movable structural element is moved out of the brewing chamber, a flow of water, initially along the first wall 11 of the movable structural element and then through the through opening 12 (i.e., a radial flow), is inhibited (i.e., an axial flow direction is less strongly imposed on the water flow within the brewing chamber), and an axial flow of water is favored (i.e., the path for an axial water flow is extended). Depending on the amount of coffee in the coffee bed, the extraction time can be optimized and the best possible coffee can be provided by selecting the degree of movement of the movable structural element (i.e., the degree of movement into or out of the brewing chamber).

[0055] Example - Inventive method

[0056] If an extraction is carried out in a radial flow direction ("efficiency mode"), the movable structural element is moved into the intermediate space in the brewing piston, i.e. a corresponding adjustment mechanism is closed. In this case, only a part of the entire brewing sieve surface is effective, namely the part located within the continuous opening of the movable structural element. In this operating state, the brewing water required for extraction is introduced via the third fluid line - past the water distribution sieve - in a radial direction onto the coffee bed. Due to this constellation, the cylindrical coffee bed is flowed through radially from the outside to the inside. The structural element moved into the intermediate space ensures that the water flow through the coffee bed over a long distance (i.e.This ensures that the water flow remains radial (i.e., along the entire radius of the coffee bed), reducing the risk of the water flow becoming axial before reaching the center of the coffee bed. The radial flow significantly increases the path the water must travel, even with very low coffee bed heights, thereby increasing extraction efficiency. This mode is used in particular when the amount of ground coffee used results in a low coffee bed, for example, when the coffee quantity is < 7 g.

[0057] If a conventional extraction is carried out, the movable structural element is moved out of the space in the brewing piston, i.e. a corresponding adjustment mechanism is opened. In this case, the entire brewing sieve surface is effective. In this operating state, the brewing water required for extraction is introduced via the second fluid line and thus evenly and completely over the entire surface of the water distribution sieve in the axial direction onto the coffee bed. Due to this constellation, the brewing water flows axially through the cylindrical coffee bed over the entire surface. The structural element moved out of the space ensures that extracted coffee, which is located in the area of ​​the brewing chamber that is to the side of the opening of the first fluid line in the direction of the wall of the brewing chamber, can also flow to the first opening of the first fluid line, i.e.This reduces the risk of a portion of the extracted coffee remaining in the brewing chamber after extraction, leaving a coffee bed saturated with this coffee. The now extracted coffee is drained through the back of the brewing sieve's support structure. This mode is used particularly when the amount of ground coffee used creates a sufficiently deep coffee bed, for example, with a coffee quantity of > 7 g.

[0058] 1: Brewing chamber;

[0059] 2: Brewing piston;

[0060] 3: Brewing sieve;

[0061] 4: first fluidic line (coffee discharge);

[0062] 5: Water distribution piston;

[0063] 6: Water distribution sieve;

[0064] 7: second fluid line (axial hot water supply line);

[0065] 8: third fluid line (radial hot water supply line);

[0066] 8': Connection of third fluid line;

[0067] 9: electric motor;

[0068] 10: movable structural element;

[0069] 11: first wall of the movable structural element;

[0070] 11': second wall of the movable structural element;

[0071] 12: through opening in the first wall of the movable structural element; 12': through opening in the second wall of the movable structural element;

[0072] 13: Space of the brewing chamber between the brewing sieve and the first opening of the first fluidic line;

[0073] 14: first opening of the first fluidic line (downstream of the brewing sieve and downstream of the gap of the brewing piston);

[0074] 15: Valve of the third fluid line;

[0075] 16: Valve of the second fluid line;

[0076] 17: first opening of the third fluid line (arranged around the water distribution strainer);

[0077] 18: second opening of the third fluid line (connected to a boiler and / or to a water heater);

[0078] 19: first opening of the second fluidic line (located inside the water distribution piston);

[0079] 20: second opening of the second fluid line (connected to a boiler and / or to a continuous flow heater);

[0080] 21: Boiler and / or instantaneous water heater;

[0081] 22: Water distribution ring (arranged around water distribution sieve);

[0082] 23: Sealing ring on the brewing piston (e.g. O-ring);

[0083] 24: Sealing ring on the water distribution piston (e.g. O-ring);

[0084] 25: radial flow / radial flow through coffee bed;

[0085] 26: axial flow / radial flow through coffee bed;

[0086] 27: Coffee bed;

[0087] L: Longitudinal axis of the brewing chamber.

Claims

Patent claims 1. Brewing unit for brewing coffee, containing or consisting of a) a brewing chamber (1); b) a brewing piston (2) which is configured to be arranged in the brewing chamber (1), wherein the brewing piston (2) contains a brewing sieve (3); c) a first fluidic line (4) which is arranged at least partially within the brewing piston (2), wherein the first fluidic line (4) is configured to discharge coffee from the brewing chamber (1) via the brewing sieve (3); d) a water distribution piston (5) which is configured to be arranged in the brewing chamber (1), wherein the water distribution piston (5) contains a water distribution sieve (6); e) a second fluidic line (7) which is arranged at least partially within the water distribution piston (5), wherein the second fluidic line (7) is configured to supply water to the brewing chamber (1) through the water distribution sieve (6) in a direction parallel to a longitudinal axis (L) of the brewing chamber (1);characterized in that the brewing unit i) contains an actuator (9), and ii) contains a movable structural element (10), wherein at least a part of the movable structural element (10) is movable in the brewing chamber (1) via the action of force of the actuator (9) and is suitable for influencing a flow direction of water in the brewing chamber (1) by this movement.; 2. Brewing unit according to claim 1, characterized in that the movable structural element (10) has a first wall (11) which is substantially perpendicular to the longitudinal axis (L) of the brewing chamber (1), wherein the first wall (11) optionally has a through opening (12), and the actuator (9) is suitable for causing a movement of the movable structural element (10) in a direction into the brewing chamber (1) and in a direction out of the brewing chamber (1), preferably i) into an intermediate space (13) of the brewing chamber (1), wherein the intermediate space (13) is arranged between the brewing sieve (3) of the brewing piston (2) and a first opening (14) of the first fluidic line (4) which is located inside the brewing piston (2), particularly preferably up to a contact of the movable structural element (10) with the brewing sieve (3);and / or ii) from an intermediate space (13) of the brewing chambers (1), wherein the intermediate space (13) is arranged between the brewing sieve (3) of the brewing piston (2) and a first opening (14) of the first fluidic line (4) located within the brewing piston (2), particularly preferably completely from the intermediate space (13); wherein the movable structural element (10) is particularly preferably designed, at least in regions, as a hollow cylinder, very particularly preferably as a circular ring.; 3. Brewing unit according to one of the preceding claims, characterized in that the movable structural element (10) has a second wall (11') which is substantially parallel to the longitudinal axis (L) of the brewing chamber (1), wherein the second wall (11') has a through-opening (12'), and the actuator (9) is suitable for causing a movement of the through-opening (12') of the movable structural element (10), preferably in such a way that i) a flow of water in the direction of the longitudinal axis (L) of the brewing chamber (1) and through the through-opening (12') of the movable structural element (10) is permitted; and / or ii) no flow of water is permitted in the direction of the longitudinal axis (L) of the brewing chamber (1) and through the through opening (12') of the movable structural element (10); wherein the movable structural element (10) is particularly preferably designed, at least in regions, as a pin with an opening, a needle valve, or a ball valve.

4. Brewing unit according to one of the preceding claims, characterized in that the movable structural element (10) i) has a through-opening (12) with a diameter in the range of 0.1 to 2 cm, preferably 0.2 to 1.5 cm, particularly preferably 0.5 to 1 cm, in a first wall (11) of the movable structural element; and / or ii) has a through-opening (12') with a diameter in the range of 0.1 to 2 cm, preferably 0.2 to 1.5 cm, particularly preferably 0.5 to 1 cm, in a second wall (11') of the movable structural element; and / or iii) contains or consists of a material selected from the group consisting of metal, metal alloy, plastic and combinations thereof.

5. Brewing unit according to one of the preceding claims, characterized in that the first fluidic line (4) i) has a first opening (14) which is located downstream of the brewing sieve (3) and downstream of an intermediate space (13) of the brewing piston (2), which is located between the first opening (14) and the brewing sieve (3); and / or ii) has a second opening fluidly connected to an outlet for dispensing coffee.

6. Brewing unit according to one of the preceding claims, characterized in that the second fluidic line (7) i) has a first opening (19) arranged within the water distribution piston (5), preferably upstream of the water distribution sieve (6), wherein the first opening (19) is suitable for supplying water to the brewing chamber (1) through the water distribution sieve (6) in a direction parallel to the longitudinal axis (L) of the brewing chamber (1); and / or ii) has a second opening (20) fluidically connected to a boiler and / or to a continuous-flow heater (21); and / or iii) contains a second valve (16), wherein the second valve (16) is preferably arranged between a first opening (19) and a second opening (20) of the second fluidic line (7), particularly preferably arranged within the water distribution piston (5) and optionally identical to a third valve (15) of the third fluidic line (8), in particular is a 3-way valve.

7. Brewing unit according to one of the preceding claims, characterized in that the brewing unit contains a third fluidic line (8) which is arranged at least partially within the water distribution piston (5), wherein the third fluidic line (8) is configured to supply water to the brewing chamber (1) i) past the water distribution sieve (6) in at least one direction radial (25) to the longitudinal axis (L) of the brewing chamber (1), preferably on a side of the water distribution sieve (1) facing the brewing chamber (1); and / or ii) within the water distribution sieve (6) in at least one direction radial (25) to the longitudinal axis (L) of the brewing chamber (1).

8. Brewing unit according to claim 7, characterized in that the third fluidic line (8) i) has a first opening (17) which is arranged in the water distribution sieve (6) or is arranged around the water distribution sieve (6), wherein the first opening (17) is suitable for supplying the brewing chamber (1) to supply water in at least one direction radial (25) to the longitudinal axis (L) of the brewing chamber (1); and / or ii) has a second opening (18) which is fluidically connected to a boiler and / or to a continuous-flow heater (21), optionally via a 3-way valve; and / or iii) contains a third valve (15), wherein the third valve (15) is preferably arranged between a first opening (17) and a second opening (18) of the third fluidic line (8) or is arranged at a second opening of the third fluidic line (8), wherein the third valve (15) is particularly preferably arranged within the water distribution piston (5) and is optionally identical to a second valve (16) of the second fluidic line (7), in particular is a 3-way valve.

9. Brewing unit according to one of the preceding claims, characterized in that the brewing unit contains a water distribution ring (22) arranged around the water distribution sieve (6), wherein the water distribution ring (22) is preferably i) fluidically connected to a first opening (17) of a third fluidic line (8) of the brewing unit; and / or ii) suitable for redirecting water flowing through the third fluidic line (8) in a radial flow direction (25);and / or iii) at least one opening, in particular at least two openings, particularly preferably at least four openings, very particularly preferably at least six openings, in particular at least eight openings, optionally at least ten openings, each of which is fluidically connected to a first opening (17) of a third fluidic line (8) of the brewing unit, wherein the water distribution ring (22) is preferably configured to supply water in the third fluidic line (8) of the brewing chamber (1) via its openings in a radial direction (25) to a longitudinal axis (L) of the brewing chamber (1) of the brewing chamber (1); 10. Brewing unit according to one of the preceding claims, characterized in that the brewing piston (2) and / or the water distribution piston (5) each have a sealing ring (23, 24), wherein the third fluidic line (8) opens into an interior of the brewing chamber (1) which is located between the sealing ring (23) of the brewing piston (2) and the sealing ring (24) of the water distribution piston (5), wherein the sealing ring (23, 24) is preferably an O-ring.

11. Coffee machine comprising a brewing unit according to one of the preceding claims and a control unit.

12. Coffee machine according to claim 11, characterized in that the control unit is configured to cause the actuator (9) of the brewing unit, preferably when the control unit receives a signal to brew a medium or low amount of coffee, i) to move a movable structural element (10) of the brewing unit with a through opening (12), which is preferably designed at least in regions as a hollow cylinder, very particularly preferably as a circular ring, into an intermediate space (13) which lies between a first opening (14) of the first fluidic line (4) and the brewing sieve (3) of the brewing piston (2), preferably until it comes into contact with the brewing sieve (3);and / or ii) to move a through opening (12') of a movable structural element (10) of the brewing unit, which is preferably designed at least in regions as a pin with an opening, needle valve or ball valve, so that a flow of water in the direction of the longitudinal axis (L) of the brewing chamber (1) and past a coffee bed is blocked by the movable structural element (10); wherein a medium or low amount of coffee is particularly preferably understood to mean an amount of coffee which forms a cylindrical coffee bed (27) in the brewing chamber (1) which has a ratio between an extension along the longitudinal axis (L) of the brewing chamber (1) and an extension perpendicular to the longitudinal axis (L) of the brewing chamber; (1) of < 0.4, preferably of < 0.3, particularly preferably of < 0.

2.

13. Coffee machine according to one of claims 11 or 12, characterized in that the control unit is configured to cause the actuator (9) of the brewing unit, preferably when the control unit receives a signal to brew a large quantity of coffee, i) to move a movable structural element (10) of the brewing unit with a through-opening, which is preferably designed at least in regions as a hollow cylinder, very particularly preferably as a circular ring, out of an intermediate space (13) which lies between a first opening (14) of the first fluidic line (4) and the brewing sieve (3) of the brewing piston (2), preferably until the movable structural element (10) is completely moved out of the intermediate space (13);and / or ii) to move a through opening (12') of a movable structural element (10) of the brewing unit, which is preferably designed at least in regions as a pin with an opening, needle valve or ball valve, so that a flow of water is permitted in the direction of the longitudinal axis (L) of the brewing chamber (1) and through the through opening (12') of the movable structural element (10); wherein a high quantity of coffee is particularly preferably understood to mean a quantity of coffee which forms a cylindrical coffee bed (27) in the brewing chamber (1) which has a ratio between an extent along the longitudinal axis (L) of the brewing chamber (1) and an extent perpendicular to the longitudinal axis (L) of the brewing chamber (1) of > 0.4, preferably of > 0.3, particularly preferably of > 0.

2.

14. Coffee machine according to one of claims 11 to 13, characterized in that the control unit is configured to open a water flow through the third fluidic line (8) i) when the control unit receives a signal from the coffee machine or a user of the coffee machine that a a low or medium amount of coffee is to be brewed, wherein a medium or low amount of coffee is particularly preferably understood to mean an amount of coffee which forms a cylindrical coffee bed (27) in the brewing chamber (1) which has a ratio between an extent along the longitudinal axis (L) of the brewing chamber (1) to an extent perpendicular to the longitudinal axis (L) of the brewing chamber (1) of < 0.4, preferably < 0.3, particularly preferably < 0.2;and / or ii) to close when the control unit receives a signal from the coffee machine or a user of the coffee machine that a large amount of coffee is to be brewed, wherein a large amount of coffee is particularly preferably understood to mean an amount of coffee which forms a cylindrical coffee bed (27) in the brewing chamber (1) which has a ratio between an extent along the longitudinal axis (L) of the brewing chamber (1) to an extent perpendicular to the longitudinal axis (L) of the brewing chamber (1) of > 0.4, preferably of > 0.3, particularly preferably of > 0.2; 15. Use of the brewing unit according to one of claims 1 to 10 or the coffee machine according to one of claims 11 to 14 for brewing coffee.

16. A method for brewing coffee, comprising or consisting of the following steps: a) conducting hot water in at least one radial direction (25) through a cylindrical coffee bed (27) in a brewing chamber (1) of a brewing unit of a coffee machine, wherein the at least one radial direction (25) is preferably understood to mean at least one direction which is substantially perpendicular to a lateral surface of the cylindrical coffee bed (27), wherein the conducting of hot water in at least one radial direction (25) through the cylindrical coffee bed (27) is particularly preferably carried out when a low or medium amount of coffee is to be brewed, wherein a medium or low amount of coffee is particularly preferably a quantity of coffee is understood which forms a cylindrical coffee bed (27) in the brewing chamber (1) which has a ratio between an extension along a longitudinal axis (L) of the brewing chamber (1) to an extension perpendicular to the longitudinal axis (L) of the brewing chamber (1) of < 0.4, preferably of < 0.3, particularly preferably of < 0.2;b) optionally: simultaneous or staggered conducting of hot water in an axial direction (26) through the cylindrical coffee bed (27), wherein the axial direction (26) is preferably understood to be a direction that is substantially perpendicular to at least one planar circular surface of the cylindrical coffee bed (27), wherein the conducting of hot water in an axial direction (26) through the cylindrical coffee bed (27) is particularly preferably carried out when a large quantity of coffee is to be brewed, wherein a large quantity of coffee is very particularly preferably understood to be a quantity of coffee that forms a cylindrical coffee bed (27) in the brewing chamber (1) that has a ratio between an extent along the longitudinal axis (L) of the brewing chamber (1) to an extent perpendicular to the longitudinal axis (L) of the brewing chamber (1) of > 0.4, preferably of > 0.3, particularly preferably of > 0.2;wherein the method is preferably carried out with a brewing unit according to one of claims 1 to 10 or with a coffee machine according to one of claims 11 to 14;

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