Brewing cylinder arrangement and use thereof, brewing unit for brewing coffee, and coffee machine

Abstract

The invention relates to a brewing cylinder arrangement which is suitable for use in a brewing unit for brewing coffee. Uses of this brewing unit are also proposed. The invention also relates to a brewing unit for brewing coffee and to a coffee machine. The brewing cylinder contains an outer cylinder which has a cylinder casing and an interior, and an inner cylinder which has a cylinder casing and an interior, wherein the inner cylinder is arranged in the interior of the outer cylinder. The brewing cylinder arrangement is characterised in that a cavity is formed at least in certain areas between the cylinder casing of the inner cylinder and the cylinder casing of the outer cylinder. With the brewing cylinder arrangement it is possible to brew a coffee at a predefined temperature reliably and independently of a state of heating of the brewing cylinder, with the result that the coffee can develop its best-possible (optimal) flavour profile and affords best-possible drinking enjoyment.

Description

[0001] Brewing cylinder arrangement and use thereof, brewing unit for brewing coffee and coffee machine

[0002] A brewing cylinder arrangement is provided which is suitable for use in a brewing unit for brewing coffee. Furthermore, uses of said brewing unit are proposed. In addition, a brewing unit for brewing coffee and a coffee machine are provided. The brewing cylinder contains an outer cylinder, which has a cylinder jacket and an interior, and an inner cylinder, which has a cylinder jacket and an interior, wherein the inner cylinder is arranged in the interior of the outer cylinder. The brewing cylinder arrangement is characterized in that a cavity is formed at least in regions between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder, and the wall thickness of the cylinder jacket of the inner cylinder is in the range from 0.1 mm to <1.5 mm. With the brewing cylinder arrangement, it is possible to safely and

[0003] Brewing coffee at a predetermined temperature in a manner that is independent of the brewing cylinder's temperature, allowing the coffee to develop its best possible (optimal) flavor profile and provide the best possible drinking experience. Brewing cylinders made of plastic (EP 3 060086 B1) or metal (US 2010 / 080886 A1) are known in the prior art for use in a brewing unit for brewing coffee.

[0004] Brewing cylinders made of plastic have the advantage that they are inexpensive to manufacture and functional features such as holders, guides and / or screw domes can be injection-molded, meaning additional functions can be easily integrated. A disadvantage of plastic cylinders, however, is the requirement for thick walls of 3 mm or more in order to withstand the mechanical stress (typically 8 bar pressure, at a brewing liquid temperature of 90° to 95°C) during a brewing process. Furthermore, only plastics that are approved for use with food can be used. In addition, these plastics do not have a high resistance to cleaning agents and / or descaling agents. The taste neutrality of these plastics is also not very high.

[0005] Metal brewing cylinders have the advantage of being significantly more neutral in taste and highly resistant to cleaning agents and descaling agents. Since metal cylinders are typically manufactured using machining processes, their wall thickness is approximately 1.5 mm. The disadvantage of metal cylinders, however, is that additional functional features (such as brackets, guides, and / or screw domes) can only be implemented using additional components, usually plastic parts.

[0006] All known brewing cylinders have the disadvantage that they absorb a large amount of heat from the brewing liquid (i.e. from hot brewing water) during brewing coffee and thus cool the brewing liquid. This cooling of the brewing liquid is particularly pronounced if no coffee has been brewed with the brewing unit for a long time, as in such cases the brewing cylinder may be at a temperature below an optimal brewing temperature (e.g. at room temperature, i.e. around 25 °C). The disadvantage of cooling the brewing liquid during the brewing process is that the temperature of the brewing liquid used to brew coffee is reduced to a value that is below an optimal value for brewing coffee. This means that the resulting coffee is not brewed at its optimal brewing temperature and therefore cannot develop its best possible (optimal) flavor profile, i.e. it tastes flat and bland.

[0007] Furthermore, when brewing small-volume coffees (such as espresso or ristretto) with a conventional brewing cylinder, the first coffee brewed after extended brewing pauses may only have a temperature of approximately 50°C to <60°C (instead of the optimal temperature of, for example, 80°C to 90°C). This can degrade the drinking experience for the user, as the brewed coffee is perceived as lukewarm rather than hot as expected.

[0008] Based on this, the object of the present invention was to provide a brewing cylinder for use in a brewing unit for brewing coffee, which attenuates and, ideally, completely overcomes at least one of the disadvantages known in the prior art. In particular, the brewing unit should make it possible to brew coffee safely and independently of a heating state of the brewing cylinder at a predetermined temperature, which develops its best possible (optimal) flavor profile and has an optimal beverage temperature, thus offering optimal drinking pleasure. Furthermore, uses of the brewing cylinder should be proposed and a brewing unit for brewing coffee and a coffee machine should be provided that have said advantage.

[0009] The object is achieved by the brewing cylinder having the features of claim 1, the brewing unit having the features of claim 13, the coffee machine having the features of claim 14 and the use having the features of claim 15. The dependent claims show advantageous further developments.

[0010] According to the invention, a brewing cylinder arrangement for use in a brewing unit for brewing coffee is provided, comprising or consisting of: a) an outer cylinder having a cylinder jacket and an interior space; b) an inner cylinder having a cylinder jacket and an interior space, wherein the inner cylinder is arranged in the interior space of the outer cylinder; characterized in that a cavity is formed at least in regions between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder, wherein the wall thickness of the cylinder jacket of the inner cylinder is in the range from 0.1 mm to <1.5 mm.

[0011] With the brewing cylinder arrangement according to the invention, it is possible to brew coffee safely and independently of the heating state of the brewing cylinder at a predetermined temperature, so that a coffee can be brewed that develops its best possible (optimal) flavor profile and has an optimal beverage temperature, thus offering optimal drinking pleasure.

[0012] This is due to the fact that between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder, at least in some areas, a cavity is formed (e.g. a cavity filled with air), as the cavity ensures that the cylinder jacket of the inner cylinder (in whose interior the brewing chamber is located, i.e. where the brewing process takes place) is thermally insulated from the cylinder jacket of the outer cylinder. As a result, the heat of the brewing liquid in an interior of the inner cylinder can only be transferred to the cylinder jacket of the inner cylinder, but due to the thermal insulation, it is only transferred very weakly or not at all to the cylinder jacket of the outer cylinder and also not to the external environment of the cylinder jacket of the outer cylinder. As a result, the temperature of the brewing liquid in the interior of the inner cylinder during the brewing process remains closer to, or even at, its original temperature, i.e.at a temperature value specified for the brewing liquid. This allows the coffee to be brewed safely at a specified temperature and develop its best possible (optimal) flavor profile. Furthermore, the coffee can be brewed at an optimal beverage temperature and thus also offers optimal drinking pleasure. The cavity is preferably filled with gas or has a vacuum. A vacuum has the advantage that no heat conduction takes place in the cavity and heat transfer is limited to thermal radiation. If the cavity is filled with a gas, the gas can contain or consist of air, nitrogen, water vapor, carbon dioxide and / or argon. These gases have the advantage that heat conduction in the cavity is very low (specific thermal conductivity <0.025 W / mK). The cavity is particularly preferably filled with air (specific thermal conductivity of air: 0.025 W / mK).Air has the additional advantage over the other gases mentioned and vacuum that the brewing cylinder arrangement can be manufactured in a simpler, more cost-effective and long-term stable manner, since there is no need to fill the cavity with a cost-intensive gas and the cavity does not have to be sealed gas-tight for long-term stability in order to prevent the filled gas from being exchanged with air.

[0013] It is also conceivable for the cavity to be connected to a steam source (e.g., a steam source of a coffee machine, such as a steam boiler of a coffee machine). This makes it possible to heat the inner cylinder with the heat of the steam by directing steam from the steam source into the cavity (e.g., preheating before brewing coffee). Consequently, it can be even better ensured that coffee can be brewed that develops its best possible (optimal) flavor profile, has the optimal beverage temperature, and offers optimal drinking pleasure.

[0014] Since the wall thickness of the inner cylinder's cylinder shell ranges from (only) 0.1 mm to <1.5 mm, it can also be better ensured that the coffee is brewed at a specified, optimal brewing temperature. This allows for a more reliable brewing of coffee with the best possible flavor profile and at the beverage temperature expected by the user, ensuring the coffee offers optimal drinking pleasure.

[0015] The inner cylinder of the brewing cylinder arrangement can contain or consist of a material selected from the group consisting of plastic, metal, metal alloy and combinations thereof. The material is preferably selected from the group consisting of metal, metal alloy and combinations thereof. The material is particularly preferred is stainless steel. A metal or a metal alloy (in particular stainless steel) has the advantage that it has greater long-term stability than plastic. Furthermore, it can be ensured that no additives commonly found in plastics (such as processing additives, dyes, glass fibers and / or flame retardants) get into the brewed coffee, which offers increased safety and even better ensures that the brewed coffee has its best possible (optimal) flavor profile and can therefore offer optimal drinking pleasure. Furthermore, metal and / or a metal alloy (e.g.B. stainless steel) is also much more resistant and taste-neutral to cleaning and descaling agents that are cyclically used in coffee machines, which increases long-term stability and allows the brewed coffee to achieve its best possible taste profile in an even safer way.

[0016] Furthermore, the inner cylinder of the brewing cylinder assembly can have a specific heat capacity of a maximum of 2000 J / kg-K, optionally a maximum of 500 J / kg-K (e.g., in the case of an inner cylinder made of metal or a metal alloy). The lower the specific heat capacity of the inner cylinder, the lower its heat absorption from the brewing liquid, i.e., the less the inner cylinder changes the specified temperature of the brewing liquid, and the better it can be ensured that the brewed coffee achieves its best possible flavor profile and has an optimal beverage temperature, thus offering optimal drinking pleasure.

[0017] In addition, the inner cylinder can have a surface towards its interior that has a mean roughness R ain the range of 0.1 pm to 1.0 pm, whereby the mean roughness preferably refers to a mean roughness that can be determined according to DIN EN ISO 4287. The advantage of a mean roughness in this range is that a seal of brewing pistons that move within the inner cylinder during a brewing process experiences only minimal wear due to friction on the inner cylinder. This increases the service life of the brewing pistons, which minimizes downtimes in the brewing cylinder arrangement and reduces the operating costs of the brewing cylinder arrangement (economic advantage). Furthermore, the inner cylinder can have a surface towards its interior that has a coefficient of friction PG for elastomeric plastics (e.g. rubbers, silicones and / or polyurethanes) in the range of 0.10 to 0.35. The advantage here is also that the brewing pistons that move within the interior of the inner cylinder during a brewing process experience only minimal wear due to friction.Downtime can be reduced and operating costs lowered. Furthermore, the risk of abraded elastomer plastics getting into the brewed coffee is minimized, further ensuring that the brewed coffee achieves its best possible flavor profile and provides optimal drinking pleasure.

[0018] Apart from that, the inner cylinder can have a surface towards its interior that was produced using a polishing process. The polishing process is preferably selected from the group consisting of chemical polishing processes, mechanical polishing processes, and combinations thereof. The chemical polishing process is particularly preferably an electrochemical polishing process, in particular electropolishing. The mechanical polishing process is particularly preferably selected from the group consisting of grinding, rolling, honing, and combinations thereof. The advantage is that the surface in the interior of the inner cylinder offers only low frictional resistance to brewing pistons, thereby minimizing frictional wear, reducing downtime, and lowering operating costs.In addition, reducing abrasion on the seal of brewing pistons can better ensure that the brewed coffee achieves its best possible flavor profile and offers optimal drinking pleasure.

[0019] In addition, the inner cylinder can have a coating towards its interior which contains or consists of a material selected from the group consisting of metal, metal alloy, ceramic, fluoroplastic and combinations thereof. The metal is preferably chromium. The ceramic preferably contains or consists of a material selected from the group consisting of aluminum oxide (Al2O3), chromium oxide (e.g. Cr2O3), titanium oxide (e.g. TiO2) and combinations thereof. The ceramic can be Silargan® (Silit-Werke GmbH & Co. KG, Riedlingen, Germany), i.e. a ceramic known in 2023 under the name Silargan®. The fluoroplastic is preferably polytetrafluoroethylene. The coating has the advantage that brewing pistons moving in the interior of the inner cylinder experience only low frictional resistance.By minimizing frictional wear on the brewing pistons, downtime can be reduced and operating costs lowered. Furthermore, it can be better ensured that the brewed coffee achieves its best possible flavor profile and offers optimal drinking pleasure. It is preferred that the coating contains or consists of a material selected from the group consisting of metal, metal alloy, ceramic, and combinations thereof. This offers ecological advantages over a coating containing or consisting of a fluoroplastic.

[0020] According to the invention, the wall thickness of the cylinder jacket of the inner cylinder is in the range from 0.1 mm to <1.5 mm, preferably 0.1 mm to 0.8 mm, particularly preferably 0.2 to 0.4 mm. Typically, the wall thicknesses of prior art brewing cylinders are 1.5 mm. A thinner wall thickness has the advantage that the cylinder jacket of the inner cylinder can have a lower mass and thus its heat absorption capacity is reduced compared to known brewing cylinders with thicker walls. This means that the brewing liquid is cooled less and it can be better ensured that the coffee is brewed at a predetermined, optimal brewing temperature. This makes it possible to dispense coffee with the best possible flavor profile and at the beverage temperature expected by the user in a safer manner, whereby the coffee can offer optimal drinking pleasure.

[0021] The cylinder jacket of the inner cylinder can, at least in some regions, in a direction perpendicular to a central axis of the cylinder jacket of the inner cylinder, have a distance from the cylinder jacket of the outer cylinder that is in the range of 0.5 mm to 8 mm, preferably 1 to 4 mm, particularly preferably 1.5 to 2.5 mm. The greater the distance, the better the thermal insulation effect of the cavity between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder. Better thermal insulation better ensures that the coffee is brewed at a predetermined, optimal brewing temperature and achieves its best possible flavor profile and optimal beverage temperature.If the cylinder jacket of the outer cylinder has a coating or film on a surface facing the cylinder jacket of the inner cylinder, this distance applies from the cylinder jacket of the inner cylinder to this coating or film on said surface of the outer cylinder. The same applies if the cylinder jacket of the inner cylinder has a coating or film on a surface facing the cylinder jacket of the outer cylinder.

[0022] In a preferred embodiment, said distance extends over at least 50%, preferably at least 60%, particularly preferably at least 70%, most particularly preferably at least 80%, in particular at least 90%, of the length of the inner cylinder, wherein the length of the inner cylinder refers to an extension of the inner cylinder in a direction parallel to a central axis of the cylinder jacket of the inner cylinder. The longer the distance over which the distance exists, the longer the cavity between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder, and the better it can be ensured that coffee is brewed with the best possible flavor profile and at the optimal beverage temperature.

[0023] The inner cylinder may have an outwardly projecting wall at an upper end of the inner cylinder, which extends from the cylinder shell of the inner cylinder to the outer cylinder. The wall is preferably arranged at least partially perpendicular to a wall of the cylinder shell of the inner cylinder.

[0024] The outwardly projecting wall can contact the outer cylinder, preferably an outwardly projecting wall of the outer cylinder that extends from the cylinder jacket of the outer cylinder away from the inner cylinder.

[0025] Furthermore, the outwardly projecting wall can contact at least one elastic element (e.g., an elastic sealing element) of the brewing cylinder assembly, which is arranged between the outwardly projecting wall of the inner cylinder and the outer cylinder. The elastic element serves as a seal between the inner cylinder and the outer cylinder and prevents liquid from penetrating the cavity of the brewing cylinder assembly.

[0026] The at least one elastic element may contain or consist of a material selected from the group consisting of elastomers, preferably thermoplastic elastomers, wherein the material is preferably selected from the group consisting of rubbers, silicones, polyurethanes and combinations thereof.

[0027] Furthermore, the at least one elastic element can contact an outwardly projecting wall of the outer cylinder. The outwardly projecting wall of the outer cylinder preferably has a first section arranged substantially perpendicular to a wall of the cylinder shell of the outer cylinder, wherein the elastic element contacts a surface of the first section. Preferably, the outwardly projecting wall of the outer cylinder has a second section connected to the first section and arranged substantially parallel to a wall of the cylinder shell of the outer cylinder, wherein the elastic element further contacts a surface of the second section.

[0028] The at least one elastic element can be designed as a ring, or as at least two, preferably at least three, optionally at least four, partial regions of a ring, wherein the partial regions of the ring preferably have a substantially equal distance from one another.

[0029] The inner cylinder can have an inwardly projecting wall at a lower end of the inner cylinder, which extends from the cylinder jacket of the inner cylinder towards the interior of the inner cylinder. The inwardly projecting wall is preferably arranged at least partially perpendicular to a wall of the cylinder jacket of the inner cylinder. The inwardly projecting wall can contact the outer cylinder, preferably contact an inwardly projecting wall of the outer cylinder, which extends from the cylinder jacket of the outer cylinder to the inner cylinder. This has the advantage that the inner cylinder rests on its inwardly projecting wall on the outer cylinder (specifically: on the inwardly projecting wall of the outer cylinder). This prevents a movement of a brewing piston in a direction from top to bottom from "taking" the inner cylinder along due to frictional force, i.e.This ensures that the inner cylinder remains in its position within the brewing cylinder assembly. Another advantage is that the cavity of the brewing cylinder assembly is sealed.

[0030] Furthermore, the inwardly projecting wall of the inner cylinder can contact at least one connecting element (or retaining element) of the brewing cylinder assembly and can be fixed to the outer cylinder by the at least one connecting element. A side of the inwardly projecting wall of the inner cylinder that contacts the at least one connecting element (= upper side of the inwardly projecting wall of the inner cylinder) can be opposite a side of the inwardly projecting wall of the inner cylinder that contacts the outer cylinder (= lower side of the inwardly projecting wall of the inner cylinder). The connecting element (or retaining element) prevents a movement of a brewing piston in a bottom-to-top direction from "carrying" the inner cylinder due to frictional force, i.e., it can be ensured that the inner cylinder remains in its position in the brewing cylinder assembly.A further advantage is that the cavity of the brewing cylinder assembly is sealed by the connecting element.

[0031] The inner cylinder can be undersized relative to the overall height of the brewing cylinder assembly. This ensures that when the connecting element (retaining element) is installed, the upper edge of the inner cylinder always rests with preload on an elastic element (i.e., a seal) between an outwardly projecting wall of the inner cylinder and an outwardly projecting wall of the outer cylinder, thus further ensuring that the cavity of the brewing cylinder assembly is tightly sealed.

[0032] The connecting element can contain or consist of a material selected from the group consisting of plastic, metal, metal alloy, and combinations thereof. The material is preferably a plastic, particularly preferably a thermoplastic. The material is particularly selected from the group consisting of polyamide, polyoxymethylene, polyvinylidene fluoride, and combinations thereof.

[0033] Furthermore, the connecting element can contact an inwardly projecting wall of the outer cylinder. The inwardly projecting wall of the outer cylinder preferably has a first section arranged substantially parallel to a wall of the cylinder shell of the outer cylinder, wherein the connecting element contacts a surface of the first section. The inwardly projecting wall of the outer cylinder particularly preferably has a second section arranged substantially perpendicular to a wall of the cylinder shell of the outer cylinder and in particular represents a (lowest) terminal section of the outer cylinder, wherein the connecting element further contacts a surface of the second section.

[0034] Furthermore, the connecting element can be designed as a holding element, wherein the holding element is preferably selected from the group consisting of clamping ring, ring with snap hook and ring with bayonet closure.

[0035] The outer cylinder can contain or consist of a material selected from the group consisting of plastic, metal, metal alloy, and combinations thereof. The material is preferably a plastic. A plastic outer cylinder has the advantage that it can be produced quickly, easily, and cost-effectively using an injection molding process, which allows economical production of the outer cylinder. Furthermore, structures of the outer cylinder can be formed more easily, quickly, and more economically (in one piece) than, for example, with an outer cylinder made of metal, which likewise facilitates the production of the outer cylinder and thus of the entire brewing cylinder arrangement. In addition, other functional features, such as holders and / or guides for the outer cylinder, can be formed onto the outer cylinder more easily, quickly, and more economically than, for example, with an outer cylinder made of metal.The outer cylinder can have a specific heat capacity of maximum 2000 J / kg-K.

[0036] Furthermore, the outer cylinder can have a surface facing its interior that is at least partially reflective of electromagnetic thermal radiation (i.e., infrared radiation). The advantage of this is that, in addition to the cavity between the inner and outer cylinders, there is a further thermal insulation measure, i.e., heat absorption by the outer cylinder is reduced even more than by the cavity between the two cylinders. This further ensures that the brewing liquid remains at its specified temperature and coffee has its best possible flavor profile and an optimal beverage temperature, i.e., that the drinking experience is optimal.

[0037] The surface that reflects electromagnetic thermal radiation can be designed as a coating with a metal, preferably aluminum. The coating can have a layer thickness in the range of 1 pm to <50 pm, preferably 1 pm to 10 pm.

[0038] Alternatively, the surface reflective of electromagnetic thermal radiation can be configured as a foil made of metal, preferably aluminum. The foil can have a layer thickness in the range of 50 μm to 0.2 mm. Optionally, the foil is applied or glued to a surface in the interior of the outer cylinder.

[0039] The brewing cylinder assembly can contain at least one brewing piston, particularly preferably two brewing pistons. The at least one brewing piston, preferably the two brewing pistons, is / are located in an interior space of the inner cylinder of the brewing cylinder assembly.

[0040] According to the invention, a brewing unit for brewing coffee is further provided, which contains a brewing cylinder arrangement according to the invention. The brewing unit preferably further contains at least one brewing piston, particularly preferably two brewing pistons. Furthermore, according to the invention, a coffee machine is provided, which contains a brewing cylinder arrangement according to the invention or a brewing unit according to the invention.

[0041] The coffee machine can have a steam source (e.g., a steam boiler) that is fluidly connected to the cavity of the brewing cylinder assembly. The advantage of this is that the coffee machine can direct (hot) steam into the cavity of the brewing cylinder assembly, thereby preheating the inner cylinder of the brewing cylinder assembly. This measure can ensure with even greater certainty that a coffee is brewed that develops its best possible (optimal) flavor profile and has the optimal beverage temperature, meaning that the drinking experience is optimal.

[0042] The coffee machine can be configured to circulate steam between the steam source and the cavity of the brewing cylinder assembly. This has the advantage that no steam leaves the coffee machine, thus saving water and the heat energy stored in the steam (an ecological and economic advantage).

[0043] Furthermore, the coffee machine can include a control unit configured to control or regulate the introduction of steam into the cavity of the brewing cylinder assembly and / or the circulation of steam between the steam source of the coffee machine and the cavity of the brewing cylinder assembly. For the regulation, the brewing cylinder assembly can have a temperature sensor configured to detect a temperature in the cavity of the brewing cylinder assembly and to send information about the temperature in the cavity to the control unit of the coffee machine. The control unit can be configured to regulate the temperature in the cavity to a temperature in the range of 60°C to 95°C (preferably 70°C to 92°C, particularly preferably 80°C to 90°C).

[0044] The use of a brewing cylinder arrangement according to the invention in a brewing unit of a coffee machine is proposed.

[0045] The subject matter of the invention will be explained in more detail with reference to the following figure, without wishing to restrict it to the specific embodiments shown here.

[0046] Figure 1 shows a side view of a brewing cylinder arrangement according to the invention. The brewing cylinder arrangement contains an outer cylinder 1, which has a cylinder jacket and an interior space 2, and an inner cylinder 3, which has a cylinder jacket and an interior space 4, wherein the inner cylinder 3 is arranged in the interior of the outer cylinder 1. A cavity 5 is formed, at least in some regions, between the cylinder jacket of the inner cylinder 3 and the cylinder jacket of the outer cylinder 1. The cavity thermally insulates the cylinder jacket of the inner cylinder 3 from the cylinder jacket of the outer cylinder 1 and thus also from the external environment of the outer cylinder 1. The inner cylinder 3 has an outwardly projecting wall 6 at its upper end. An elastic element 7 is arranged between the outwardly projecting wall 6 of the inner cylinder 3 and an outwardly projecting wall 10 of the outer cylinder 1.The gaps indicated in Figure 1 between the elastic element 7 on the one hand and the inner cylinder 3 and the outer cylinder 1 on the other hand serve only to make the various components easier to see; they do not actually exist (to ensure tightness at these points). Furthermore, the inner cylinder 3 has an inwardly projecting wall 8 at its lower end, which contacts an inwardly projecting wall 11 of the outer cylinder 1. A connecting element 9, which contacts the inwardly projecting wall 8 of the inner cylinder 3 and a (second) section of an inwardly projecting wall 11 of the outer cylinder 1 or presses the inwardly projecting wall 8 of the inner cylinder 3 and the (second) section of the inwardly projecting wall 11 of the outer cylinder 1 together, fixes the inner cylinder 3 to the outer cylinder 1.The gaps indicated in Figure 1 between the connecting element 9 on the one hand and the inner cylinder 3 and the outer cylinder 1 on the other hand, as well as the gap indicated at this point in Figure 1 between the inner cylinder 3 and the outer cylinder 1, serve only to improve the visibility of the various components; however, they do not actually exist (in order to ensure tightness at these points). In the embodiment shown here, the outer cylinder 1 has, at least in some regions, on a side facing the inner cylinder 3, a surface 12 that reflects electromagnetic thermal radiation and is implemented, for example, as an aluminum layer.

[0047] Figure 2 shows the brewing cylinder arrangement according to the invention from Figure 1 in a side view from above. In this view, the shape of the connecting element 9, among other things, is particularly clearly visible.

[0048] Figure 3 shows the brewing cylinder arrangement according to the invention from Figures 1 and 2 in a side view, wherein the brewing cylinder arrangement here contains a (lower) brewing piston 13, which is present in the interior 4 of the inner cylinder 3 of the brewing cylinder arrangement.

[0049] 1: outer cylinder;

[0050] 2: Interior of outer cylinder;

[0051] 3: inner cylinder;

[0052] 4: Interior of inner cylinder;

[0053] 5: Cavity (between the cylinder shell of the inner cylinder and the cylinder shell of the outer cylinder);

[0054] 6: outwardly projecting wall of the inner cylinder;

[0055] 7: elastic element (between the outwardly projecting wall of the

[0056] inner cylinder and the outer cylinder);

[0057] 8: inwardly projecting wall of the inner cylinder;

[0058] 9: Connecting element (fixes inner cylinder to the outer cylinder);

[0059] 10: outwardly projecting wall of the outer cylinder;

[0060] 11: inwardly projecting wall of the outer cylinder;

[0061] 12: Surface of the outer cylinder, which is preferably at least partially reflective of electromagnetic thermal radiation;

[0062] 13: Brewing piston.

Claims

Patent claims 1. Brewing cylinder arrangement for use in a brewing unit for brewing coffee, containing or consisting of: a) an outer cylinder having a cylinder jacket and an interior space; b) an inner cylinder having a cylinder jacket and an interior space, wherein the inner cylinder is arranged in the interior space of the outer cylinder; characterized in that a cavity is formed at least in regions between the cylinder jacket of the inner cylinder and the cylinder jacket of the outer cylinder, wherein the wall thickness of the cylinder jacket of the inner cylinder is in the range from 0.1 mm to <1.5 mm.

2. Brewing cylinder arrangement according to the preceding claim, characterized in that the inner cylinder contains or consists of a material that i) is selected from the group consisting of plastic, metal, metal alloy, and combinations thereof, wherein the material is preferably selected from the group consisting of metal, metal alloy, and combinations thereof, wherein the material is particularly preferably stainless steel; and / or ii) has a specific heat capacity of a maximum of 2000 J / kg-K, optionally a maximum of 500 J / kg-K.

3. Brewing cylinder arrangement according to one of the preceding claims, characterized in that the inner cylinder has a surface in the direction of its interior which i) a mid-rough value R ain the range from 0.1 µm to 1.0 µm, wherein the mean roughness preferably refers to a mean roughness determinable according to DIN EN ISO 4287; and / or ii) has a coefficient of friction PG to elastomeric plastics in the range from 0.10 to 0.35; and / or iii) was produced via a polishing process, wherein the polishing process is preferably selected from the group consisting of chemical polishing processes, mechanical polishing processes and combinations thereof, wherein the chemical polishing process is particularly preferably an electrochemical polishing process, in particular electropolishing, and / or the mechanical polishing process is particularly preferably selected from the group consisting of grinding, rolling, honing and combinations thereof;and / or iv) has a coating which contains or consists of a material selected from the group consisting of metal, metal alloy, ceramic, fluoroplastic and combinations thereof, wherein the metal is preferably chromium, the ceramic preferably contains or consists of a material selected from the group consisting of aluminum oxide, chromium oxide, titanium oxide and combinations thereof, and / or the fluoroplastic is preferably polytetrafluoroethylene.; 4. Brewing cylinder arrangement according to one of the preceding claims, characterized in that the wall thickness of the inner cylinder shell is in the range of 0.1 mm to 0.8 mm, preferably 0.2 to 0.4 mm.

5. Brewing cylinder arrangement according to one of the preceding claims, characterized in that the cylinder jacket of the inner cylinder has at least in some regions, in a direction perpendicular to a central axis of the cylinder jacket of the inner cylinder, a distance from the cylinder jacket of the outer cylinder which is in the range of 0.5 mm to 8 mm, preferably 1 to 4 mm, particularly preferably 1.5 to 2.5 mm, wherein the distance is preferably over at least 50%, preferably at least 60%, particularly preferably at least 70%, very particularly preferably at least 80%, in particular at least 90%, of a length of the inner cylinder, wherein the length of the inner cylinder refers to an extension of the inner cylinder in a direction parallel to a central axis of the cylinder jacket of the inner cylinder.

6. Brewing cylinder arrangement according to one of the preceding claims, characterized in that the inner cylinder has an outwardly projecting wall at an upper end of the inner cylinder, which extends from the cylinder jacket of the inner cylinder to the outer cylinder, wherein the wall is preferably arranged at least partially perpendicular to a wall of the cylinder jacket of the inner cylinder, wherein the wall particularly preferably i) contacts the outer cylinder, preferably an outwardly projecting wall of the outer cylinder, which extends from the cylinder jacket of the outer cylinder away from the inner cylinder; and / or ii) contacts at least one elastic element of the brewing cylinder arrangement that is arranged between the outwardly projecting wall of the inner cylinder and the outer cylinder.

7. Brewing cylinder arrangement according to claim 6, characterized in that the at least one elastic element contains or consists of a material selected from the group consisting of elastomers, preferably thermoplastic elastomers, wherein the material is preferably selected from the group consisting of rubbers, silicones, polyurethanes and combinations thereof.

8. Brewing cylinder arrangement according to one of claims 6 or 7, characterized in that the at least one elastic element i) contacts an outwardly projecting wall of the outer cylinder, wherein the outwardly projecting wall of the outer cylinder preferably has a first section which is substantially is arranged perpendicular to a wall of the cylinder jacket of the outer cylinder, wherein the elastic element contacts a surface of the first section, wherein the outwardly projecting wall of the outer cylinder preferably has a second section which is connected to the first section and is arranged substantially parallel to a wall of the cylinder jacket of the outer cylinder, wherein the elastic element further contacts a surface of the second section; and / or ii) is designed as a ring, or as at least two, preferably at least three, optionally at least four, partial regions of a ring, wherein the partial regions of the ring preferably have a substantially equal distance from one another.

9. Brewing cylinder arrangement according to one of the preceding claims, characterized in that the inner cylinder has an inwardly projecting wall at a lower end of the inner cylinder, which extends from the cylinder jacket of the inner cylinder towards the interior of the inner cylinder, wherein the inwardly projecting wall is preferably arranged at least partially perpendicular to a wall of the cylinder jacket of the inner cylinder, wherein the wall particularly preferably i) contacts the outer cylinder, preferably contacts an inwardly projecting wall of the outer cylinder, which extends from the cylinder jacket of the outer cylinder to the inner cylinder; and / or ii) contacts at least one connecting element of the brewing cylinder arrangement and is fixed to the outer cylinder by the at least one connecting element.

10. Brewing cylinder arrangement according to claim 9, characterized in that the connecting element contains or consists of a material selected from the group consisting of plastic, metal, metal alloy and combinations thereof, wherein the material The material is preferably a plastic, particularly preferably a thermoplastic, wherein the material is in particular selected from the group consisting of polyamide, polyoxymethylene, polyvinylidene fluoride and combinations thereof; and / or 11. Brewing cylinder arrangement according to one of claims 8 or 9, characterized in that the connecting element i) contacts an inwardly projecting wall of the outer cylinder, wherein the inwardly projecting wall of the outer cylinder preferably has a first section which is arranged substantially parallel to a wall of the cylinder jacket of the outer cylinder, wherein the connecting element contacts a surface of the first section, wherein the inwardly projecting wall of the outer cylinder particularly preferably has a second section which is arranged substantially perpendicular to a wall of the cylinder jacket of the outer cylinder and in particular represents a final section of the outer cylinder, wherein the connecting element further contacts a surface of the second section;and / or ii) is designed as a holding element, wherein the holding element is preferably selected from the group consisting of clamping ring, ring with snap hook and ring with bayonet closure; 12. Brewing cylinder arrangement according to the preceding claim, characterized in that the outer cylinder i) contains or consists of a material selected from the group consisting of plastic, metal, metal alloy and combinations thereof, wherein the material is preferably a plastic; and / or ii) has a specific heat capacity of at most 2000 J / kg-K; and / or iii) has a surface towards its interior which is at least partially reflective for electromagnetic thermal radiation, wherein the material which is reflective for electromagnetic thermal radiation The reflective surface is preferably designed as a coating with a metal, preferably aluminum, which particularly preferably has a layer thickness in the range from 1 pm to <50 pm, in particular 1 to 10 pm, or the surface reflective for electromagnetic thermal radiation is preferably designed as a foil made of metal, preferably aluminum, which particularly preferably has a layer thickness in the range from 50 pm to 0.2 mm and is optionally applied or glued to a surface in the interior of the outer cylinder.

13. Brewing unit for brewing coffee, comprising a brewing cylinder attachment. Arrangement according to one of the preceding claims, wherein the brewing unit preferably further contains at least one brewing piston, particularly preferably two brewing pistons.

14. Coffee machine comprising a brewing cylinder arrangement according to one of claims 1 to 12 or a brewing unit according to claim 13.

15. Use of a brewing cylinder arrangement according to one of claims 1 to 12 in a brewing unit of a coffee machine.

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