Heated brewing head for a coffee machine and coffee machine comprising heated brewing head

Abstract

The invention relates to a brewing head assembly (40) for a coffee machine (100). The brewing head assembly (40) comprises a brewing head (50) having a shower (50) and a heating element (80). The heating element (80) is arranged on the brewing head (50) and is designed to heat the brewing head (50) before and / or during a process for producing a coffee beverage. The invention further relates to a coffee machine (100) comprising a brewing head assembly (40) of this kind.

Description

[0001] Heated brewing head for a coffee machine and coffee machine with heated brewing head

[0002] Technical area

[0003] This description relates to the technical field of the mechanical preparation of coffee beverages. In particular, the description relates to a brewing head assembly for a coffee machine and a coffee machine with such a brewing head assembly. In particular, the brewing head assembly has a heated brewing head.

[0004] Technical background

[0005] Coffee beverages have been consumed for a long time. The general principle is essentially the same: a coffee bean is roasted, then the roasted coffee bean is ground into coffee powder, and then a liquid, usually hot water, is applied to the coffee powder. During this final step, the liquid absorbs, among other things, flavors from the coffee powder and can be consumed as a coffee beverage.

[0006] There are various manual and mechanical options for preparing coffee beverages. Coffee machines are particularly popular.

[0007] Coffee machines can be constructed according to different principles. Typically, a coffee machine contains a reservoir for ground coffee. Hot water is then passed through the ground coffee and then collected in a drinking vessel.

[0008] The coffee grounds reservoir can be sized to hold enough coffee grounds for one or more servings of the coffee beverage. The ground coffee can either be introduced into the reservoir in its pre-ground state, or coffee beans can be ground first and immediately before brewing, and the resulting ground coffee is then added to the reservoir. The liquid is then either applied to the ground coffee under pressure or flows through the ground coffee without pressure, simply under the influence of gravity. Other coffee machines are designed to hold pre-portioned ground coffee in a variety of containers and to pump hot water through these containers.

[0009] A fundamental difference between existing coffee machine types is whether the roasted coffee beans are freshly ground before brewing or whether the coffee powder is already ground. For a high-quality coffee beverage, it can be advantageous and desirable to grind the coffee beans immediately before brewing, as the coffee powder can lose flavor and aroma if left standing for long periods.

[0010] Other fundamental differences are whether the water is pressed through the coffee powder under pressure and whether a sieve contains coffee powder for one, two or more servings.

[0011] Another important parameter that affects the taste and quality of a coffee beverage is the temperature of the water that is applied to the coffee powder.

[0012] DE 10 2021 102 743 B3 and WO 2022 / 167 560 A2 describe an automatically adjustable coffee machine which works with portafilter technology and is designed for preparing a coffee beverage based on different types of coffee beans.

[0013] Description It can be considered a task to improve temperature control in the mechanical production of coffee beverages.

[0014] This object is achieved by the subject matter of the independent claim. Further embodiments emerge from the dependent claims and the following description.

[0015] According to one aspect, a brewing head assembly for a coffee machine is provided. The brewing head assembly comprises a brewing head with a shower and a heating element. The heating element is arranged on the brewing head and is configured to heat the brewing head before and / or during a coffee beverage preparation process.

[0016] Typically, the water used to make a coffee beverage is heated in a boiler and then transported through a piping system to the coffee grounds. In this boiler, the water is heated to a predetermined temperature. This temperature can also be monitored and set to the predetermined temperature using a temperature control system. However, it can happen that the water heated in the boiler releases thermal energy, or cools down, as it is transported through the piping system to the coffee grounds. Thus, the water does not flow through the coffee grounds at the predetermined temperature, but has already released some of its thermal energy. This can have a detrimental effect on the quality and taste of the resulting coffee beverage.

[0017] To compensate for this disadvantage, the present proposal is to couple a heating element to the brewing head. This allows the brewing head to be heated to extract less thermal energy from the water at this point, just before the water hits the coffee grounds, or even to add thermal energy back to the brewing head. The heating element is located on the brewing head, at the point where the water directly hits the coffee grounds.

[0018] This design has the advantage that the brewing head assembly can be heated to a predetermined temperature, so that the water used in the preparation of a coffee beverage, which is typically heated by the coffee machine in a boiler or a separate container, releases as little thermal energy as possible before the heated water flows through the coffee grounds. This ensures that the temperature of the water exiting the brewing head exhibits no significant, or at most, very slight, deviation from the specified temperature.

[0019] According to one embodiment, the heating element is arranged on the brewing head at a rear side of the brewing head opposite the shower.

[0020] The heating element serves, among other things, to heat the brewing head and the shower head, ensuring that these two components extract as little thermal energy from the water as possible—ideally none at all. In fact, the heated brewing head can even add thermal energy to the water, increasing its temperature.

[0021] The heating element can be designed as a continuous-flow heater, so that the water used to make the coffee first flows through the heating element, thus imparting thermal energy to the water. However, the heating element is also located on the brewing head, transferring thermal energy to the brewing head and heating it.

[0022] According to another embodiment, the heating element rests flat against the brewing head. The thermal energy is therefore transferred from the heating element to the brewing head primarily by conduction, because the heating element rests directly against the brewing head or is thermally coupled to the brewing head.

[0023] For example, the heating element can be attached to a flat surface of the brewing head by resting one surface of the heating element on the surface of the brewing head, and the heating element and brewing head are fixed relative to each other in this position, for example, by a screw connection or a clamp connection. It is possible to apply a thermally conductive paste between the adjacent surfaces of the heating element and the brewing head.

[0024] According to a further embodiment, the heating element is an electric heating element.

[0025] A coffee machine is typically powered by electricity, and part of the electrical energy can be used to heat the heating element thermally coupled to the brewing head to a predetermined temperature. The heating element is designed, for example, as a heating resistor, which can also be referred to as a heating conductor. A heating resistor is an electrical component that converts electrical energy into thermal energy, and whose temperature correlates with the supplied electrical power.

[0026] According to a further embodiment, the brewing head arrangement has a temperature detection unit which is thermally coupled to the brewing head and is designed to detect a temperature of the brewing head.

[0027] The temperature detection unit is, for example, a temperature sensor, which is arranged on the brewing head to measure the temperature of the brewing head. A thermistor, for example, can be used as a temperature sensor. This is a component with a temperature-dependent electrical resistance. The current temperature can be determined using the known relationship between temperature and the value of the electrical resistance at certain temperature values.

[0028] According to a further embodiment, the brewing head is movably mounted in the brewing head assembly in such a way that the brewing head can be moved within a predetermined range of motion along a direction of movement. The direction of movement includes a vertical directional component, which corresponds to the direction in which a portafilter assembly is pressed against the brewing head.

[0029] The heating element described here can be used particularly advantageously in a brewing head assembly with a movable brewing head. Because the heating element is located directly on the brewing head, the brewing head can be heated even if it moves and assumes different positions within the brewing head assembly. If the brewing head is moved, the heating element simply moves with it.

[0030] The brewing head assembly described here can be used, for example, in a portafilter machine, in which a defined amount of ground coffee (or coffee powder) is contained in a sieve. The sieve is coupled to the brewing head assembly, and the ground coffee is enclosed by the sieve and the brewing head. Pressurized water heated to a predetermined temperature is then dispensed from the brewing head. This water should flow through the entire ground coffee as evenly and uniformly as possible, and at the desired or predetermined water temperature, in order to achieve an optimal brewing process. The water leaves the sieve, and the ground coffee is retained. The sieve can now be removed from the brewing head assembly, and the used ground coffee disposed of.

[0031] The brewing head, including the heating element, is mounted movably within the brewing head assembly. This allows the brewing head to be moved when the fill level of the portafilter assembly with ground coffee varies. This type of coffee machine can handle different fill levels of a portafilter assembly with ground coffee. This coffee machine is particularly suitable for using different or different types of coffee beans, which require different amounts of ground coffee to prepare a coffee beverage.

[0032] According to one embodiment, the brewing head assembly comprises a suspension which holds the brewing head movably in a housing of the brewing head assembly, wherein the suspension comprises a guide element and an elastic element, wherein the guide element is coupled to the brewing head and is arranged to guide the brewing head in the housing along the direction of movement, and wherein the elastic element is arranged between the brewing head and the housing of the brewing head assembly in order to exert a force on the brewing head in the direction of the vertical direction component.

[0033] The guide element can be a pin or a rail, for example. The guide element is structurally designed to allow the brewing head a certain range of movement. If the guide element is designed as a pin, the pin can be guided, for example, in an opening in the housing. The pin can have two longitudinal sections with different diameters. The longitudinal section with a smaller diameter is guided in the opening in the housing. If the longitudinal section with the larger diameter hits the housing, the limit of the brewing head's range of movement is reached. Such a limit preferably exists in both directions of movement of the brewing head, i.e. upwards and downwards.

[0034] For example, the guide element can be dimensioned so that the brewing head can move by a few millimeters, e.g. 5 mm or up to 1 cm.

[0035] The elastic element is arranged in the brewing head assembly in such a way that it forces the brewing head into an initial position, i.e. exerts a force on the brewing head so that it is moved into its initial position in the brewing head assembly.

[0036] Without any external force acting on the brewing head, the brewing head is returned to its starting position by the suspension. This starting position corresponds to the state when no portafilter is inserted into the brewing head assembly. When a portafilter with ground coffee is inserted into the brewing head assembly, the ground coffee in the portafilter presses against the nozzle and the brewing head. Depending on the amount of ground coffee in the portafilter and how far the portafilter is screwed into the brewing head assembly, a force is exerted on the brewing head. The ground coffee pushes the brewing head upwards from its starting position against the force exerted by the elastic element.

[0037] For example, the elastic element is a compression spring or a tension band, such as a rubber band. The elastic element exerts a force on the brewing head in the form of a compressive or tensile force. This force counteracts the compressive force or vertical movement exerted by the portafilter assembly during insertion into the brewing head assembly.

[0038] According to a further embodiment, the elastic element is a compression spring. The compression spring can be pre-tensioned.

[0039] The preload of the compression spring determines the force that the brewing head exerts when moving against the compression force of the compression spring. With this force, the brewing head presses the ground coffee in the sieve of the portafilter assembly. According to another aspect, a coffee machine with a brewing head assembly is specified. The brewing head assembly is a brewing head assembly as described above and below. The coffee machine is, in particular, a so-called portafilter machine.

[0040] According to one embodiment, the coffee machine further comprises a portafilter assembly with a sieve, wherein the portafilter assembly is selectively insertable into and removable from the brewing head assembly, wherein the brewing head assembly is designed such that, in an inserted state of the portafilter assembly, the shower of the brewing head extends into a receiving volume of the sieve and rests on the ground coffee.

[0041] This means that the pressure on the nozzle is not exerted directly by the sieve or portafilter against the force of the elastic element, for example, against the pressure of the compression spring, but rather is exerted via the ground coffee onto the nozzle of the brewing head. This allows the ground coffee to be pressed into the receiving volume of the sieve if necessary. The ground coffee in the portafilter assembly is pressed according to the force of the elastic element.

[0042] This ensures that the shower rests on the ground coffee with a predefined force before and after the brewing process, even if the filling level of the sieve with ground coffee varies within a certain range.

[0043] It is conceivable for the brewing head assembly to have an adjustment option for the pressure force exerted by the elastic element. For this purpose, an adjusting screw can be arranged on the brewing head, which increases or decreases the preload of the elastic element. In this way, the pressure force exerted on the ground coffee is also varied. According to a further embodiment, the brewing head has a seal, wherein the seal is arranged circumferentially on a lateral outer wall of the brewing head and, when the portafilter assembly is inserted, seals against an inner surface of the sieve.

[0044] The height of the sieve and the depth of penetration of the brewing head into the receiving volume of the sieve for ground coffee are designed in such a way that the seal is always at least partially in contact with the inner surface of the sieve at all permitted filling levels of the sieve with ground coffee and also when the brewing head moves during the brewing process, thus sealing the receiving volume against the unwanted leakage of liquid.

[0045] The seal preferably extends continuously over the entire circumference of the side outer wall of the brewing head.

[0046] According to a further embodiment, the suspension comprises a plurality of guide elements and a plurality of elastic elements.

[0047] The multiple guide elements are arranged at a distance from one another on the brewing head and the brewing head assembly. For example, the guide elements are arranged equidistant from one another, thereby guiding the brewing head in a defined direction of movement. Likewise, the elastic elements are arranged equidistant from one another in order to exert the most evenly distributed force possible on the brewing head and the ground coffee.

[0048] However, the brewing head can also be mounted with some mechanical play in the brewing head assembly so that the brewing head, for example, allows a tilting movement relative to the direction of movement or pressing direction of the portafilter assembly, whereby the position and orientation of the brewing head can be adjusted to the surface of the ground coffee in the sieve.

[0049] According to a further embodiment, the guide element is a pin which is attached to the brewing head and is movable relative to the housing.

[0050] For example, the pin extends through an opening in a wall of the housing and is movable in this opening in the longitudinal direction of the pin.

[0051] According to a further embodiment, the elastic element is a compression spring.

[0052] A compression spring can, for example, be designed as a spiral spring and offers resistance or force to an applied force.

[0053] The compression spring is arranged in the brewing head assembly in such a way that it exerts a compressive force on the brewing head across the entire predetermined range of movement of the brewing head and presses the brewing head against the pressing direction of the portafilter assembly. When a portafilter assembly is inserted into the brewing head assembly and pressed against the brewing head, the brewing head exerts a compressive force on the ground coffee in the sieve of the portafilter assembly as soon as the portafilter assembly has reached a corresponding position. If the portafilter assembly is pressed further against the compressive force of the brewing head, the brewing head gives way when the force exerted by the portafilter assembly on the brewing head exceeds the compressive force of the compression spring and the brewing head moves into the brewing head assembly in the pressing direction of the portafilter assembly.

[0054] According to a further embodiment, the elastic element is arranged to exert a compressive force on the brewing head over the entire predetermined range of movement of the brewing head in the brewing head arrangement along the direction of movement. A coffee machine with a brewing head arrangement as described here makes it possible to use a portafilter arrangement with different fill levels of the ground coffee in the sieve. It is conceivable that ground coffee from different types of coffee beans is used for successive brewing processes, and the fill level of the ground coffee in the sieve varies from brewing process to brewing process. The elastic element exerts a force on the brewing head and holds the brewing head in its starting position. If the portafilter arrangement is inserted into the brewing head arrangement, the portafilter arrangement, with the ground coffee contained therein, moves towards the brewing head until the ground coffee rests against the brewing head.If the portafilter assembly is moved further in this state, the ground coffee is pressed against the underside of the brewing head, i.e., against the shower head. If the force exerted by the portafilter assembly on the brewing head exceeds the force exerted by the elastic element, the brewing head moves with the portafilter assembly. In other words, the brewing head is moved in a direction opposite to the force exerted by the elastic element.

[0055] The coffee machine described here is, in particular, a so-called portafilter machine. In this case, the portafilter assembly is typically inserted into the brewing head assembly with a rotating motion. During this rotating motion, the portafilter assembly is moved toward the brewing head assembly to enclose a space between the portafilter assembly and the brewing head assembly. This space contains the ground coffee, which is then perfused with pressurized water heated to a predetermined temperature to brew the coffee beverage.

[0056] The movable brewing head allows for the pressure applied to the ground coffee to be controlled and, in particular, takes into account the fact that the fill level of the ground coffee in the sieve can vary. The movable brewing head can react precisely to this varying fill level while still maintaining a predetermined pressure on the ground coffee within a certain fill level range.

[0057] Short description of the characters

[0058] Some details are described in more detail below using the attached drawings. The illustrations are schematic and not to scale. Like reference numerals refer to like or similar elements. They show:

[0059] Fig. 1 is a schematic representation of a portafilter arrangement.

[0060] Fig. 2 is a schematic representation of a brewing head arrangement with a portafilter arrangement mounted therein.

[0061] Fig. 3 is a schematic representation of a brewing head.

[0062] Fig. 4 is a schematic representation of the brewing head from Fig. 3 from a different perspective.

[0063] Fig. 5 is a schematic representation of a brewing head arrangement according to a first variant with a brewing head and a heating element in a first state.

[0064] Fig. 6 is a schematic representation of the brewing head arrangement from Fig. 5 in a second state.

[0065] Fig. 7 is a schematic representation of a brewing head assembly according to a second variant with a brewing head and a heating element in a first state. Fig. 8 is a schematic representation of the brewing head assembly from Fig. 7 in a second state.

[0066] Fig. 9 is a schematic representation of a coffee machine with a brewing head arrangement.

[0067] Detailed description

[0068] Fig. 1 shows a portafilter arrangement 10. The portafilter arrangement 10 has a portafilter 20 and a sieve 30. The portafilter 20 consists of a body 23 or a portafilter body and a handle 21. An outlet 22 is located on the body 23. The body 23 defines a space into which the sieve 30 is inserted. The sieve 30 is usually cylindrical. A circumferential side wall laterally delimits a receiving volume 31. The side wall has an inner surface 32 and the inner surface 32 encloses the receiving volume 31. The sieve 30 further has a collar or widening 33. The collar 33 extends circumferentially at an upper opening of the receiving volume 31. The sieve 30 is inserted into the portafilter 20. The bottom of the sieve 30 is provided with a plurality of small holes.Pressurized water is forced into the receiving volume 31, flows through the ground coffee, absorbs aroma and flavor substances from the ground coffee, and leaves the receiving volume 31 through the holes in the bottom of the sieve 30. The prepared coffee beverage flows out of the outlet 22.

[0069] A portafilter arrangement 10 as shown in Fig. 1 is known in connection with so-called portafilter machines.

[0070] Fig. 2 shows a brewing head arrangement 40 with a

[0071] Portafilter assembly 10. The portafilter assembly 10 is inserted into the brewing head assembly 40, for example, by a rotational movement 24. When the rotational movement 24 is performed, for example, by rotating the portafilter assembly 10 on the handle 21, the portafilter assembly 10 simultaneously performs a vertical movement 25 and is pressed toward the brewing head 50 and the shower 52.

[0072] When the portafilter assembly 10 is inserted, the nozzle 52 of the brewing head 50 rests on the ground coffee in the sieve 30. Depending on the fill level of the ground coffee in the sieve 30, the brewing head 50 is moved in the housing 42 in the direction of arrow 25 of the vertical movement of the portafilter assembly 10.

[0073] In some examples of the brewing head assembly 40 described here, the brewing head 50 is movably mounted in the housing 42 and can thus respond to varying fill levels of the ground coffee in the sieve 30. This results in the brewing head 50 being pressed onto the surface of the ground coffee with a nearly constant force in a specific area. The mechanism of the brewing head, which serves to fulfill this function, will now be described with reference to Fig. 3 and Fig. 4.

[0074] Fig. 3 shows a perspective view of a brewing head assembly 40. The brewing head assembly 40 has a housing 42. A suspension 44 and an elastic element 46 in the form of a compression spring are arranged in the housing 42. The brewing head 50 is also arranged in the housing 42 and movably mounted therein.

[0075] The shower 52 is located on the underside of the brewing head 50. The shower 52 releases pressurized, heated water onto the ground coffee contained in the sieve 30. The shower 52 is surrounded by an outer wall 53. A seal 54 is arranged circumferentially on the outer wall 53. When the portafilter assembly is connected to the brewing head assembly, as shown in Fig. 2, the brewing head 50 extends into the sieve 30, and the seal 54 seals with the inner surface 32 of the sieve 30.

[0076] Fig. 4 shows a perspective view of the brewing head assembly 40 from Fig. 3. A guide element 45 in the form of a pin and an elastic element 46 in the form of a compression spring are shown in the housing 42. Of course, the brewing head assembly 40 can have more than one guide element and one elastic element, although only one guide element and one elastic element are shown in Fig. 4.

[0077] The brewing head 50 is mounted in the housing 42 such that the brewing head 50 can move in both directions along the direction of movement shown by the arrow 47. The compression spring 46 presses the brewing head downward. When a portafilter assembly is inserted into the brewing head assembly, as shown in Fig. 2, the ground coffee presses the brewing head upward against the force exerted by the compression spring 46. The pin 45 has a head which is arranged outside the housing 42. The longitudinal axis of the pin 45 runs along the direction of movement 47 of the brewing head 50. The head of the pin, which is arranged outside the housing 42, limits the downward movement of the brewing head. The pin 45 extends through an opening in the housing 42. The pin 45 is designed such that it limits a range of movement of the brewing head 50.If, for example, the brewing head 50 is pushed upwards, at some point an end face or a stop of the pin 45 hits the housing 42 and stops the upward movement of the brewing head 50.

[0078] For reasons of clarity, Fig. 4 shows only part of the mechanism for moving the brewing head 50. As already described above, the brewing head assembly can have several guide elements and elastic elements, which can be arranged spaced apart from one another on the brewing head and the housing. Furthermore, the brewing head assembly has a connection for a water hose through which the heated and pressurized water is supplied to the brewing head. This water hose is not shown here for reasons of clarity, although the person skilled in the art will have knowledge of how to use and connect such a water hose based on the available prior art.

[0079] Fig. 5 shows a cross-sectional view of a brewing head assembly 40. The brewing head 50 is mounted in the housing 42 such that the brewing head 50 can perform a vertical movement. This vertical movement is enabled by guide elements 45, on which an elastic element 46 in the form of a compression spring is arranged to press the brewing head 50 downward from the upper wall of the housing 42. The brewing head 50 is connected to the guide elements 45. When the brewing head 50 moves vertically, the guide elements 45 move with respect to the upper wall of the housing 42 against the compressive force of the elastic elements 46.

[0080] In Fig. 5, the brewing head arrangement 40 is shown in a first state in which the brewing head 50 has reached its lowest point, i.e., is pressed maximally in the direction of the coffee powder in the receiving volume 31 of the sieve 30. This state can be seen in that a lower limit 48 of the guide elements 45 rests on the housing 42, thus preventing further movement of the brewing head in the direction of the sieve 30. The shower 52 of the brewing head 50 rests on the coffee powder in the sieve 30. Furthermore, Fig. 5 shows that the seal 54, which runs circumferentially around a lateral surface of the brewing head 50, rests against the inner surface of the sieve 30 and seals the receiving volume 31.

[0081] A heating element 80 is arranged on the rear side of the brewing head 50, i.e., on the surface of the brewing head 50 opposite the shower 52. The heating element 80 rests flat on the rear side of the brewing head 50 and is in direct thermal contact with the brewing head 50. The heating element 80 can be heated by supplying electrical energy and thus transfers thermal energy to the brewing head 50. The water flowing via the water line 41 through the brewing head 50 and the shower 52 thus loses less thermal energy. Ideally, the heating element 80 heats the brewing head 50 to the temperature of the hot water used for coffee preparation, so that there is no temperature gradient between the hot water and the brewing head.

[0082] The brewing head assembly has a control unit 70. The control unit 70 can be part of the brewing head assembly 40 or the coffee machine that includes the brewing head assembly 40. The control unit 70 is coupled to a temperature sensing unit 85. The temperature sensing unit 85 is thermally coupled to the brewing head 50 to sense a temperature of the brewing head 50. The temperature sensing unit 85 transmits a sensed signal to the control unit 70. The sensed signal corresponds to the current temperature of the brewing head 50. Based on the current temperature of the brewing head 50 and a predetermined temperature value, the control unit 70 determines the amount of electrical energy that must be supplied to the heating element 80 to heat the brewing head 50 to the predetermined temperature value.For this purpose, the control unit 70 may be coupled to an actuator for supplying electrical energy to the heating element 80 in order to selectively increase or decrease the amount of electrical energy supplied to the heating element 80.

[0083] Fig. 6 shows the brewing head arrangement from Fig. 5, but with the difference that the brewing head 50 is in a different state than shown in Fig. 5.

[0084] In Fig. 6, pressurized water is fed from the brewing head into the receiving volume 31 via the water line 41. The water pressure slightly lifts the brewing head 50, which can be seen from the guide elements resting against the upper limit 49. This creates a gap 55 between the shower head and the coffee powder in the receiving volume 31. This gap contributes to the water being evenly distributed over the surface of the coffee powder in the receiving volume 31.

[0085] Regardless of the position of the brewing head 50 or whether the brewing head 50 is moved along the intended direction of movement, the heating element 80 moves with the brewing head 50. Thus, the heating element 80 can supply thermal energy to the brewing head 50 in any position.

[0086] Figs. 7 and 8 show an alternative embodiment of a brewing head assembly 40. In this embodiment, the brewing head 50 is not necessarily spring-mounted, but is pressed onto the coffee powder in the inserted portafilter assembly 10 via a lever assembly 90. It is of course also conceivable in this alternative embodiment for the brewing head 50 in the brewing head assembly 40 to be spring-mounted in addition to the movement via the lever assembly 90 in order to adapt the pressure of the brewing head 50 on the coffee powder in the portafilter assembly independently of the fill level of the sieve with coffee powder.

[0087] In Fig. 7, the heating element 80 is arranged so as to rest flatly on the back or top of the brewing head 50 in order to heat the brewing head 50 to a desired temperature as described above. In the position shown in Fig. 7, the brewing head 50 is not resting on the coffee grounds in the portafilter assembly 10. This can also be seen from the fact that the lever assembly 90 is in an open state. Furthermore, in Fig. 7, the sieve is not resting against the seal 54.

[0088] Fig. 8 shows the embodiment of Fig. 7 in a closed state. The lever assembly 90 has been brought into the closed state, whereby the brewing head 50 has been inserted into the sieve of the portafilter assembly 10 and the collar of the sieve rests against the seal 54. In the embodiment of Figs. 7 and 8, the heating element 80 is also arranged on the movable brewing head 50 and thermally coupled thereto, as already described with reference to Figs. 5 and 6.

[0089] Fig. 9 schematically shows a coffee machine 100 with a brewing head assembly 40. The brewing head assembly 40 is in particular a brewing head assembly 40 as shown in Figs. 2 and 5 to 8 and with a brewing head 50 as shown in Figs. 3 and 4.

[0090] Even though a movable brewing head 50 was used in Figs. 3 to 8 and the heating element 80 was described in connection with a movable brewing head 50, it should be expressly pointed out that the heating element 80 does not necessarily have to be used with a movable brewing head 50, but rather can also be used with a static brewing head 50 that is not movable with respect to the brewing head arrangement 40.

[0091] Additionally, it should be noted that "comprising" or "having" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limitations.

[0092] List of reference symbols

[0093] 10 portafilter arrangement

[0094] 20 portafilters

[0095] 21 Handle

[0096] 22 Outlet

[0097] 23 Corpus

[0098] 24 Rotational movement

[0099] 25 Contact direction, vertical movement

[0100] 30 sieve

[0101] 31 recording volume

[0102] 32 inner surface

[0103] 33 collar, widening

[0104] 40 Brewing head arrangement

[0105] 41 water pipe

[0106] 42 housings

[0107] 44 Suspension

[0108] 45 Guide element, pin

[0109] 46 elastic element, spring

[0110] 47 Direction of movement, spring travel

[0111] 48 lower limit

[0112] 49 upper limit

[0113] 50 brewing head

[0114] 52 Shower

[0115] 53 Exterior wall

[0116] 54 Seal

[0117] 55 space

[0118] 70 Control unit

[0119] 80 heating element

[0120] 85 Temperature detection unit 90 Lever arrangement

[0121] 100 coffee machines

Claims

Patent claims 1. A brewing head assembly (40) for a coffee machine (100), the brewing head assembly (40) comprising: a brewing head (50) with a shower (52); a heating element (80); wherein the heating element (80) is arranged on the brewing head (50) and is configured to heat the brewing head (50) before and / or during a coffee beverage preparation process.

2. Brewing head arrangement (40) according to claim 1, wherein the heating element (80) is arranged on the brewing head (50) on a rear side of the brewing head (50) opposite the shower (52).

3. Brewing head arrangement (40) according to claim 1 or 2, wherein the heating element (80) lies flat against the brewing head (50).

4. Brewing head assembly (40) according to one of the preceding claims, wherein the heating element (80) is an electrical heating element.

5. Brewing head arrangement (40) according to one of the preceding claims, further comprising a temperature detection unit (85) which is thermally coupled to the brewing head (50) and is designed to detect a temperature of the brewing head (50).

6. Brewing head arrangement (40) according to one of the preceding claims, wherein the brewing head (50) is movably mounted in the brewing head arrangement (40) in such a way that the brewing head (50) can be moved within a predetermined range of movement along a direction of movement (47); wherein the direction of movement (47) contains a vertical directional component which corresponds to a pressing direction (25) of a portafilter arrangement (10) on the Brewing head (50).

7. Brewing head assembly (40) according to claim 6, wherein the brewing head assembly (40) has a suspension (44) which holds the brewing head (50) movably in a housing (42) of the brewing head assembly (40); wherein the suspension (44) has a guide element (45) and an elastic element (46); wherein the guide element (45) is coupled to the brewing head (50) and is arranged to guide the brewing head (50) in the housing (42) along the direction of movement (47); wherein the elastic element (46) is arranged between the brewing head (50) and the housing (42) of the brewing head assembly (40) in order to exert a force on the brewing head (50) in the direction of the vertical direction component.

8. Brewing head assembly (40) according to claim 7, wherein the elastic element (46) is a compression spring.

9. Coffee machine (100) with a brewing head arrangement (40) according to one of the preceding claims.

10. The coffee machine (100) according to claim 9, further comprising a portafilter assembly (10) with a sieve (30); wherein the portafilter assembly (10) is selectively insertable into and removable from the brewing head assembly (40); wherein the brewing head assembly (40) is configured such that, in an inserted state of the portafilter assembly (10), the shower (52) of the brewing head (50) extends into a receiving volume (31) of the sieve (30) and rests on the ground coffee.

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