Coffee machine with movably supported brewing head

Abstract

Disclosed is a coffee machine (100) having a brewing head arrangement (40). The brewing head arrangement (40) has a brewing head (50) with a shower (50). 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 along a direction of movement (47) within a predetermined range of movement. The direction of movement (47) includes a vertical directional component corresponding to a pressing direction of a portafilter arrangement (10) on the brewing head (50).

Description

[0001] Coffee machine with movable brewing head

[0002] Technical area

[0003] The present description relates to the technical field of the mechanical preparation of coffee beverages, in particular the description relates to a coffee machine with a brewing head arrangement in which a brewing head is movably mounted.

[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] 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.

[0012] Description

[0013] The object can be considered to improve a coffee beverage production process in which pressurized water is forced through a predetermined amount of ground coffee. This object is achieved by the subject matter of the independent claim. Further embodiments emerge from the dependent claims and the following description.

[0014] According to the invention, a coffee machine with a brewing head assembly is provided. The brewing head assembly has a brewing head with a spray nozzle. 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 pressing direction of a portafilter assembly against the brewing head.The brewing head assembly has a suspension which holds the brewing head movably in a housing of the brewing head assembly, wherein the suspension has 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 directional component. The coffee machine further has a portafilter assembly with a sieve, wherein the portafilter assembly can be selectively inserted into and removed from the brewing head assembly, wherein the brewing head assembly is designed such that, when the portafilter assembly is inserted, the shower of the brewing head extends into a receiving volume of the sieve and rests on the ground coffee.The brewing head has a seal, wherein the seal is arranged circumferentially on a lateral outer wall of the brewing head and seals against an inner surface of the sieve when the portafilter assembly is inserted.

[0015] The coffee machine described here is 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 brewing head. Pressurized water heated to a specified temperature is then released from the brewing head. This water should flow as evenly and evenly as possible through the entire ground coffee to ensure optimal brewing. 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 can be disposed of.

[0016] The brewing head is movably mounted 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.

[0017] 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. 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] According to one embodiment, the elastic element is a compression spring, wherein the compression spring is under a prestress.

[0022] The preload of the compression spring determines the force the brewing head exerts when moving against the compression force of the compression spring. With this force, the brewing head presses against the ground coffee in the sieve of the portafilter assembly. The elastic element is arranged so that, due to the preload, it pushes the brewing head toward the ground coffee in the sieve. In other words, the elastic element exerts a force on the brewing head to move the brewing head from a retracted position to an extended position.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] It is conceivable that the brewing head assembly has an adjustment option for the pressure 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 exerted on the ground coffee is also varied.

[0027] The brewing head has a seal, wherein the seal is arranged circumferentially on a lateral outer wall of the brewing head and seals against an inner surface of the sieve when the portafilter assembly is inserted.

[0028] 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.

[0029] The seal preferably extends continuously over the entire circumference of the side outer wall of the brewing head.

[0030] The seal is preferably arranged on a cylindrical section of the brewing head. When the brewing head moves in the sieve along its direction of movement (into or out of the sieve), the seal is moved together with the brewing head relative to the inner wall of the sieve. Because the seal is arranged on a cylindrical section of the brewing head, the sealing effect remains constant whether the brewing head moves in the sieve (which also has a cylindrical outer wall) or is at different heights. Further preferably, the seal is arranged on the brewing head in such a way that the seal does not move relative to the brewing head when the brewing head is moved relative to the sieve.

[0031] According to a further embodiment, the suspension comprises a plurality of guide elements and a plurality of elastic elements.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] According to a further embodiment, the elastic element is a compression spring.

[0037] A compression spring can, for example, be designed as a spiral spring and offers resistance or force to an applied force.

[0038] 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.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.

[0039] A coffee machine with a brewing head assembly as described here allows the use of a portafilter assembly with varying fill levels of ground coffee in the sieve. It is conceivable that ground coffee from different coffee bean varieties 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. When the portafilter assembly is inserted into the brewing head assembly, the portafilter assembly, 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.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.

[0040] The coffee machine described here is, in particular, a so-called portafilter machine. Here, the portafilter assembly is typically inserted into the brewing head assembly with a rotary movement. During this rotary movement, the portafilter assembly is moved towards 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 permeated with pressurized water heated to a predetermined temperature to brew the coffee beverage. The movable brewing head makes it possible to dose the pressure force acting on the ground coffee and, in particular, takes into account 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 and yet rest on the ground coffee with a predetermined force within a certain fill level range.

[0041] Short description of the characters

[0042] 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:

[0043] Fig. 1 is a schematic representation of a portafilter arrangement.

[0044] Fig. 2 is a schematic representation of a brewing head arrangement with a portafilter arrangement mounted therein.

[0045] Fig. 3 is a schematic representation of a brewing head.

[0046] Fig. 4 is a schematic representation of the brewing head from Fig. 3 from a different perspective.

[0047] Fig. 5 is a schematic representation of a coffee machine with a brewing head arrangement.

[0048] Detailed description 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 a widened portion 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 multitude 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.

[0049] A portafilter arrangement 10 as shown in Fig. 1 is known in connection with so-called portafilter machines.

[0050] Fig. 2 shows a brewing head assembly 40 with a portafilter assembly 10 coupled thereto. 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.

[0051] In the inserted state of the portafilter assembly 10, the shower 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

[0052] Direction of arrow 25 of the vertical movement of the portafilter arrangement 10.

[0053] A special aspect of the brewing head assembly 40 described here is that the brewing head 50 is movably mounted in the housing 42 and can thus react to different fill levels of the ground coffee in the sieve 30 and is pressed onto the surface of the ground coffee in a certain area with a virtually constant force. The mechanism of the brewing head, which serves to fulfill this function, will now be described with reference to Fig. 3 and Fig. 4.

[0054] 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.

[0055] The shower 52 is located on the underside of the brewing head 50. The shower 52 releases pressurized, heated water onto the ground coffee in the sieve 30. The shower 52 is surrounded by an outer wall 53. A seal 54 is arranged around the outer wall 53.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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 arrangement can have a plurality of guide elements and elastic elements, which can be arranged at a distance from one another on the brewing head and the housing. Furthermore, the brewing head arrangement 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 know from the available prior art how to use and connect such a water hose. Fig. 5 schematically shows a coffee machine 100 with a brewing head arrangement 40. The brewing head arrangement 40 is in particular a brewing head arrangement 40 as shown in Fig. 2 and with a brewing head 50 as shown in Figs. 3 and 4.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.

[0060] List of reference symbols

[0061] 10 portafilter arrangement

[0062] 20 portafilters

[0063] 21 Handle

[0064] 22 Outlet

[0065] 23 Corpus

[0066] 24 Rotational movement

[0067] 25 Contact direction, vertical movement

[0068] 30 sieve

[0069] 31 recording volume

[0070] 32 inner surface

[0071] 33 collar, widening

[0072] 40 Brewing head arrangement

[0073] 42 housings

[0074] 44 Suspension

[0075] 45 Guide element, pin

[0076] 46 elastic element, spring

[0077] 47 Direction of movement, spring travel

[0078] 50 brewing head

[0079] 52 Shower

[0080] 53 Exterior wall

[0081] 54 Seal

[0082] 100 coffee machines

Claims

Patent claims 1. A coffee machine (100) with a brewing head assembly (40), wherein the brewing head assembly (40) has a brewing head (50) with a shower (52); wherein the brewing head (50) is movably mounted in the brewing head assembly (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 assembly (10) against the brewing head (50); wherein the brewing head assembly (40) has a suspension (44) which movably holds the brewing head (50) 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 arrangement (40) in order to exert a force on the brewing head (50) in the direction of the vertical directional component; further comprising a portafilter arrangement (10) with a sieve (30); wherein the portafilter arrangement (10) is selectively insertable into and removable from the brewing head arrangement (40); wherein the brewing head arrangement (40) is designed such that, in an inserted state of the portafilter arrangement (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; wherein the brewing head (50) has a seal (54); wherein the seal is on a lateral outer wall (53) of the brewing head (50); is arranged circumferentially and in the inserted state of the Portafilter arrangement (10) seals against an inner surface (32) of the sieve (30).

2. Coffee machine (100) according to claim 1, wherein the elastic element (46) is a compression spring; wherein the compression spring is under a prestress.

3. Coffee machine (100) according to claim 1 or 2, wherein the suspension (44) has a plurality of guide elements (45) and a plurality of elastic elements (46).

4. Coffee machine (100) according to one of the preceding claims, wherein the guide element (45) is a pin which is attached to the brewing head (50) and is movable relative to the housing (42).

5. Coffee machine (100) according to one of the preceding claims, wherein the elastic element (46) is arranged to exert a compressive force on the brewing head (50) over the entire predetermined range of movement of the brewing head (50) in the brewing head arrangement (40) along the direction of movement (47).

Images