Coffee machine and method of preparing coffee beverage

Abstract

The invention relates to a coffee machine (1) comprising a machine unit (2) and a filter carrier unit (50) which can be removed from the machine unit (2) and has a coffee receiving space (51) and a brewing filter (52), the machine unit (2) comprises a movably mounted brewing piston (4), a brewing water preparation unit (60) for generating hot water and outputting pressurized hot water into a coffee receiving space (51) of the filter carrier unit (50), and holding and guiding means (40) for receiving and holding the filter carrier unit (50) on the machine unit (2). The holding and guiding means (40) comprise linear guiding means (41) for linearly introducing the filter carrier unit (50) into the machine unit (2).

Description

Technical Field

[0001] The invention belongs to the field of coffee machines and relates to a coffee machine according to the preamble of independent claim 1, the coffee machine having a machine unit and a mobile filter device that can be removed from the machine unit for producing, in particular brewing, a coffee beverage. The invention also relates to a method for producing, in particular brewing, a coffee beverage. Background Art

[0002] A coffee machine with a portable filter device (abbreviated as portable filter) is also called a portable filter machine. Portable filter machines are common among coffee machines. Portable filter machines exist for both private households and the catering industry. Portable filter machines operate in a semi-automatic manner through certain operating steps that are implemented manually. Therefore, according to the common state of the art, the portable filter that receives the coffee powder is manually removed from the coffee machine in order to fill the coffee powder before the brewing process and to remove the coffee grounds after the brewing process.

[0003] In particular, coffee powder in this specification is understood to be coffee that has been ground, thus ground coffee. Coffee grounds in this specification are understood to be the compacted residue after the brewing process, which is also referred to as coffee sediment.

[0004] With portafilter machines, ground coffee is filled into a portafilter outside the coffee machine. Some portafilter devices include an attached grinder. Here, the portafilter, separate from the coffee machine, is held under the dispensing opening of the grinder for filling with ground coffee and is then manually fastened to the coffee machine in the brewing position.

[0005] This is in contrast to coffee machines which are operated in a fully automatic manner and with which the ground coffee enters the brewing chamber directly from an integrated grinder and the coffee grounds are automatically discharged into an integrated catch container after the brewing program has ended.

[0006] Typically, the portafilter is fastened to the coffee machine via a quick-release fastener. Known portafilters comprise a portafilter housing having several radially outwardly projecting protrusions which interact with guide profiles provided on a portion of the machine at the connection section and form a bayonet fastener between the portafilter and the connection section in this context. In order to attach the portafilter to the coffee machine, the portafilter is applied to the connection section from below in such a way that the protrusions on the portafilter engage in the guide profiles. The portafilter is then fastened to the coffee machine while applying a rotational movement with the handle.

[0007] This type of fastening mechanism has the disadvantage that the attachment of the portafilter is rather cumbersome and difficult. For example, the portafilter must be applied to the connecting section from below in the correct angular position so that the projection engages in the guide contour. In addition, increased forces are required to fasten the portafilter by a rotational movement. If the guide contour is soiled, for example with coffee grounds, then in some cases the portafilter cannot be fastened in the desired rotational position.

[0008] For example, EP 3954256 A1 describes a portable filter machine with a portable filter as is known from the prior art.

[0009] The coffee powder is compacted in the coffee receiving space of the portafilter device, which is performed before the brewing process and is particularly important, for example, for preparing espresso with crema, and for some portafilter machines this is achieved by pressing the portafilter upwards against a stationary tamper fastened to the coffee machine. Such portafilter machines usually use different filter baskets by which the amount of coffee powder used for the brewing process can be varied.

[0010] However, portafilter machines for compacting coffee powder (so-called "tamping") are also known, which machines comprise a movable brewing piston which can be pressed downwards towards the portafilter via a manual lever. Summary of the invention

[0011] The object of the present invention is therefore to propose a coffee machine with a portafilter device which allows a simple and quick attachment of the portafilter device to the coffee machine.

[0012] Furthermore, it is an object of the present invention to propose a coffee machine which allows a defined compaction of the coffee powder, even given different fillings of the portafilter with coffee powder and without using filter inserts of different sizes.

[0013] Another object is to provide a coffee machine which ensures simple, rapid and, in particular, reliable filling of a portafilter device with coffee powder.

[0014] Another object is to provide a coffee machine with a grinder that allows a residue-free change of the coffee type.

[0015] At least one of the objects is achieved by the features of the independent claim. The dependent claims, the description and the drawings contain special embodiments and further developments of the invention.

[0016] The coffee machine comprises a machine unit and a portable filter device having a coffee receiving space and a brewing filter, the portable filter device being removable from the machine unit. The machine unit comprises a movably mounted brewing piston, a brewing water preparation device for producing hot water and delivering the hot water under pressure to the coffee receiving space of the portable filter device, and a holding and guiding device for receiving and holding the portable filter device on the machine unit.

[0017] "Removable" means in particular that the mobile filter device can be completely separated from the machine unit without being permanently connected to the machine unit. In this context, the mobile filter device can in particular be removed from the machine unit or attached to the machine unit via a handle. In particular, the attachment and removal of the mobile filter device is achieved in a tool-free manner.

[0018] In particular, the portafilter device can be removed from the machine unit for removing coffee grounds after a brewing process. In addition, the portafilter device unit can also be removed from the machine unit in order to fill the portafilter device with coffee powder.

[0019] The invention is characterized in that the holding and guiding device comprises a linear guide device for linear, ie rectilinear, insertion of the mobile filter device into the machine unit.

[0020] In particular, the mobile filter device can also be withdrawn again from the machine unit via the linear guide by a corresponding linear, ie straight, reverse movement.

[0021] In particular, the linear guide comprises two parallel running guide profiles, such as guide rails, which are spaced apart from one another. The guide profiles can form guide grooves or guide channels.

[0022] The linear guide device is in particular arranged below the brewing unit and possibly below the device for conveying coffee powder, in particular the device for producing and conveying coffee powder.

[0023] The linear guide can be arranged on the carrier plate or be part of the carrier plate.The brewing unit and possibly the device for conveying coffee powder, in particular the device for producing and conveying coffee powder, can be arranged or fastened on the carrier plate.

[0024] In particular, the portafilter device comprises a portafilter housing in which the coffee receiving space is arranged. Guide bodies, in particular at least two oppositely disposed guide bodies, which interact with the linear guide device to form a linear guide, are arranged laterally on the portafilter housing. The guide bodies are in particular designed as lateral guide rods, which extend in particular parallel to one another.

[0025] The linear movement performed via the linear guide is in particular horizontal.

[0026] In particular, the mobile filter device can be inserted into the machine unit via a linear guide along or parallel to the insertion plane. In particular, the insertion plane is aligned horizontally.

[0027] However, horizontal movement or insertion into the plane requires that the coffee machine or machine unit is supported on a horizontal support.

[0028] In particular, the linear guide is a sliding guide, with which the guide body slides in a linear guide or in a guide profile.

[0029] The portable filter device, which is mounted or held in a linear guide, can be moved in the machine unit into a brewing position for brewing coffee.

[0030] The portable filter device can be pushed or moved into the brewing position via a linear guide, in particular in a linear movement.

[0031] The brewing position is formed in the machine unit, in particular below the brewing unit. In particular, it corresponds to the position that the mobile filter device has or assumes during the brewing process.

[0032] According to a further development of the invention, the machine unit comprises means for conveying and in particular producing and conveying ground coffee into the coffee receiving space of the portafilter device.

[0033] The portable filter device, which is mounted or held in a linear guide, can be moved in the machine unit into a filling position for conveying ground coffee into a coffee receiving device of the portable filter device.

[0034] The portafilter device can be pushed or moved via the linear guide, in particular in a linear movement, into a filling position in which the coffee receiving space of the portafilter device can be filled with coffee powder.

[0035] The filling program is different from the brewing position. The filling position and the brewing position are located in a common horizontal plane.

[0036] The filling position is formed in the machine unit, in particular below the grinder. However, the filling position in the machine unit can also be formed below the coffee powder delivery device. The coffee powder delivery device can include a container for storing coffee powder, which container must be filled with coffee powder manually.

[0037] The portable filter device, which is mounted or held in a linear guide, can be moved in the machine unit between a filling position and a brewing position.

[0038] The portable filter device, which is pushed linearly into the machine unit via a linear guide, can be moved in the machine unit between a filling position and a brewing position.

[0039] The portable filter device is movable in the machine unit between a filling position and a brewing position, in particular in a plane, very particularly in a horizontal plane.

[0040] The movement of the mobile filter device between the filling position and the brewing position may be a linear movement. This is particularly the case when the mobile filter device is moved between the filling position and the brewing position in a linear guide.

[0041] The movement of the portafilter device between the filling position and the brewing position may be a pivoting movement, which will be described in more detail below.

[0042] Given the movement between the filling position and the brewing position in the linear guide, via which the portable filter device has been inserted into the machine unit, the portable filter device is mounted or held in the machine unit.

[0043] According to a first embodiment variant, the brewing position and the filling position are arranged one after the other along the insertion axis of the portafilter device.

[0044] In particular, the filling position is arranged after the brewing position in the insertion direction. To start a brewing program, the portafilter is pushed into the machine unit in a linear movement until the filling position is assumed, and after filling the portafilter with coffee powder, the portafilter is retracted into the brewing position in a linear reverse movement. After the brewing program is completed, the portafilter is completely pulled out of the machine unit as a continuation of the linear reverse movement.

[0045] Alternatively, the filling position can also be arranged before the brewing position in the insertion direction. To start the brewing program, the portafilter device is pushed into the machine unit in a linear movement until the filling position is assumed. After filling the portafilter device with coffee powder, the portafilter device is pushed further into the brewing position as a continuation of the linear insertion movement. After the brewing program is completed, the portafilter device is pulled completely out of the machine unit in a linear reverse movement, past the filling position.

[0046] According to this embodiment, the linear guide is attached to the machine unit, in particular in an immovable or stationary manner.

[0047] According to a second embodiment variant, the linear guide is pivotably mounted on the machine unit via a pivot axis arranged perpendicular to the insertion plane. The portable filter device pushed into the machine unit via the linear guide is pivotably mounted with the linear guide between a filling position and a brewing position.

[0048] In this case, the portable filter device can be inserted into a working position relative to the linear guide device, in which working position the portable filter device can be pivoted between a filling position and a brewing position relative to the device for conveying or producing and conveying coffee powder and relative to the brewing unit.

[0049] According to a further development of the invention, latching means can be provided which allow the mobile filter device to assume a latched position in one or more of the following positions:

[0050] - filling position (first embodiment variant);

[0051] - Brewing position (first embodiment variant);

[0052] - Working position (second embodiment variant).

[0053] The latching device is designed to position the mobile filter device in the respective position by assuming the latched position. The latching device in particular enables precise positioning in the respective position. The latching device in particular enables self-centering of the mobile filter device in the respective position.

[0054] In particular, the latching means is designed such that the portable filter unit can be pushed or pulled back further beyond the latching position, possibly by means of increased force.

[0055] The latching means can be, for example, a spring-loaded button or a ball, which engages in a groove of the linear guide in a corresponding position during the linear movement of the mobile filter device. The spring-loaded button or the ball can be arranged, for example, on the mobile filter device, in particular on the guide body. The groove can be arranged, for example, in a guide rail or a guide groove or a guide channel.

[0056] In particular, the recess comprises a chamfer in the insertion direction and opposite to the insertion direction, which simplifies the movement of the mobile filter device out of the latching position in both directions, that is to say reduces the forces. This is relevant in particular if the mobile filter device is to be moved further beyond the latching position.

[0057] According to a further development of the invention, a stop means as an insertion limit can be provided in the machine unit, in particular on the holding and guiding device or the linear guide, by means of which stop means the mobile filter device can be positioned in one of the following positions:

[0058] - filling position (first embodiment variant);

[0059] - Brewing position (first embodiment variant);

[0060] - Working position (second embodiment variant).

[0061] The locking means enables exact positioning of the mobile filter unit in the respective position, in particular by abutting the locking means.

[0062] In particular, the mobile filter device comprises a handle for manually inserting the mobile filter device into the machine unit and manually extracting the mobile filter device from the machine unit.

[0063] In particular, the coffee receiving space of the portafilter device can be formed by a filter basket with a brewing filter, which is integrated into the portafilter housing. In particular, the coffee receiving space of the portafilter device can be formed by a filter basket with a brewing filter, which is fixedly built into the portafilter housing. However, the filter basket can also be removable.

[0064] Since according to the invention a movably mounted brewing piston is pushed into the coffee receiving space of the portafilter device for compacting (tamping) the coffee powder and for closing the brewing chamber, no filter inserts of different sizes are required for different amounts of coffee powder.

[0065] The brewing piston is in particular part of a brewing unit which is formed in the machine unit and comprises a piston tamper. The piston tamper is arranged at the brewing side. In particular, the piston tamper is connected to a piston rod which is guided in a piston rod housing. The brewing piston and the piston rod housing are in particular part of a brewing unit in the machine unit.

[0066] In particular, the brewing unit together with the portafilter device forms a brewing group.

[0067] In particular, the brewing piston is driven. The drive can be realized manually, for example via a lever mechanism, or can also be carried out via a piston drive via a control device.

[0068] The piston drive may comprise an electric motor. The brewing piston may thus be driven by the electric motor via a drive shaft.

[0069] The piston drive may also comprise a hydraulic drive, by which a hydraulic pressure is established in the pressure chamber via a hydraulic fluid, such as water, which pushes the brewing piston into the brewing position. The hydraulic pressure may be, for example, between 2 and 3 bar.

[0070] The hydraulic drive can be a water pump of the brewing water preparation device of the machine unit. Therefore, the hydraulic fluid is water from a water tank of the brewing water preparation device. The drive here is achieved via the hydraulic pressure generated by the water pump and acting on the brewing piston.

[0071] The coffee receiving space or in particular the coffee receptacle formed in the coffee receiving space is arranged in a stationary or immovable manner in the machine unit, in particular during a brewing program. The same applies to portable filter devices.

[0072] The coffee receiving space of the portable filter device forms a particularly funnel-shaped widening towards the outside in the region of the receiver opening. The receiver opening corresponds to the opening pointing towards the brewing unit of the machine unit and through which the brewing piston and its piston tamper engage into the coffee receiving space surrounded by the brewing chamber. Usually, the filling of the coffee receiving space with coffee powder takes place via the receiver opening.

[0073] The funnel-shaped widening enables self-centering of the portafilter device in the brewing position due to the piston tamper which moves downwards and engages into the brewing piston in the coffee receiving space.

[0074] The device for producing and delivering ground coffee comprises in particular a grinder, such as a conical grinder.

[0075] The conical grinder is characterized by an inner stationary grinding cone and an outer driven grinding ring surrounding the grinding cone. The grinding ring is driven in particular by a drive member, such as an electric motor. In particular, a drive member of the drive member, such as a drive shaft, and a lateral surface of the grinding ring form a drive partner for driving the grinding ring. The lateral surface of the grinding ring is formed in particular with a rough pattern, such as corrugations or teeth.

[0076] The conical grinder is particularly designed and arranged in the machine unit so that the ground coffee powder falls downwards from the conical grinder and is not guided by gravity into the coffee receiving space arranged below of the mobile filter device which is pushed into the filling position in the machine unit.

[0077] With conventional conical grinders for driving the grinding cone, the coffee powder is guided downwards obliquely on an inclined guide surface. The guide surface is provided, among other things, due to the fact that a direct, in particular unguided, downward guidance of the coffee powder vertical device is not possible for space reasons. This is due, among other things, to the drive of the grinding cone, which is arranged below the grinding cone in the extension of the cone axis.

[0078] After the grinding process, a small amount of ground coffee still adheres to the guide surface, so that after changing the coffee beans, ground coffee residues from the initial grinding process of the previous grinding process still enter the portafilter. This disadvantage is overcome by the existing cone grinder.

[0079] For this purpose, the grinding ring and the grinding cone are arranged in particular in a housing. The housing can be one part or several parts. The grinding ring is rotatably mounted in the housing, in particular via a bearing, such as a ball bearing.

[0080] Starting from the cone base, the grinding cone tapers upwards. The stationary grinding cone is connected to the housing, in particular via a connecting web. The cone axis of the grinding cone is in particular vertically aligned.

[0081] Very particularly, the grinding cone is connected at its two cone ends to the housing, in particular in each case via a connecting web.

[0082] In particular, the connecting webs extend transversely to the (geometric) cone axis of the grinding cone. For example, the connecting webs starting from the cone axis can extend radially or in a star-shaped manner outwardly toward the housing.

[0083] In particular, one or more through openings for passing the coffee beans downwards into the grinder are formed between the connecting webs at the upper end of the grinding cone.

[0084] In particular, one or more through openings for passing the coffee powder downwards out of the grinder are formed between the connecting webs at the lower end of the grinding cone, ie the cone base.

[0085] The invention also relates to a method for brewing a coffee beverage with a coffee machine as described above. According to the definition, all types of coffee that can be prepared with a portafilter machine belong to the term coffee beverage. These are, for example, black coffee, espresso, strong coffee, super espresso, etc. Furthermore, according to the definition, all types of preparation with milk as an addition, such as cappuccino or latte macchiato, belong to the term coffee beverage. For this purpose, the coffee machine may also include milk preparation means, such as a milk frother.

[0086] For activating a brewing program and in particular also for selecting a coffee preparation type, the coffee machine can comprise an input device, for example with a display.

[0087] The machine unit also comprises control devices for operating individual components or devices, such as pumps, valves and possibly piston drives, grinders or input devices.

[0088] Thus, in particular, the piston drive is also controlled via the control device. For example, the amount or degree of coffee compaction can be set via an input device or a preset. The control device then controls the compaction pressure (piston pressure) exerted on the coffee powder via the piston drive based on the corresponding specification for coffee compaction (degree or amount of coffee compaction).

[0089] The method is characterized in that, for brewing coffee, the portafilter device is pushed into the machine unit via a linear guide by a linear movement and, after the brewing program is completed, is pulled out of the machine unit again in a linear reverse movement.

[0090] In the preparation of a brewing program, the portable filter device can be filled with coffee powder outside the machine unit and pushed into the machine unit in a linear movement into the brewing position.

[0091] Alternatively, the portable filter device can also be pushed into the machine unit in the empty state in a linear motion. Filling in the machine unit is achieved via integrated means for conveying, in particular for producing and conveying coffee powder.

[0092] According to a first embodiment variant, in which the filling position and the brewing position are arranged one after the other along the insertion axis, for brewing coffee the portafilter device is first pushed into the filling position via a linear guide in a linear movement and, after filling the coffee receiving space with coffee powder, is retracted into the brewing position in a linear reverse movement. In this case, the filling position is arranged after the brewing position in the insertion direction.

[0093] Alternatively, i.e. if the filling position is arranged in front of the brewing position in the insertion direction, for brewing coffee the mobile filter device can firstly be pushed into the filling position in a linear movement via a linear guide and, after filling the coffee receiving space with coffee powder, can be pushed further into the brewing position as a continuation of the linear insertion movement.

[0094] According to a second variant, in which the portafilter device is pivotable together with the linear guide, for brewing coffee the portafilter device is pushed into the machine unit via the linear guide in a linear motion and into a working position relative to the linear guide. For filling the coffee receiving space with coffee powder and brewing coffee, the portafilter device in the working position relative to the linear guide is pivoted together with the linear guide relative to the device for conveying or producing and conveying coffee powder and relative to the brewing unit between a filling position and a brewing position.

[0095] When the mobile filter device is pushed into the machine unit, the working position can be located outside the filling position, so that after insertion into the machine unit the mobile filter device must first be pivoted into the filling position and then into the brewing position. The filling position and the brewing position are therefore defined by the combination of the working position of the mobile filter device and the pivot position of the linear guide.

[0096] When the portafilter device is pushed into the machine unit, the working position can also correspond to the filling position given a corresponding pivot position, so that after filling with coffee powder the portafilter device only needs to be pivoted into the brewing position.

[0097] After the portafilter device filled with coffee powder has been positioned in the brewing position, the brewing program is started according to two embodiment variants by the piston drive advancing the brewing piston parallel to the piston axis in the direction of the coffee receiving space into its brewing position.

[0098] The piston axis is arranged in particular perpendicularly to the insertion direction or the insertion plane of the mobile filter device. In particular, the piston axis extends perpendicularly to the receiving opening of the mobile filter device.

[0099] The piston tamper of the brewing piston can perform the function of a coffee tamper or tamper by compacting or pushing the coffee in the coffee receiving space. The degree of coffee compaction can be determined by the piston pressure, which can be set by the control device.

[0100] The brewing piston remains in its brewing position during the brewing program and forms a (closed) brewing chamber together with the portable filter device. The brewing piston can be locked in the brewing position by a locking device, in particular a mechanical locking device. The locking device can be actuated, for example, by a piston drive.

[0101] The water pump now pumps water from the water tank into the brewing chamber. The water is heated on the way by the heating unit. The heated brewing water is introduced into the brewing chamber under pressure via a brewing water supply device guided through the piston tamper.

[0102] The brewed coffee flows downwardly out of the portafilter device through a coffee outlet opening at the bottom of the portafilter device, ie into a provided beverage vessel.

[0103] At the end of the brewing program, the supply of hot brewing water is stopped and the brewing water pressure in the brewing chamber is reduced. The brewing chamber is opened by moving the brewing piston back into its initial position and the receiving opening of the coffee receiving space is released. The portable filter device is now completely removed from the machine unit via a linear (reverse) movement via the linear guide device.

[0104] The coffee grounds can now be removed from the portafilter, for example by knocking them off. The portafilter can then be ready for a new brewing program.

[0105] The coffee machine according to the invention is characterized by the following advantages:

[0106] - simple and quick attachment of the mobile filter device to the machine unit and simple and quick removal of the mobile filter device from the machine unit, in particular without requiring significant force;

[0107] - Portable filter baskets of different sizes are no longer necessary, thanks to the movable brewing piston, which allows individual coffee compaction and also allows different fillings of the coffee receiving space with a given coffee grounds;

[0108] - Due to the movable brewing piston, there is no need to tighten the portafilter against the (stationary) tamper on the machine unit to tamp the coffee;

[0109] - a separate arrangement for coffee compaction, due to a brewing piston which, via a control device and by a piston drive, can be advanced in a controlled manner into the coffee receiving space or brewing chamber;

[0110] The coffee type can be changed without residue, since the coffee grounds are conveyed unguided from the conical grinder into the coffee receiving space of the portable filter device. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] The subject matter of the invention is explained in more detail below by means of specific embodiments represented in the attached drawings. In each case, schematically shown in:

[0112] Figure 1a : A perspective view of a first embodiment of an arrangement of a brewing unit and a grinder as well as a linear guide device of a portafilter machine and a portafilter device, seen obliquely from the front;

[0113] Figure 1b :according to Figure 1a cross-section of the arrangement;

[0114] Figure 1c :Based on observation from the rear Figure 1a Another perspective view of the arrangement;

[0115] Figure 2 : A perspective view of a mobile filter device viewed obliquely from above;

[0116] Figure 3 :Based on observation from below Figure 1a A perspective view of the linear guide device without the movable filter device;

[0117] Figure 4a : A perspective view of a second embodiment of an arrangement of a brewing unit and a grinder as well as a linear guide device of a portafilter machine and a portafilter device, viewed obliquely from below;

[0118] Figure 4b :Based on observation from the front Figure 4a A perspective view of the arrangement of

[0119] Figure 4c :Based on observation from the front Figure 4a Another perspective view of the arrangement;

[0120] Figure 5 : Based on Figures 1a to 1c A schematic diagram of a mobile filter machine with an arrangement of

[0121] Figure 6 :Based on observation from below Figures 1a to 1c Perspective view of a grinder. DETAILED DESCRIPTION

[0122] According to Figures 1a to 1c In a first embodiment of the invention, the coffee machine 1 comprises a brewing unit 10 and a device 30 for producing and conveying ground coffee with a conical grinder 31. A holding and guiding device 40 having a linear guide device 41 is arranged below the brewing unit 10 and the device 30. The linear guide device 41 comprises two guide rails 42a, 42b extending parallel to each other, arranged at a distance from each other, and each guide rail comprising a guide groove 44 for slidably receiving a guide rod 55 on a portable filter device 50.

[0123] Furthermore, the coffee machine 1 comprises a portable filter device 50 having a portable filter housing 54 and a gripping body 53 for holding the portable filter device 50. Two guide rods 55 extending laterally parallel to each other on both sides of a receiving opening 56 are arranged on the outside on the portable filter device housing 54 for insertion into the guide grooves 44 of the guide rails 42a, 42b.

[0124] The brewing unit 10 and the device 30 with the conical grinder 31 are arranged one behind the other along the insertion axis EA, wherein the device 30 with the conical grinder 31 is arranged behind the brewing unit 10 in the insertion direction ER.

[0125] The portable filter device 50 can be pushed into the machine unit 2 of the coffee machine 1 via guide rods 55 which laterally engage in the guide grooves 44 of the guide rails 42a, 42b. The machine unit 2 corresponds to the coffee machine 1 without the portable filter device 50.

[0126] Among other things, the portafilter device 50 can be pushed into the filling position FS in which it is arranged below the device 30 or the grinder 31. The holding and guiding device 40 forms an end stop 45 which represents an insertion limit and at the same time ensures an exact positioning of the portafilter device 50 in the filling position FS in order to fill the portafilter device 50 with coffee powder 22. This means that the portafilter device 50 assumes the filling position FS when it reaches the stop 45.

[0127] The cone grinder 31 comprises a multi-part housing 35, in which a grinding cone 32 and a grinding ring 33 surrounding the grinding cone 32 are arranged. Starting from the cone base, the grinding cone 32 tapers along the cone axis. The grinding ring 33 is rotatably mounted in the housing 35 around the cone axis of the grinding cone 32 via a bearing, such as a ball bearing, and is driven via an electric motor 34. A grinding gap is formed between the grinding ring 33 and the grinding cone 32, into which the coffee beans are fed from above and ground by the grinding ring rotating around the cone axis. The ground coffee powder leaves the grinding gap at the lower end in the cone base area and falls downward due to gravity.

[0128] The grinding cone 32 is arranged in a rigid, ie immovable manner and is connected at its two cone ends via several connecting webs 36a, 36b to the housing 35. Starting from the cone axis, the connecting webs 36a, 36b extend radially outwards towards the housing 35 in a star-shaped manner.

[0129] A plurality of through openings for allowing coffee beans to enter the conical grinder 31 downward in the direction of gravity G are formed at the upper end of the grinding cone between the connecting webs 36a (see Figure 1c ).

[0130] Several through openings for allowing coffee powder 22 to enter the coffee receiving space 51 of the mobile filter device 50 downwardly from the cone grinder 31 in the gravity direction G are formed between the connecting webs 36b at the lower end of the grinding cone (ie on the cone base).

[0131] However, it is not absolutely necessary for the coffee machine to include an integrated grinder as represented in the figures. For example, the grinder can also be arranged or integrated on the coffee machine in such a way that the portable filter device is already filled with coffee powder before being inserted into the machine unit. Furthermore, it is also possible that the coffee machine does not have a grinder and that the coffee powder can be obtained from a separate coffee grinder or supply store.

[0132] The mobile filter device 50 comprises a filter basket 49 which is received in a mobile filter housing 54 with a brewing filter 52 forming the base of the filter basket 49. The filter basket 49 forms a coffee receiving space 51 for receiving coffee powder 22. This is open to the top. Therefore, the filter basket 49 comprises a receiving opening 56 leading to the top. This is located opposite the brewing filter 52. The coffee receiving space 51 is designed in a cylindrical manner, but comprises a circumferential funnel-shaped widening 57 in the region of the receiving opening 56. The filter basket 49 in this embodiment example is fixedly connected to the mobile filter housing 54 and therefore cannot be removed. However, the filter basket 49 may also be removable. The filter basket 49 may likewise be an integral component of the mobile filter housing 54.

[0133] After filling the coffee receiving space 51 of the portafilter 50 with coffee powder 22 , the portafilter 50 is retracted in a linear reverse motion into the brewing position BS via the linear guide 41 . In the brewing position, the portafilter 50 is located below the brewing unit 10 .

[0134] As from Figure 2 and Figure 3 As can be seen more clearly in FIG, the linear guide device 41 and the mobile filter device 50 comprise latching means 43, 59 which cooperate with each other and which allow an accurate self-centering positioning of the mobile filter device 50 in the brewing position BS. In the present embodiment example, a latching recess 41 is formed in the guide groove 44 of the guide rails 42a, 42b, into which recess a spring-loaded ball 59 arranged on a guide rod 55 of the mobile filter device 50 engages. The latching recesses 43 each form an entry and exit ramp along the insertion direction ER and opposite to the insertion direction ER. The ramp serves to reduce the force with which the mobile filter device 50 is pushed out or pulled out of the latched position, so that the mobile filter device 50 can be pushed out or pulled out beyond the latched position, or pushed out or pulled out of the latched position again, without requiring too much force.

[0135] The brewing unit 10 comprises a brewing piston 4 having a piston rod 5 guided in a piston rod housing 7 and a piston tamper 6, which is arranged at the lower end, i.e. facing the mobile filter device 50, and is guided in a piston tamper guide housing 19. The piston tamper guide housing 19 comprises a piston rod guide tube 15, through which the piston rod 5 is guided from the piston rod housing 7 into the piston tamper guide housing 19. The piston axis KA extends perpendicularly to the insertion direction ER or the insertion plane EE of the mobile filter device 50 and therefore also perpendicularly to the receiving opening 56 of the mobile filter device 50.

[0136] To start the brewing process, the brewing piston 4 is moved downwards from its initial position AK by the piston drive 21 in the direction of gravity G towards the coffee receiving space 51 of the portable filter device 50. In this context, the piston tamper 6 moves into the coffee receiving space 51 and compacts or presses the coffee powder together. In other words, the so-called tamping is performed by the brewing piston 4. The advancement of the brewing piston 4 is completed when the brewing position BK is reached. The coffee receiving space 51 closed by the piston tamper 6 now forms the brewing chamber 3.

[0137] The piston drive 21 and also the piston pressure therewith, which in turn is a measure of the compaction of the coffee, is controlled via the control device 20. The piston drive 21 can be an electric drive or a hydraulic drive. With regard to the latter, as explained in more detail below, a hydraulic fluid, such as water, is introduced into the pressure chamber 9 via a supply device 25. The hydraulic drive of the brewing piston 4 can be realized via a water pump 62 of the brewing water preparation device 60, which will be described below in detail. Figure 5 Further explanation.

[0138] The coffee machine or machine unit 2 further comprises a brewing water preparation device 60 having a water tank 61, a water pump 62 and a heating unit 63 for supplying hot water under pressure into the brewing chamber 3 (see also Figure 5 ). Hot brewing water is introduced into the brewing chamber 3 under pressure via a brewing water supply 18 which is guided through the piston tamper 6.

[0139] The mobile filter device 50 comprises a coffee outlet opening 58 arranged below the brewing filter 52. The coffee brewed in the brewing chamber 3 and compacted through the brewing filter 52 flows downwardly through the brewing filter 52, ie into a beverage vessel (not shown).

[0140] The brewing piston 4 interacts with a return spring 8. In the present embodiment, this spring corresponds to a compression spring 8 in the form of a helical spring surrounding the piston rod 5. After the brewing program is completed, as the piston pressure decreases, the compression spring 8, which is pressed together when the brewing piston 4 is advanced toward the portable filter device 50, presses the brewing piston 4 back into its initial position AK again. Given a piston drive 21, such as an electric drive that actively moves the brewing piston 4 backwards, a return means, such as a return spring, is not necessarily required.

[0141] The brewing piston 4 further comprises a piston guide sleeve 24, by which the brewing piston 4 is axially guided in the piston rod housing 7. The piston guide sleeve 24 is arranged in an upper end section of the brewing piston 4 towards the pressure chamber 9.

[0142] According to the present embodiment, the brewing piston 4 is locked in the brewing position BK by means of the locking device 11 with respect to the axial direction opposite to the advancement direction of the brewing piston 4. The locking serves, among other things, to release the piston drive 21. Therefore, the piston pressure applied by the piston drive 21 on the brewing piston 4 for compacting the coffee powder 22 is significantly lower than the brewing water pressure, which is established in the brewing chamber by the water pump 62 of the brewing water preparation device 60 and acts on the brewing piston 4 as a counterpressure. Due to the locking of the brewing piston 4 during the brewing process, it is not necessary to establish a counterpressure corresponding to the brewing water pressure by means of the piston drive. However, the locking device 11 is not absolutely necessary. Furthermore, the piston drive 21 itself can also achieve locking.

[0143] according to Figures 1a to 1c The embodiment of FIG. 4 shows a special embodiment of a locking device, which is characterized in that the locking device is also activated via the piston drive 21 .

[0144] In the present case, the piston drive 21 applies hydraulic pressure to the brewing piston 4 via a hydraulic fluid and via a hydraulic pump. To this end, the hydraulic fluid is introduced via a supply device 25, such as a piston water supply device, into the pressure chamber 9, which is delimited, among other things, by the movable brewing piston 4. The pressure chamber 9 is Figure 1b The pressure chamber 9 does not extend spatially downwards into the brewing position BK until the brewing piston 4 has been moved downwards out of its starting position AK.

[0145] If through Figure 5 Explained in more detail, the hydraulic pump may also correspond to the water pump 62 of the brewing water preparation device 60 , and the hydraulic fluid may be water from the water tank 61 of the brewing water preparation device 60 .

[0146] Due to the pressure of the hydraulic fluid (eg water) flowing into the pressure chamber 9 , the brewing piston 4 is moved downwards from its starting position AK into the brewing position BK in the direction of the portable filter unit 50 against the restoring force of the restoring spring 8 .

[0147] The pressure chamber 9 is delimited to the top by the piston rod housing 7. The piston rod housing 7 is mounted axially movably relative to the piston tamper guide housing 19 via two connecting screws 23 and is therefore mounted axially movably relative to the piston rod guide tube 15 along the connecting screws 23. The connecting screws 23 thus form a guide section, in particular without a thread, for axially guiding the axially movable piston rod housing 7. The piston rod housing 7 is held in the initial position via two compression springs 17, which press the piston rod housing 7 downwards. The compression springs 17 are designed as helical springs and each surrounds the connecting screws 23.

[0148] The downward axial movement of the brewing piston 4 ends when the brewing position BK is reached. The further increased pressure in the pressure chamber 9 now exerts a corresponding force on the piston rod housing 7, which in this way moves the piston rod housing 7 slightly upward in the direction opposite to the piston movement, overcoming the restoring force of the compression spring 17.

[0149] The annular actuating element 12 of the locking device 11, which is likewise moved upwards and surrounds the piston rod guide tube 15, is also connected to the piston rod housing 7. The actuating element 12 forms a radial distance to the piston rod guide tube 15 in the upper section, in this way creating an annular cavity or gap. In the lower section, the actuating element 12 is in sliding contact with the piston rod guide tube 15 and is supported thereon. The upper section and the lower section merge into each other via a guide bevel.

[0150] The piston rod guide tube 15 comprises, at the level of the actuating element 12 , a radial through-opening 14 , in which the ball 13 is movably mounted.

[0151] The piston rod 4 comprises a plurality of annular peripheral grooves 16 and the balls 13 can engage in the grooves 16 .

[0152] In the unlocked position, the piston rod housing 7 and together with the actuating element 12 are held in a lower initial position by the restoring force of the compression spring 17. The upper section of the actuating element 12 with the annular cavity or gap is located at the level of the radial through-opening 14. The ball 13 is retracted from the radial through-opening 14 and engages in the annular cavity.

[0153] If the brewing piston 4 now reaches the brewing position BK, as mentioned above, the piston rod housing 7 is slightly lifted in the axial direction together with the actuating element 12. In this way, the lower section of the actuating element 12 is moved upwards together with the annular gap, in which way, due to the upward movement of the lower section, the ball 13 is moved radially inwards back into the through-opening 14. The guiding bevel between the upper section and the lower section ensures that the ball 13 is not stuck by the actuating element 12, but is moved uniformly into the through-opening 14.

[0154] The ball 13 which has now moved back into the radial through-opening 14 on the other side engages in the groove 16 on the piston rod 15 and effects locking of the brewing piston 4 in the brewing position BK. The ball 13 thus acts as a locking body.

[0155] As long as the hydraulic pressure in the pressure chamber 9 is able to press the piston rod housing 7 upwards against the restoring force of the compression spring 17 , the locking is maintained.

[0156] After the brewing program is completed, the pressure in the pressure chamber 9 is reduced, in which way the piston rod housing 7 moves downwards together with the actuating element 12 back into the initial position due to the restoring force of the compression spring 17. The upper section of the actuating element 12 together with the annular gap between the actuating element 12 and the piston rod guide tube 15 is again located at the height of the radial through-opening 14.

[0157] Due to the reduced pressure in the pressure chamber 9, the restoring force exerted by the compression spring 8 on the brewing piston 4 again becomes dominant. Due to the pressure of the compression spring 8 and accordingly the upward movement of the brewing piston 4 by the compression spring 8, the ball 13 moves out of the groove 16, back into the radial through-opening 14 and into the annular gap located behind it.

[0158] The locking is released and, due to the restoring force of the compression spring 8 , the brewing piston 4 springs back upwards into the initial position AK.

[0159] Figure 5 A particular further development of the coffee machine 1 is shown, which is characterized in that the brewing piston 4 is driven, that is to say advanced in the brewing position BK, by a water pump 62 of a brewing water preparation device 60. The water pump 62 receives water from a water tank 61 via a supply water duct 64. The water pump 62 is connected to the brewing water supply 18 on the piston tamper 6 via a brewing water duct 66. A heating unit 63, i.e. a thermal module or a continuous heater, is arranged along the brewing water duct 66 for heating the brewing water flowing through the brewing water duct 66. The water pump 62 pumps water under pressure from the water tank 61 via the brewing water duct 66 into the brewing chamber 3. The brewing water is heated by the heating unit 63 on its way through the brewing water duct 66.

[0160] A 3 / 2-way valve 72 is arranged on the brewing water duct 66 , said valve comprising a further connection for draining residual water after a brewing process into a catch container such as a drip tray. The 3 / 2-way valve 72 is switched via the control device 20 .

[0161] The water pump 62 is also connected to a piston water conduit 65, via which water is pumped from the water tank 61 into the pressure chamber 9 in the piston rod housing 7 (see Figure 1b ) for advancing the brewing piston 4 from the initial position AK into the brewing position BK.

[0162] The piston water conduit 65 includes a check valve 71 which prevents water from flowing back from the pressure chamber 9 into the water pump 62. In addition, a 3 / 2-way valve 70 is arranged in the piston water conduit 65 between the check valve 71 and the pressure chamber 9. A return water conduit 67 is connected to the 3 / 2-way valve 70, via which the piston water can be led back into the water tank 61. A pressure gauge 73 for monitoring the pressure in the pressure chamber 9 is located on the piston water conduit 65.

[0163] In order to advance the brewing piston 4 from the initial position AK into the brewing position BK, the water pump 62 pumps water from the water tank 61 into the piston water line 65 and builds up a piston pressure specified by the control device 20 .

[0164] After the brewing piston 4 has reached its brewing position BK and is locked, the heated water pump 62 pumps water from the water tank 61 through the brewing water duct 66 into the brewing chamber 3 and builds up a brewing pressure which is usually greater than the piston pressure.

[0165] The water pump 62 is switched between the piston water line 65 and the brewing water line 66 or between the piston water supply and the brewing water supply via the control device 20. The non-return valve 71 in the piston water line 65 prevents a pressure loss in the pressure chamber 9 when the water pump 62 is switched from the piston water line 65 to the brewing water line 66.

[0166] The pressure in the brewing water duct 66 is released at the end of the brewing program and the 3 / 2-way valve is switched by the control device 20 so that the remaining water is discharged into a catch container (not shown).

[0167] Furthermore, the pressure in the piston water line 65 is also released and the 3 / 2-way valve 70 is switched so that the piston water is conducted back into the water tank 61 via the return supply water line 67 .

[0168] Figures 4a to 4c A second embodiment of a machine unit, respectively a holding and guiding device 140, is shown. The holding and guiding device 140 comprises a carrier plate 143 on which a linear guide 141 is pivotably arranged via a pivot axis S.

[0169] The linear guide device 141 also includes two guide rails 142a, 142b, which extend parallel to each other, are arranged at a certain distance from each other, and each guide rail 142a, 142b includes a guide groove 144 for slidingly receiving the guide rod 55 of the mobile filter device 50. The mobile filter device 50 corresponds to Figures 1a to 1c , 2 and 3 of the first embodiment of the mobile filter device 50.

[0170] Likewise, the device 30 for producing and delivering coffee powder and the brewing unit 10 correspond in particular to the method according to Figures 1a to 1c The first embodiment of the invention provides a device for producing and delivering coffee powder and a brewing unit.

[0171] However, in the second embodiment, the device 30 and the brewing unit 10 and correspondingly the filling position FS and the brewing position BS of the portable filter device 50 are not arranged one after the other in the insertion direction. Instead, the device 30 and the brewing unit 10 and correspondingly the filling position FS and the brewing position BS are arranged along a (geometric) circular line, the center of which is formed by the pivot axis S.

[0172] The mobile filter device 50 can now be inserted into the linear guide 141 into the working position in a linear motion. The working position can be set by an insertion restriction, such as a stop. The working position is located on the same circular line on which the filling position FS and the brewing position BS are arranged. Now, by pivoting the mobile filter device 50 about the pivot axis S in the pivot direction SR, the mobile filter device 50 can be pivoted alternately into the filling position FS and the brewing position BS.

[0173] Since according to this embodiment variant there is only one insertion position, in particular the working position, this can be defined by the stop.Latching means, as provided according to the first embodiment in the case of two insertion positions one after the other, are not necessary.

Claims

1. A coffee machine (1) comprising a machine unit (2) and a mobile filter device (50) having a coffee receiving space (51) and a brewing filter (52), the mobile filter device (50) being removable from the machine unit (2), wherein: The machine unit (2) comprises a movably mounted brewing piston (4), a brewing water preparation device (60) for producing hot water and conveying it under pressure into a coffee receiving space (51) of the mobile filter device (50), and a holding and guiding device (40) for receiving and holding the mobile filter device (51) on the machine unit (50). Features The holding and guiding device (40) comprises a linear guiding device (41) for linearly inserting the mobile filter device (50) into the machine unit (2).

2. The coffee machine (1) according to claim 1, characterized in that The linear guide (41) comprises two guide profiles extending in parallel and spaced apart from each other.

3. The coffee machine (1) according to claim 1 or 2, characterized in that: The coffee receiving space (51) is arranged in a mobile filter housing (54) of the mobile filter device (50), and a guide body (55) which interacts with the linear guide device (41) to form a linear guide is arranged laterally on the mobile filter housing (54).

4. The coffee machine (1) according to any one of claims 1 to 3, characterized in that A portable filter device (50) held in the linear guide (41) can be moved in the machine unit (2) into a brewing position (BS) for brewing coffee.

5. The coffee machine (1) according to any one of claims 1 to 4, characterized in that The portable filter device (50) can be pushed into the brewing position (BS) in a linear movement via the linear guide device (41).

6. The coffee machine (1) according to any one of claims 1 to 5, characterized in that The machine unit (2) comprises a device (30) for conveying, in particular producing and conveying, ground coffee into a coffee receiving space (51) of the portable filter device (50).

7. The coffee machine according to claim 6, characterized in that A portable filter device (50) held in the linear guide device (41) can be moved in the machine unit (2) into a filling position (F) for conveying coffee powder into a coffee receiving space (51) of the portable filter device (50).

8. The coffee machine (1) according to any one of claims 6 to 7, characterized in that The portable filter device (50) can be pushed into a filling position (F) via the linear guide device (41) in a linear motion, in which the coffee receiving space (51) of the portable filter device (50) can be filled with coffee powder.

9. The coffee machine (1) according to any one of claims 6 to 8, characterized in that The filling position (F) is different from the brewing position (BS).

10. The coffee machine (1) according to any one of claims 6 to 9, characterized in that A portable filter device (50) held in the linear guide device (41) is movable in the machine unit (2) between a filling position (F) and a brewing position (BS).

11. The coffee machine (1) according to any one of claims 6 to 10, characterized in that The portable filter device (50) is movable in the machine unit between a filling position (F) and a brewing position (BS) in a plane, in particular in a horizontal plane.

12. The coffee machine (1) according to any one of claims 6 to 11, characterized in that The movement between the filling position (F) and the brewing position (BS) is a linear movement or a pivoting movement.

13. The coffee machine (1) according to any one of claims 6 to 12, characterized in that The brewing position (BS) and the filling position (F) are arranged one behind the other along an insertion axis (EA).

14. The coffee machine (1) according to claim 13, characterized in that The filling position (F) is arranged behind the brewing position (B) in the insertion direction (ER).

15. The coffee machine (1) according to any one of claims 6 to 14, characterized in that The linear guide device (41) is pivotably mounted on the machine unit (2) via a pivot axis (S) arranged perpendicular to the insertion plane (EE), and the mobile filter device (50) pushed into the machine unit (2) via the linear guide device (41) is pivotably mounted together with the linear guide device (41) between the filling position (F) and the brewing position (B).

16. The coffee machine (1) according to any one of claims 1 to 15, characterized in that Latching means (43, 44) are provided, which are designed such that positioning of the portafilter device (50) in the brewing position (B) is achieved by assuming a latched position.

17. The coffee machine (1) according to any one of claims 6 to 16, characterized in that A locking device (45) is provided, on which the portable filter device (50) can be positioned in a filling position (B).

18. The coffee machine (1) according to any one of claims 1 to 17, characterized in that The coffee receiving space (51) of the mobile filter device (50) widens outwards in a funnel-shaped manner in the area of ​​the receiving opening (56), wherein the funnel-shaped widening (57) in the brewing position (B) enables self-centering of the mobile filter device (50) by engaging a downwardly moving brewing piston (4) in the coffee receiving space (51).

19. The coffee machine according to any one of claims 1 to 18, characterized in that The device (50) for producing and conveying coffee powder comprises a conical grinder (31) having an internally stationary grinding cone (32) and an externally driven grinding ring (33) surrounding the grinding cone (32), wherein the conical grinder (31) is designed and arranged in the machine unit (2) so that the ground coffee powder falls downwards from the conical grinder (31) without being guided by gravity (G) into a coffee receiving space (51) arranged below of a mobile filter device (50) positioned in a filling position (F).

20. The coffee machine according to any one of claims 1 to 19, characterized in that The cone grinder (31) comprises a housing (35) receiving the grinding cone (32) and the grinding ring (33), and the stationary grinding cone (32) is connected to the housing (35) via a connecting web (36).

21. A method for brewing coffee using a coffee machine (1) according to any one of claims 1 to 20, characterized in that To brew coffee, the portable filter device (51) is pushed into the machine unit (2) via linear guides (42a, 42b, 55) by a linear movement and, after the brewing process is completed, is pulled out of the machine unit (2) again in a linear reverse movement.

22. The method according to claim 21, characterized in that To brew coffee, the portable filter device (50) is first pushed into a filling position (F) via the linear guide (42a, 42b, 55) in a linear movement and, after filling the coffee receiving space (51) with coffee powder, is retracted into a brewing position (B) in a linear reverse movement.

23. The method according to any one of claims 21 to 22, characterized in that To brew coffee, the portable filter device (50) is pushed into the machine unit (2) in a linear movement via the linear guide (42a, 42b, 55) and, to fill the coffee receiving space (51) with coffee powder and to brew coffee, the portable filter device is pivoted together with the holding and guiding device (40) between a filling position (F) and a brewing position (B).

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