Coffee grinder sensor

Abstract

A sensor unit 5 for use in combination with a coffee brewing machine 1 and a separate coffee bean grinder 2, the sensor unit 5 being a unit separate from the coffee brewing machine 1 and from the coffee bean grinder 2. The sensor unit 5 comprises a base 27 located below the coffee dispenser 9 and in the brewed coffee supply area 19 of the coffee brewing machine 1, at least one load cell 15 for measuring the weight of a cup 11 placed on an upper surface 30 of the base 27 as a function of time for filling it with coffee using the coffee dispenser 9, and at least one central processing unit 17 for collecting and at least temporarily storing data received from the load cell 15 and for transmitting the data received from the load cell 15 to the coffee bean grinder 2, the central processing unit 17 comprising at least one wired or wireless communication for data exchange with the coffee bean grinder 2 and for controlling the grinding process of the coffee bean grinder 2.

Description

[Technical field]

[0001] The present invention relates to a sensor unit for use with a separate coffee brewing machine and a separate coffee grinder. Further, the present invention relates to users of such sensors and to methods of operation of such sensors. [Background technology]

[0002] Starting with coffee beans, the coffee extraction process involves grinding the coffee beans and then extracting coffee from the ground coffee beans by supplying a pre-set amount of hot water into a corresponding extraction chamber.

[0003] There are different ways to set up this process. There are combined fully automatic machines that need to be supplied with water and coffee beans, which are ground and transferred automatically to a brewing chamber, after which a preset amount of hot water is automatically introduced into said chamber and the coffee runoff is collected in a cup. Control in these machines is a delicate matter, since the goal is to provide a coffee of as reliable and constant quality as possible, including additional features such as, for example, providing the right amount of foam on top of the coffee, being able to distinguish espresso from other types of coffee, etc. This fully integrated machine and the corresponding control are known, for example, from US Pat. No. 5,399,433 and US Pat. No. 5,499,433.

[0004] These combined fully automatic machines are rarely used in commercial high quality coffee brewing environments, where there are generally separate coffee brewing machines and coffee bean grinders. The reasons are manifold: so-called baristas want the freedom to adapt the parameters regarding the grinding and brewing processes; a good grinding machine requires a different environment, different materials, different manufacturing focus, and different electronics than a good coffee brewing machine; and having these two important elements in only one machine reduces the flexibility regarding replacement in case of damage.

[0005] There are two different markets for these high-end machines: one for coffee brewing machines and one for coffee bean grinding machines. Coffee brewing machines are highly controlled machines with various sensors and control mechanisms to ensure that water at the right pressure and temperature is supplied to the brewing chamber, typically in the form of a porta filter, as required and according to a corresponding pressure and temperature profile. A portafilter (sometimes spelled "porta-filter" or "portafilter") is a component of an espresso maker that holds the ground espresso beans (coffee powder) before and during the brewing process. The portafilter is equipped with a handle, which allows the person brewing the espresso to hold the portafilter unit, on the one hand, to insert it into a corresponding opening in the coffee bean grinding machine and fill it with coffee powder, and on the other hand, to transfer it to the coffee brewing machine, attach it to the coffee brewing machine, typically using a bayonet mechanism, and empty it again after the brewing process by removing it and turning it over. Another part of the portafilter is the filter basket, which fits within the exterior of the portafilter. The filter basket is usually made of metal and has small holes that act as a screen, allowing the brewed espresso to pass downward to the bottom and out the holes or chute into the cup placed underneath.

[0006] US Pat. No. 5,399,433 discloses the possibility of using a flow meter sniffer as a separate unit connected to the extraction machine and of controlling the grinder using parameters determined by the flow meter sniffer.

[0007] US Pat. No. 5,399,633 and US Pat. No. 5,499,623 disclose measuring water flow in a brewing machine for brewing control.

[0008] US Pat. No. 5,399,633 generally discloses the control of the grinder according to the parameters of the extractor, i.e. the extraction process.

[0009] US Patent No. 5,393,633 discloses the idea of ​​using a load cell in the foot of the grinder to weigh the coffee grounds in the grinder and using corresponding data from a load cell underneath the coffee grounds receptacle to control the coffee brewing machine.

[0010] US Pat. No. 5,399,623 and US Pat. No. 5,499,633 disclose load cells integrated into an extraction machine.

[0011] Patent document 9 discloses an extraction quality measuring device comprising an electronic scale, a thermometer, a position maintaining device and an operation / control unit. The electronic scale comprises a platform used to position a container containing an extract. The thermometer has a measuring part. The position maintaining device is used to hold the measuring part of the thermometer at a measuring position. The operation / control unit is used to receive measuring signals from the electronic scale and the thermometer, respectively. The measuring position corresponds to a specific position of the container when the container is placed on the platform, such that the thermometer measures the temperature of the extract at the measuring position.

[0012] Patent document 8 discloses a coffee supply system, which comprises a number of grinding machines containing different coffee bean mixes, a coffee machine, a filter holder containing a dose of coffee powder and placed in each grinding machine, suitable for filling the coffee powder to form a desired dose of coffee powder, and suitable for placing in the coffee machine for infusing the coffee powder, a CPU operatively connected to the grinding machines and the coffee machine, and a user interface operatively connected to the CPU and configured to send input parameters selected by a user based on a desired coffee type to the CPU. The CPU is configured to receive the input parameters sent by the user interface and to calculate output parameters suitable for controlling the grinding machines and the coffee machine.

[0013] US Patent No. 6,399,633 discloses a coffee machine with a weighing system for measuring the weight of the liquid coffee extracted in a cup, and a coffee grinding machine with a weighting system for measuring the weight of the coffee powder provided in a filter holder. The coffee machine comprises a control unit provided with a memory in which infusion rates of different types of coffee are stored, and the coffee grinding machine comprises a control unit operatively connected to the control unit of the coffee machine and transmitting information about the weight of the coffee powder contained in the filter holder. The control unit of the coffee machine uses the information received from the coffee grinding machine to extract coffee that satisfies the infusion rate selected by an operator.

[0014] Patent Document 10 discloses a method and system for managing an extraction process, in which a solution is produced by mixing a solvent with a solute, and a beverage is extracted from the solution. The system includes a temperature sensor device for detecting a temperature change of the solvent per unit time to generate temperature information, a first measuring device for detecting a weight increase of the beverage per unit time to generate first weight information and for counting an elapsed time in the extraction process to generate timing information, and a computing device for comparing preset standard condition information with the temperature, first weight, and timing information. If any of the temperature, first weight, and timing information generated in a particular unit time does not match the standard condition information for the same unit time, a warning message is displayed on the computing device to remind the operator performing the extraction to stop extracting the beverage. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] U.S. Patent No. 4,767,632 [Patent Document 2] German Patent No. 3107549 [Patent Document 3] European Patent Application Publication No. 3662794 [Patent Document 4] International Publication No. 2014 / 207281 [Patent Document 5] International Publication No. 2009 / 010190 [Patent Document 6] European Patent Application Publication No. 3162256 [Patent Document 7] International Publication No. 2012 / 146641 [Patent Document 8] European Patent Application No. 3797654 [Patent Document 9] US Patent Application Publication No. 2018 / 199752 [Patent Document 10] US Patent Application Publication No. 2017 / 295983 Summary of the Invention

[0016] The coordination of the operation of the coffee bean grinder machine and the separate coffee extraction machine is carried out by a barista. However, such an experienced person is not always available or some further automation and control is desired, making it necessary to coordinate the operation of these two separate elements. The object of the present invention is therefore to enable the coordination of the operation of the coffee bean grinder machine and the separate coffee extraction machine in a way that is as simple as possible and at the same time as effective and reliable as possible, without interfering with the equipment.

[0017] In particular, considering that coffee brewing machines usually have their own control and operating schemes that do not need to be influenced or adapted to implement the corresponding control, the aim is to provide a method for controlling a coffee bean grinder in such a way that it is optimally matched to the corresponding operation of the coffee brewing machine.

[0018] Thus, according to a first aspect of the invention, there is provided a sensor unit for use in combination with a coffee extraction machine and a separate coffee bean grinder, said sensor unit being a unit that is separate from said coffee extraction machine and separate from said coffee bean grinder, said sensor unit comprising: a bottom portion located below the coffee dispenser and within an extracted coffee supply area of ​​the coffee brewing machine; At least one load cell for measuring the weight of a cup placed on the top surface of the base as a function of time in order to fill the coffee using the coffee dispenser; at least one central processing unit for collecting and at least temporarily storing the data received from said load cells (usually the "brewing profile", i.e. the curve profile of weight vs. time and temperature vs. time, preferably including the time between the first drop and the last drop) and for transmitting the data received from said load cells to said coffee bean grinder, which is provided with at least one wired or wireless communication for data exchange with said coffee bean grinder and controls the grinding process of said coffee bean grinder; A sensor unit is proposed comprising:

[0019] The need for connectivity between coffee machines and grinders is an ever-increasing market demand. Coffee machines contain important information such as water flow into the coffee cup, temperature, and extraction time, among other useful details. These parameters are useful for the barista, who sets the distance of the grinder discs and further variables of the coffee grinder that result in different outputs, e.g. grinding time, or grind weight, grinding speed, and so on, varying the consistency (coarseness) of the coffee until the right taste is achieved in the coffee cup. This whole process can be automated if information is shared between the grinder and the coffee machine via a connection protocol, and if that information is used with intelligent algorithms that optimize the extraction and grind size.

[0020] The idea here is to have a separate sensor unit that can be placed in any coffee machine between the cup and the base of the coffee machine (e.g. on the base of the coffee machine, but other external fixing means are also possible), so that no cumbersome installation is necessary. The sensor unit tracks the weight and, if desired, the temperature of the coffee poured into the cup over the infusion period, usually as a function of time, and sends this information to the grinder, which adjusts (electronically) the grind size and adjusts further variables of the coffee grinder which result in different outputs as required, e.g. grinding time, or grinding weight, grinding speed, etc., so that the loop reaches the required extraction.

[0021] The biggest advantage of this solution is that it does not require direct signal acquisition from the coffee machine. Currently, to acquire the brewing parameters, a tight integration with the specific coffee machine is required. In an installed base, this means incorporating the entire set of coffee machines. A machine-independent solution would be truly versatile, with less integration and customization.

[0022] What is unique is that this separate sensor unit communicates information to the grinder, and even more unique is that it does not actually communicate information from the coffee machine, but rather from the cup to the grinder. Essentially, this separate sensor unit can be used in any receiver, be it an espresso machine, a filter coffee machine, or any receiver that receives weight. The sensor unit records weight, time, and temperature, but whereas US Pat. No. 5,399,633, for example, records information from a flow meter installed in the coffee machine, requiring an integrated solution, this sensor unit is a completely flexible solution.

[0023] When referring to a cup in this context, it includes any type of container commonly used to receive coffee, and thus includes espresso cups, coffee cups, but also latte macchiato glasses, and the like.

[0024] The approximate dimensions of the device are typically: Width: 110mm-120mm (for only one cup, if multiple cups are placed next to each other this is usually multiplied by the number of cups), Length: 110mm-120mm, Height: 20mm-40mm (less or in the range), and height with optional thermal camera (max 160mm). The design is ultimately carried out to allow both the mat and the cup to be placed under the group head of the coffee machine.

[0025] The specifications of the weight cell can be as follows: Maximum possible weight: usually 500g to 1000g, Minimum possible weight: usually an accuracy of 0.1g is sufficient.

[0026] The thermal camera is an optional feature.

[0027] The weight can be tared to always be 0g when a cup is placed on the sensor unit. This can be achieved by the touch of a button, or alternatively by using a switch that tares to 0 as soon as the first drop hits the cup.

[0028] The sensor unit can be adapted for only one cup, but can also be adapted to place two cups next to each other, for example in the case of a portafilter with two outlets. In that case there may be only one load cell in the corresponding housing, or there may be a separate load cell for each of the cups. Typically in that case there is only one central processing unit, even if there are multiple places for the cups.

[0029] According to a preferred embodiment, the sensor unit further comprises at least one further sensor for measuring the temperature of the coffee dispensed or present in said cup, preferably as a function of time, directly or indirectly, preferably directly.

[0030] Preferably, the further sensor is an optical temperature sensor.

[0031] The data obtained from the further sensors is transmitted to the central processing unit where it is collected and at least temporarily stored and, accordingly, transmitted to the coffee bean grinder either simultaneously with or before or after the transmission of the data received from the load cell.

[0032] A further sensor is preferably mounted on or in a sensor arm which projects vertically above said top surface, preferably at a height suitable and adapted to measure, preferably optically, the temperature of the coffee entering or being in said cup.

[0033] The further sensor is preferably mounted at a height of at least 50 mm, preferably at least 75 mm, preferably in the range of 75 mm to 160 mm, or in the range of 80 mm to 120 mm above said top surface, and more preferably has its optical axis pointing diagonally downwards into the interior of a cup placed on said top surface.

[0034] The sensor arm is preferably located behind said cup, preferably near or adjacent to a rear wall of the brewed coffee dispensing area of ​​the coffee brewing machine.

[0035] The bottom may have a vertical height in the range of 2 mm to 40 mm, preferably in the range of 5 mm to 20 mm, more preferably in the range of 7 mm to 15 mm; The bottom may have a horizontal length and / or width in the range of 50 mm to 140 mm, preferably in the range of 80 mm to 120 mm, and / or The height of the sensor arm above the top surface may be in the range of 75mm to 160mm, preferably in the range of 80mm to 120mm.

[0036] The base typically comprises a housing, preferably made of a thermoplastic material, having a bottom surface and a top surface on which the cup is placed, said housing comprising a load cell, a central processing unit and a power source in the form of a battery and / or a wired power source, the sensor unit being preferably suitable to be placed on the bench of the coffee brewing machine without modifying the bench or the entire coffee brewing machine.

[0037] The separate sensor may further comprise input and output devices, in particular a display, for displaying the status, visualizing the measured values, displaying the power level in case of power supply by rechargeable battery, displaying the connectivity of the wireless connection to the grinder, etc. The sensor unit may also comprise an input device or, instead of a separate input / output device of the sensor unit, may comprise means for further communication with a mobile device for individual sensor settings, using the input / output possibilities of the mobile device (mobile phone) via a correspondingly adapted app. For this purpose, a Bluetooth or Wi-Fi connection may be provided, i.e. the separate sensor may be integrated into a local Wi-Fi system connected to the Internet, whereby it may be controlled and / or monitored by using a corresponding app essentially independently of the place where the app is used.

[0038] Preferably, the sensor comprises means for taring the weight measurement by the load cell at the moment the cup is placed on the top surface, said taring being triggered manually by a corresponding operating button or by an electric or electronic control, preferably triggered when the weight cell detects the first drop of coffee hitting the cup.

[0039] The central processing unit transmits data to the coffee bean grinder, preferably by wireless communication to the grinder control unit, preferably by one of the standards selected from Bluetooth, BLE, ZigBee, Z-wave, 6LoWPAN, Thread, LoRaWAN, 2G, 3G, 4G, 5G, LTE, NFC.

[0040] The central processing unit transmits the data received from the load cells as a function of time, typically including the rate of change as a function of time.

[0041] Furthermore, the present invention relates to the use of the above-mentioned sensor unit as a separate unit for use with a coffee brewing machine and a separate coffee bean grinder. According to this use, the above-mentioned sensor unit as a separate unit is displaced into the coffee supply area of ​​an existing coffee brewing machine, essentially without modifying the existing coffee brewing machine, and is connected to the coffee bean grinder for data exchange, and at least one or a combination of the grinding time, grinding degree, amount of coffee powder of the coffee bean grinder is adapted according to the data provided by the separate sensor unit to the coffee bean grinder, preferably without further data exchange between the coffee bean grinder and the coffee brewing machine next to the sensor unit. The proposed use is therefore like an upgrade process, without direct hardware interference with the existing coffee brewing machine and the existing coffee bean grinder. Many existing coffee bean grinders and coffee brewing machines provide interfaces for data exchange and control. The proposed use and the proposed separate unit can therefore be surprisingly easily used in such situations. Because all that is needed to improve the quality of coffee is to add a separate unit, link it to the interface of the coffee bean grinder and the coffee brewing machine, and integrate the corresponding data of the separate unit into the control process of the grinder.

[0042] Additionally, the present invention relates to a method of operation of a coffee brewing machine, a separate coffee bean grinder and a separate sensor unit as described above, wherein the separate sensor unit is displaced, essentially without modifying the coffee brewing machine, into an existing brewed coffee supply area of ​​the coffee brewing machine and connected to the coffee bean grinder for data exchange, and wherein the grinding time and / or grinding degree and / or amount of coffee powder of the coffee bean grinder are adapted depending on the data provided by the separate sensor unit to the coffee bean grinder, without further data exchange between the coffee bean grinder and the coffee brewing machine.

[0043] A coffee bean grinder typically comprises at least one grinder module, at least one coffee bean container, at least one grinder control unit with means for data exchange with a separate sensor unit, and preferably a load cell for measuring the weight of coffee grounds into a portafilter located in the coffee grounds feed area of ​​the coffee bean grinder.

[0044] A coffee brewing machine typically comprises at least one water tank, at least one water pump, at least one water heater, an interface for a portafilter, and an extracted coffee supply area below the portafilter in which a cup is placed into which the liquid coffee is filled during the brewing process.

[0045] Last but not least, the present invention relates to a kit of parts comprising the above-mentioned sensor unit, a separate coffee bean grinder and a separate coffee brewing machine.

[0046] Further embodiments of the invention are defined in the dependent claims.

[0047] Preferred embodiments of the present invention are described below with reference to the drawings, which are intended to illustrate the present preferred embodiments of the present invention and are not intended to limit the invention. [Brief description of the drawings]

[0048] [Figure 1] FIG. 1 is a schematic diagram of the coffee brewing machine and a separate coffee bean grinding machine and communication and control as proposed in this application. [Diagram 2] FIG. 2 is a schematic diagram of a sensor unit according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Figure 1 shows two physically separate machine entities: a coffee brewing machine 1 and a separate coffee bean grinder 2. The coffee brewing machine 1 comprises, in a housing 3, a water tank 4, a pump 6, a water flow heater 7 and an interface to a portafilter, usually in the form of a mounting using a bayonet mechanism. As shown by the solid line, there is a water flow from the water tank 4 to the pump 6, which then passes through the heater 7. The heater is attached to a corresponding power supply (not shown) and heats the water to the desired temperature. An additional valve (not shown) is provided to ensure that not only the desired temperature but also the desired pressure is reached. This line continues downstream of the water heater 7 to an interface 8.

[0050] The coffee brewing machine 1 typically comprises an brewed coffee supply area 19, such as a cut-out or recess in a housing 3, which can be used to insert a portafilter 9 by holding a handle 10 and firmly attaching it to a corresponding interface 8. Furthermore, a user input / output device 13 is provided. Once the portafilter has been inserted in the area 19 and attached to the interface 8, the user can start the desired brewing process by interacting with the interface 13. The coffee is then brewed and flows into a coffee cup 11, which is located on a corresponding platform 12 of the machine 1.

[0051] The control of the coffee brewing machine 1 is carried out by a corresponding brewer control unit 14. Data transmission lines are indicated by dashed lines. The control unit 14 is usually provided with a data line to a sensor that detects the water level in the water container 4. The control unit 14 also has a data line to a pump, so as to control the speed and / or duration of the pump's operation. Furthermore, there are data and control lines to the heater 8, in order to adapt and control the heating process. As mentioned above, in addition to the elements shown, there are usually valves and further sensor elements, which are also controlled by the control unit 14 or which are used for control by the control unit 14.

[0052] The coffee bean grinder 2 also has a separate housing 22. On this housing there is usually a coffee bean container 20, which is open at the top and can be refilled with coffee beans. At the bottom end of the coffee bean container 20, which usually converges towards the bottom, there is the actual grinding mechanism or grinder module 24, i.e. the actual grinding elements, usually one ring-shaped stationary grinder element and one cone-shaped rotating grinder element, which is driven by a motor. Furthermore, there is an automatic adjustment mechanism that adjusts the motor rotation speed, if necessary the motor torque, and the width of the slot between the two grinder elements to adjust the resulting grind size. The control of the coffee bean grinder 2 is coordinated by a grinder control unit 26. The corresponding data lines are shown in dashed lines. The grinder also usually comprises user input / output devices (not shown) that communicate with the grinder control unit 26 or are integral with it. Furthermore, the coffee bean grinder 2 can be equipped with a load cell 25, which measures the weight of coffee dispensed into a portafilter placed on a corresponding holder, which is inserted into the coffee grounds dispense area in a separate foot 23 and cooperates with the foot / load cell. This load cell 25 is also in data connection with a grinder control unit 26, which receives information about the effective weight of the coffee grounds filled in the portafilter.

[0053] According to a first aspect of the invention, a separate sensor unit 5 is provided, which simply rests on the base 12 and forms itself an upright platform for the cup 11. The separate sensor unit 5 is therefore located between the cup 11 and the base 12 of the coffee machine. The coffee machine does not have to be adapted in any way, the installation only requires displacing the separate sensor unit 5 into the brewed coffee dispensing area 19 and, if necessary, attaching the sensor unit 5 to a power supply. This attachment can be an independent power supply attachment, but also a direct or indirect attachment to the coffee machine power supply.

[0054] 2, the sensor unit includes a bottom housing 27 within which is provided a load cell 15 for measuring the weight of an object placed on a cupping surface 30. The sensor unit has its bottom surface 31 placed on the top surface of the platform 12.

[0055] In addition, the sensor unit 5 comprises a central processing unit 17, which is connected to the output of the load cell and to a power supply 18, which in this case is connected to a power supply line 29. The power supply can be based on a rechargeable battery concept, so that the sensor unit can be charged overnight for use the next day. If the grinder allows both modes (adjustment of grinding settings by connection or adjustment of grinding settings directly by the user), the user can also choose to switch off the sensor unit and take manual operation of the grinder.

[0056] The sensor unit 5 further comprises an upright sensor arm 28, on the upper part of which the optical temperature sensor 16 is arranged. This sensor 16 is also connected to a central processing unit 17 (the connection is indicated by a dashed line). The central processing unit is further provided with a wireless communication module (schematically indicated by an arrow) for data communication with the grinder, for example by Bluetooth, or more specifically to the grinder control unit 26. The grinder control unit 26 is itself provided with means for wireless communication with the sensor unit 5.

[0057] The grinder is thus able to continuously monitor and calculate the state of the coffee machine and control the parameters required for a certain extraction process (i.e. the fineness of the coffee grounds and / or the amount of coffee grounds) solely on the basis of a small number of pre-settings and the data obtained from the sensor unit. The pre-settings mainly relate to the desired extraction time and its permissible upper or lower deviations at which a correction controlled by the grinder should be initiated, the desired amount of water and the thresholds for its adjustment for the recipe selected by the coffee machine, and / or the desired flow rate profile. In addition, these pre-settings can be assigned to a memory structure, for example a recipe, so as to be able to switch in a very simple way between different extraction processes resulting from the extraction of different drinks by the coffee machine. The switching between the different pre-settings can be done manually by the user on the grinder itself or automatically by the coffee machine without user intervention by sending additional information to the grinder about the current recipe state (or a change in the recipe).

[0058] The exact information content of the data provided by the sensor unit depends on the type of load cell and / or temperature sensor.

[0059] Between the detected start and end points of the brewing process, the grinder can easily determine the brewing process parameters, such as the amount of coffee used in this shot, the brewing time, and then the flow profile and temperature.

[0060] By calculating one or more of these extraction process parameters, the grinder can autonomously, without any additional information from the coffee machine, adjust the adjustment of the grinding disc (i.e. the distance between the rotating and fixed blades) and / or the amount of coffee grounds, e.g. by a corresponding timing of the grinding, and, if necessary, can be further controlled by the grinder's weight cell and further variables of the coffee grinder resulting in different outputs, e.g. grinding time, grinding speed, etc.

[0061] In the simplest example, the grinder simply adjusts the spacing of the grinding blades based on one brewing process parameter, e.g., brewing time. If the predefined "ideal" brewing time (e.g., 25 seconds) given to the grinder falls below a predefined value (e.g., 24 seconds) or threshold value (1 second in this case) derived from the analysis of the last shot ticks, the grinder automatically increases the fineness of the grind of the coffee powder by reducing the spacing between the grinding blades or grinding disks, and vice versa. In this embodiment, it is important that the grinder consistently grinds the same amount of coffee, which is controlled either by time, weight, or a combination of time and weight.

[0062] However, it is also possible to analyze only the amount of coffee produced per shot. If a predefined "ideal" amount of coffee (e.g. 10 g) given to the grinder is exceeded by a predefined value (e.g. 12 g) resulting from the analysis of the integral of the ticks of the last shot, the grinder will automatically increase the coarseness of the coffee powder by increasing the spacing between the grinding blades or grinding discs, and vice versa.

[0063] It is also possible to graphically analyze the extraction profile (i.e. weight of extracted coffee extract versus time) and to define upper and lower limits along the entire curve.

[0064] In another embodiment of the invention, the distance between the grinding blades (or grinding discs) is kept constant. If the extraction time is exceeded, the amount of coffee grounds is reduced and vice versa.

[0065] In a further embodiment, the coarseness of the coffee grounds and their dosage (weight) are controlled by the grinder. In this case, at least two extraction process parameters are required: for example, the extraction time and, optionally, the amount of coffee, are the analytical data for each shot. If both the amount of coffee and the extraction time are too high, the amount of coffee grounds needs to be increased and the coarseness of the coffee grounds needs to be increased. In another example, if the extraction time is too high and the amount of water is too low, the amount of coffee grounds needs to be decreased and the coarseness of the coffee grounds needs to be increased.

[0066] A big advantage of all embodiments of the present invention is that the barista only needs to focus on the grinder and not on the coffee machine. In daily work, the barista's main recipe is a double espresso. By using the grinder's app or GUI, the barista defines once in the grinder's permanent memory the ideal extraction time, the ideal water usage, and / or the ideal flow profile and control parameters (i.e. grinding blade distance and / or coffee powder amount) that will give the perfect taste to his double espresso cup. The rest is done autonomously by the grinder.

[0067] In another example, especially if this complex brewing process has to be performed by an unskilled user, the coffee machine sends additional information to the grinder to control the recipe (i.e. pre-settings and grinding parameters) rather than the grinder. In this case, the sensor unit sends to the grinder all the parameters required to control the brewing process by the grinder, e.g. ideal brewing time, ideal amount of coffee and / or ideal brewing profile (g / sec), and control parameters, rather than grinding disk adjustments. If wireless communication between the sensor unit and the grinder is preferred, the sensor unit and the coffee machine can use two separate transmitters and the grinder can have only one receiver if the protocol is e.g. Bluetooth.

[0068] According to an alternative realisation, the coffee brewing machine may be provided with a dedicated interface to which a corresponding sensor unit is attached. The interface may be provided by a data line in the housing 3. [Explanation of symbols]

[0069] 1 Coffee brewing machine 2. Coffee bean grinder 3 in 1 housing 4. Water tank 5 Separate Sensor Unit 6. Water Pump 7. Water flow heater 8 Interface to portafilter 9. Portafilter 10 9 Handle 11 cups 12 Cup stand 13 User Input / Output Devices 14 Extractor control unit 15 5 load cells 16 5 temperature sensors 17 5 CPU 18 5 Power 19 Extracted coffee supply area 20 Coffee Bean Container 21 Coffee powder supply area 22 2 Housing 23 2 separate legs 24 Grinder Module 25 2 load cells 26 Grinder Control Unit 27 5 Bottom / Housing 28 5 sensor arm 29 Power Line 30 5 cup top 31 Bottom of 27 32 Back wall of 19 Solid line Water piping Dashed line Data / signal line

Claims

1. A sensor unit (5) for use in combination with a coffee brewing machine (1) and a separate coffee bean grinder (2), comprising: the sensor unit (5) being a unit separate from the coffee extraction machine (1) and from the coffee bean grinder (2); The sensor unit (5) comprises: a bottom (27) located below the coffee dispenser (9) and in the extracted coffee supply area (19) of said coffee brewing machine (1); at least one load cell (15) for measuring the weight of a cup (11) placed on the upper surface (30) of said base (27) as a function of time in order to fill it with coffee using said coffee dispenser (9); at least one central processing unit (17) for collecting and at least temporarily storing the data received from said load cells (15) and for transmitting the data received from said load cells (15) to said coffee bean grinder (2), said central processing unit having at least one wired or wireless communication for data exchange with said coffee bean grinder (2) and for controlling the grinding process of said coffee bean grinder (2); The sensor unit comprises:

2. 2. The sensor unit (5) according to claim 1, further comprising at least one further sensor (16) for measuring, directly or indirectly, the temperature of the coffee dispensed or present in the cup (11), preferably as a function of time, Preferably, the further sensor (16) is an optical temperature sensor (16); The sensor unit, wherein the data obtained from the further sensor (16) is transmitted to the central processing unit (17), where it is collected and at least temporarily stored, and thereafter transmitted to the coffee bean grinder (2) simultaneously with or before or after the transmission of the data received from the load cell (15).

3. A sensor unit (5) as claimed in claim 2, wherein the further sensor (16) is mounted on or in a sensor arm (28) which projects vertically above the top surface (30), preferably to a height suitable and adapted for measuring, preferably optically, the temperature of the coffee entering or being in the cup (11).

4. The sensor unit (5) according to claim 2 or 3, wherein the further sensor (16) is mounted at a height of at least 50 mm, preferably at least 75 mm, preferably in the range of 75 mm to 160 mm or in the range of 80 mm to 120 mm above the top surface (30), and further preferably has its optical axis directed obliquely downwards into a cup (11) placed on the top surface (30).

5. 4. The sensor unit (5) according to claim 3, wherein the sensor arm (28) is arranged behind the cup (11), preferably near or adjacent to a rear wall (32) of the extracted coffee supply area (19) of the coffee brewing machine (1).

6. A sensor unit (5) according to claim 3 or 5, said bottom (27) having a vertical height in the range of 2 mm to 40 mm, preferably in the range of 5 mm to 20 mm, more preferably in the range of 7 mm to 15 mm; and / or said bottom (27) has a horizontal length and / or width in the range of 50 mm to 140 mm, preferably in the range of 80 mm to 120 mm; and / or The sensor unit, wherein the height of the sensor arm (28) above the upper surface (30) is in the range of 75 mm to 160 mm, preferably in the range of 80 mm to 120 mm.

7. A sensor unit (5) according to any one of claims 1 to 3, characterized in that the base (27) comprises a housing, preferably made of a thermoplastic material, having a bottom surface (31) and a top surface (30) on which the cup (11) is placed, The housing contains the load cell (15), the central processing unit (17) and a power source (18) in the form of a battery and / or a wired power source; The sensor unit (5) is preferably suitable to be placed on the base (12) of the coffee brewing machine (1) without modifying the base (12) of the coffee brewing machine (1) or the entire coffee brewing machine.

8. A sensor unit (5) according to any one of claims 1 to 3, comprising means for taring the weight measurement by the load cell (15) at the moment when a cup (11) is placed on the upper surface (30), The sensor unit, wherein the tare can be initiated manually by a corresponding operating button or by an electrical or electronic control, preferably the electrical or electronic control can be initiated when the weight cell detects the first drop of coffee hitting the cup.

9. The sensor unit (5) according to any one of claims 1 to 3, wherein the central processing unit (17) transmits data to the coffee bean grinder (2) by wireless communication to a grinder control unit (26), preferably by one of the standards selected from Bluetooth, BLE, ZigBee, Z-wave, 6LoWPAN, Thread, LoRaWAN, 2G, 3G, 4G, 5G, LTE, NFC.

10. 4. The sensor unit (5) according to any one of claims 1 to 3, wherein the central processing unit (17) transmits data received from the load cells (15) as a function of time, including a rate of change as a function of time.

11. Use of a sensor unit (5) according to any one of claims 1 to 3 as a separate unit for use with a coffee brewing machine (1) and a separate coffee bean grinder (2).

12. A method for operating a coffee brewing machine (1), a separate coffee bean grinder (2) and a separate sensor unit (5) according to any one of claims 1 to 3, comprising: said separate sensor unit (5) being displaced into an existing extracted coffee supply area (19) of said coffee brewing machine (1) essentially without modifying said coffee brewing machine (1) and being connected to said coffee bean grinder (2) for data exchange, The method, wherein the grinding time and / or grinding degree and / or amount of coffee powder of the coffee bean grinder (2) are adapted depending on data provided to the coffee bean grinder (2) by the separate sensor unit (5) without further data exchange between the coffee bean grinder (2) and the coffee extraction machine (1).

13. 13. The method according to claim 12, wherein the coffee bean grinder (2) comprises at least one grinder module (24), at least one coffee bean container (20), at least one grinder control unit (26) equipped with means for data exchange with the separate sensor unit (5) and preferably a load cell (25) for measuring the weight of coffee grounds into a portafilter arranged in a coffee grounds feed area (21) of the coffee bean grinder (2).

14. 13. The method according to claim 12, wherein the coffee brewing machine (1) comprises at least one water tank (4), at least one water pump (6), at least one water heater (7), an interface (8) for a portafilter (9) and an extracted coffee supply area (19) below the portafilter (9) for placing a cup (11) that is filled with liquid coffee during the brewing process.

15. A kit of parts comprising a sensor unit according to any one of claims 1 to 3, a separate coffee bean grinder (2) and a separate coffee brewing machine (1).

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