Coffee Bean Grinder

Abstract

Coffee bean grinder (1), comprising at least one grinder module (4), at least one coffee bean supply (2), and a coffee grounds dispensing area (6) having a bracket (13) on which a portafilter (9) filled with coffee grounds is placed for the process of dispensing the coffee grounds into the portafilter (9), characterized in that the coffee bean grinder (1) comprises a proximity sensor for detecting the presence of the portafilter (9) on said bracket (13), said proximity sensor being at least indirectly coupled to a grinder control unit (5), said proximity sensor being a non-contact proximity sensor (16).

Description

[Technical field]

[0001] The present invention relates to an improved coffee bean grinder, as well as a method of operating the same and a method of upgrading existing prior art coffee bean grinders. [Background technology]

[0002] Starting with coffee beans, the coffee extraction process involves a grinding step in which the coffee beans are ground, followed by a step of extracting coffee from the ground coffee beans by supplying a preset amount of hot water into the corresponding extraction chamber.

[0003] Coffee bean grinders, especially when used in a professional environment, are highly specialized and sophisticated devices that need to produce as quickly as possible the desired amount of freshly ground coffee powder that is dispensed into a portafilter, which is then used in the actual coffee machine for the brewing process. In order to be able to produce ground coffee powder as quickly and reliably as possible, current coffee bean grinders are electronically controlled, i.e. highly automated devices, in that the grinding process is controlled according to user input and / or automatically according to the detected quality of the coffee beans.

[0004] One of the problems associated with coffee bean grinders is that intensive use and the coffee grounds produced cause significant wear to the machine components, which essentially includes any component that is directly or indirectly exposed to the outside world or exposed to coffee beans and / or coffee grounds.

[0005] Patent document 1 relates to a coffee grinder comprising a main body having an inlet for introducing coffee beans therein and an outlet for dispensing coffee powder therefrom, a group of grinders arranged within the main body for grinding the coffee beans, a drive unit connected to the grinders for driving them, a control unit connected to the drive unit for sending start / stop command signals to the drive unit, a carrier element for supporting the filter carrier such that the filter carrier is positioned below the outlet, a load cell connected to the carrier element for weighing the filter carrier and connected to the control unit for sending a weight signal indicative of the weight of the filter support, and a proximity sensor for detecting the presence of the filter support on the carrier element.

[0006] US 2005 / 0133963 A1 relates to a coffee grinding machine having a dispensing duct connected to a grinder unit for dispensing the coffee in a filter supported by a filter holder. The filter holder is arranged above a support platform connected to a load cell which measures the amount of ground coffee contained in the filter and transmits an indicated weight value of the ground coffee contained in the filter to a control unit so as to stop the grinder unit when the weight of the ground coffee contained in the filter is equal to one dose. The load cell is inside a support frame which houses the grinder unit and the electric motor used to operate the grinder unit. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] German Utility Model No. 202019102316 [Patent Document 2] US Patent Application Publication No. 2016 / 143481 Summary of the Invention

[0008] The object of the present invention is therefore to propose an improved coffee bean grinder device that makes it possible to produce coffee powder very quickly and consistently, more reliably, in particular in a professional environment, with the intention of providing a device that requires minimal maintenance and is as consistently controlled as possible.

[0009] For this reason, the invention proposes an improvement to a coffee bean grinder comprising at least one grinder module, at least one coffee bean supply and a coffee grounds distribution area having a bracket on which the portafilter (9) filled with coffee grounds is placed for the process of distributing the coffee grounds into the portafilter.

[0010] Known conventional coffee bean grinders are either manually triggered by a barista when a portafilter is placed on the bracket, or have a mechanical proximity sensor in the form of a push button located on or in the bracket or on the wall of the coffee bean grinder, said push button being activated by contact with the portafilter. For this reason, these models of coffee bean grinders are equipped with a proximity sensor that detects the presence of the portafilter on said bracket, said proximity sensor being at least indirectly linked to the grinder control unit. For example, a proximity sensor mechanical switch is used to automatically trigger and start the actual grinding process.

[0011] A problem with these mechanical switches has been found to be that the presence of moving parts makes them insufficiently reliable: dust, especially fine particles of coffee grounds, can get into the slots between the moving parts, leading to malfunctions and even complete failure of the corresponding mechanical switch under continuous and intensive use. Another problem is that during intensive use of the portafilter, its metal parts may reach very high temperatures, which can harm the mechanical switch if it comes into contact with them, and also that during intensive use the operator may roughly move the portafilter into the corresponding bracket, which can lead to simple mechanical damage of the mechanical switch.

[0012] As a result, the grinding process stops working reliably after a certain time, or does not work at all due to a complete failure of the mechanical switch, which leads to increased maintenance costs and corresponding downtime of the coffee bean grinder. Very often, these mechanical switches have to be cleaned or even replaced.

[0013] Therefore, according to the invention, these mechanical proximity contact sensors are replaced by non-contact proximity sensors, whose practical use in this field turns out to essentially solve all the problems, since they do not contain any moving mechanical parts and can be housed in a corresponding housing or placed in the coffee bean grinder housing behind its wall. Furthermore, the use of non-contact proximity sensors opens up new perspectives for controlling coffee bean grinder devices.

[0014] In contrast to mechanical proximity sensors, non-contact proximity sensors can provide information not only about the presence of a portafilter, but also about the proper positioning of the portafilter and / or the type of portafilter, since they essentially measure how an object enters the sensing field, rather than simply providing a yes or no signal as mechanical switches do. Thus, non-contact proximity sensors make available a rich set of parameters for control and can be used, for example, to identify whether a proper approved portafilter is being used and to reject grinding if an incorrect portafilter is being used, or to identify a certain type of portafilter and then initiate a corresponding grinding process (type of grinding, amount of ground coffee, etc.) suitable and adapted for this type of portafilter. Furthermore, such proximity sensors can be used to control the grinding process in the sense that they make it possible to detect not only whether a portafilter is present, but also whether it is properly positioned below the corresponding conduit that delivers the coffee grounds, and to issue a warning to the operator if the portafilter is not properly positioned.

[0015] According to a preferred embodiment, the contactless proximity sensor can be an ultrasonic sensor, a capacitive sensor, a photoelectric sensor (e.g. similar to a light barrier), an electronic image sensor (CMOS and CCD), a laser distance sensor, or a sensor based on magnetic field effects (inductive sensor), or the sensor can be a sensor using a combination of these sensing mechanisms.

[0016] The sensor is preferably not only capable of sensing the presence of a portafilter, but also can be used to identify the type of portafilter (e.g., by sensing at least one of the following: shape, material, reflectivity, identification means such as a barcode or QR code, or passive / active transponder (e.g., Near Field Communication (NFC))), the status of the portafilter (degree of filling, method of positioning, etc.).

[0017] Typically, coffee bean grinders do not include a load cell to sense the weight of the portafilter, and control over the portafilter is provided solely through the use of a non-contact proximity sensor.

[0018] According to a first preferred embodiment, said non-contact proximity sensor is a metallic object sensor, which can be used very efficiently for safety reasons, preventing the actual triggering of the grinding process in case of the proximity of a non-metallic object or the recognition of the hand-held portafilter, which is usually metal-based.

[0019] The non-contact proximity sensor is preferably a sensor that generates a magnetic field and senses a perturbation of said magnetic field when at least a part of the portafilter enters said field, for example by detecting a change in current and / or voltage (or a change in resistance, or a change in impedance or power consumption) supplied to an electric or electronic component that generates the magnetic field, preferably in the form of a coil.

[0020] The non-contact proximity sensor may for example comprise a magnetic field generating coil wound at least partially, and preferably several times, around a core, preferably a ferrite core.

[0021] The non-contact proximity sensor preferably has a nominal sensing distance (Sn) in the range of 2mm to 10mm, preferably in the range of 3mm to 5mm.

[0022] The non-contact proximity sensor is typically arranged on the rear wall of the coffee grounds distribution area of ​​the coffee bean grinder, preferably at a height that essentially corresponds to the height of the peripheral wall of the portafilter resting on said bracket. However, the non-contact proximity sensor can also be integrated into said bracket or located below the portafilter. The non-contact proximity sensor can also be located above the portafilter, for example in the vicinity of a conduit used to distribute the coffee grounds into the portafilter. Furthermore, the non-contact proximity sensor can be arranged or integrated inside such a conduit.

[0023] It is further preferred that such a non-contact proximity sensor is arranged in a separate housing which can be mounted on the rear wall of the coffee grounds dispensing area, for example at a height which preferably corresponds to the height of the peripheral wall of the portafilter mounted on the bracket.

[0024] Preferably, such a housing of a non-contact proximity sensor houses the printed circuit board and the elements generating the sensing field. Such a housing can be placed behind the wall of the coffee bean grinder housing or can be integrated into such a housing, but can also be placed on the surface of such a coffee bean grinder housing, with the sensor wiring passing through a small hole in the coffee bean grinder housing.

[0025] The elements within such a housing are preferably enclosed or embedded in a dustproof and / or waterproof manner, preferably by being embedded within a potting.

[0026] As noted above, a non-contact proximity sensor typically and preferably detects different types of portafilters and / or the manner and proper positioning of the portafilter and can trigger sensing signals that enable the grinder control unit to distinguish between these different types and use that distinction for control purposes, or to issue a warning signal if the portafilter is improperly positioned, improperly installed, or of the wrong type.

[0027] This detection may take the form of at least one of the following circumstances: Scanning (e.g. optical, magnetic, electromagnetic, etc.) of a corresponding code (which may be a barcode, QR code, passive or active transponder, text, numbers, or a combination of these and may involve optical character recognition) incorporated within or located on the portafilter, identifying the portafilter individually or with respect to its type. Recognition of the type of portafilter by specific sensor feedback, e.g. by type of capacitive and / or magnetic and / or optical sensor signal. Geometric recognition (image recognition), which can be implemented in the form of two-dimensional recognition (silhouette or part recognition) or in the form of three-dimensional shape recognition. Portafilter weight and volume recognition.

[0028] As mentioned, this more sophisticated sensing can be used for control and / or monitoring and / or user interaction, for example with individualized tracking and recording and / or calculations, with issuance of warnings and / or instructions to the user responsive to detected portafilter, portafilter filling, portafilter status, etc., directly controlling the machine and initiating further actions responsive to detected portafilter functionality.

[0029] These methods may involve pre-programming the portafilter characteristics into a library within the machine, or, if the machine is connected to the Internet or another external database, establishing a link to a corresponding library available via the Internet or an external database.

[0030] Furthermore, the invention relates to a method for operating such a grinder, according to which the non-contact proximity sensor, upon detection of the portafilter, preferably triggers a signal which is sent to a grinder control unit, which is preferably used by the grinder control unit to start the grinding process and / or to dispense coffee grounds from an intermediate storage container into said portafilter. The signal can also be used to start a corresponding dialogue with the operator by the interface of the coffee bean grinder, e.g. triggering a selection process regarding the grinding quality.

[0031] The signal of the non-contact proximity sensor is preferably capable of distinguishing between different types of portafilters, and preferably using this distinction the grinder control unit controls the grinding process, in particular with regard to at least one parameter, such as the grinding time, the width of the grinding slot, the weight of the ground coffee, the type of coffee fed to the grinder, the grinding speed, or a combination thereof.

[0032] Furthermore, the invention relates to a method for upgrading a coffee bean grinder comprising at least one grinder module, at least one supply of coffee beans and a coffee grounds distribution area with a bracket on which a portafilter filled with coffee grounds is placed for a process of dispensing the coffee grounds into the portafilter, the coffee bean grinder comprising a proximity sensor for detecting the presence of the portafilter on said bracket, said proximity sensor being at least indirectly coupled to a grinder control unit. According to the proposed upgrading process, said mechanical proximity sensor is replaced by a non-contact proximity sensor, preferably arranged in a separate housing attached to the rear wall of the coffee grounds distribution area, at a height corresponding to the height of the peripheral wall of the portafilter placed on said bracket.

[0033] Further embodiments of the invention are defined in the dependent claims.

[0034] 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]

[0035] [Figure 1] FIG. 1 is a schematic side view of a coffee bean grinder according to the prior art. [Diagram 2] FIG. 2 is a schematic diagram showing a coffee bean grinder according to the present invention in a side view. [Diagram 3] FIG. 3 shows a horizontal cross section of a non-contact proximity sensor and an approaching portafilter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Figure 1 shows a schematic side view of a prior art coffee bean grinder 1. At the top there is a coffee bean container 2 which contains the coffee beans. Gravity allows the coffee beans in the coffee bean container 2 to enter the actual grinder module 4 which grinds the coffee beans into the desired coffee powder. Then, using a conduit (not shown), the ground coffee powder is guided to a coffee powder distribution area 6. The coffee powder distribution area 6 is typically a recessed area of ​​the coffee bean grinder 1.

[0037] The coffee bean grinder 1 comprises a grinder control unit 5 and a user input / output device 14, typically in the form of a display and push buttons or in the form of a touch screen, for interaction with an operator of the machine. Furthermore, in this embodiment, a load cell 7 is provided in a separate foot 8, which is a weight sensor used to control the amount of coffee grounds dispensed into the portafilter 9. The dashed lines indicate signal and control wiring between the corresponding elements, by which the grinder control unit is connected to and controllably interacts with the grinder module 4 and the user input / output device. Furthermore, the grinder control unit interacts with the load cell 7 in order to receive a corresponding weight signal and to utilize this weight signal for controlling the grinding and / or dispensing process. Furthermore, the device comprises power supply elements for supplying power to the control and operating elements, indicator lights, etc., by means of corresponding wiring, these additional elements being not specifically shown but being known to the person skilled in the art.

[0038] The portafilter 9 comprises a gripper 10, operated by the operator, by means of which the portafilter is attached in the typical shifting and planar movements to the actual brewing module of the coffee brewing machine. The gripper 10 is used, when operating the coffee bean grinder 1, to place the portafilter 9 on a portafilter support 11, which in this case comprises a vertical member 12 resting on the foot 8 and allowing the weight measurement, and a horizontal bracket 13. Normally, the portafilter 9 enters between the two arms of this horizontal bracket 13 and remains resting on them during the grinding and dispensing steps.

[0039] Furthermore, this prior art coffee bean grinder 1 is equipped with a mechanical proximity sensor 15, typically in the form of a mechanical push button, which is arranged on the rear wall of the coffee grounds dispensing area 6 at a height such that when the portafilter 9 is placed on the bracket 13, the mechanical proximity sensor is pressed and a corresponding signal is delivered to the grinder control unit 5, for example to initiate a corresponding display on the user input / output device 14.

[0040] 2 shows a similar schematic illustration, but now, instead of the prior art proximity sensor, a non-contact proximity sensor 16 is provided. As can be seen, this non-contact proximity sensor 16 does not touch the portafilter 9, but is at a safe distance from it.

[0041] Figure 3 shows a detailed view of a possible contactless proximity sensor 16 in a schematic horizontal cross section of the machine according to figure 2. In this embodiment, the proximity sensor 16 is arranged in a housing 20 that is essentially mounted in or on the rear wall of the abovementioned coffee grounds distribution area, at the height of the portafilter 9. In this housing, a printed circuit board 21 is installed that is signal wired (wires not shown here) to the grinder control unit 5. The printed circuit board 21 can further be wired to the power supply. The printed circuit board can also include intelligence in the sense that the signal generated by the actual sensing element is processed, for example simply to generate a yes / no signal, or preferably to generate information about the portafilter, for example the type of portafilter, the positioning of the portafilter, etc., which is delivered to the grinder control unit, especially when using a corresponding sensor for repowering or upgrading an existing machine.

[0042] In this particular case, the non-contact proximity sensor is in the form of a magnetic sensor. The actual sensing element comprises a ferrite core 22 with coil wiring 23 as a part of it. The core can be permanently magnetized and the coil can simply be used to detect magnetic field disturbances, or the core can be magnetized by a coil and magnetic field disturbances are detected by changes in drive current and / or voltage in the coil. The components within the housing 20 are incorporated within a potting 24, making the entire sensor element 16 an element that can be easily used to upgrade existing machines.

[0043] When switched on, the sensor generates a magnetic field, which is diagrammatically represented by magnetic field lines 26. A portafilter 9 with a perforated filter plate 18 and a metallic peripheral wall 19 approaches the sensor 16, in the illustrated example at a distance D that does not trigger the sensor, and when it approaches further, at a certain moment reaches a sensing distance, at which the non-contact proximity sensor generates a corresponding signal and transmits it to the grinder control unit. Preferably, such a sensor has a nominal sensing distance Sn of 3.5 mm, the actual sensing distance typically fluctuates within a range of ±10% of that value. The hysteresis is preferably less than 10% of the actual sensing distance. Such a sensor can be operated with a supply voltage of 5 V and a no-load supply current of less than 10 mA. The maximum thermal drift of the actual sensing distance should be less than 10% and the switching frequency should be in the range of 1 kHz. [Explanation of symbols]

[0044] 1 coffee bean grinder 2 Coffee Bean Containers 3 in 1 housing 4 Grinder Module 5 Grinder Control Unit 6 Coffee powder distribution area 7 Load Cell 8 1 separate foot 9. Portafilter 10 9 gripping part 11 Portafilter support 12 11 vertical members 13 11 Bracket parts 14 User Input / Output Devices 15 Mechanical Proximity Sensor 16 Non-contact proximity sensor 17 9 Back wall 18 9 hole filter plate 19 9 Peripheral wall 20 16 Housing 21 Printed Circuit Board 22 Ferrite core 23 Coil 24 Potting 25 20 Front 26 Schematic magnetic field lines D Distance from portafilter Sn Nominal sensing distance

Claims

1. A coffee bean grinder (1), comprising: At least one grinder module (4); at least one supply of coffee beans (2); a coffee grounds distribution area (6) having a bracket (13) on which the portafilter (9) filled with coffee grounds is placed for the process of distributing the coffee grounds into said portafilter (9); Equipped with the coffee bean grinder (1) is equipped with a proximity sensor to detect the presence of a portafilter (9) on the bracket (13); The proximity sensor is at least indirectly coupled to a grinder control unit (5); The proximity sensor is a non-contact type proximity sensor (16), the non-contact type proximity sensor (16) is a sensor for detecting metallic objects, a sensor for generating a magnetic field, and a sensor for sensing perturbations of the magnetic field when at least a part of the portafilter (9) enters the magnetic field; The coffee bean grinder, characterized in that the non-contact proximity sensor (16) is capable of detecting different types of portafilters (9) and / or the manner and proper positioning of the portafilters and of inducing sensing signals that enable the grinder control unit (5) to distinguish between these different types and use this distinction for control purposes, or to issue a warning signal in case of an improperly positioned, improperly mounted or improper type of portafilter.

2. 2. The grinder (1) according to claim 1, wherein the non-contact proximity sensor (16) is a sensor which generates a magnetic field, preferably in the form of a coil (23), by detecting changes in current and / or voltage supplied to an electrical or electronic component which generates the magnetic field.

3. 3. The grinder (1) according to claim 1 or 2, wherein the non-contact proximity sensor (16) comprises a magnetic field generating coil (23) wound at least partially around a core, preferably a ferrite core.

4. Grinder (1) according to any one of claims 1 to 3, wherein the non-contact proximity sensor has a nominal sensing distance (Sn) in the range of 2 mm to 10 mm, preferably in the range of 3 mm to 5 mm.

5. Grinder (1) according to any one of claims 1 to 4, wherein the non-contact proximity sensor (16) is arranged on the rear wall of the coffee grounds distribution area (6) at a height that essentially corresponds to the height of the peripheral wall (19) of a portafilter (9) mounted on the bracket (13).

6. Grinder (1) according to any one of claims 1 to 5, in which the non-contact proximity sensor (16) is arranged in a separate housing (20) that can be attached to the rear wall of the coffee powder distribution area (6) at a height corresponding to the height of the peripheral wall (19) of a portafilter (9) mounted on the bracket (13), preferably said housing housing a printed circuit board (21) and elements (22, 23) generating a sensing field.

7. 7. The grinder according to claim 6, wherein the elements within the housing (20) are preferably mounted in a dustproof and / or waterproof manner by being mounted in a potting (24).

8. A method for operating a grinder according to any one of claims 1 to 7, wherein the non-contact proximity sensor (16) upon detection of a portafilter (9) induces a signal which is sent to the grinder control unit (5).

9. 9. The method according to claim 8, wherein the signal of the proximity sensor (16) is utilized by the grinder control unit (5) to start the grinding process and / or to dose coffee grounds from an intermediate storage container into the portafilter (9).

10. 10. The method according to claim 8 or 9, wherein the signal of the non-contact proximity sensor (16) distinguishes between different types of portafilters (9) and the grinder control unit (5) controls the grinding process with regard to at least one parameter, in particular the grinding time, the width of the grinding slot, the weight of the coffee grounds, the type of coffee fed to the grinder, the grinding speed or a combination thereof.

11. A method for upgrading a coffee bean grinder (1), comprising the steps of: The coffee bean grinder (1) comprises: At least one grinder module (4); at least one supply of coffee beans (2); a coffee grounds distribution area (6) having a bracket (13) on which the portafilter (9) filled with coffee grounds is placed for the process of distributing the coffee grounds into said portafilter (9); Equipped with the coffee bean grinder (1) is equipped with a proximity sensor to detect the presence of a portafilter (9) on the bracket (13); The proximity sensor is at least indirectly coupled to a grinder control unit (5); replacing the proximity sensor with a non-contact type proximity sensor (16); the non-contact type proximity sensor (16) is a sensor for detecting metallic objects, a sensor for generating a magnetic field, and a sensor for sensing perturbations of the magnetic field when at least a part of the portafilter (9) enters the magnetic field; The non-contact proximity sensor (16) is capable of detecting different types of portafilters (9) and / or the manner and proper positioning of the portafilters and triggering sensing signals that enable the grinder control unit (5) to distinguish between these different types and use this distinction for control purposes, or to trigger sensing signals that cause a warning signal to be issued in case of an improperly positioned, improperly mounted, or improper type portafilter.

12. 12. A method for upgrading a coffee bean grinder (1) according to claim 11, wherein the proximity sensor is arranged in a separate housing (20) preferably attached to the rear wall of the coffee powder distribution area (6) at a height corresponding to the height of the peripheral wall (19) of a portafilter (9) resting on the bracket (13).

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