RU2833752C1 - Coffee bean grinder - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: group of inventions relates to food industry, in particular to coffee beans grinding devices. Device (1) for grinding coffee beans comprises at least one grinding module (4), at least one source (2) of coffee beans and ground coffee discharge zone (6) equipped with bracket (13), on which portafilter (9) filled with ground coffee is installed to discharge ground coffee into portafilter (9). Coffee bean grinding device (1) comprises a presence sensor designed to detect presence of portafilter (9) on bracket (13). Presence sensor is at least indirectly connected to the device control unit (5). Presence sensor is proximity sensor (16) of presence. Contactless presence sensor (16) is able to recognize different types of portafilters (9) and/or method of portafilter installation and its correctness and to initiate a trigger signal, which enables the device control unit (5) to distinguish between these different types and use this difference for control purposes or to send a warning signal in case of incorrect placement, incorrect loading or incorrect type of portafilter. Disclosed is a method of controlling a coffee bean grinding device and a method of upgrading coffee beans grinding device (1).

EFFECT: higher reliability and stability of ground coffee preparation.

15 cl, 3 dwg

Description

Field of technology

The invention relates to an improved device for grinding coffee beans, as well as to a method for controlling a device for grinding coffee beans and a method for modernizing existing devices for grinding coffee beans in the prior art.

State of the art

The process of brewing coffee from beans involves the steps of grinding coffee beans and then extracting coffee from the ground beans by feeding a given amount of hot water into the appropriate brewing chamber.

Coffee bean grinders, especially if they are professionally designed, are specialized high-performance devices that must produce the required amount of freshly ground coffee to be fed into the portafilter at the highest possible speed. The portafilter is then used directly in the coffee machine to brew the coffee. To ensure the ability to produce ground coffee as quickly and reliably as possible, modern coffee bean grinders are designed as highly automated devices with electronic control, i.e. devices in which the control of the grinding process depends on user commands and/or on the automatically determined quality of the coffee beans, etc.

One of the problems inherent in coffee bean grinding devices is that intensive use of the device and the resulting ground coffee result in high wear of the mechanical components, which include essentially all components directly or indirectly exposed to external influences or contact with coffee beans and/or ground coffee.

Patent document DE 202019102316 U1 describes a coffee grinding device comprising: a housing having an inlet opening for introducing coffee beans into it and an outlet opening for discharging ground coffee therefrom; grinding means arranged in the housing and intended for grinding coffee beans; drive devices connected to the grinding means for setting it in motion; a control unit connected to the drive device for sending a start/stop command to the drive devices; a carrier element supporting a filter holder so that it is located under the outlet opening; a load sensor connected to the carrier element for weighing the filter holder; wherein the load sensor is connected to the control unit for transmitting a weight signal to the control unit, which indicates the weight of the filter support; a presence sensor that recognizes the presence of the filter support on the carrier element.

The patent document US-A-2016143481 describes a coffee grinding machine equipped with a dispensing channel that communicates with the grinding unit and is designed to dispense coffee into a filter supported by a filter holder. The filter holder is located above a support platform connected to a load cell that weighs the amount of ground coffee contained in the filter and transmits the value of this weight to the control unit in such a way as to stop the operation of the grinding unit when the weight of the ground coffee contained in the filter reaches one dose. The load cell is located inside the support frame that accommodates the grinding unit and the electric motor that drives it.

The essence of the invention

Thus, the objective of the invention is to develop an improved device for grinding coffee beans, characterized by increased reliability and allowing very fast and stable preparation of ground coffee, in particular, in professional use. The aim of the invention is to develop a device characterized by a minimum need for technical maintenance and maximum control stability.

Accordingly, the present invention proposes an improvement of a device for grinding coffee beans, comprising at least one grinding module, at least one source of coffee beans, and also a zone for discharging ground coffee, equipped with a bracket on which a portafilter filled with ground coffee is installed for discharging ground coffee into the portafilter.

Known coffee bean grinding devices are activated either manually by the barista, after installing the portafilter on the bracket, or by a mechanical presence sensor, made in the form of a push button provided on the bracket, in the bracket or on the wall of the coffee bean grinding device, wherein said button is activated by contact with the portafilter. Thus, these models of coffee bean grinding devices contain a presence sensor for detecting the presence of the portafilter on the bracket, wherein this presence sensor is at least indirectly connected to the control unit of the device. For example, a mechanical switch of the presence sensor is used for automatic initiation and start of the grinding process.

A problem with such mechanical switches has now been discovered, which is that the presence of moving parts leads to insufficient reliability. Dirt, in particular small particles of ground coffee, get into the cracks between the moving parts, which, with prolonged and intensive use, causes malfunctions or even complete failure of the mechanical switches. Another problem is that with intensive use of the portafilter, its metal part can heat up to very high temperatures, which can result in damage to the mechanical switch when in contact with the heated part of the portafilter, and also that with intensive use, operators can carelessly slide the portafilter into the corresponding bracket, which leads to banal mechanical damage to the mechanical switch.

As a result, the grinding process stops starting reliably after a certain time or does not start at all due to a complete failure of the mechanical switch. This leads to increased maintenance costs and downtime of the coffee grinding devices. Very often, it is necessary to clean or even replace the mechanical switches.

The invention proposes to replace such mechanical presence sensors with contactless presence sensors. It has been found that the use of contactless presence sensors in this area of technology really allows to eliminate all problems, since contactless presence sensors do not contain moving mechanical parts and can be placed in a corresponding housing or can be located inside the housing of the coffee bean grinder behind its wall. In addition, the use of contactless presence sensors opens up new possibilities for controlling coffee bean grinders.

Unlike mechanical presence sensors, proximity sensors can provide information not only on the presence of a portafilter but also on the correct positioning of the portafilter and/or the type of portafilter, since proximity sensors do not simply transmit a “yes” or “no” signal like mechanical switches, but in fact measure the penetration of an object into the sensing field. Therefore, proximity sensors make it possible to monitor a variety of parameters and can be used, for example, for the following purposes: to determine whether the correct and approved portafilter is being used; to prohibit grinding if the wrong portafilter is being used; to identify a certain type of portafilter and then start the appropriate grinding process (grind type, amount of ground coffee, etc.) suitable and adapted to this type of portafilter. In addition, such a presence sensor makes it possible to determine not only the presence but also the correct positioning of the portafilter under the corresponding channel supplying ground coffee and can be used to control the grinding process in the sense that a warning is displayed to the operator in the event of an incorrect positioning of the portafilter.

In a preferred embodiment of the invention, the contactless presence sensor may be an ultrasonic sensor, a capacitive sensor, a photoelectric sensor (such as a light barrier), an electronic image sensor (CMOS and CCD), a laser distance sensor, or a sensor based on the effect of a magnetic field (inductive sensor). In addition, the sensor may be a sensor using a combination of such sensing mechanisms.

Preferably, the sensors can not only detect the presence of a portafilter, but also be used to identify the type of portafilter (e.g. by detecting at least one of the following parameters: shape, material, reflectivity, identification means such as a barcode or QR code, or a passive/active transponder (e.g. near field communication (NFC)), the state of the portafilter (filling degree, placement method, etc.).

Typically, the coffee bean grinder does not contain a load cell to detect the weight of the portafilter, and the portafilter is controlled only by a non-contact presence sensor.

According to a first preferred embodiment of the invention, the contactless presence sensor is a metal object detection sensor. This embodiment can be very effective for safety purposes, since it prevents the grinding process from being started in the event of a non-metallic object approaching, while the approach of a hand-inserted portafilter, which usually contains metal parts, will be routinely recognized.

Preferably, the contactless presence sensor is a sensor generating a magnetic field that detects a disturbance of the magnetic field when at least part of the portafilter enters it. For example, this occurs by detecting a change in the current and/or voltage supplied to the magnetic field-generating electrical or electronic part, preferably in the form of a coil (or a change in resistance, or a change in impedance, or energy consumption).

The contactless presence sensor may comprise a coil generating a magnetic field, which is at least partially or, preferably, several times wound around a core, preferably a ferrite core.

Preferably, the contactless presence detector has a nominal sensitivity range (Sn) of 2-10 mm, preferably 3-5 mm.

The contactless presence sensor is usually located on the rear wall of the ground coffee discharge zone in the coffee bean grinding device, and preferably substantially at a level corresponding to the height of the circumferential wall of the portafilter located on the bracket. However, the contactless presence sensor can also be built into said bracket or can be located under the portafilter. It can also be located above the portafilter, for example, near the channel through which the ground coffee enters the portafilter. In addition, it can be located on such a channel or built into it.

According to another preferred embodiment, the contactless presence sensor is located in a separate housing, which can be fixed to the rear wall of the ground coffee discharge zone at a level that preferably corresponds to the height of the circumferential wall of the portafilter located on this bracket.

Preferably, such a housing of a contactless presence sensor is provided with a printed circuit board and an element generating a sensitive field. Such a housing can be placed either behind the wall of the housing of the coffee bean grinder or built into this housing, but it can also be placed on the surface of the housing of the coffee bean grinder, and the sensor wires pass through a small hole in the housing of the coffee bean grinder.

Preferably, the components contained within the housing are placed or embedded therein in a manner that is protected from dirt and/or moisture, preferably encapsulated.

As indicated above, in a typical case, which is also preferred, the contactless presence sensor is capable of detecting different types of portafilters and/or the method of installing the portafilter and its correctness, and of sending a signal that allows the control unit of the device to distinguish between these different types and to use the detected difference for control purposes or to send a warning signal in the event of incorrect placement, incorrect loading or incorrect type of portafilter. Such recognition can be performed in at least one of the following ways:

• scanning (e.g. by optical, magnetic, electromagnetic field, etc.) the corresponding code embedded in or located on the portafilter and identifying the specific portafilter or its type (the code may be a barcode, QR code, passive or active transponder, text, numbers or combinations of the above, and may require optical character recognition);

• recognition of the portafilter type based on the sensor feedback signal, for example, based on the signal type of a capacitive and/or magnetic and/or optical sensor;

• geometric recognition (pattern recognition), which can be implemented in the form of two-dimensional recognition (recognition of silhouettes or sections) or three-dimensional shape recognition;

• recognition of portafilter weight and volume.

As noted above, such more sophisticated recognition may be used for control and/or monitoring and/or user interaction, such as customized tracking and reporting and/or accounting, with warnings and/or instructions to the user based on the detected portafilter, the fill level of the portafilter, the state of the portafilter, etc., with direct control of the machine based on the detected portafilter and initiation of subsequent actions.

These methods may include pre-programming the portafilter characteristics into a library stored in the machine, or, if the machine is connected to the Internet or other external database, linking to appropriate libraries accessible via the Internet or external database.

Furthermore, the invention relates to a method for controlling the above-described device for grinding coffee beans. In a preferred embodiment of such a method, said contactless presence sensor, upon detecting a portafilter, generates a signal transmitted to the control unit of the device, which is preferably used by the control unit of the device to initiate the grinding process and/or to unload ground coffee from an intermediate storage container into said portafilter. The signal can also be used to initiate a corresponding dialogue with the operator via the interface of the device, for example to start the process of selecting the grinding quality.

Preferably, the signal of the proximity sensor allows different types of portafilters to be distinguished. Preferably, using this distinction, the control unit of the device controls the grinding process, in particular controls at least one of the following parameters: grinding time, grinding gap width, weight of ground coffee, type of coffee supplied to the device, rotation frequency of the device, or a combination of the above.

Furthermore, the invention relates to a method for upgrading a device for grinding coffee beans, comprising at least one grinding module, at least one source of coffee beans, and a ground coffee discharge zone equipped with a bracket, on which a portafilter filled with ground coffee is installed for discharging ground coffee into the portafilter. The device for grinding coffee beans comprises a presence sensor intended for detecting the presence of a portafilter on the bracket, wherein the presence sensor is at least indirectly connected to the control unit of the device. In the proposed method of upgrading, the said mechanical presence sensor is replaced by a contactless presence sensor, preferably placed in a separate housing, which is preferably installed on the rear wall of the ground coffee discharge zone, at a level corresponding to the height of the circumferential wall of the portafilter located on the said bracket.

Other variants of the invention are disclosed in the dependent claims.

Brief description of the drawings

Preferred embodiments of the invention are disclosed below with reference to the drawings, wherein the drawings are not limiting in nature, but serve only to illustrate the preferred embodiments. The drawings show:

Fig. 1: schematic side view of a device for grinding coffee beans according to the prior art.

Fig. 2: schematic side view of the coffee bean grinding device proposed in the present invention.

Fig. 3: Horizontal section of the proximity sensor and approaching portafilter.

Implementation of the invention

Fig. 1 schematically shows a side view of a prior art device 1 for grinding coffee beans. In its upper part there is a container 2 for coffee beans, containing coffee beans. Under the action of gravity, the coffee beans in the container 2 fall into a grinding module 4, which grinds the coffee beans into coffee powder of the required characteristics. Then the ground coffee is directed through a channel (not shown) into a ground coffee discharge zone 6, which is usually a recessed zone in the device 1 for grinding coffee beans.

The device 1 for grinding coffee beans comprises a device control unit 5, and also, as a rule, a user input/output device 14, for example, in the form of a display and buttons or a touch screen, intended for interaction with the machine operator. In addition, in this embodiment, a load sensor 7 is provided in a separate platform 8, which is a weight sensor used to control the amount of ground coffee unloaded into the portafilter 9. The broken lines show the signal and control wires between the corresponding elements, thanks to which the device control unit is connected to the grinding module 4 and to the user input/output device and interacts with them in a controllable manner. In addition, it interacts with the load sensor 7, receiving a corresponding weight signal and using it to control the grinding and/or unloading process. In addition, the device comprises power elements for supplying power via corresponding wires to the control elements, as well as to the working elements, indicators, etc.; The mentioned additional elements are not shown in the figures explicitly, since they are well known to those skilled in the art.

The portafilter 9 comprises a handle 10, which is manipulated by the operator. By means of this handle 10, the portafilter is fixed to the brewing module of the coffee machine by a standard movement of shifting and turning. The handle 10, in the case of manipulation with the device 1 for grinding coffee beans, is used for installing the portafilter 9 on the portafilter support 11. In this case, the portafilter support 11 comprises a horizontal bracket 13 and a vertical element 12, resting on the platform 8 with the possibility of measuring the weight. Typically, the portafilter 9 is inserted between two arms of the said horizontal bracket 13, on which the portafilter is held during the grinding and unloading processes.

In addition, this known device 1 for grinding coffee beans is equipped with a mechanical presence sensor 15, usually made in the form of a mechanical button. This mechanical presence sensor 15 is located on the rear wall of the zone 6 for unloading ground coffee, and at such a height that when the portafilter 9 is installed on the bracket 13, the mechanical presence sensor goes into a pressed state, and a corresponding signal is sent to the device control unit 5, for example, to initiate a corresponding display on the user input/output device 14.

Fig. 2 shows a similar schematic representation, but this time not with a presence sensor known from the prior art, but with a contactless presence sensor 16. As shown in this figure, the contactless presence sensor 16 does not come into contact with the portafilter 9, but is located at a safe distance from it.

Fig. 3 shows the components of a possible embodiment of a contactless presence sensor 16 in a schematic horizontal section of the machine shown in Fig. 2. In this embodiment of the invention, the contactless sensor 16 is placed in a housing 20 mounted in or on the rear wall of the above-mentioned ground coffee discharge zone, essentially at the level of the portafilter 9. A printed circuit board 21 is located in this housing, connected by signal wires to the control unit 5 of the device (the wires are not shown in the figure). In addition, it can be connected to the power supply line. The printed circuit board may also contain intelligent functions, in particular if said sensor is used for retrofitting or upgrading existing machines, in the sense that the signal generated by the sensing elements is processed, for example, either to generate a simple yes/no signal or (preferably) to generate information about the portafilter, such as the type of portafilter, the location of the portafilter, etc., with subsequent transmission of the signal to the control unit of the device.

In this particular case, the contactless presence sensor is designed as a magnetic sensor. The sensitive elements contain a ferrite core 22, part of which contains a coil wire 23. The core can be permanently magnetized, and the coil can be used simply to detect magnetic field disturbances. Alternatively, the core can be magnetized by the coil, and the magnetic field disturbance is detected by a change in the exciting current and/or voltage in the coil. The components in the housing 20 are filled with a compound 24, as a result of which this sensor element 16 can be easily used as a single unit when upgrading machines known from the state of the art.

When the sensor is in the on state, it generates a magnetic field, schematically shown by the lines of force 26. The portafilter 9, comprising a perforated filter plate 18 and a metal circumferential wall 19, when approaching the sensor 16 at a distance D, shown in the figure, does not cause the sensor to operate, but when approaching further, it enters, at a certain point, the sensitivity range, in which the contactless presence sensor generates a corresponding signal and transmits this signal to the control unit of the device. In the preferred case, the sensor has a nominal sensitivity range Sn of 3.5 mm, but the actual sensitivity range is usually ± 10% of this value. The hysteresis is preferably less than 10% of the actual sensitivity range. Such a sensor can operate at a supply voltage of 5 V with an open-circuit current of less than 10 mA. The maximum thermal drift of the actual sensitivity range should be less than 10%, and the switching frequency should be in the range of 1 kHz.

List of item numbers:

1 - device for grinding coffee beans,

2 - container for coffee beans,

3 - device body 1,

4 - grinding module,

5 - device control unit,

6 - ground coffee unloading zone,

7 - load cell,

8 - separate platform of device 1,

9 - portafilter,

10 - portafilter handle 9,

11 - portafilter support,

12 - vertical element of support 11,

13 - support bracket 11,

14 - user input/output device,

15 - mechanical presence sensor,

16 - contactless presence sensor,

17 - rear side wall of portafilter 9,

18 - perforated filter plate of portafilter 9,

19 - portafilter circumferential wall 9,

20 - sensor body 16,

21 - printed circuit board,

22 - ferrite core,

23 - coil,

24 - compound,

25 - front surface of the body 20,

26 - schematic magnetic field lines,

D - distance from the portafilter,

Sn - nominal sensitivity range.

Claims (15)

1. A device (1) for grinding coffee beans, comprising at least one grinding module (4), at least one source (2) of coffee beans, and a zone (6) for discharging ground coffee, equipped with a bracket (13), on which a portafilter (9) filled with ground coffee is mounted for discharging ground coffee into the portafilter (9), wherein the device (1) for grinding coffee beans comprises a presence sensor designed to detect the presence of a portafilter (9) on the bracket (13), wherein this presence sensor is at least indirectly connected to the control unit (5) of the device, wherein the presence sensor is a contactless presence sensor (16), characterized in that the contactless presence sensor (16) is capable of recognizing different types of portafilters (9) and/or the method of installing the portafilter and its correctness and initiating a trigger signal allowing the control unit (5) of the device to distinguish between these different types and to use this difference for control purposes or to send a warning signal in the event of improper placement, improper loading, or incorrect type of portafilter. 2. The device according to item 1, characterized in that the contactless presence sensor (16) is a sensor for detecting metal objects. 3. The device according to claim 2, characterized in that the contactless presence sensor (16) is a sensor that generates a magnetic field and registers the disturbance of this magnetic field when at least part of the portafilter (9) is introduced into it. 4. The device according to item 3, characterized in that the contactless presence sensor (16) is a sensor that generates a magnetic field and is triggered when a change in current and/or voltage is detected, supplied to the magnetic field-generating electrical or electronic part, preferably made in the form of a coil (23). 5. The device according to claim 3 or 4, characterized in that the contactless presence sensor (16) comprises a magnetic field generating coil (23), at least partially wound around a core, preferably a ferrite core. 6. A device according to any of the preceding paragraphs, characterized in that the contactless presence sensor has a nominal sensitivity range (Sn) of 2-10 mm, preferably 3-5 mm. 7. A device according to any of the preceding paragraphs, characterized in that the contactless presence sensor (16) is located on the rear wall of the ground coffee unloading zone (6) at a level corresponding to the height of the circumferential wall (19) of the portafilter (9), located on the bracket (13). 8. A device according to any of the preceding paragraphs, characterized in that the contactless presence sensor (16) is placed in a separate housing (20), which can be installed on the rear wall of the zone (6) for unloading ground coffee at a level corresponding to the height of the circumferential wall (19) of the portafilter (9), located on the bracket (13), and in this housing a printed circuit board (21) and a sensitive field generating element (22, 23) are preferably located. 9. The device according to item 8, in which the components placed in the said housing (20) are embedded therein with protection against the ingress of dirt and/or moisture. 10. The device according to item 8, in which the components placed in the said housing (20) are embedded in it with protection from dirt and/or moisture by filling them with a compound (24). 11. A method for controlling a device according to any of the preceding paragraphs, in which the contactless presence sensor (16), upon detecting the portafilter (9), generates a signal transmitted to the device control unit (5). 12. The method according to claim 11, in which the signal from the presence sensor (16) is used by the control unit (5) of the device to start the grinding process and/or unloading ground coffee from the intermediate storage container into the portafilter (9). 13. The method according to claim 11 or 12, wherein the signal of the contactless presence sensor (16) distinguishes between different types of portafilters (9), and the control unit (5) of the device controls the grinding process, in particular at least one of the following parameters: grinding time, width of the grinding gap, weight of ground coffee, type of coffee fed into the device, rotation frequency of the device or a combination of the above. 14. A method for upgrading a device (1) for grinding coffee beans, comprising at least one grinding module (4), at least one source (2) of coffee beans, and a zone (6) for unloading ground coffee, equipped with a bracket (13), on which a portafilter (9) filled with ground coffee is installed for unloading ground coffee into the portafilter (9), wherein the device (1) for grinding coffee beans comprises a presence sensor designed to detect the presence of a portafilter (9) on the bracket (13), wherein this presence sensor is at least indirectly connected to the control unit (5) of the device, in which the said presence sensor is made as a contactless presence sensor (16), wherein the contactless presence sensor (16) is capable of recognizing different types of portafilters (9) and/or the method of installing the portafilter and its correctness and initiating a trigger signal allowing the control unit (5) of the device to distinguish between these different types and to use this difference for control purposes or to send a warning signal in the event of improper placement, improper loading, or incorrect type of portafilter. 15. The method according to claim 14, wherein the presence sensor is placed in a separate housing (20), preferably installed on the rear wall of the zone (6) for unloading ground coffee at a level corresponding to the height of the circumferential wall (19) of the portafilter (9), located on the bracket (13).