Coffee grinder, coffee machine and method for grinding coffee in coffee grinder

Abstract

The invention relates to a coffee grinder, a coffee machine and a method for grinding coffee in a coffee grinder. The coffee grinder is characterized in that it has a two-part housing in order to ensure a maximum stability of the coffee grinder in a minimum installation space. The coffee grinder also has a DC motor. The motor enables a coffee grinder to provide ground coffee with maximum service life in a minimum possible installation space without any prolonged operation delay (e.g., due to coffee powder clogging). The coffee grinder can be used in a coffee machine. Furthermore, a coffee grinder or coffee machine can be used in a coffee grinding method, the coffee machine and method having the same advantages.

Description

[0001] A coffee grinder, a coffee machine, and a method for grinding coffee in a coffee grinder are provided. The coffee grinder is characterized in that its housing consists of two parts, thereby ensuring maximum stability of the coffee grinder in a minimal installation space. The coffee grinder also has a DC motor. This motor enables the coffee grinder to provide ground coffee with a maximum service life in the smallest possible installation space without any prolonged operational delays (e.g., due to clogging of coffee powder). The coffee grinder can be used in a coffee machine. Furthermore, the coffee grinder or coffee machine can be used in a coffee grinding method, wherein the same advantages as those of the coffee machine and the method apply.

[0002] A coffee grinder for a fully automatic or semi-automatic coffee machine comprises a multi-part housing, a bean container on top, and a drive consisting of an alternating current (AC) motor or a direct current (DC) motor. The coffee beans are usually ground using a conical grinder or grinding disc. In situations where high demands are placed on the grinding performance and the fineness of the grind, a grinding mechanism with a grinding disc is usually used. The coffee beans are ground between two grinding discs arranged in the housing of the coffee grinder. One of the two grinding discs remains stationary, while the other rotates. Adjusting the distance between the two grinding discs adjusts the fineness of the grind (coarser / finer). Typically, a standard motor is used in the drive, which is coupled to the grinding mechanism.

[0003] Coffee grinder manufacturers often obtain the motors for their coffee grinders from third-party manufacturers. A disadvantage is that if the third-party manufacturer modifies their motor (e.g., size), the coffee machine manufacturer must also modify the grinder housing, potentially requiring additional components. This represents a significant expense for the coffee machine manufacturer in terms of both time and money.

[0004] Currently, many coffee grinders are powered by AC motors. These have the advantage of being powered directly from the mains, without straining the coffee machine's power supply. However, AC motors have the disadvantage of relatively low starting torque. To ensure that even relatively hard coffee beans can be ground, AC motors must be significantly oversized, which means they are relatively large and require a large amount of installation space in the coffee grinder. Another disadvantage of AC motors is their low efficiency, meaning they generate high levels of waste heat and experience thermal expansion during operation.

[0005] One advantage of conventional DC motors is that, unlike AC motors, they do not need to be oversized since they already generate high torque at start-up and can operate under overload conditions. However, a disadvantage is that the power supply unit of the DC motor must be designed to be correspondingly large in order to be able to supply the high current required at start-up. Another disadvantage of operating the motor at very high starting currents under overload conditions is that it shortens the service life of the DC motor. Conventional DC motors also have the disadvantage of not showing stability at high frequencies and not offering any possibility of monitoring the speed. In addition, conventional DC motors generally exhibit poor efficiency since the high motor speed frequency requires the use of a gearbox. Another disadvantage is that their speed frequency depends on the load. Using such a motor in a coffee grinder means that the amount of ground coffee depends on the fill level of the bean container and the type of beans.

[0006] On this basis, the object of the present invention is to provide a coffee grinder, a coffee machine, and a method for grinding coffee in a coffee grinder that no longer suffer from at least one of the disadvantages known from the prior art. In particular, the coffee grinder, the coffee machine, and the method should allow for the provision of ground coffee with a maximum service life in the smallest possible installation space and without any prolonged operational delays (e.g., due to clogging of the coffee powder). The coffee grinder, the coffee machine, and the method should also preferably enable the provision of high-quality ground coffee with minimal current load, minimal noise pollution, and / or a constant dosing capacity.

[0007] This object is achieved by a coffee grinder having the features of claim 1, by a coffee machine having the features of claim 12, and by a method having the features of claim 14. The dependent claims show advantageous further embodiments.

[0008] According to the invention, the coffee grinder is provided with a two-part housing comprising

[0009] a) an upper portion of the housing having an interior space suitable for accommodating coffee beans;

[0010] b) a housing lower portion connected to the housing upper portion and having an interior space suitable for accommodating a DC motor (preferably a brushless DC motor);

[0011] c) a grinding disc assembly comprising or consisting of a first upper non-rotatable grinding disc and a second lower rotatable grinding disc, the first grinding disc being arranged opposite the second grinding disc, the coffee grinder being configured to vary the distance from the first grinding disc to the second grinding disc; and

[0012] d) a DC motor (preferably a brushless DC motor) having a stator, a rotor, and a motor shaft, the motor shaft being connected to the rotor and the second grinding disk, the stator and the rotor being arranged in the interior space of the housing lower part, and the motor shaft being arranged in the housing lower part and at least partially in the housing upper part;

[0013] Therein, the coffee grinder is configured to rotate the second grinding disc relative to the first grinding disc by moving the rotor of the DC motor.

[0014] The coffee grinder according to the invention is ideal for providing ground coffee with a maximum service life in the smallest possible installation space and without any prolonged operating delays (eg due to clogging of the coffee powder).

[0015] This is because the grinder housing consists of only two parts, which requires fewer parts and connecting elements and thus enables a smaller design and greater long-term stability. The required installation space is further reduced by arranging the DC motor inside the housing of the coffee grinder (specifically, in the lower part of the housing). In addition, when the DC motor is equipped with a rotational position sensor, the speed frequency of the DC motor is controllable and even adjustable. Among other things, the DC motor can also rotate clockwise and counterclockwise, so that a grinding disc that becomes stuck during operation due to coffee residues can be quickly released and operation can be continued, thereby avoiding long operating delays due to clogged coffee powder and potentially extending the service life of the coffee grinder.

[0016] If a brushless DC motor is used instead of a DC motor, this makes the coffee grinder suitable for providing high-quality ground coffee with minimal current load, minimal noise pollution, an even longer service life, consistent dosing capacity, and even smaller installation space. This motor does not have brushes like traditional DC motors, but is electronically commutated, and therefore shows less sensitivity to wear and tear and is quieter in operation. In addition, brushless DC motors are significantly more energy-efficient than traditional DC motors and require less installation space for the same power output as traditional DC or AC motors (due to the lack of brushes). Brushless DC motors also generate less heat than traditional DC motors, which can ensure high-quality coffee powder. In addition, brushless DC motors inherently have a rotation angle sensor that can be used to adjust their speed frequency. This means that, for example, a possible drop in speed frequency under high load can be quickly readjusted (i.e., compensated by increasing the motor power), thereby ensuring constant dosing capacity.

[0017] The upper housing part of the coffee grinder can be connected to the lower housing part via a reversible connection. The reversible connection is preferably selected from a friction connection, a form-fit connection, and combinations thereof. Particularly preferably, the reversible connection is selected from a clamping connection, a threaded connection, a clip connection, a hook connection, a connection via a corrugated surface, and combinations thereof. In particular, the reversible connection is a screw-clamp connection via a clamping ring. The advantage of the connection via the clamping ring is that the upper housing part can be rotated 360° relative to the lower housing part. This means that even with a fully assembled coffee grinder, the outlet for the ground coffee (e.g., a through-hole in the upper housing part of the coffee grinder) can still be flexibly rotated in the desired direction. This can be advantageous, for example, if the coffee machine has two coffee grinders according to the present invention and the outlets for the ground coffee for both grinders must be adjusted to the inlet of the coffee machine's brewing group. This adjustment can therefore be performed more quickly and easily.

[0018] The coffee grinder may have a through-hole extending from the interior space within the coffee grinder to the exterior space of the coffee grinder, and may be configured to deliver ground coffee through the through-hole (i.e., the coffee grinder may have an outlet for the ground coffee). The through-hole is preferably arranged in the upper portion of the housing. Furthermore, the through-hole is preferably connected to a conduit, wherein the conduit is optionally connected to the upper housing portion via a connection selected from a plug connection, a threaded connection, and combinations thereof. The conduit can make it easier to adjust or guide the outlet of the ground coffee into the inlet of the brewing group of the coffee machine or into the handle of the coffee machine.

[0019] To support the motor shaft, the coffee grinder may have a bearing element in the lower part of the housing.

[0020] The bearing element preferably has an external thread, via which it is screwed to the housing lower part, the external thread preferably having a pitch in the range of 0.2 mm to 1.0 mm, particularly preferably 0.3 mm to 0.8 mm, very particularly preferably 0.4 mm to 0.6 mm, in particular 0.5 mm. It has been found that a pitch in this range is advantageous for finely adjusting the distance between the second and first grinding discs, i.e., for finely adjusting the degree of grinding.

[0021] In a preferred embodiment, the bearing element is preferably connected to the variable displacement motor via a gear meshing with a pinion of the variable displacement motor. The variable displacement motor is specifically configured to change the position of the bearing element and the motor shaft mounted therein relative to the longitudinal axis of the motor shaft. Alternatively, the variable displacement motor may be included in a coffee grinder or in a coffee machine having a coffee grinder according to the present invention. In principle, as a conceivable alternative to this preferred embodiment, the position of the bearing element and the motor shaft mounted therein may be changed relative to the longitudinal axis of the motor shaft without user assistance, for example by manually rotating the bearing element.

[0022] The motor shaft of the DC motor is preferably configured to change its position in the direction of the longitudinal axis of the motor shaft. Since the motor shaft is connected to the second grinding disk, the configuration that changes the position in the direction of the longitudinal axis of the motor shaft achieves the advantage that the distance between the second grinding disk and the first grinding disk (and therefore the fine grinding setting of the coffee beans) can be adjusted by axially moving the motor shaft. To make this possible, the motor shaft is preferably connected to a bearing element of a motor shaft mount, preferably in an area of ​​the motor shaft arranged in the lower part of the housing, whereby the variable displacement motor for a coffee grinder or a coffee machine including a coffee grinder is configured to cause a change in the position of the bearing element and the motor shaft mounted therein toward the longitudinal axis of the motor shaft by rotating its rotor.

[0023] Furthermore, the motor shaft may be connected to a rotor of a DC motor in a region of the motor shaft arranged in the housing lower part, wherein the DC motor is configured to rotate the motor shaft about a longitudinal axis of the motor shaft by rotating its rotor.

[0024] In addition, the motor shaft can be connected to a second (i.e., lower, rotatable) grinding disk via a grinding disk holder, preferably in an area of ​​the motor shaft located in the upper part of the housing. The advantage of using a grinding disk holder to connect the motor shaft to the second grinding disk is that it is simple and cost-effective to establish a power transmission connection between the motor shaft and the second grinding disk. For example, when replacing the second grinding disk, the grinding disk does not need to be adjusted to the motor shaft geometry. Compared to coffee grinders with multiple adapters and drives, the relatively direct connection between the second grinding disk and the motor shaft via the grinding disk holder also improves the concentricity and axial runout of the second grinding disk. Improving concentricity and axial runout can ensure that the fine grind setting remains as consistent as possible when the coffee grinder is in operation.

[0025] The first grinding wheel and / or the second grinding wheel may comprise or consist of a material selected from metals, ceramics and combinations thereof, preferably a material selected from steel, ceramics and combinations thereof, in particular a material selected from X210CrW12 steel and Al2O3 ceramics.

[0026] Furthermore, the outer diameter of the first grinding wheel and / or the second grinding wheel can be 30 to 80 cm, preferably 55 to 70 cm, in particular 65 cm.

[0027] Furthermore, the first grinding wheel and / or the second grinding wheel can be arranged in the housing upper part.

[0028] The coffee grinder may have a feed element (for coffee) located in the upper part of the housing. The feed element may have a spindle with a spindle axis. The feed element is preferably configured to rotate (about its spindle axis) and, in doing so, to transport the coffee beans to the grinding disc assembly. The advantage of this is that the coffee beans are fed evenly into the grinding disc assembly, which ensures more consistent grinding results (e.g. in terms of grind amount and / or fine grind setting). The feed element may have a protective shield that is configured to prevent access to the interior of the upper part of the housing. This can help prevent potential injury to the user of the coffee grinder. The feed element is preferably connected to the second, lower, rotatable grinding disc. This means that the feed element can be rotated by rotating the second grinding disc, i.e. the feed element can rotate together with the second grinding disc. The feed element is preferably screwed to the motor shaft (and the second, lower, rotatable grinding disc).

[0029] The second bottom rotatable grinding disc and the grinding disc support can be an integral body. In this case, changing the second grinding disc also will relate to changing the grinding disc support.

[0030] In an advantageous embodiment, the second lower rotatable grinding disc is connected to the grinding disc holder via a connection selected from a friction connection, a form-fit connection, and combinations thereof, wherein the connection is particularly a threaded connection. This design has the advantage that the grinding disc holder does not need to be replaced when the second grinding disc is replaced. This saves material and costs, and is therefore more economical and environmentally friendly.

[0031] DC motors can be equipped with either brushes or brushless DC motors. The advantage of a brushless DC motor is that it already has a rotational position sensor. This can be used to adjust its speed frequency, ensuring that the dosing capacity of the coffee grinder remains consistent. In addition, since there are no brushes to conduct electricity, brushless DC motors generate less heat during operation than traditional DC motors, ensuring higher quality ground coffee. Since there is no carbon in a brushless DC motor, the current load is lower and the service life is longer (because there are no friction losses due to the brushes). In addition, brushless DC motors allow for quieter operation (because there is no noise from rubbing carbon) and more compact coffee grinder designs (because there is no carbon to take up space).

[0032] The preferred DC motor is a DC motor without a housing, optionally a DC motor equipped with brushes but without a housing, or a brushless DC motor without a housing. One advantage of a DC motor without a housing is that a coffee grinder manufacturer who purchases a DC motor without a housing (optionally also brushless) from a third-party manufacturer is no longer dependent on the manufacturer's specific motor housing shape, which is also easy to change. This increases the flexibility of the coffee grinder manufacturer and reduces its manufacturing costs. In addition, a DC motor without a housing (optionally brushless) occupies less space than a DC motor with a housing (optionally brushless), which can further reduce the installation space required for the coffee grinder. This is because in this embodiment, the lower part of the housing of the coffee grinder according to the invention (and at least some areas of the upper part of the housing) can represent the (only) housing of the DC motor without a housing.

[0033] The DC motor may have a wattage of from 50 to 500 watts. Wattage within this range has proven to be advantageous for grinding coffee.

[0034] In a preferred embodiment, the DC motor has a height in the range of 25 to 70 mm, particularly preferably in the range of 35 to 45 mm, in particular 40 mm, and / or has a diameter in the range of 50 to 120 mm. These dimensions allow a very compact coffee grinder to be provided.

[0035] A coffee grinder, preferably a DC motor in the coffee grinder, may include a control unit. The control unit is configured to control or regulate the speed and frequency of the DC motor. Furthermore, the control unit may be configured to control or regulate the direction of rotation of the DC motor's rotor. For this regulation, the DC motor must include a rotational position sensor.

[0036] In a preferred embodiment, the DC motor therefore has a rotational position sensor, wherein the rotational position sensor is preferably selected from an optical rotational position sensor, a magnetic rotational position sensor, and a combination thereof, wherein the rotational position sensor particularly preferably comprises or consists of a Hall sensor and / or a GMR sensor. The advantage of the rotational position sensor is that it can control the DC motor speed frequency, which means that it can quickly compensate for possible drops in speed frequency due to high loads, thereby ensuring a consistent dosing capacity of the coffee grinder.

[0037] Preferably, the control unit for the coffee grinder, preferably for a DC motor of the coffee grinder, is configured to control the DC motor speed frequency based on at least one signal from the rotational position sensor.

[0038] Furthermore, preferably, the control unit for the coffee grinder, preferably the control unit of the DC motor of the coffee grinder, is configured to control or adjust the direction in which the rotor of the DC motor rotates based on at least one signal from the rotational position sensor. By controlling the direction of rotation, the first and second grinding discs can be prevented from getting stuck in the coffee beans or coffee grounds (i.e., potentially clogging the grinder), so that the coffee grinder can continue to operate.

[0039] Therefore, preferably, the control unit of the coffee grinder, preferably the control unit of the DC motor of the coffee grinder, is configured to detect a blockage in the DC motor based on at least one signal from the rotational position sensor and, in case of detected blockage, to reverse the direction of rotation of the DC motor for a specific time period, in particular 1 to 5 seconds, and / or for a specific degree of rotation, in particular 0.25 to 10 revolutions.

[0040] In another preferred embodiment, the control unit of the coffee grinder, preferably the control unit of the DC motor of the coffee grinder, is configured to detect the grinding point of the first grinding disc on the second grinding disc based on at least one signal from the rotational position sensor and, if the grinding point is detected, define it as the coffee grinder setting for the finest grind. To detect the grinding point, preferably, in addition to the at least one signal from the rotational position sensor, the current consumption of the DC motor is also taken into account, whereby the grinding point is detected by a decrease in speed frequency at a constant current consumption or by an increase in current consumption at a constant speed frequency.

[0041] The upper part and / or the lower part of the coffee grinder housing has a wall thickness of between 1 and 5 mm at least in certain areas.

[0042] The housing upper part and / or the housing lower part of the coffee grinder may comprise or consist of a material selected from metal, plastic and combinations thereof, preferably a material selected from die-cast aluminum, die-cast zinc, steel, plastic and combinations thereof.

[0043] Furthermore, the housing upper part and / or the housing lower part of the coffee grinder can have a height, at least in some regions, in the range between 50 mm and 150 mm.

[0044] Furthermore, the upper housing part and / or the lower housing part of the coffee grinder may have a diameter in the range between 50 mm and 150 mm, at least in some regions.

[0045] Furthermore, the upper housing part and / or the lower housing part of the coffee grinder can have the shape of a hollow cylinder at least in certain regions.

[0046] A sensor element for detecting the degree of grinding can be positioned at the base of the lower portion of the coffee grinder's housing. The sensor element is configured to detect the distance between the sensor element and a bearing element for mounting a motor shaft of a DC motor. A control unit for a coffee grinder according to the present invention, or a control unit for a coffee machine including a coffee grinder according to the present invention, can be configured to determine the degree of grinding of the coffee grinder according to the present invention (or coffee) based on the information from the sensor element.

[0047] According to the present invention, there is also provided a coffee machine comprising the coffee grinder according to the present invention. The coffee machine is preferably a semi-automatic or fully automatic coffee machine.

[0048] The DC motor of the coffee grinder of the coffee machine can have a rotational position sensor, preferably a rotational position sensor selected from optical rotational position sensors, magnetic rotational position sensors and combinations thereof, wherein the rotational position sensor particularly preferably comprises or consists of a Hall sensor and / or a GMR sensor.

[0049] A control unit for a coffee grinder and / or coffee maker may be configured to adjust the DC motor speed frequency based on at least one signal from the rotational position sensor.

[0050] Furthermore, the control unit of the coffee grinder and / or coffee machine may be configured to control in which direction the rotor of the DC motor rotates.

[0051] Furthermore, the control unit of the coffee grinder and / or coffee machine can be configured to detect a blockage of the DC motor and, if a blockage is detected, to reverse the direction of rotation of the DC motor for a specific time period, in particular 1 to 5 seconds, and / or a specific degree of rotation, in particular 0.25 to 10 revolutions.

[0052] Furthermore, the control unit of the coffee grinder and / or the coffee machine can be configured to detect a grinding point of the first grinding disc on the second grinding disc and, in case the grinding point is detected, to define it as a setting for the finest grind of the coffee grinder, wherein, for detecting the grinding point, in addition to at least one signal from the rotational position sensor, the current consumption of the DC motor is optionally taken into account, wherein the grinding point is optionally detected by a decrease in the rotational speed frequency at a constant current consumption or by an increase in the current consumption at a constant speed frequency.

[0053] According to the present invention, there is also provided a method for grinding coffee in a coffee grinder, comprising the following steps:

[0054] a) providing a coffee grinder or coffee machine according to the invention;

[0055] b) filling the upper portion of the coffee grinder housing with coffee beans or coarsely ground coffee; and

[0056] c) Ground coffee beans or coarsely ground coffee.

[0057] In the method, the DC motor of the coffee grinder can have a rotational position sensor, preferably a rotational position sensor selected from optical rotational position sensors, magnetic rotational position sensors and combinations thereof, wherein the rotational position sensor particularly preferably comprises or consists of a Hall sensor and / or a GMR sensor.

[0058] In the method, the DC motor speed frequency may be controlled based on at least one signal from a rotational position sensor.

[0059] Furthermore, the method may be used to control in which direction a rotor of a DC motor rotates based on at least one signal from a rotational position sensor.

[0060] Furthermore, in the method, a blockage in the DC motor can be detected based on at least one signal from a rotational position sensor, and if a blockage is detected, the direction of rotation of the DC motor can be reversed for a specific time period, in particular 1 to 5 seconds, and / or for a specific degree of rotation, in particular 0.25 to 10 revolutions.

[0061] Among other things, the method makes it possible to detect a grinding point of the first grinding disc on the second grinding disc based on at least one signal from a rotational position sensor, and in the event of detection of the grinding point, the grinding point can be defined as a setting for the finest grind of the coffee grinder, wherein, for detecting the grinding point, in addition to the at least one signal from the rotational position sensor, the current consumption of the DC motor is optionally taken into account, wherein the grinding point is optionally detected by a decrease in the rotational speed frequency at a constant current consumption or by an increase in the current consumption at a constant speed frequency.

[0062] The above-described method steps can be performed by a control unit of the DC motor, by a control unit of the coffee grinder or by a control unit of the coffee machine.

[0063] The subject matter according to the invention will be explained in more detail with reference to the following drawings, without intending to limit it to the specific embodiments shown here.

[0064] Figure 1The interior of a specific coffee grinder design according to the present invention is schematically shown. The coffee grinder comprises an upper housing part 1 having an interior space 2 configured to accommodate coffee beans and a lower housing part 3 connected to the upper housing part 1. In this design, it can be seen that the upper housing part 1 is connected to the lower housing part 3 by a screw-clamp connection 11 via a clamping ring 12. The clamping ring 12 allows the upper housing part 1 to rotate 360° relative to the lower housing part 3. The arrangement of the feed element 21 and its protective shield 22 is also shown here. The feed element 21 serves to feed coffee (beans) and to secure the first grinding disc 5 to the upper housing part 1 of the coffee grinder. The protective shield prevents the user from accidentally entering the interior space 2 of the upper housing part 1 and can thus prevent potential user injuries. The upper housing part 1 has a through hole, which is connected to a conduit 14. The conduit 14 is attached to the upper housing part 1 via a threaded connection 15.

[0065] Figure 2 A cross section of a particular coffee grinder design according to the present invention is schematically shown, showing, in addition to Figure 1 Other parts of the coffee grinder besides those shown. For example, the interior space 4 of the lower housing portion 3 of the coffee grinder is shown in greater detail. It can be seen that the coffee grinder includes a grinding disc assembly comprising a first, upper, non-rotatable grinding disc 5 and a second, lower, rotatable grinding disc 6, the first grinding disc 5 being arranged opposite the second grinding disc 6. The coffee grinder is configured to vary the distance between the first grinding disc 5 and the second grinding disc 6. Furthermore, the coffee grinder includes a brushless DC motor having a stator 8 and a rotor 9, which is connected to the second grinding disc 6. The coffee grinder is configured to rotate the second grinding disc 6 relative to the first grinding disc 5 by moving the brushless DC motor's rotor 9, which is transmitted to the motor shaft 10. It can also be seen that the motor shaft 10 is connected to a bearing element 16 for press-fit mounting. The bearing element 16 has external threads 17, through which it is screwed to the lower housing portion 3. Furthermore, the bearing element 16 is connected to a gear 19, which meshes with a pinion (not shown) in a variable displacement motor 18. The variable motor 18 can be used to move the bearing element 16 in one direction along the longitudinal axis of the motor shaft 10, thereby moving the motor shaft 10 and, therefore, the second grinding disk 6 connected to the motor shaft 10 via the grinding disk holder, toward and away from the first grinding disk (i.e., changing the fineness of the coffee grind). In this design, a sensor element 25 is provided at the bottom of the housing lower portion 3 to detect the fine grind setting. The sensor element is configured to detect the removal of the sensor element 25 from the bearing element 16. The fine grind setting of the coffee grinder (or coffee) can be derived from this distance information.

[0066] Figure 3The various parts of a particular coffee grinder design according to the present invention and how they are assembled into a complete coffee grinder are schematically shown.

[0067] Figure 4A and Figure 4B The connection between the housing upper part 1 and the housing lower part 3 via the clamping ring 12 is shown for a particular coffee grinder design according to the invention. Figure 4B A clamping ring 12 is shown for securing the housing upper part 1 to the housing lower part 3 via a screw connection 11. The advantage of the clamping ring 12 is that the housing upper part 1 can be rotated 360° relative to the housing lower part, allowing the outlet for ground coffee on the housing upper part to be easily and flexibly moved as required.

[0068] Reference Signs List

[0069] 1: Upper part of the shell;

[0070] 2: The internal space above the shell;

[0071] 3: lower part of the shell (or part thereof);

[0072] 4: The internal space at the bottom of the shell;

[0073] 5: The first upper non-rotatable grinding disc;

[0074] 6: The second lower rotatable grinding disc;

[0075] 7: Brushless DC motor;

[0076] 8: stator of brushless DC motor;

[0077] 9: Rotor of brushless DC motor;

[0078] 10: Motor shaft of brushless DC motor;

[0079] 11: threaded connection;

[0080] 12: Clamping ring;

[0081] 13: through hole;

[0082] 14: catheter;

[0083] 15: threaded connection;

[0084] 16: Bearing component, used to install the motor shaft;

[0085] 17: External thread for mounting the bearing element of the motor shaft;

[0086] 18: variable motor (for example, the coffee grinder itself);

[0087] 19: gear;

[0088] 20: grinding disc support (for supporting the second lower rotatable grinding disc);

[0089] 21: feeding element;

[0090] 22: Protective shield at the feed element

[0091] 23: upper motor bearing;

[0092] 24: lower motor bearing;

[0093] 25: Sensor for detecting the degree of grinding.

Claims

1. A coffee grinder having a two-part housing, comprising a) an upper portion of the housing having an interior space suitable for accommodating coffee beans; b) a housing lower portion connected to the housing upper portion and having an interior space suitable for accommodating a direct current (DC) motor; c) a grinding disc assembly comprising or consisting of a first upper non-rotatable grinding disc and a second lower rotatable grinding disc, the first grinding disc being arranged opposite the second grinding disc, the coffee grinder being configured to vary the distance from the first grinding disc to the second grinding disc; and d) a DC motor having a stator, a rotor, and a motor shaft connected to the rotor and the second grinding disk, the stator and the rotor being arranged in the interior space of the housing lower part, and the motor shaft being arranged in the housing lower part and, at least in some areas, in the housing upper part; Therein, the coffee grinder is configured to rotate the second grinding disc relative to the first grinding disc by moving the rotor of the DC motor.

2. Coffee grinder according to the preceding claim, characterized in that The upper shell part is connected to the lower shell part via a reversible connection, wherein the reversible connection is preferably selected from a friction connection, a form-fitting connection and a combination thereof, wherein the reversible connection is particularly preferably selected from a clamping connection, a threaded connection, a clip connection, a hook connection, a connection via a corrugated surface and a combination thereof, wherein the reversible connection is in particular a screw-clamping connection via a clamping ring.

3. Coffee grinder according to any one of the preceding claims, characterized in that The coffee grinder has a through hole from the interior space of the coffee grinder to the exterior space of the coffee grinder and is configured to transfer ground coffee through the through hole, wherein the through hole is preferably i) arranged in the upper part of the housing; and / or ii) connected to a conduit, said conduit being connected to said housing upper part, optionally via a connection selected from a plug-in connection, a threaded connection and a combination thereof; being screwed on.

4. Coffee grinder according to any one of the preceding claims, characterized in that The coffee grinder has a bearing element in the lower part of the housing for mounting the motor shaft, the bearing element preferably i) has an external thread via which the bearing element is screwed to the housing lower part, the external thread preferably having a pitch in the range of 0.2 mm to 1.0 mm, particularly preferably 0.3 mm to 0.8 mm, very particularly preferably 0.4 mm to 0.6 mm, in particular 0.5 mm; and / or ii) connected to a variable motor, preferably via a gear meshing with a pinion of the variable motor, wherein the variable motor is in particular configured to change the position of the bearing element and the motor shaft mounted therein towards the longitudinal axis of the motor shaft, wherein the variable motor is optionally comprised by the coffee grinder or by a coffee machine having the coffee grinder.

5. Coffee grinder according to any one of the preceding claims, characterized in that The motor shaft of the DC motor is preferably configured to change position along the direction of the longitudinal axis of the motor shaft. i) connected to a bearing element for mounting the motor shaft, preferably in a region of the motor shaft arranged in the lower part of the housing, wherein the variable motor of the coffee grinder or of a coffee machine comprising the coffee grinder is configured to cause a change in the position of the bearing element and of the motor shaft mounted therein by rotating its rotor in the direction of the longitudinal axis of the motor shaft; and / or ii) being connected to the rotor of the DC motor in a region of the motor shaft arranged in the lower portion of the housing, the DC motor being configured to rotate the motor shaft about the longitudinal axis of the motor shaft by rotating its rotor; and / or iii) is connected to the second, lower, rotatable grinding wheel via a grinding wheel holder, particularly preferably in the region of the motor shaft located in the housing upper part.

6. Coffee grinder according to any one of the preceding claims, characterized in that The first grinding wheel and / or the second grinding wheel i) comprises or consists of a material selected from metal, ceramic and a combination thereof, preferably a material selected from steel, ceramic and a combination thereof, more preferably a material selected from X210CrW12 steel and Al2O3 ceramic; and / or ii) has an outer diameter in the range of 30 to 80 cm, preferably 55 to 70 cm, in particular 65 cm; and / or iii) is arranged in the upper part of the housing.

7. Coffee grinder according to any one of the preceding claims, characterized in that The second grinding disc i) is integral with the grinding disc support; or ii) connected to the grinding disc holder, preferably via a connection selected from a friction connection, a form-fit connection and combinations thereof, wherein the connection is in particular a screw connection.

8. Coffee grinder according to any one of the preceding claims, characterized in that The DC motor i) is a DC motor equipped with brushes or a brushless DC motor, preferably a DC motor equipped with brushes but without a housing, or a brushless DC motor without a housing; and / or ii) having a wattage in the range of 50 to 500 watts; and / or iii) has a height in the range of 25 to 70 mm, particularly preferably in the range of 35 to 45 mm, in particular 40 mm; and / or iv) having a diameter in the range of 50 to 120 mm.

9. Coffee grinder according to any one of the preceding claims, characterized in that The coffee grinder, preferably the DC motor of the coffee grinder, has a control unit, which is preferably configured to i) controlling or regulating the speed frequency of the DC motor; and / or ii) Controlling or regulating the direction of rotation of the rotor of the DC motor.

10. Coffee grinder according to the preceding claim, characterized in that The DC motor has a rotational position sensor, wherein the rotational position sensor is preferably selected from an optical rotational position sensor, a magnetic rotational position sensor and a combination thereof, wherein the rotational position sensor particularly preferably comprises a Hall sensor and / or a GMR sensor or consists thereof, and wherein the control unit of the coffee grinder, preferably the control unit of the DC motor of the coffee grinder, is preferably configured, based on at least one signal of the rotational position sensor, i) adjusting the speed frequency of the DC motor; and / or ii) controlling or adjusting the direction of rotation of the rotor of the DC motor; and / or iii) detecting a blockage of the DC motor and, if a blockage is detected, reversing the direction of rotation of the DC motor for a specific time period, in particular 1 to 5 seconds, and / or a specific degree of rotation, in particular 0.25 to 10 revolutions; and / or iv) detecting a grinding point of the first grinding disk on the second grinding disk and, if the grinding point is detected, defining it as a setting for the finest grind of the coffee grinder, wherein for detecting the grinding point, in addition to at least one signal from the rotational position sensor, the current consumption of the DC motor is preferably also taken into account, wherein the grinding point is optionally detected by a decrease in speed frequency at a constant current consumption or by an increase in current consumption at a constant speed frequency.

11. Coffee grinder according to the preceding claim, characterized in that The housing upper part and / or the housing lower part i) having a wall thickness in at least some areas in the range of 1 to 5 mm; and / or ii) comprises or consists of a material selected from metal, plastic and combinations thereof, preferably a material selected from die-cast aluminum, die-cast zinc, steel, plastic and combinations thereof; and / or iii) has a height in the range of 50 to 150 mm; and / or iv) having a diameter in the range of 50 to 150 mm; and / or v) Has a hollow cylindrical shape in some areas.

12. A coffee machine comprising a coffee grinder according to any one of the preceding claims, wherein The coffee machine is preferably a semi-automatic coffee machine or a fully automatic coffee machine.

13. The coffee machine according to claim 12, characterized in that The DC motor of the coffee grinder of the coffee machine has a rotational position sensor, wherein the rotational position sensor is preferably selected from optical rotational position sensors, magnetic rotational position sensors and combinations thereof, wherein the rotational position sensor particularly preferably comprises or consists of a Hall sensor and / or a GMR sensor, and The control unit of the coffee grinder and / or the coffee machine is configured, based on at least one signal of the rotational position sensor, i) adjusting the speed frequency of the DC motor; and / or ii) adjusting the direction of rotation of the rotor of the DC motor; and / or iii) detecting a blockage of the DC motor and, if a blockage is detected, reversing the direction of rotation of the DC motor for a specific time period, in particular 1 to 5 seconds, and / or a specific degree of rotation, in particular 0.25 to 10 revolutions; and / or iv) detecting a grinding point of the first grinding disk on the second grinding disk and, if the grinding point is detected, defining it as a setting for the finest grind of the coffee grinder, wherein, for detecting the grinding point, in addition to at least one signal from the rotational position sensor, the current consumption of the DC motor is optionally taken into account, wherein the grinding point is optionally detected by a decrease in speed frequency at a constant current consumption or by an increase in current consumption at a constant speed frequency.

14. A method of grinding coffee in a coffee grinder, comprising the steps of: a) providing a coffee grinder according to any one of claims 1 to 11, or a coffee machine according to any one of claims 12 to 13; b) filling the upper portion of the housing of the coffee grinder with coffee beans or coarse ground coffee; and c) grinding the coffee beans or coarsely ground coffee.

15. The method according to claim 14, characterized in that The DC motor has a rotational position sensor, wherein the rotational position sensor is preferably selected from an optical rotational position sensor, a magnetic rotational position sensor and a combination thereof, wherein the rotational position sensor particularly preferably comprises a Hall sensor and / or a GMR sensor or consists thereof, and based on at least one signal of the rotational position sensor, i) adjusting the speed frequency of the DC motor; and / or ii) adjusting the direction of rotation of the rotor of the DC motor; and / or iii) detecting a blockage of the DC motor and, if a blockage is detected, reversing the direction of rotation of the DC motor for a specific time period, in particular 1 to 5 seconds, and / or a specific degree of rotation, in particular 0.25 to 10 revolutions; and / or iv) detecting a grinding point of the first grinding disk on the second grinding disk and, if the grinding point is detected, using the grinding point as a setting for a finest grind of the coffee grinder, wherein, in addition to at least one signal from the rotational position sensor, the current consumption of the DC motor is optionally taken into account for detecting the grinding point, wherein the grinding point is optionally detected by a decrease in speed frequency at a constant current consumption or by an increase in current consumption at a constant speed frequency; The above method steps can optionally be performed by a control unit of the DC motor, by a control unit of the coffee grinder or by a control unit of the coffee machine.

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