COFFEE BEAN GRINDER

Abstract

Coffee bean grinder (1) comprising at least one grinder module (4), at least one supply of coffee beans (2) as well as a ground coffee dispensing area (6) with a bracket (13), onto which are porta filter (9) to be filled with ground coffee is put for the process of dispensing ground coffee into said porta filter (9), wherein the coffee bean grinder (1) comprises a proximity sensor for detecting the presence of a porta filter (9) on said bracket (13), and wherein said proximity sensor is at least indirectly coupled to a grinder control unit (5), characterised in that said proximity sensor is a contactless proximity sensor (16).

Claims

1-15. (canceled)

16. A coffee bean grinder comprising at least one grinder module, at least one supply of coffee beans as well as a ground coffee dispensing area with a bracket, onto which are porta filter to be filled with ground coffee is put for the process of dispensing ground coffee into said porta filter, wherein the coffee bean grinder comprises a proximity sensor for detecting the presence of a porta filter on said bracket, and wherein said proximity sensor is at least indirectly coupled to a grinder control unit, wherein said proximity sensor is a contactless proximity sensor.

17. The grinder according to claim 16, wherein said contactless proximity sensor is a sensor for detecting metal objects.

18. The grinder according to claim 17, wherein said contactless proximity sensor is a sensor generating a magnetic field, and sensing the perturbation of said magnetic field upon entry of at least part of the porta filter into said magnetic field.

19. The grinder according to claim 18, wherein said contactless proximity sensor is a sensor generating a magnetic field, sensing by detecting a change of the current and/or voltage supplied to a magnetic field generating electrical or electronic part.

20. The grinder according to claim 18, wherein said contactless proximity sensor comprises a magnetic field-generating coil which is at least partially wound around a core.

21. The grinder according to claim 16, wherein said contactless proximity sensor has a nominal sensing distance (Sn) in the range of 2-10 mm.

22. The grinder according to claim 16, wherein said contactless proximity sensor is located at a rear wall portion of the ground coffee dispensing area essentially at a height which corresponds to the height of a circumferential wall of a porta filter put on said bracket.

23. The grinder according to claim 16, wherein said contactless proximity sensor is located in a separate housing which can be mounted on a rear wall portion of the ground coffee dispensing area at a height which corresponds to the height of the circumferential wall of a porta filter put on said bracket.

24. The grinder according to claim 23, wherein the elements in said housing are embedded in a dirt and/or waterproof manner.

25. The grinder according to claim 16, wherein the contactless proximity sensor is able to detect different types of porta filter and to trigger a sensing signal allowing the grinder control unit to distinguish these different types and to use that distinction for control purposes.

26. A method for operating a grinder according to claim 16, wherein said contactless proximity sensor, upon detection of a porta filter, triggers a signal transmitted to the grinder control unit.

27. The method according to claim 26, wherein the signal of the proximity sensor is used by the grinder control unit to initiate the grinding process and/or to release ground coffee from an intermediate storage container into said porta filter.

28. The method according to claim 26, wherein the signal of the contactless proximity sensor discriminates between different types of porta filter, and wherein the grinder control unit controls the grinding process.

29. A method for upgrading coffee bean grinder comprising at least one grinder module, at least one supply of coffee beans as well as a ground coffee dispensing area with a bracket, onto which a porta filter to be filled with ground coffee is put for the process of dispensing ground coffee into said porta filter, said coffee bean grinder comprising a proximity sensor for detecting the presence of a porta filter on said bracket, and wherein said proximity sensor is at least indirectly coupled to a grinder control unit, wherein said proximity sensor is replaced by a contactless proximity sensor.

30. The method for upgrading coffee bean grinder according to claim 29, wherein said proximity sensor is located in a separate housing.

31. The grinder according to claim 18, wherein said contactless proximity sensor is a sensor generating a magnetic field, sensing by detecting a change of the current and/or voltage supplied to a magnetic field generating electrical or electronic part, in the form of a coil.

32. The grinder according to claim 18, wherein said contactless proximity sensor comprises a magnetic field-generating coil which is at least partially wound around a Ferrite core.

33. The grinder according to claim 16, wherein said contactless proximity sensor has a nominal sensing distance (Sn) in the range of 3-5 mm.

34. The grinder according to claim 16, wherein said contactless proximity sensor is located in a separate housing which can be mounted on a rear wall portion of the ground coffee dispensing area at a height which corresponds to the height of the circumferential wall of a porta filter put on said bracket, and wherein said housing houses a printed circuit board and sensing field generating element.

35. The grinder according to claim 23, wherein the elements in said housing are embedded in a dirt and/or waterproof manner by being embedded in a potting.

36. The method according to claim 26, wherein the signal of the contactless proximity sensor discriminates between different types of porta filter, and wherein the grinder control unit controls the grinding process, in terms of at least one of the following parameters: time of grinding, width of the grinding slot, weight of ground coffee, type of coffee supply to the grinder, grinder speed, or a combination thereof.

37. The method for upgrading coffee bean grinder according to claim 29, wherein said proximity sensor is located in a separate housing, to be mounted on a rear wall portion of the ground coffee dispensing area at a height which corresponds to the height of the circumferential wall of a porta filter put on said bracket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

[0036] FIG. 1 shows a schematic drawing of a coffee bean grinder in a side view according to the prior art;

[0037] FIG. 2 shows a schematic drawing of a coffee bean grinder in a side view according to the invention;

[0038] FIG. 3 shows in a horizontal cut the contactless proximity sensor and an approaching porta filter.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] FIG. 1 schematically represents a prior art coffee bean grinder 1 in a side view. On top there is a coffee bean container 2 comprising the coffee beans. By gravity the coffee beans in that coffee bean container 2 are allowed to enter the actual grinder module 4 grinding the coffee beans to the desired coffee powder. A conduit (not illustrated) is then used to guide the ground coffee to a ground coffee dispensing area 6, which is typically a recessed area of the coffee bean grinder 1.

[0040] The coffee bean grinder 1 comprises a grinder control unit 5 as well as typically a user input/output device 14, for example in the form of display and push buttons, or a touchscreen, to interact with the operator of the machine. Furthermore, in this embodiment there is provided a load cell 7 in a separate foot portion 8, and this load cell is a weight sensor which is used to control the amount of ground coffee dispensed into the porta filter 9. Dashed lines illustrate signal and control wiring between corresponding elements, so the grinder control unit is connected to and interacting controllably with the grinder module 4 as well as with the user input/output device. Furthermore it interacts with the load cell 7 by receiving corresponding weight signal and using it for controlling the grinding and/or dispensing process. Furthermore, the device includes power supply elements for supplying power to the control elements as well as the operating elements, indicator lights et cetera, with corresponding wiring, these additional elements are not specifically illustrated and are known to the skilled person.

[0041] The porta filter 9 comprises a handle 10, which is manipulated by the operator, by way of this handle 10 the porta filter is attached to the actual brewing module of a coffee brewing machine in the typical shift and twist motion. The handle 10 in case of manipulation of the coffee bean grinder 1 is used for putting the porta filter 9 onto the porta filter support 11. In this case the porta filter support 11 has a vertical member 12 which rests on the foot portion 8 to allow for weight measurement, and a horizontal bracket 13. Normally the porta filter 9 enters between two arms of this horizontal bracket 13 to rest on them during the grinding and dispensing process.

[0042] Furthermore, this prior art coffee bean grinder 1 is equipped with a mechanical proximity sensor 15, typically in the form of a mechanical pushbutton. This mechanical proximity sensor 15 is located on a rear wall of the ground coffee dispensing area 6 and at a vertical height such that when putting the porta filter 9 on the bracket 13 the mechanical proximity sensor is pressed, and a corresponding signal is delivered to the grinder control unit 5 for example for initiating a corresponding display on the user input/output device 14.

[0043] FIG. 2 represents an analogous schematic representation, however this time not with a prior art proximity sensor, but with a contactless proximity sensor 16. As one can see this contactless proximity sensor 16 is not contacting the porta filter 9 and is at a safe distance therefrom.

[0044] FIG. 3 shows the details of a possible contactless proximity sensor 16, in a schematic horizontal cut through a machine according to FIG. 2. In this embodiment, the proximity sensor 16 is located in a housing 20 which is mounted in or on the rear wall of the above-mentioned ground coffee dispensing area, essentially at a height of the porta filter 9. In this housing there is located a printed circuit board 21 which is signal-wired to the grinder control unit 5 (wiring not illustrated here). It may furthermore be wired to a power supply line. The printed circuit board may also contain intelligence itself, in particular if the corresponding sensor is used for repowering or upgrading of existing machines, in the sense that the signal generated by the actual sensing elements is processed, for example to either generate just a yes/no signal, or, as preferred, to generate information about the porta filter, for example about the type of the porta filter, the positioning of the porta filter, et cetera, to be delivered to the grinder control unit.

[0045] In this particular case, the contactless proximity sensor is in the form of a magnetic sensor. The actual sensing elements comprise a Ferrite core 22, a section of which comprises a coil wiring 23. The core may be permanently magnetised and the coil be used simply for detection of a disturbance in the magnetic field, or the core may be magnetised by the coil and the disturbance in the magnetic field is then detected by a change in the drive current and/or voltage in the coil. The components within that housing 20 are embedded in a potting 24, which makes this sensor element 16 as a whole and element which can be easily used for upgrading an existing machine.

[0046] Switched on, the sensor produces a magnetic field which is schematically illustrated by way of the field lines 26. The porta filter 9, comprising the perforated filter plate 18 and a metal circumferential wall section 19, approaching the sensor 16, in the representation at a distance D not triggering the sensor, if approaching further will reach the sensing distance at a certain moment, and at this sensing distance the contactless proximity sensor will generate a corresponding signal and transmit it to the grinder control unit. Preferably, such a sensor has a nominal sensing distance Sn of 3.5 mm, the real sensing distance normally varying in a range of ±10% around that value. The hysteresis is preferably less than 10% of the real sensing distance. Such a sensor can work with the supply voltage of 5 V with a no-load supply current of less than 10 mA. The maximum thermal drift of the real sensing distance should be less than 10% and the switching frequency should be in the range of 1 kHz.

TABLE-US-00001 LIST OF REFERENCE SIGNS 1 coffee bean grinder 2 coffee bean container 3 housing of 1 4 grinder module 5 grinder control unit 6 ground coffee dispensing area 7 load cell 8 separate foot portion of 1 9 porta filter 10 handle of 9 11 porta filter support 12 vertical member of 11 13 bracket member of 11 14 user input/output device 15 mechanical proximity sensor 16 contact-less proximity sensor 17 back side wall portion of 9 18 perforated filter plate of 9 19 circumferential wall section of 9 20 housing of 16 21 printed circuit board 22 Ferrite core 23 coil 24 potting 25 front surface of 20 26 schematic field lines of magnetic field D distance from porta filter Sn nominal sensing distance