Coffee machine provided with a coffee mill and process to control the coffee mill of the coffee machine

Abstract

A control unit, a pump for supplying infusion water, a boiler for heating the infusion water, an infusion unit, a coffee mill, and a user interface including a selector for a beverage and/or a ground coffee dose. The coffee mill has a hopper for coffee beans, a rotating and a non-rotating grinder, a motor for directly or indirectly driving the rotating grinder, all with capability to adjust the distance between the grinders. A first sensor detects a number of turns and/or speed of the motor and/or of the rotating grinder. A second sensor detects a distance between the grinders. The control unit stores an algorithm for calculating a correct dose of ground coffee, configured to receive the value of ground coffee selected and the distance between the grinders to automatically generate the number of motor turns necessary to obtain the correct dose of ground coffee.

Claims

1. A coffee machine (1) comprising: a control unit (3), a pump (4) for supplying infusion water, a boiler (6) for heating the infusion water, an infusion unit (7), a coffee mill (2) comprising a hopper (10) for coffee beans, a rotating grinder (11) and a non-rotating grinder (12), a motor (13) for driving the rotating grinder (11), and an adjuster that controls a distance between the grinders (11, 12), a user interface (8) comprising at least a selector (9) for a beverage or a ground coffee dose, a first sensor (23) for detecting a number of turns of the rotating grinder (11), and a second sensor (22) for detecting a distance between the grinders (11, 12), wherein the control unit (3) stores an algorithm for calculating a correct dose of ground coffee, said algorithm configured to receive as an input from the selector (9) a value of ground coffee dose selected and from the second sensor (22) a value of the distance between the grinders (11, 12) to automatically generate as an output a value of a number of total turns that the rotating grinder (11) must perform, at the certain value of the distance between the grinders (11,12), to obtain the correct dose of ground coffee, said control unit (3) configured to receive as an input from the first sensor (23) a present value of a number of turns of the rotating grinder (11) to produce a stop signal for stopping the motor (13) upon reaching said number of total turns.

2. The coffee machine (1) of claim 1, further comprising a selector that adjusts said number of total turns calculated by the algorithm.

3. The coffee machine (1) of claim 2, wherein said selector comprises a flavor selector (25) comprised in said user interface (8).

4. The coffee machine (1) of claim 1, further comprising a third sensor (26) for detecting a resence in the hopper (10) of a minimum amount of coffee beans.

5. The coffee machine (1) of claim 1, wherein infusion parameters are pre-set.

6. The coffee machine (1) of claim 1, further comprising at least one infusion selector that adjusts infusion parameters.

7. The coffee machine (1) of claim 6, wherein said at least one infusion selector that adjusts the infusion parameters comprises at least one selector switch comprised in said user interface (8).

8. A process to control a coffee mill (2) of a coffee machine (1), wherein said coffee machine (1) comprises: a control unit (3), a pump (4) for supplying infusion water, a boiler (6) for heating the infusion water, an infusion unit (7), a user interface (8) comprising at least a selector (9) for a beverage or a ground coffee dose, and wherein said coffee mill (2) comprises: a hopper (10) for coffee beans, a rotating grinder (11) and a non-rotating grinder (12), a motor (13) for driving the rotating grinder (11), and an adjuster that controls a distance between the grinders (11, 12), wherein the control unit (3) operates a grinding cycle according to the following steps: acquiring from the selector (9) a selection of a ground coffee dose; acquiring a value of a distance between the grinders (11, 12); calculating a number of total turns that the rotating grinder (11) must perform during the grinding cycle to obtain a correct dose of ground coffee on a basis of the acquired selection of the ground coffee dose and the acquired value of the distance between the grinders (11, 12); activating the grinding cycle by driving in rotation the rotating grinder (11); acquiring, during the grinding cycle, a present value of a number of turns of the rotating grinder (11); and stopping rotation of the rotating grinder (11) upon reaching said number of total turns calculated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional features and advantages of the invention will become more apparent from the description of a preferred but non-exclusive embodiment of the coffee machine and of the process to control the coffee mill of the coffee machine according to the invention, illustrated by way of non-limiting example in the appended drawing, in which:

(2) FIG. 1 shows a diagram of a coffee machine with an incorporated coffee mill in accordance with the invention; and

(3) FIG. 2 shows a possible construction of the coffee mill in greater detail.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(4) With reference to the cited figures, a coffee machine 1 provided with a coffee mill 2 is shown.

(5) In addition to the coffee mill 2, the coffee machine 1, in a known manner, comprises a control unit 3 in communication with a pump 4 for supplying infusion water connected on the inlet side to a tank 5 or directly to the mains water supply, a boiler 6 for heating the infusion water, an infusion unit 7, and user interface means 8 comprising at least a selector 9 for a beverage and/or a ground coffee dose.

(6) The user interface means 8 can comprise selectors of varying nature; for example, the selector 9 can be a knob or a mechanical or virtual pushbutton, created in the latter case by means of touch screen technology.

(7) The interface means 8 are generally positioned on the control panel of the coffee machine.

(8) A construction of an already known type of coffee mill 2 is described below purely by way of example.

(9) The coffee mill 2 comprises a hopper 10 for coffee beans, a pair of grinders 11, 12, a motor 13 for driving the grinders 11, 12 in relative rotation, and means for adjusting the distance between the grinders 11, 12.

(10) In particular, the coffee mill 2 comprises a rotating grinder 11 and a non-rotating grinder 12 that are coaxial relative to an axis 14 and delimit a gap 15, which determines the particle size, where grinding takes place.

(11) The rotating grinder 11 is drivable in rotation about the axis 14 by means of the motor 13, whilst suitable means for adjusting the gap 5 comprising a ring nut 16 are operatively engaged with the non-rotating grinder 12 to make it translate in parallel with the axis 14 so as to be able to modify the width of the gap 15.

(12) In particular, a tooth 17 projecting radially from the outer perimeter of a receptacle 18 supporting the non-rotating grinder 12 engages with a cam profile 19 present along the inner lateral wall of the adjustment ring nut 16, which in turn has outer teeth 20 meshing with a gear 21 borne by the shaft of a sensor 22 which enables a calculation of the width of the gap 15.

(13) One of the grinders, in particular the rotating one 11, further has a clutch (not shown) which disengages it from the motor 13 when a moment of friction is created between the grinders 11, 12, blocking their reciprocal rotation.

(14) The blockage of the relative rotation between the grinders 11, 12 can be caused by the presence of small stones, coconut peels and other impurities in the coffee to be ground.

(15) Grinders with a different construction from the one just described can obviously be provided and fall within the scope of the invention.

(16) Advantageously, the coffee machine 1 comprises a first sensor 23 for detecting the number of turns and/or speed of the motor 13 and/or of the grinders 11, 12 and the second sensor 22 for detecting the distance between the grinders 11, 12.

(17) The first sensor 23 is preferably a proximity sensor capable of performing the measurement without direct contact.

(18) The second sensor 22 can in turn be a potentiometric transducer which reads the angular position of the ring nut 16 or else a laser sensor, an extensometer, a capacitive sensor, a potentiometer, an encoder, etc.

(19) The first sensor 23 and the second sensor 22 are in communication with the control unit 3 of the coffee machine 1.

(20) Moreover, the control unit 3 of the coffee machine 1 stores an algorithm for calculating the correct dose of ground coffee.

(21) Advantageously, the calculation algorithm is configured to receive as an input from the selector 9 the value of ground coffee selected and from the second sensor 22 the value of the distance between the grinders 11, 12 so as to automatically generate as an output the value of the number of total turns that the motor 13 must perform at a given distance between the grinders 11, 12 to obtain the correct dose of ground coffee.

(22) The control unit 3 is further configured to receive as an input from the first sensor 23 the current value of the number of turns and/or of the speed of the motor 13 and/or of the rotating grinder 11, so as to produce a stop signal for stopping the motor 13 upon reaching the number of total turns calculated.

(23) Number of turns means an angular spatial parameter expressed, for example, in degrees and/or number of pulses corresponding to an angular value.

(24) Calculating the ground coffee dose on the basis of a number of turns is extremely more precise than calculating it on the time basis used up to now, as it is not affected by any variations in the speed of the motor 13 and/or grinders 11, 12, which can occur during grinding, for example because of a variable trend in the relative motion resisting torque between the grinders 11, 12 and/or variations in the power supply voltage depending on the site of installation of the coffee machine.

(25) Advantageously, the coffee machine 1 also comprises fine manual adjustment means for adjusting the number of total turns calculated by the algorithm.

(26) Said adjustment means enable the user to personalise the flavour as desired by modifying the amount of ground coffee compared to the one calculated by the algorithm.

(27) The fine manual adjustment means comprise, for example, a flavour selector 25 provided in the interface means 8.

(28) Advantageously, the coffee machine 1 also comprises a third sensor 26 for detecting the presence in the hopper 10 of a minimum amount of coffee beans.

(29) The third sensor 26 communicates with the control unit 3 to prevent grinding when the presence of an amount of beans insufficient to produce the correct ground coffee dose selected is detected in the hopper 10.

(30) The infusion parameters comprise, in particular, the boiler temperature, and/or the duration of the infusion process and/or the phases thereof (pre-infusion and actual infusion), and/or the pressure and/or flow rate during the (pre-infusion and actual infusion).

(31) The infusion parameters can be pre-set but, advantageously, the coffee machine 1 can also have fine manual adjustment means for adjusting the infusion parameters, for example made up once again of one or more selectors 27 provided in the interface means 8.

(32) The grinding process is carried out as follows.

(33) The control unit 3 acquires from the selector 9 the selection, made by the user, of the dose of coffee to be ground, as it is associated with the selected beverage, and from the second sensor 22 it acquires the value of the distance between the grinders 11, 12.

(34) The control unit 3 enters into the calculation algorithm the value of ground coffee selected and the value of the distance between the grinders 11, 12.

(35) The calculation algorithm automatically generates as an output the value of the number of total turns that the motor 13 must perform to obtain the correct dose of ground coffee.

(36) At this point the control unit activates the grinding process by driving in rotation the motor 13, which in turn drives in rotation the grinders 11, 12.

(37) While the motor 13 is rotating, the control unit 3 acquires from the first sensor 23 the current value of the number of turns and/or of the speed of the motor 13 and/or of the grinder 11.

(38) If it directly acquires the number of turns, the control unit 3 compares the current number of turns with the one calculated by the algorithm and stops the rotation of the motor 13 when the current number of turns reaches number of total turns calculated by the algorithm.

(39) If, on the other hand, it acquires the speed of the motor 13 or grinder 11, the control unit 3 performs an integration in the time domain of the acquired data to derive therefrom the current number of turns, which is again compared with the one calculated by the algorithm in order to stop the rotation of the motor 13 when the current number of turns reaches number of total turns calculated by the algorithm.

(40) The coffee machine and the method of controlling the coffee mill incorporated therein as thus conceived are susceptible of numerous modifications and variants, all falling within the scope of the inventive concept; moreover, all of the details are replaceable with technically equivalent elements.

(41) The materials used, as well as the dimensions, may in practice be of any type, according to needs and the state of the art.