Coffee machine with milk dispensing device and related method for controlling a current milk dispensing cycle

Abstract

A coffee machine (1) comprising a milk dispensing device (4) having a jug (6) containing milk, from which milk is extracted by means of a flow of steam fed to a Venturi effect chamber connected to the jug (6), wherein the machine body has optical means (12) for detecting the level of milk (14) present in said jug (6), comprising at least first operating infrared optical means (12a, 12b) for detecting at least a first level (L1) of milk in said jug (6) in the vicinity of which, wherein a controller is configured to control a current milk dispensing cycle based at least on the signal acquired by the optical detection means.

Description

Detailed Implementation

[0001] This invention relates to a coffee machine with a milk dispensing device and a related method for controlling the current milk dispensing cycle.

[0002] As is well known, there are many types of coffee machines on the market today. In addition to traditional coffee dispensers, these machines are equipped with devices for emulsifying and / or heating milk. Typically, in these machines, the milk dispensing device includes a pot containing milk and a lid that closes the pot. This lid has a Venturi effect chamber, which is capable of drawing the milk present in the pot through a flow of steam appropriately generated by the boiler of the coffee machine.

[0003] In some cases, an infrared optical device is provided to detect the level of milk present in the jug, and the milk dispensing cycle is controlled by the infrared optical device. The milk dispensing cycle is extended until the jug is completely emptied so that no milk residue is left inside.

[0004] If the kettle is completely emptied, the boiler must be stopped before the distribution cycle ends to avoid the generation of steam that could be dangerous to the user.

[0005] However, precise control of the milk distribution cycle is often quite complex, because milk distribution can depend on a variety of factors even at the same steam temperature, pressure, and flow rate.

[0006] In addition to the temperature of the milk, these factors also include the type of milk used, which can be of various sources, such as animal or plant, such as cow's milk, goat's milk, soy milk, almond milk, etc.

[0007] The technical objective of this invention is to eliminate the shortcomings of the prior art mentioned above.

[0008] Within the scope of this technical task, one object of the present invention is to design a coffee machine having a device for emulsifying and heating milk, which allows for automatic adaptation of the milk dispensing cycle in a universal manner so that the pot is emptied.

[0009] Within the scope of this technical task, another object of the present invention is to design a coffee machine that allows for automatic adaptation of the milk dispensing cycle to avoid incorrect operation of the equipment used for emulsifying and heating milk.

[0010] This task is accomplished by a coffee machine comprising a main body, an electronic controller, a water pump, a boiler for generating steam from the water, a steam distributor equipped with a shut-off solenoid valve, and a dispensing device for dispensing milk emulsified and / or heated by the steam. The device has a pot containing the milk and a lid that closes the pot. The lid has a Venturi effect chamber connected to the steam distributor and the pot for drawing out the milk present in the pot. An optical device is also provided for detecting the level of milk present in the pot. The optical device includes at least a first operating infrared optical device for detecting at least near a first level of milk in the pot. The controller is characterized by storing a nominal value of the transition time of the signal from a preset first threshold near the first level to a second threshold, and a nominal value of a first delay between the moment the boiler is deactivated and the moment the first level of milk is detected.

[0011] During the execution of the current milk distribution cycle, obtain the current value of the transition time;

[0012] If the current transition time is different from the nominal transition time, the current milk distribution cycle is executed with the current value of the first delay modified relative to the nominal value of the first delay.

[0013] In a preferred embodiment of the invention, the electronic controller is configured to: increase or decrease the current value of the first delay relative to the corresponding nominal value in the current milk distribution cycle if the current transition time is greater than or less than the nominal transition time.

[0014] In a preferred embodiment of the invention, the electronic controller is configured to execute the current dispensing cycle at a current value of a second delay between the moment the pump is deactivated and the moment the first level of milk is detected, wherein the current value of the second delay is explicitly derived from the current value of the first delay.

[0015] In a preferred embodiment of the invention, the optical device for detecting the level of milk present in the pitcher includes at least a second operable infrared optical device for detecting at least near a second level of milk, wherein the second level is lower than the first level. In a preferred embodiment of the invention, the electronic controller is configured to execute the current dispensing cycle at a current value of a third delay between the moment the solenoid valve is closed and the moment the second level of milk is detected, wherein the current value of the third delay is explicitly derived from the current value of the first delay. In a preferred embodiment of the invention, the first optical device includes a first transmitter IR and a first receiver IR positioned at the first level, and the second optical device includes a second transmitter IR and a second receiver IR positioned at the second level.

[0016] In a preferred embodiment of the invention, the second optical device is arranged near the bottom of the pot.

[0017] In a preferred embodiment of the invention, if the first liquid level is not detected within a specific time interval from the moment the solenoid valve is opened, the electronic controller excludes the aforementioned control over the current dispensing cycle.

[0018] In this case, the current dispensing cycle for executing the recipe will be executed after the predefined settings for the recipe are executed, wherein the timing of shutting off the pump and boiler and the timing of closing the solenoid valve are predefined.

[0019] The present invention also discloses a method for controlling the milk dispensing cycle of the coffee machine.

[0020] In practice, during the execution of the current milk distribution cycle, the machine can automatically reset the delay by modifying the delay relative to the nominal delay.

[0021] In fact, it has been found that there is a specific correlation between the type of milk used and the signal obtained by the first detection device near the first liquid level of the milk.

[0022] The signal obtained depends on the specific chemical / physical properties of the milk used, such as its source (animal or plant), and for milk of the same source, it depends on temperature, fat content, etc.

[0023] Advantageously, this established correlation has been used to adapt the execution of the current milk allocation cycle.

[0024] The result is that if the pot is already filled with the correct amount of milk for the selected recipe, then almost all of the pot's contents can be dispensed according to the selected recipe, regardless of the type of milk used and without generating steam.

[0025] Further features and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a coffee machine having a device for emulsifying and heating milk, illustrated by a non-limiting example in the accompanying drawings, wherein:

[0026] Figure 1 This is a front view of a coffee machine without equipment for emulsifying and heating milk;

[0027] Figure 2 This is a perspective view of a coffee machine in which the equipment used for emulsifying and heating milk is disconnected from the main body of the machine;

[0028] Figure 3 This is a front view of a coffee machine in which the equipment for emulsifying and heating milk is connected to the main body of the machine.

[0029] Figure 4 This is a cross-sectional side view of a device connected to an external steam distributor for emulsifying and heating milk;

[0030] Figure 5 The trend of the signal acquired by the first optical detection device over time is shown by dashed lines, and the trend of the signal acquired by the second optical detection device over time is also shown by dashed lines.

[0031] Figure 6 The trend of signals acquired by the first optical detection device for three different types of milk present in the pot during time interval F1 is shown;

[0032] Figure 7 A diagram showing a milk dispensing cycle controlled by an optical detection device is presented.

[0033] Figure 8 The trend of signals acquired by the first optical detection device for three different types of milk present in the pot is shown (reversed for ease of observation), and specifically, the diagram illustrates the transition time of the signal from a first threshold preset near a first liquid level of milk to a second threshold.

[0034] Figure 9 A simplified table is shown to determine the type of milk present in the pot.

[0035] With particular reference to the above-mentioned figures, the coffee machine as a whole, which has equipment for emulsifying and heating milk, is indicated by the number 1.

[0036] The coffee machine 1 includes a machine body 2 having a coffee dispenser 3 and a device 4 for emulsifying and / or heating milk on the same surface.

[0037] An electronic controller (not shown) is installed in the coffee machine 1 in a known manner. A water pump (not shown), a boiler for generating steam from water (not shown) supplied by the pump, and an external distributor 10 for the steam flow generated by the boiler, which is equipped with a shut-off solenoid valve 30, are connected to the electronic controller.

[0038] The device 4 has a pitcher 6 containing milk 14 and a lid 7 for closing the pitcher.

[0039] For reasons that will become clearer below, pot 6 is made of a transparent material.

[0040] The lid contains a Venturi effect chamber 9, to which a pipe 21 for removable connection to a steam distributor 10, an air intake pipe 22 possibly equipped with an adjustable opening shut-off valve, an intake pipe 23 for intake of milk present in the kettle 6, and a pipe 18 for dispensing heated and / or emulsified milk are connected.

[0041] Device 4 is removably associated with machine 1 by being in a cantilevered position relative to machine body 2, in such a way that pot 6 is kept at a distance from the resting surface 24 of the machine on which cups or other containers are usually positioned.

[0042] Specifically, at least one cup 11 for collecting coffee and / or emulsified and / or heated milk may be placed on the resting surface 24.

[0043] An optical device 12 is installed in the main body 2 of the machine to detect the level of milk present in the pot 6.

[0044] The optical detection device includes at least first infrared optical devices 12a and 12b, specifically a first transmitter IR and a first receiver IR, which operate to detect the level of milk present in the pot 6 at least near a first milk level L1.

[0045] The optical detection device 12 preferably further includes a second infrared optical device 12c, 12d, specifically a second transmitter IR and a second receiver IR, which are operable to detect the level of milk present in the pot at least near a second liquid level L2 below the first liquid level L1.

[0046] The second liquid level of milk, L2, is near the bottom 13 of the pitcher 6.

[0047] Specifically, the detection device 12 is placed on the main body 2 of the machine 1, and is also spaced apart from the resting surface 24 so as to face the lower area of ​​the pot 6.

[0048] Advantageously, the electronic controller is configured to store a nominal value of the transition time of the signal from a first threshold S1 preset near a first liquid level L1 to a second threshold S2, and a nominal value of a first delay between the moment the boiler is shut down and the moment the first liquid level L1 of milk is detected.

[0049] The electronic controller is also configured to acquire the transition time Δt of the signal from a first threshold S1 to a second threshold S2 during the execution of the current milk dispensing cycle. x The current value of x, where x = a, b, c, etc., and "a", "b", "c", etc. identify the type of milk used.

[0050] In order to execute the user-selected recipe, if the current transition time of the signal from the first threshold S1 to the second threshold S2 is different from the nominal transition time, the electronic controller modifies the current value dt of the first delay relative to the corresponding nominal value. 1a Execute the current milk distribution cycle.

[0051] The electronic controller is configured to: if the current transition time of the signal from the first threshold S1 to the second threshold S2 is higher or lower than the nominal transition time, then in the current milk dispensing cycle, increase or decrease the current value dt of the first delay relative to the corresponding nominal value. 1a .

[0052] The electronic controller is also configured to use the current value dt of the second delay between the moment the pump is stopped and the moment the first milk level L1 is detected. 1b Execute the current allocation loop, where the current value dt of the second delay is... 1b Explicitly from the current value dt of the first delay 1a Export.

[0053] Furthermore, the electronic controller is configured to execute the current dispensing cycle at the current value dt2 of a third delay between the moment the solenoid valve 30 is closed and the moment t2 when the second milk level L2 is detected, wherein the current value dt2 of the third delay is explicitly derived from the current value dt of the first delay. 1a Export.

[0054] If the first liquid level L1 is not detected within a specific time interval starting from the moment the solenoid valve 30 is opened, the controller disables the aforementioned control of the current distribution cycle and replaces it with a preset control during the execution of the current distribution cycle.

[0055] With the help of Figures 5 to 8 This illustrates a simplified scenario of how the current milk distribution cycle is performed.

[0056] The user loads the amount of milk into the pitcher, which corresponds to the amount required for the recipe to be executed, as indicated by the reference notch marking on pitcher 6.

[0057] In any case, the amount of milk loaded must exceed the minimum level above L1, which is also indicated by the notch on pitcher 6.

[0058] The recipe can be a latte macchiato with only milk, a cappuccino with only milk, or double milk, etc.

[0059] The user has selected a specific type of milk, such as cow's milk, soy milk, or almond milk, and we use "a" to indicate that specific type of milk.

[0060] Users control the execution of recipes from the coffee machine's dashboard.

[0061] After the pump and boiler have been activated, the electronic controller commands the solenoid valve 30 to open at time t0=0 and milk dispensing thus begins.

[0062] During the dispensing process, the milk level in the jug drops to near level L1.

[0063] The first infrared optical devices 12a and 12b will send the signal detected near the liquid level L1 to the electronic controller.

[0064] The electronic controller processes the acquired signal and calculates time Δt. a The signal uses this time to travel from the first threshold S1 to the second threshold S2.

[0065] The value Δt corresponds to the milk type "a" present in pot 6. a The nominal value used to potentially correct the first delay for shutting off the boiler: if Δt a Unlike the nominal transition time, the electronic controller sets the current value dt of the first delay, which is different from the nominal value of the first delay. 1a .

[0066] Mathematical functions will be able to explicitly define the degree of correction.

[0067] Since t1 is defined as the moment when the milk level L1 in pot 6 is detected, during the time interval between t0 and t1, solenoid valve 30 is opened, and pump and boiler are turned on.

[0068] Since t is defined 1a =t1+dt 1a Therefore, at t1 and t 1a Between these conditions, the current distribution cycle is executed when the boiler is turned on, the pump is turned on, and solenoid valve 30 is obviously open.

[0069] At time t 1a The boiler is shut down and thus begins to reduce steam generation.

[0070] The electronic controller also automatically sets the current value dt of the second delay used to shut down the pump.1b And the current value dt2 of the third delay used to close the solenoid valve.

[0071] The current value dt of the second delay 1b The current value dt2 of the third delay can be explicitly linked to the current value dt of the first delay. 1a It uses mathematical functions to calculate. For example, dt 1b It can be equal to dt 1a Twice as much.

[0072] Since t is defined 1b =t1+dt 1b Therefore, in t 1a With ti b During the time interval between these events, the current allocation cycle is executed when the boiler is shut down and the pump is turned on, while from time t... 1b Initially, the current distribution cycle continues even when the pump is turned off, and solenoid valve 30 remains open.

[0073] As the current dispensing cycle continues, the milk level in the jug drops further, approaching level L2.

[0074] Since t2 is defined as the moment when the milk level L2 in pot 6 is detected, at t 1b During the time interval between t2 and t2, solenoid valve 30 remains open, while the pump and boiler are shut off.

[0075] Since t is defined 2a = t2 + dt2, therefore the solenoid valve 30 remains open until the moment t when the solenoid valve finally closes. 2a .

[0076] At time t 2a The current milk distribution cycle has ended, which corresponds to the complete emptying of pot 6.

[0077] If the user has loaded milk type "b" or "c" into pot 6 to perform the same recipe, the electronic controller will calculate the time Δtb or Δtc it takes for the signal to travel from the first threshold S1 to the second threshold S2, and will correct the nominal value of the first delay used to shut off the boiler in a different way, and thus correct the second and third delays.

[0078] Figure 5 The trend of the signal acquired by the detection device 12 for the current dispensing cycle as described above is shown when using milk type "a".

[0079] F0 indicates the time interval during which the signal (specifically, the signal acquired by the first pair of sensors 12a, 12b) remains above threshold S1 and the milk level is above L1; F1 indicates the time interval after F0 during which the signal is between threshold S1 and threshold S2 and the milk level is near level L1; F2 indicates the time interval after F1 during which the signal travels below threshold S2 and the milk level is included between L1 and L2; F3 indicates the time interval after F2 during which the signal (specifically, the signal acquired by the second pair of sensors 12c, 12d) is below threshold S3 and the milk level is near level L2; and F4 indicates the time interval after F3 during which the signal is below threshold S3 and the milk level is below level L2.

[0080] When the amount of milk loaded into the pot is equal to or even less than the nominal amount of milk allocated associated with the nominal dispensing cycle, the control of the current dispensing cycle, which is thus executed, allows the pot to be almost completely emptied, thereby interrupting dispensing without producing unwanted steam ejection.

[0081] Finally, the electronic controller is configured to disable the aforementioned controls for the current distribution cycle in certain circumstances and execute the same recipe by following predefined and dedicated settings for each recipe: specifically, the electronic controller also stores reference times for each recipe for shutting off the pump and boiler and for closing solenoid valve 30 (starting from the moment solenoid valve 30 is opened).

[0082] If the user has loaded much more milk into the pitcher than the recipe requires, the recipe will be executed via this predefined setting.

[0083] To assist users in this regard, as shown in the figure and as already mentioned, the pot 6 may be provided with one or more reference notches for properly filling the pot according to the selected recipe.

[0084] Therefore, if the electronic controller determines that the reference time for shutting off the boiler has elapsed before the liquid level L1 has been reached, it disables the correction for the nominal delay provided by the moments when liquid levels L1 and L2 are detected and implements control through predefined settings.

[0085] In these cases, since a large amount of milk is available compared to the amount required to execute the formula, there is no risk of steam ejection, so intervention by the detection system IR is not necessary. In fact, in any case, some milk will remain in the jug at the end of the current dispensing cycle.

[0086] If the milk level loaded by the user is substantially correct, intervention by the detection system IR is necessary. The result is that, for the same formula, the amount of milk dispensed may vary depending on the type of milk used, but will always ensure that the jug is almost completely emptied without any steam escaping.

[0087] It should be noted that the upper sensor IR and the lower sensor IR can operate in combination or selectively to improve signal resolution.

[0088] For example, at interval F1, it is preferable that only the upper sensors IR 12a, 12b are active, so that the electronic controller can process signals acquired at a higher sampling frequency.

[0089] Coffee machines with such a design for emulsifying and heating milk are easily subject to numerous modifications and variations, all of which fall within the scope of the inventive concept; furthermore, all details can be replaced by technically equivalent components.

[0090] In practice, the materials and dimensions used can be determined according to needs and existing technology.

Claims

1. A coffee machine (1) comprising a machine body (2), an electronic controller, a water pump, a boiler for generating steam from water, a steam distributor (10) provided with a shut-off solenoid valve (30), and a dispensing device (4) for dispensing milk emulsified and / or heated by the steam, the device (4) having a pot (6) containing the milk and a lid (7) for closing the pot (6), the lid having a Venturi effect chamber (9) connected to the steam distributor (10) and the pot (6) for drawing out the milk present in the pot (6), and further provided with an optical device (12) for detecting the level of milk (14) present in the pot (6), the optical device comprising at least a first operating infrared optical device (12a, 12b) for acquiring a signal at least near a first level (L1) of milk in the pot (6), characterized in that, The controller is configured to: - Store the nominal value of the transition time of the signal from a first preset threshold (S1) near the first liquid level (L1) to a second preset threshold (S2), and the nominal value of the first delay between the moment the boiler is shut down and the moment the first liquid level (L1) of milk is detected; - During the execution of the current milk distribution cycle, acquire the transition time (Δt) of the signal from the first preset threshold (S1) to the second preset threshold (S2). x The current value of ). -If the current transition time (∆t) x The current value (dt) of the first delay is modified relative to the nominal value of the first delay, which is different from the nominal transition time. 1a ) Execute the current milk distribution cycle.

2. The coffee machine (1) according to claim 1, characterized in that, The electronic controller is configured to: if the current transition time is greater than or less than the nominal transition time, increase or decrease the current value (dt) of the first delay relative to the corresponding nominal value in the current milk distribution cycle. 1a ).

3. The coffee machine (1) according to claim 1, characterized in that, The electronic controller is configured to use the current value (dt) of the second delay between the moment the water pump is deactivated and the moment the first milk level (L1) is detected. 1b ) execute the current milk distribution cycle, wherein the current value (dt) of the second delay 1b ) explicitly from the current value (dt) of the first delay 1a Export.

4. The coffee machine (1) according to claim 1, characterized in that, The optical device for detecting the level of milk present in the pot (6) includes at least a second operating infrared optical device for detecting at least near a second level (L2) of milk, wherein the second level (L2) is lower than the first level (L1).

5. The coffee machine (1) according to claim 4, characterized in that, The electronic controller is configured to execute the current milk dispensing cycle at the current value (dt2) of a third delay between the moment the solenoid valve (30) is closed and the moment (t2) when the second liquid level (L2) of milk is detected, wherein the current value (dt2) of the third delay is explicitly derived from the current value (dt) of the first delay. 1a Export.

6. The coffee machine (1) according to any one of claims 4 and 5, characterized in that, The first operational infrared optical device includes a first transmitter IR and a first receiver IR positioned at the first liquid level (L1), and the second operational infrared optical device includes a second transmitter IR and a second receiver IR positioned at the second liquid level (L2).

7. The coffee machine (1) according to claim 6, characterized in that, The second operating infrared optical device is arranged near the bottom of the pot (6).

8. The coffee machine (1) according to claim 6, characterized in that, The first operating infrared optical device and the second operating infrared optical device operate selectively or in combination.

9. The coffee machine (1) according to claim 1, characterized in that, During the execution of the current milk dispensing cycle, if the first liquid level (L1) is not detected within a specific time interval from the moment the solenoid valve (30) is opened, the controller disables the aforementioned control of the current milk dispensing cycle.

10. A control method for controlling a current milk dispensing cycle in a coffee machine (1), the coffee machine comprising a machine body, an electronic controller, a water pump, a boiler for generating steam from water, a steam distributor equipped with a shut-off solenoid valve, and a dispensing device (4) for dispensing milk emulsified and / or heated by the steam, the device (4) having a pot (6) containing the milk and a lid (7) for closing the pot (6), the lid having a Venturi effect chamber connected to the steam distributor and the pot (6) to draw out the milk present in the pot (6), and an optical device for detecting the level of the milk present in the pot (6), the optical device comprising at least a first operating infrared optical device for detecting a first level of milk in the pot (6), characterized in that, The control method includes the following steps: - The nominal value of the transition time of the stored signal from a first threshold preset near the first liquid level (L1) to a second threshold, and the nominal value of the first delay between the moment the boiler is shut down and the moment the first liquid level (L1) of milk is detected; - During the execution of the current milk distribution cycle, obtain the current value of the transition time; -If the current transition time (∆t) x The current value (dt) of the first delay is modified relative to the nominal value of the first delay, which is different from the nominal transition time. 1a ) Execute the current milk distribution cycle.

11. The control method according to claim 10, characterized in that, The current value (dt) of the second delay between the moment the water pump is stopped and the moment the first milk level (L1) is detected. 1b ) execute the current milk distribution cycle, wherein the current value (dt) of the second delay 1b ) explicitly from the current value (dt) of the first delay 1a Export.

12. The control method according to claim 11, wherein the optical device for detecting the level of milk present in the pot (6) comprises at least a second operable infrared optical device for detecting a second level (L2) of milk near the bottom of the pot (6), wherein the second level (L2) is lower than the first level (L1), characterized in that, The control method further includes the following steps: - The current milk dispensing cycle is executed at the current value (dt2) of a third delay between the moment the solenoid valve (30) is closed and the moment (t2) when the second liquid level (L2) of the milk is detected, wherein the current value (dt2) of the third delay is explicitly derived from the current value (dt) of the first delay. 1a Export.

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