Process and apparatus for controlling the preparation of beverages

DESCRIPTION

Field of the Invention

[0001] The invention relates to a method and an apparatus for controlling the preparation of beverages. More particularly, the invention relates to a brewing method and an apparatus, including an electronic controller for controlling a method of preparing freshly brewed hot beverages obtained by filtering with pressurized hot water from ground edible products such as tea, coffee, herbal preparations and the like.

State of the art

[0002] The invention is intended for use in fully automatic hot drink dispensing devices for homes, offices, catering facilities or so-called HoReCa facilities. The device according to the invention can also be used to prepare hot drinks from soluble products, i.e. so-called instant beverages.

[0003] Fully automatic beverage dispensing devices, especially those steaming hot beverages made from ground fresh ingredients, are not yet appreciated for the exceptional quality of the beverages. An espresso prepared by hand by a skilled bartender (barista) is still perceived as a drink better than that prepared by an automatic machine.

[0004] The steps for manually preparing an espresso have been described in several publications. These steps include: ensuring the correct temperature of all the elements involved in dispensing the beverage; weighing out an amount of ground roasted coffee (e.g., 6.5 grams); the grinding of the coffee is adapted to a suitable particle size, ensuring that climatic factors, especially relative humidity, do not alter the ideal grinding size for regularly achieving the correct brewing time (e.g. 25 for 40 cc); tamping the coffee inside the brew chamber, usually attached to the handle, to obtain the correct brewing time by proper extraction of the coffee cube.

[0005] Many patents are directed to applying the above concepts to improve coffee quality.

[0006] EP0554650 to Cavazzuti and Annibali discloses that the ideal roast fines size for an espresso is 25 to 395 microns, and preferably 195 to 240 microns.

[0007] In FR2477001 to Grossi, the brewer comprises a mechanical grinder system for modifying the average particle size of the coffee. The size of the modification is based on the discrepancy between the brewing time actually needed to make one espresso and the standard brewing time (set at 30 seconds), considered to be the ideal brewing time.

[0008] In US4767632 to Meier, he teaches measuring the trajectory of the compression piston and the time required to prepare a preset beverage volume to compare this data with the stored data and to use any difference between these parameters as a means of modifying the amount of coffee and the particle size of the ground coffee during brewing more drinks.

[0009] US 5,645,230 to Marogna discloses a coffee grinding and dispensing device provided with means for detecting ambient moisture and for modifying the distance of the grinding blade accordingly to provide a finer or coarser particle size.

[0010] The above solutions are not sufficient as many other factors can influence a proper preparation of the coffee.

ΕΡ 1 802 222 Β1

[0011] In some cases, the ground coffee deposit is deposited on a coffee chute located above the brewing chamber: less coffee reaches the brewing chamber until the ground coffee deposit settles to discharge more of the ground coffee into the chamber. Variable amounts of coffee in the brewing chamber can also be caused by the lack of precise measuring devices: this is the case when the grinder is operated for a preset time, when coffee with different particle sizes is fed into the volume chambers, e.g. due to wear of the grinder.

[0012] EP1306040 to Mestek, EP0486434 to Torma and other documents describes a plunger for closing a brew chamber using a "compensation spring", ie a mechanically resilient means for temporarily changing the internal volume of the brew chamber. This solution is based on the physical properties of the spring, the amount of coffee and the water pressure inside the brew chamber, and certainly does not provide an adaptive response to conditions dictated by other factors, such as the type of coffee to be prepared or the desired extraction yield.

[0013] The above-discussed documents do not address problems related to the type of coffee prepared, the volume, the amount of ground coffee used, or any other considerations suggested by market preference or economy. It should also be taken into account that the coffee concept can be interpreted differently and that the coffee machine has to respond to different end-user demands. Moreover, in a dispensing device using pre-filled capsules containing ground coffee, the capsules do not undergo any further grinding of the coffee contained therein and therefore cannot be changed.

[0014] There is therefore a need for a brewing method and apparatus that can automatically compensate for many changes in product or dispensing conditions in order to obtain consistently good coffee quality. Although US 4,767,632 A discloses a process for monitoring brewing parameters and making modifications between cycles, there is also a need for a method and apparatus that performs these compensations in real time, i.e. during the same brewing procedure.

The essence of the invention

The object of the invention is to solve the above problems and to provide a brewing method and device that continuously maximizes the quality and efficiency of extraction of hot beverages obtained from ground fresh ingredients filtered in the brew chamber by adjusting parameters. Another object of the invention is to illustrate a brewing system that not only adapts to changed conditions within preset thresholds, but that modifies its settings by monitoring the brewing conditions transmitted by the brewing system sensors during the brewing cycle.

[0016] Another object of the invention is to reduce coffee spattering typically associated with a predetermined height of the beverage spout in beverage dispensing devices using beverage containers with different edge heights.

[0017] The objects are realized by the invention which relates to a method for controlling the brewing of hot beverages according to claim 1. 1.

[0018] The invention also relates to beverage dispensing devices according to claim 1. 5.

The invention provides a method and apparatus for controlling and monitoring a brewing method and modifying it in accordance with one or more parameters that may be stored in the controller of the brewing system.

ΕΡ 1 802 222 Β1

The method according to the invention compares at least one of the data monitored by the same controller during the brewing step with at least one previously stored data and, as a result of the comparison, directs and controls by correct means the best real-time adaptation of the current brewing cycle to ideal conditions. brewing.

[0021] In other words, the invention monitors and changes, if necessary during the same brewing, the brewing method parameters according to a plurality of parameters set in the memory of the brewing system controller. According to a preferred aspect of the invention, the real-time data detected is incoming hot water or the flow rate of the prepared beverage, and the parameter to be modified is selected from the hot water supplied to the brew chamber, the flow rate of the beverage or a combination thereof. According to a further aspect of the invention, the flow rate of the beverage is adapted by modifying the capacity of the brew chamber; for this purpose the device comprises for the brew chamber one or two pistons independently controlled by motors to modify the chamber capacity.

[0022] According to a further advantageous aspect of the invention, the flow rate of the drink is modified by controlling the flow rate of the hot water entering the brew chamber. This is done by using more than one pump, by varying the speed of the water pump, or by using valve means that deflects part of the flow or restricts it. Another object of the invention is a beverage dispensing device with at least two vibrating pumps connected in series.

[0023] More generally, the beverage flow rate modifying means are selected from at least one of: brew chamber capacity modifying means; means for modifying the flow rate of the hot water entering the brew chamber; possibly also means for controlling the yield of a beverage from the brew chamber. Additionally, means for modifying the grinding parameters of the coffee may also be used.

[0024] Yield control means may be implemented by valve means on the beverage outlet line, where valve operation is controlled by a controller in a real-time feedback system.

According to a further advantageous aspect, the aims are achieved by setting parameters for a programmed sequence of actions needed to complete the beverage brewing cycle and monitoring both the stored data and the actual data received during the brewing step by modifying the flow rate, possibly also the pressure in the brew chamber and mean particle size to approximate the defined dispensing path, by a range of ideal dispensing curves relating flow rate to time, pressure, and fluid volume for each stored beverage sequence.

[0026] In particular, the control of the flow rate of the beverage and the sequence of the brewing steps is performed using one or two motors which independently operate one or two sealing pistons of the brew group, at least one flow rate detector and valve means arranged in fluid communication above the brew chamber. a means of serving hot water, means of draining a drink, liquid waste discharge means; and driver boards connecting the various components.

[0027] By controlling and modifying the flow rate of the hot water supplied to the brewing chamber, it is possible to improve the quality of the coffee brewed from the capsules, where the compression and particle size are not modified.

Description of the figures of the drawing

ΕΡ 1 802 222 Β1

[0028] The invention will now be further disclosed with reference to the accompanying non-limiting drawings, wherein Fig. 1 shows a side view of the device of the invention at the end of the dispensing step;

Figure 2 is a top view of the device of Figure 1;

Figure 3 is a sectional view of the apparatus of Figure 1;

Figure 4 is a sectional view of the device with two pistons aligned before reaching the brewing position;

Figure 5 shows a cross-sectional view similar to Figure 4 with the pistons in the brewing position;

Figure 6 is a cross sectional view similar to Figure 5 with the brew chamber being larger and in a different position;

Figure 7 is a schematic diagram of a water circuit for controlling the water flow rate;

Figure 8 is a sectional side view of a further embodiment of the infusion assembly of the invention;

Figure 9 shows a sectional top view of the assembly of Figure 8;

Fig. 10 is a sectional front view of the assembly of Figs. 8 and 9, and Fig. 11 is a further diagram of the water circuit according to the invention.

Description of the preferred embodiments

With reference to Figures 1-6, the brewing device 1 according to the invention preferably comprises a cylindrical brew chamber 2 made of a metal such as stainless steel or brass, a Teflon-coated material or plastic with at least one side 3, which can be opened to drain the used material from which the drink was brewed.

[0030] In use, two brewing pistons 4, 5 are provided at opposite ends of the chamber 2 for hermetic sealing during the brewing step. At least one piston (5 in the embodiment shown) is moveable from an open position in which the piston 5 is outside the chamber (see Fig. 2) to discharge the brewed material, to the closed brewing position. Means are also provided to control the maximum displacement of each of the pistons to keep the minimum volume inside the chamber not less than a preset value; overall the value is 56 cc.

Two filters 6, 7 are mounted facing each other in the upper region of each of the pistons 4 and 5. The filters are provided in a known manner with a plurality of openings, preferably having regular sizes and diameters ranging from 0.15 to 1 mm and positioned for optimal water distribution and extraction of the coffee cube.

[0032] The pistons 4 and 5 are respectively operated by two independent motors 9 and 8 to which the pistons are connected by means adapted to move the two pistons axially with respect to the brew chamber. Motors, preferably direct current, are connected to worm screws 8A and 9A which act on blocks 10 and 11 to move them up or down. The blocks 10 and 11 are connected to the pistons 4 and 5 respectively, allowing both pistons to be moved in the forward and rearward directions, independently of the second piston or other elements associated with the brew group.

[0033] The motors 8 and 9 are independently reversible and are activated by a microprocessor electronic controller board which includes a splitter suitable for independently driving the two motors and monitoring by braking or other signal applied to its load. This parameter is used to define the pressure opposed to the pistons by the ground ingredient compressed in the brew chamber. Both engines can be equipped with means for

EP 1 802 222 Β1 detects the offset length of the respective piston. Suitable means are e.g. an encoder, Hall sensor, optical switches and the like.

One of the pistons, in the embodiment shown, the piston 4 is provided with a port 12 or the like for feeding hot water under pressure from a source, not shown, to the brew chamber 2. Beverage drainage means 13 for releasing the brewed liquid into the user's beverage container. they are associated with the piston 5, i.e. integral with it, and move with the piston 5. Discharge means 13 shown in Fig. 1-6 include a rigid conduit to which a further flexible conduit (not shown) is connected for delivering the brewed beverage to the cup.

Figs. 8-10 show another embodiment of the device according to the invention in which like elements are numbered in Figs. 1-6 with an addition 8. In this embodiment, the two pistons 84 and 85 are coaxial with the respective worm screws. 89A and 88A, each operated by an electric motor (not shown) through shafts 28 and 29 positioned halfway up the brew group. Shafts 28 and 29 are respectively connected to vertical shafts 30 and 31 that support gears 32 and 33 connected to worm screws 88A and 89A. Filters 86 and 87 are provided on each piston for filtering the ground coffee as previously explained. Fig. 8 also shows a chute 34 for ground coffee.

Referring to Figure 7, the device of the invention comprises a pump 14 for generating the required pressure for the brewing method in fluid communication with the water supply 12 of the brew chamber 2 and connected to a water source, such as a water tank 15. The preferred flow rate is at least 0.7 to 10 cl / s, typically 1-2 cl / s for espresso coffee, the pressure of the hydraulic circuit is in the range 0.1 MPa to 2 MPa, preferably in the range 0.3 to 1 , 8 MPa.

[0037] The pressurized water leaving pump 14 is heated to a temperature ranging from 70 to 110 degrees Celsius, preferably from 80 to 100 degrees Celsius.^s Celsius, using a pressurized water heating device 19, such as a boiler tank or a flash-heater provided by a water tank 15 (or mains water supply). Temperature control means 20 associated with water pipes, brew chamber 2 or beverage circuits are also provided; the means 20 is adapted to convey information in real time (i.e. actual data detected during brewing the beverage) on the temperature of at least one of the heated circuit elements other than the water heating device, to the controller board 16.

The diagram in fig. 7 also shows the measuring means 17 for detecting the flow of the prepared drink or, alternatively, the means 18 for detecting the flow rate of the water supplied to the brew chamber 2. Both means as well as other sensor means of the apparatus according to the invention are connected to the plate. controller 16 via circuitry or relays. Preferred flow meters have a scanning unit capable of controlling differences in flow at least as low as 0.5 ml / s, and preferably 0.1 ml / s; additionally, a flow meter detector, mass sensor, flow detector or other methods of verifying the output flow rate can be arranged in the beverage discharge means to monitor the actual yield of the dispensing device in real time.

According to the invention, the controller board 16 has digital memory means and means capable of transmitting and retrieving from external sources settings relating to the various phases typical of the brewing method, which controller board is logically or electrically connected to all electrically

ΕΡ 1 802 222 Β1 operated elements contained in the brewing system, and preferably has a microcontroller having a Ram of at least 28K and a clock of 5 Ghz.

[0040] The digital software is integrated in the controller board or is provided in logical connection with the board 16. The software is designed to control and direct a plurality of means in the correct order to control the different steps of the brewing cycle. The parameters for the preferred brewing sequence are stored for each individual beverage available to the user in the memory of the controller.

[0041] The brewing sequence parameters may be modified at a remote location using a computer with dedicated software. New settings can be loaded into controller memory using flash-EPROM, electronic tag, relay, or other remote electronic file transfer system. Some, preferably simpler, parameter settings may be left to be modified by the users of the dispensing device by using means for communicating the input command to the controller, such as buttons, keypad, touch screen, or via other devices such as a portable, wired or wireless terminal for use on site devices. The current active settings are stored in the controller's memory and can be retrieved for remote control. The controller may use any of the systems available to those of skill in the art to retrieve and reload this data, such as GPRS, modem connection for internet access to a central data bank, contactless memories, handheld terminal, flash-eprom memories or other means suitable for conveying digital information. The operating software, typically contained in a driver board, also allows the preselection of different sensitivity levels for the modification process.

[0042] At least one coffee bean hopper 21 and a grinder 22 attached thereto, or alternatively, a receptacle for a freshly ground edible product such as coffee or tea, or with means adapted to deliver a measured amount of ground coffee to the brew chamber, are provided in a method known per se in the art. Additionally, one or more containers for soluble instant ingredients may be provided.

[0043] The measuring means for controlling the amount of coffee produced in the brewing chamber can be volumetric or time-based using a conclusion table, for example listing the service time of the grinders and the expected coffee volumes, depending on the average particle size of the coffee.

[0044] In a preferred embodiment of the invention, reservoir 21 is provided with sensor means 23 for detecting relative air humidity and temperature near or inside the coffee receptacle. The sensor 23 and the grinder 22 are connected to the plate 16 for providing and receiving information. The apparatus of the invention also comprises measuring means (not shown) for monitoring the exact stroke length of each piston, for example by detecting it by inference, using encoder equipped motors, stepper motors, electromechanical systems or by interconnecting electronic sensors using systems available to those skilled in the art such as Hall effect sensors or others, with the respective motor shafts of the two motors controlling the brewing pistons or their parts, in the latter case, for detecting the actual positions of the two separate pistons.

[0045] The apparatus is further provided with means for transmitting an input command recognized as a valid input command by the controller, the input command being used to provide instructions to the controller regarding the type of drink ordered by the user of the device, for example a customer or a bartender. The input method may include a keyboard,

ΕΡ 1 802 222 Β1 for example of the numerical or alphanumeric type, a simple membrane panel using pictograms, or an interactive panel such as an LCD touch screen or other common physical interfaces for sending brewing or dispensing instructions to the machine. The selected option can also be sent via a tag or a relay directly to a tag scanner or tag reader near the camera and digitally connected to the driver board. Alternatively, input data to start a brewing cycle may be provided to the controller by any signal, for example generated by a coin insertion or other money commit, recognized by the device controller as an acceptable input.

[0046] The above means include known means for providing the user of the device with information regarding the device status, such as LED indicators, LCD or plasma screen, vacuum fluorescent display, as well as means for digitally transmitting information to a remote location physically separated from the device.

[0047] According to the invention, a favorable parameter for control and possible modification is the flow rate of the hot water supplied to the brew chamber 2 or of the hot drink exiting the brew chamber.

[0048] As mentioned, changes or modifications to the brewing parameters include modifications to the flow rate of the hot water supplied to the chamber and / or the chamber capacity. Additionally, the size (e.g., mean particle size) of the milled brewing material, the hot water pressure, the absorption level of the piston control motors, the pressure of the beverage outlet fluid, or the diameter of the openings making a complete free passage in a filter located downstream of the outlet may also be modified.

[0049] It is preferable to control, i.e. vary or modify, the hot water flow rate or chamber capacity, rather than reducing the flow rate of the beverage using a valve downstream of the beverage. In fact, changing these parameters is easier and cleaner than directly changing the flow rate of a hot drink: valve means located under the brew chamber (or dissolution chamber) inevitably contact the drink, potentially causing cross contamination problems when dispensing different types of beverages, deposit build-up, bacterial contamination and the like.

[0050] It has been found that, when the hot water input flow rate is modified to maintain a constant amount of coffee brewed per time unit, i.e. to maintain the dispensing time in the range of 10 to 30 seconds, and preferably 15 to 25 seconds, most variations of the remaining parameters are can be included and corrected automatically.

[0051] In other words, according to the invention,

- the flow rate of the hot beverage or hot water is detected: this is the real-time data obtained of the brewing method to be monitored;

the detected real time flow rate data is compared with the stored hot beverage flow rate data, the stored flow rate may be different for different ground edible ingredients or beverage types;

- if a correction is needed, the hot beverage flow rate is corrected by changing the capacity of the brew chamber or by changing the flow of hot water supplied to the brew chamber.

[0052] In a preferred embodiment of the invention, there are no mechanical means to control the flow of the hot beverage between the brew chamber and the beverage delivery means, i.e. a discharge,

EP 1 802 222 Β1 from which the beverage is delivered to the cup: no change in the brewing parameters is made in or above the brew chamber.

[0053] In an embodiment of the invention, the following procedure is performed to modify or alter the flow rate of the hot water supplied.

As soon as the pressure in the brew chamber is established and the water progressively traverses the coffee block, the flow rate indicated by the measuring device, at least one of which is in fluid communication with the water supply means to the brew chamber, is used as a feedback signal for the change brewing parameters after a programmable delay or by starting the pump.

[0055] In the absence of a flow rate indication, even after a programmable delay, the dispensing device is set to an "idle" state and the actual interface displays this information to the users of the device.

[0056] Assuming a positive flow rate reading monitored by at least a flow rate indicator located upstream of and in fluid communication with the brew chamber, the controller compares the reading to a comparable ideal brewing curve value associated with the particular beverage prepared.

[0057] In the event of a discrepancy between the two data, in the first embodiment, at least one of the stroke lengths of the piston is changed due to the feedback so that the capacity of the brew chamber 2 is modified and the flow rate is kept as close as possible to the preset dispensing curve. The controller-controlled minimum offset step should not change the internal capacity of the chamber for capacities greater than 0.5cc, preferably 0.3cc.

[0058] In a second embodiment of the invention, the flow rate of the water supplied to the brew chamber is varied and modified. This can be done, for example, by using a pump having variable speed, such as a rotary pump, to introduce pressurized water into the brew chamber. A change in speed can also be obtained by changing the vibration frequency of a vibration pump.

[0059] Alternatively, as shown in Fig. 7, when the sensor 18 informs the controller 16 to reduce the flow rate of the supplied water, the valve 24 is operated to send a portion of the water flow to the circuit including the compressed air chamber 25 and connected to the reservoir 15 with pump or with discharge means.

[0060] A preferred embodiment is shown in Fig. 11, wherein the apparatus of the invention comprises two series connected pumps 14 and 14A. Preferably, the two pumps are vibration pumps and are operated separately or at the same time as required by the brewing procedure. Suitable pumps are e.g. those produced by Ulka (Italy).

[0061] It has been found that when two or more pumps are connected in series, it is possible to operate both pumps at the same time, achieving a flow rate increase of up to about 80% and a dosing time reduction of about 45-50%. These values ​​are obtained when two identical vibration pumps are connected in series, but not when connected in parallel. By using two Ulka E7 vibration pumps, the flow rate increased from 2.45 ml / s to 4.23 ml / s and the preparation time for an espresso (approximately 47 ml) was reduced from 20.4 s to 11.2 s. Two or more other pumps may be used in place of two (or more) identical pumps.

[0062] The method will include first activating one or both of the pumps as required by the drink to be prepared, e.g. coffee brewed through a filter comprising e.g. 150 ml will be

ΕΡ 1 802 222 Β1 initially required two pumps to maintain dosing, ie brewing time within the required range of 10 to 35 seconds. If the data detected during the brewing step is different from the stored data, one pump will be stopped or slowed down to reach the required values.

[0063] As mentioned and illustrated above, in addition to the flow rate, further data may additionally be detected and further parameters modified or changed. The following sequence of operational steps for a selected drink, for example "espresso" coffee, depicts an embodiment making full use of all parameters and data received. in real time. Operation of the dispensing device begins when the user transmits an input command to the controller. First, check that the grinding level is correctly adjusted. Sensors 23 located close to the grinder 22 or coffee container 21 detect the current value of the relative humidity and optionally also the temperature in the air. The controller 16 includes software for storing historical comparable data monitored by the sensors at intervals programmable by the device manufacturer.

[0064] The controller software may use multiple methods to evaluate the available data, both current and historical, for example, summing each series of stored data or parts thereof, thus computing statistically significant data such as arithmetic or calculated means. A preferred calculation criterion is the lag time between the monitoring time and the brewing time, so that the readings for the last twenty-four hours, preferably the last one to nine hours, should be given more weight.

[0065] Preferably, the controller software comprises a means of trending, for example, comparing the current readings with the stored data readings at various time intervals, such as for example the last one to twenty-four hours, suitably stored in memory.

In contrast to available systems, the invention compares previously recorded data with current readings to determine favorable criteria for influencing grinder blade modifications so that the user of the apparatus may opt to maintain changes based on real-time data, or more traditionally, by slower cutting speed for blade distances, for example for less stringent quality standards.

[0067] A grinder blade distance setting motor provided with means for detecting the actual blade distance or alternatively for measuring the travel distance of the blade steering motor, for example from a fully closed position to an actual position. When a difference between the stored data greater than a predetermined threshold is detected, the motor is activated to modify the blade distance accordingly. In the brew chamber 2 or 82, a pre-selected dose of coffee (e.g. set at 6.5 g in the controller) with a predetermined average particle size is dispensed according to the monitored relative air humidity and trend value as well as the type of selected beverage.

[0068] After the coffee beans have been ground, a brewing step is performed.

[0069] Generally, in the brewing cycle of the invention, four distinct stages are provided and the brewing system comprises sensors suitable for providing the controller board with information regarding hot beverage flow rate, hot water flow rate, one or two piston travel length and power absorption. motors connected to them, the temperature of the measures suitable for

ΕΡ 1 802 222 Β1 heat transfer to the brew chamber. As previously mentioned, all sensors are connected via a wired connection or relay type connection to the controller board 16 which also receives information regarding the setting of the coffee grinder blades supplying the brewing chamber and the type of beverage required by the user, thereby selecting a group of preset parameters during a specific cycle brewing.

[0070] The brewing cycle begins when, after filling the brew chamber with a measured amount of coffee, the closing piston 5 moves from the open filling position to the closed brewing position (Fig. 5).

[0071] In a preliminary phase, at least one of the engines 8, 9 connected to the pistons reaches a preset, programmable absorption level, set as a threshold parameter in the controller memory for immediate disconnection of the motor drive, when the preset level is reached by the motor drive.

[0072] The set absorption level depends not only on the amount of coffee, but for example on programming data instructing the closing of the brewing piston or the pistons with a predetermined amount of coffee inside the chamber. A predetermined amount of coffee may be stored as historical data combined with an absorption reading to establish a correlation to be used for the statistical information and preventive maintenance information.

[0073] The coffee cube is compressed from an irregular shape defined by the means used to transfer it into the brew chamber, for example a pyramidal shape into a cylindrical shape, with a compression level depending on a preset threshold parameter.

[0074] When the piston has reached the programmed travel length with the squeezed coffee cube, the programmed amount of water can be sprayed over the coffee cube. It is preferable to use the pump 14 with means adapted to control the flow of the pump to allow this spraying step to be carried out at a reduced flow rate, possibly at least 40% less than that normally used in the brewing step.

[0075] This optional step is performed to pre-wet the coffee cube as needed and with a programmable amount of pressurized hot water from the water supply means, to minimize the negative effects in terms of beverage quality and extraction efficiency, which the preferential paths in the coffee cube tend to be creation.

[0076] After the predetermined amount of water has been dispensed by the coffee cube, the brewing unit stops for a preset amount of time, less than twenty seconds, preferably between one and ten seconds.

[0077] Alternatively, the drain may be temporarily closed to create a pressure increase to obtain a similar pre-wetting step without taking a pause.

[0078] The entire pre-wetting step may be omitted, especially in the case of making American coffee, to indicate a different nature, for example the so-called 300 ml "typical coffee" drink from traditional espresso coffee, where the pre-wetting is most often used and usually higher is preferred. extraction efficiency.

[0079] When dispensing beverages based on leaf tea, mat or herbal preparations, longer discharges of pre-wetting water and longer pauses before the actual brewing phase starts are implemented to maximize the quality of the extraction.

[0080] Similarly, if soluble drinks are to be used in the chamber, pre-wetting water may be used to maximize the dissolution of the soluble ingredient in the liquid.

ΕΡ 1 802 222 Β1

[0081] The second step begins after the controller activates the means associated with at least one of the two brew pistons to bring the brew chamber into a closed, sealed brew position.

[0082] In a first embodiment, the motors 8 and 9 are then deactivated such that the two pistons are held in a pre-programmed position depending on the type of drink to be prepared, expressed in terms of the length of the stroke or preferably the power absorption of each of the two piston steering motors.

[0083] In a first embodiment, the motors are adapted by means of allowing the motors to remain activated during the compression of the coffee cube until they reach a threshold level for absorption, and then during the actual brewing phase, so that absorption of the at least one motor can be used as feedback criterion.

[0084] Offset length and power absorption data, or relationship data therebetween, as well as their frequency, are stored in the memory of controller 16 for potentially fetching preventive maintenance information from memory of the controller.

[0085] Steaming by pressurized means is typically carried out in two different ways: from the top to the bottom of the bar or from the bottom to the top. In the embodiment shown in the figures, infusion is carried out in the second way, although the first method is equally useful.

[0086] Both embodiments solve one problem associated with users using a beverage dispensing device with beverage containers of different shapes, especially heights, such as porcelain cups, espresso cups, coffee cups, small jugs and the like.

[0087] Typically the containers may be adapted to fit the dispensing area of ​​a dispensing device, however their edge heights commonly range from 4 to 30 cm, most typically from 6 to 20 cm.

To solve this problem, a coffee spout is used which is connected to the relevant piston and the beverage discharge means, by means of which the programmed displacement lengths of both pistons during the dispensing phase enable the spout 13, in accordance with the preset required beverage preparation, to move to one of the multiple preset positions. Accordingly, the drain spout can be moved exactly over the edges of cups with different edge heights from the bottom, such as a cappuccino cup, espresso cup or mug, or alternatively, the drain spout can pass to different drainage means adapted for instance to dispense one or two coffees.

[0089] The controller, depending on the pre-set parameters, can execute brewing cycles with different travel lengths for each piston to maintain the correct coffee cube pressure for the selected beverage type while minimizing the distance between the edge of the container and the flow of the prepared beverage being dispensed from the spout or also for the selected beverage type. providing the end of the drain with access to an alternative beverage outlet, for example to reverse the run-off to two different dosing drains.

[0090] Since both pistons can be moved to raise or lower the height of the spout with respect to the edge of the beverage container, it can be controlled irrespective of the amount of coffee used or the type of coffee desired to fit the container used in the vessel area. The height of the beverage outlet spout depends on the preset type of beverage or beverage container required by the user which corresponds to the preset parameters in the memory of the controller.

ΕΡ 1 802 222 Β1

[0091] In the embodiment of the attached drawing, the brewing unit is able to offset the height of the beverage discharge means within a defined range, in this case between 10 cm for single brewing cycles and 7 cm for double brewing cycles.

[0092] As soon as the pistons have completed the programmed advancement paths, hot water is fed into the brew chamber through a filter placed on the piston equipped with water supply means, i.e. a filter 7 or 87 of piston 4 or 84. The hot water supply means is in fluid communication with the pump (s) 14 and 14A, possibly with one three-way valve or preferably two separate valves to separately manage the hot water supply and residual liquid coffee waste and flow rate measuring device 18.

[0093] The flow rate control for this step is performed as discussed earlier, i.e. by using one or more of the plurality of vibration pumps, by changing the speed of the pump or by changing the capacity of the chamber. Additionally, a reduction in the flow rate through the valve may be performed.

[0094] Finally, after the preset volume of water has been fully dispensed in the brew chamber and from there into the final container, the controller starts a sequence directed to draining the used ground coffee. First, at least one of the pistons is moved by suitable transmission means from the now end closed brew position to a position defined by a travel length greater than that of the end closed brew position. A plurality of offset lengths are stored in the memory of the controller, which may be used according to a predefined matching criterion for different types of coffee beverages dispensed or amounts of liquid allowed in the ground coffee used.

[0095] The displacement motion is performed to increase the pressure in the brew chamber so that less residual liquid is kept inside the coffee cube due to the higher pressure thus achieved. As soon as the travel length is reached, the controller opens a water circuit (not shown) to drain the remaining amount of coffee and water in the delivery tube, coffee cube and brew chamber.

[0096] This can alternatively be done by using two separate valves each individually controlling the water supply to the brew chamber and a purge circuit directed to drain the liquid remaining at the end of the brew cycle inside the brew chamber, the coffee cube and the water circuits, or alternatively by using one three-way a valve due to which, preferably, the previous embodiment with two separate valves, it allows for separate control of the supply and discharge means, such that the brewing cycle can delay the shut-off of the water supply and the opening of the discharge means for used waste liquid residues.

[0097] It is noteworthy that all mentioned parameters are stored in the memory of the controller for statistical purposes and can be retrieved and modified at any time by means available to those skilled in the art, which have previously been mentioned.