Method of operation of a grinding apparatus and corresponding grinding apparatus

Abstract

The invention concerns a method of operation of a grinding apparatus (10) comprising a grinding device (13) provided with a chamber (24) in which bean grinding members (25) are disposed, which is able to carry out at least one procedure for the complete emptying of said chamber (24), and a grinding apparatus (10) that implements this method.

Description

[0001] “METHOD OF OPERATION OF A GRINDING APPARATUS AND CORRESPONDING GRINDING APPARATUS”

[0002] FIELD OF THE INVENTION

[0003] Some embodiments described here concern a method of operation of a grinding apparatus, in particular a method for achieving a complete emptying of the chamber containing the grinders, and the corresponding grinding apparatus that implements this method. The invention also concerns a machine for preparing beverages which integrates the grinding apparatus, and the corresponding method for preparing beverages.

[0004] BACKGROUND OF THE INVENTION

[0005] In the sector of machines for preparing beverages, those for producing coffeebased beverages, mainly for domestic or semi-professional use, in which the beverage is obtained, for example, by brewing a powdered aromatic mixture, are particularly known.

[0006] These machines generally comprise a brewing unit and a grinding device for producing the powdered aromatic mixture in the machine itself, starting from coffee beans contained in a specific hopper, which can be fixed on the structure of the machine or removable.

[0007] In recent years, machines with removable type hoppers have become increasingly popular, allowing consumers to easily change the variety of beans to be used, choosing them, for example, from Coffea Arabica, Coffea Robusta, or Canephora, Coffea Liberica and Coffea Excelsa, simply by replacing the hopper instead of manually emptying the fixed hopper and then filling it with another variety.

[0008] In general, hoppers of the removable type have a lower aperture, selectively closable by means of one or more closing elements and through which the coffee beans can enter the grinding device.

[0009] In known machines, both when the hopper’s lower aperture is closed and also when the hopper is removed from the machine, a certain quantity of residual coffee, both in the form of beans as well as powder, remains inside the grinding device.

[0010] Usually, this quantity of coffee is comprised between about 5 and about 10 grams, and is sufficient to allow the delivery of an additional dose of a coffeebased beverage.

[0011] The presence of the aforementioned residual coffee in the grinding device constitutes a non-negligible problem, in particular if one wants to change the coffee variety; in fact, in the latter case, during the preparation of the specific beverage, contamination may occur between the new coffee variety present in the hopper and the residual coffee variety present in the grinding device.

[0012] In addition, the presence of residual coffee can lead to further drawbacks, such as for example the deterioration or malfunction of the grinding device’s grinders, thus also leading to a worse quality of the coffee delivered.

[0013] To avoid these problems and / or drawbacks, it is therefore necessary to discharge, or remove, the residual coffee present in the grinding device.

[0014] This operation is usually performed manually, without a specific guided procedure. For example, very often it may be necessary to rotate, or overturn, the machine itself making the residual coffee come out, dirtying the surrounding environment. This, however, only achieves an approximate removal of the residual coffee; in fact, while the beans can be removed fairly easily, the correct emptying of the powdered part of the coffee is much harder to achieve.

[0015] Other solutions provide an automated procedure, selectable by a user, to carry out the grinding of the beans that have accumulated inside the grinding device and empty it before inserting a new batch of coffee beans. This procedure substantially provides to activate the grinding device for a predefined fixed time interval, suitable to grind any residual coffee beans and remove the ground coffee powder.

[0016] A disadvantage of these solutions is caused by the fact that, in order to guarantee a complete emptying of the grinding device, since the quantity of residual beans is not known, it is necessary to keep the grinders active for an extended time interval. This time interval has to take into account both the time required to grind the maximum quantity of beans that can be contained in it, and also the fact that, as the quantity of beans gradually decreases, they tend to jump and bounce inside the grinding device, since their weight force is not sufficient to keep a layer of beans in contact with the grinders. Consequently, it is necessary to consider a longer time interval than would normally be required to grind the maximum quantity of beans that can be contained in the grinding device. It is also known that the noise generated by the grinding device increases considerably when the grinders rotate substantially idly, that is, without coffee beans, therefore it is very annoying for a user.

[0017] In known solutions, therefore, too short a fixed time interval entails the risk of not guaranteeing the complete emptying of the grinding device, while an excessive time interval leads to a prolonged and annoying noise.

[0018] To try to solve this problem, solutions are known that provide to detect the electric current absorbed by the motor that drives the grinders, or the torque generated by them, in order to determine when there are no more residual beans inside the grinding device and to be able to stop the grinders. Such solutions, however, require the presence of appropriate sensors associated with the motor or grinders, which can lead to an increase in overall costs.

[0019] WO 2023 / 123988 Al describes a grinding apparatus of a known type and the corresponding method of operation. US 2011 / 215178 Al describes a method for detecting a quantity of beans in a container. US 2020 / 163485 Al describes a beverage preparation machine.

[0020] There is therefore the need to perfect a method of operation of a grinding apparatus and a corresponding grinding apparatus that implements this method, which can overcome at least one of the disadvantages of the state of the art. In particular, one purpose of the present invention is to provide a method of operation of a grinding apparatus which guarantees that the grinding device is emptied completely and at the same time keeps the noise generated to a minimum.

[0021] Another purpose of the present invention is to provide a method for emptying a grinding device which does not require the use of sensors associated with the motor or the grinders.

[0022] Another purpose is to provide a method of operation of a grinding apparatus that is able to adapt to the effective operation of the apparatus over time.

[0023] Another purpose of the invention is to provide a machine and perfect a method for preparing a beverage in which the emptying of any residual material present in the grinding device occurs automatically, without the need for manual intervention by a user.

[0024] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0025] SUMMARY OF THE INVENTION

[0026] The present invention is set forth and characterized in the independent claims.

[0027] The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0028] In accordance with the above purposes, a method of operation of a grinding apparatus is provided, the apparatus comprises a grinding chamber in which selectively drivable grinding members are disposed.

[0029] The grinding members can be flat or conical type grinders. In general, by grinding device here and hereafter in the description we mean a component suitable to reduce the size of the products to be ground, transforming food products in the form of beans, grains or seeds, such as coffee beans or suchlike, into a powdered substance with a desired granulometry.

[0030] The operating method according to the invention comprises a step of determining a current grinding flow rate of the grinding device, a processing step in which there is calculated an emptying time interval necessary to grind a predefined reference bean quantity and correlated to a maximum bean quantity that can be contained in a containing chamber of the grinding device with the current flow rate determined, and an emptying step in which the grinding members are activated for a duration corresponding to the emptying time interval calculated.

[0031] Doing so achieves at least the advantage of being able to dynamically adapt the emptying time interval in which to keep the grinding members active every time a complete emptying thereof is required, based on the real operation of the grinding device, correlated to the current flow rate, so as to guarantee the grinding and removal of the beans present in the grinding device and at the same time limit the duration of the noise generated to a minimum.

[0032] Here and hereafter in the description, by the term “flow rate” we mean the quantity of powdered substance produced in a unit of time, which in turn is correlated to the quantity of beans ground in a unit of time. The flow rate can be considered in terms of volume or weight in relation to a unit of time.

[0033] Preferably, the quantity of powder considered is in terms of weight.

[0034] The flow rate can vary both as a function of the characteristics of the grinding device itself, for example the torque generated or the wear of the grinders, and also as a function of the characteristics of the coffee beans, including for example the size of the beans, their species, such as Arabica or Robusta, and their roasting level. In addition, the level at which the grinding device is set, correlated to the granulometry to be achieved, also has an influence on the flow rate.

[0035] The method according to the invention in fact provides to monitor the trend of the grinding device’s flow rate over time, at each preparation of a dose of powdered substance, or with a predefined frequency, so as to know its current value and be able to use it to define the emptying time. In this way, during normal steady state operation, when the flow rate stabilizes around a maximum flow rate value, the emptying time interval will have a minimum duration, while in an initial start-up instant of the grinding device, or when the grinders show any signs of wear, the emptying time interval will have a longer duration. In any case, the time interval will be such as to guarantee the grinding of the reference bean quantity and therefore the emptying of the grinding device.

[0036] According to one aspect of the invention, the predefined reference bean quantity that is considered is greater than the maximum bean quantity contained in the grinding device, that is, in the containing chamber thereof. According to another aspect of the invention, the reference been quantity in weight is comprised between 1.01 and 2 times the maximum bean quantity that can be contained in the grinding device.

[0037] According to preferred embodiments, the reference been quantity is comprised between 1.1 and 1.3 times the maximum bean quantity. The value of the maximum quantity contained in the grinding device can be a value defined in the design phase, estimated on the basis of the volume comprised between the grinders of the grinding device and the bottom of a hopper that feeds the beans.

[0038] Since beans of different species have different sizes, and the number and quantity in grams that can accumulate in this volume can be very different from one case to another, the maximum quantity could for example be considered as the one there would be in the case of beans of a given type or having a predefined average size. The maximum quantity value can be defined in the design phase and be stored in a memory unit.

[0039] According to one aspect of the invention, the value of the reference bean quantity can be determined on the basis of experimental tests and stored in a memory unit.

[0040] According to some embodiments, it could also be provided that different values of maximum quantity and reference quantity, or a possible reciprocal proportionality coefficient, which are correlated to one or more of either a variety of beans, roasting level or desired granulometry level, are stored in the memory unit.

[0041] In accordance with another aspect of the invention, the method according to the present invention for determining the flow rate of the grinding device provides to measure, for each preparation of a dose of coffee powder, the volume of a tablet of powdered substance obtained and the grinding time actually elapsed between the start and stop of the grinding members.

[0042] According to one aspect of the invention, the method provides to detect the height of the tablet obtained by means of an encoder.

[0043] According to another aspect of the invention, the method provides to detect the grinding time by means of a time meter which can for example be inside a control unit or a microcontroller.

[0044] According to some embodiments, the method provides to determine the flow rate on the basis of a value of the weight of the powdered substance obtained with a given set grinding time interval and the grinding time measured.

[0045] According to some embodiments, the weight value is a datum estimated on the basis of a volume of the tablet, calculated as a function of the measured height, multiplied by a parameter defining a density of the coffee powder.

[0046] In accordance with one aspect of the invention, the density can be considered as a constant value, defined in the design phase and stored in the memory unit.

[0047] According to possible variants, the density can be determined as a function of information relating at least to the roasting level of the coffee beans, for example given by a user through a user interface.

[0048] According to these variants, it can be provided that a plurality of different values of the density of the coffee powder are stored in the memory unit, each associated with a roasting level of the beans, and the method can provide to select on each occasion the density value to be considered in order to determine the flow rate based on the information received from the user interface.

[0049] In accordance with some embodiments, there is also provided a grinding apparatus for preparing a dose of coffee powder, which comprises a container for the coffee beans, a grinding device configured to receive the coffee beans and grind them, obtaining the dose of coffee powder, flow rate determination means configured to determine a current grinding flow rate of the grinding device, and a control and command unit configured and programmed to carry out a method for emptying the grinding device according to the present invention. In particular, suitable algorithms and computer programs can be stored in the memory unit which the control unit can implement in order to carry out the operating method according to the invention.

[0050] According to another aspect, the apparatus comprises a removable type container for the beans, provided with a closing bottom which, when the container is inserted and connected in a housing compartment of the apparatus, remains substantially open and the coffee beans are fed to the grinding device by gravity.

[0051] According to this embodiment, it can be provided that the emptying method according to the invention is carried out following the receipt of a command from a user and the possible detection of the closure of the bottom.

[0052] According to a variant, the apparatus comprises a removable type container for the beans provided with a closing bottom having an outlet aperture offset with respect to a central axis, and suitable rotatable type feeding means which can be driven by means of a drive member and are configured to feed on each occasion a desired dose of coffee beans from the container to the grinding device. In this variant, the emptying method according to the invention can advantageously be carried out for each beverage preparation.

[0053] The present invention also concerns a machine for preparing beverages comprising a grinding apparatus according to the invention and a method for managing the machine which comprises executing an operating method according to the invention.

[0054] DESCRIPTION OF THE DRAWINGS

[0055] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0056] - fig. 1 is a schematic and simplified representation along a section on a vertical plane of a grinding apparatus in accordance with a first variant of the invention; - fig. 2 is a schematic view of a machine for preparing a beverage in which the apparatus of fig. 1 is integrated;

[0057] - fig. 3 is a schematic and simplified representation of a grinding apparatus in accordance with a variant of the present invention;

[0058] - figs. 4a-4b are enlarged details of a brewing unit of the machine of fig. 2 in a first and a second operating configuration;

[0059] - fig. 5 is a block diagram of a method of operation of the grinding apparatus according to the invention;

[0060] - fig. 5a is a block diagram of a step of the method of fig. 5.

[0061] We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0062] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

[0063] With reference to fig. 1, this shows a grinding apparatus 10 according to the present invention, usable to grind coffee beans 11 or parts thereof, although other types of food substances, such as for example seeds, cereals, barley, etc., are not excluded.

[0064] The apparatus 10 comprises a hopper 12, that is, a container suitable to contain and feed the beans 11 , and a grinding device 13 configured to grind the beans 11 and obtain a powdered substance with a desired granulometry.

[0065] In the example given here, the hopper 12 can be removably inserted in a housing compartment 14, in particular made in a frame 15 shaped so as to internally define a space 16 for accommodating the operating components. A detection device 28 connected to the control unit 18 and configured to detect the presence of the hopper 12 in the housing compartment 14, that is, detect if the hopper 12 is associated with the grinding device 13, can be associated with the housing compartment 14. According to other embodiments, the hopper 12 can be of the fixed and nonremovable type.

[0066] According to the embodiments of figs. 1 and 2, the hopper 12 is provided with at least one lower aperture 17 for the exit of the beans C toward the grinding device 13. The hopper 12 can also comprise a lid 18 and a protection element 19 disposed inside it to prevent possible injuries to a user caused by the grinding device 13.

[0067] With the lower aperture 17 there is operatively associated a closing bottom 20, of a known type and not described in detail, configured to selectively close the lower aperture 17 so that the hopper 12 can assume a non-operating condition when the lower aperture 17 is closed (fig. 1), or an operating condition when the lower aperture 17 is open (fig. 2).

[0068] In the case shown in figs. 1 and 2, the hopper 12 is of the type configured to feed the beans 11 to the grinding device 13 by gravity when the lower aperture 17 is open, filling substantially the entire space available in the grinding device 13 below.

[0069] According to other embodiments, for example shown with reference to fig. 3, it can also be provided that the hopper 12 is provided with means 21 for feeding the beans, for example a rotating member 22 comprising one or more blades 23 for moving the beans 11 toward the lower aperture 17, or a dosing device, not shown, for supplying a predefined dose of coffee beans to the grinding device 13 on each occasion. The rotating member 22 can be selectively driven by means of a motor, not shown.

[0070] The grinding device 13 can comprise a chamber 24 for accumulating and grinding the beans 11 , in which one or more grinding members are disposed, for example a pair of grinders 25 of which at least one grinder 25 is driven selectively and made to rotate by a command member of a known type, such as for example an electric motor 26, commanded by a control unit 30.

[0071] The chamber 24 substantially delimits the space comprised between the bottom of the hopper 12 and the bottom of the grinding device 13.

[0072] The chamber 24 comprises a first section 31, a second section 32 and a third section 33, which are communicating with each other and disposed respectively one below the other. The first section 31 is disposed in proximity to or in contact with the lower aperture 17 and is configured to receive the beans 11 coming from the hopper 12.

[0073] The grinders 25 are disposed in the second section 32, and both beans 11 as well as at least a part of powdered substance can be present.

[0074] The third section 33 is configured to contain substantially only the powdered substance and a conveying duct 34 is associated with it, which has the function of conveying and directing the exiting powder.

[0075] The apparatus 10 also comprises flow rate determination means 51 configured to determine a current grinding flow rate FR of the grinding device 13.

[0076] According to some embodiments, the flow rate determination means 51 comprise one or more sensors 36 configured to measure and / or determine a weight of the coffee powder ground by means of the grinding means 25 and a time meter 37, in particular configured to measure an effective grinding time tm during the operation of the grinding device 13, as will be explained in more detail below.

[0077] The apparatus 10 also comprises an electronic type control unit 30, connected to the operating components to regulate their operation. The control unit 30 can be for example a CPU, a microprocessor or a controller.

[0078] The control unit 30 is in particular programmed and configured to execute a method for emptying the grinding device 13 according to the present invention, which will be described in greater detail below. According to some embodiments, the control unit 30 is configured to execute the emptying method following receipt of a specific emptying command received by means of a user interface 27 connected to the control unit 30.

[0079] According to this embodiment, the apparatus 10 can also comprise detection means 38, configured to verify whether the lower aperture 17 is open or closed, that is, whether the bottom 20 is in the opening and closing position, and send a signal to the control unit 30 which can be configured to offer the user, through the interface 27, one or more options to proceed with emptying the grinding device 13 in the event the closing position is recognized. The interface 27 can comprise a touch sensitive screen 29 or a display screen, and possible buttons for making selections or giving commands.

[0080] In addition or alternatively, it can also be provided that the control unit 30 executes the emptying method at each preparation of a dose of powdered substance which is fed to the grinding device 13.

[0081] The grinding apparatus 10 can be of the autonomous or stand-alone type, configured to supply doses of powder into a filter-holder or other collection element, or be integrated into a machine 40 for preparing beverages of the automatic or even semi-automatic type, usable to prepare a beverage starting from a powdered substance, for example shown in fig. 2.

[0082] The machine 40, in addition to the grinding apparatus 10 and its components, also comprises a brewing unit 41 configured to prepare a beverage, a hydraulic circuit, not shown in the drawings, for feeding water to the brewing unit 41, and a delivery unit 42, fluidically connected to the brewing unit 41, which allows to deliver the prepared beverage into a container 43, for example a cup, a mug, or suchlike.

[0083] In the case of an apparatus 10 integrated in a machine 40 for preparing beverages, the control unit 30 can be a central control unit of the machine 40 itself, for example a CPU or a microcontroller. The machine 40 also comprises a user interface 27 through which a user can select a certain beverage, for example espresso coffee, and possibly customize it according to their tastes, for example by selecting between “normal”, “lungo” (long) or “ristretto” (short) coffee, or by setting a more or less strong and intense flavor. Based on the data received from the user interface 27, the control unit 30 is configured to determine the quantity of powder Qc required to prepare the beverage selected, and consequently the quantity of beans to grind.

[0084] In the case of a stand-alone apparatus 10, the user interface 27 can be configured to directly receive indications regarding the quantity of powder Qc to be prepared. Figs. 4a, 4b schematically show the brewing unit 42, which can essentially comprise a containing body 44, open upward, which internally defines a brewing chamber 45 configured to contain a certain amount of powder Qc to be brewed.

[0085] The containing body 44 is fluidically connected to the delivery unit 43 by means of a distribution duct 46.

[0086] The containing body 44 cooperates on one side with a closing piston 47, which is disposed in a fixed position outside the containing body 44 and is provided with delivery members 48 for delivering pressurized hot water onto the powder present in the brewing chamber 45.

[0087] Furthermore, an ejection piston 49 is disposed sliding in the brewing chamber 44 and is provided with respective outlet members 50 which are connected to the distribution duct 46 to allow the exit of the certain beverage during the brewing process. In a first operating condition, shown in fig. 4a, the containing body 44 is closed at the top by the closing piston 47 and the ejection piston 49 compresses the coffee powder present in the brewing chamber 45 in such a way as to make it essentially take the shape of a disc, known in the field by the term “tablet”.

[0088] In a second operating condition, shown in fig. 4b, the containing body 44 is spaced apart from the closing piston 47 and cooperates with the ejection piston 49 to allow, through the action of a pushing member, the ejection of the aforementioned tablet from the brewing chamber 45, discharging it into a specific discharge zone, not shown.

[0089] Fig. 5 schematically shows a block diagram of a method for operating the grinding apparatus 10.

[0090] The operating method comprises the execution of at least one procedure for completely emptying the grinding device 13 in order to remove substantially all the beans and coffee powder present therein.

[0091] According to some embodiments, the emptying procedure comprises a step of determining a current flow rate FR of the grinding device 13, a processing step in which there is calculated an emptying time interval Ats necessary to grind a predefined reference bean quantity Qref which is correlated to a maximum bean quantity Qmax that can accumulate in the chamber 24 of the grinding device 13 with the current flow rate FR determined, and an emptying step in which the grinding members 25 are activated for a duration corresponding to the emptying time interval Ats calculated.

[0092] According to some embodiments, the emptying time interval Ats can be calculated by means of the following formula:

[0093] The method provides to monitor the trend of the flow rate of the grinding device

[0094] 13 over time, so as to know its current value and be able to use it to define the emptying time interval Ats.

[0095] According to some embodiments, the method can provide to monitor the flow rate at each preparation of a dose of coffee powder or, in the case of a machine 40, at each beverage preparation, or with a predefined frequency, for example every 3, 4, 5, 10 preparations.

[0096] According to some embodiments, the maximum quantity Qmax can be a value defined in the design phase and correlated to the size of the chamber 24.

[0097] According to some embodiments, the value of the maximum quantity Qmax can be estimated on the basis of the volume comprised between the grinders 25 of the grinding device 13 and the bottom of the hopper 12.

[0098] Since beans of different species have different sizes and the number and quantity in grams that can accumulate in this volume can be very different from one case to another, the maximum quantity could for example be considered as the one there would be in the case of beans of a given type.

[0099] According to some embodiments, the value of the reference bean quantity Qref can be determined based on experimental tests and stored in a memory unit 35. This value can be fixed.

[0100] According to some embodiments, it can also be provided that different values of maximum quantity Qmax and reference bean quantity Qref for different types of coffee beans are stored in the memory unit 35, for example based on the roasting level of the beans or their variety. In this case, it can be provided that suitable information on the coffee beans to be used can be acquired through the interface 27, on the basis of which the control unit 30 can select the appropriate Qmax, Qref values on each occasion.

[0101] According to some variants, the flow rate can be defined as the quantity in volume of coffee powder obtained in a unit of time, for example cubic centimeters / second.

[0102] According to some embodiments, the quantities in the formula above are in terms of weight, and the flow rate is defined as the quantity of ground beans by weight in a unit of time, for example grams / second.

[0103] The reference bean quantity Qref can be comprised between 1.01 and 2 times the maximum quantity Qmax.

[0104] According to preferred embodiments, the reference bean quantity Qref is comprised between 1.1 and 1.3 times the maximum quantity Qmax.

[0105] Considering for example a chamber 24 suitable to contain a maximum quantity Qmax of 10g, the reference bean quantity Qref can be comprised between 10.01 and 20 g, and in particular between 11g and 13g.

[0106] By calculating the emptying time interval Ats on the basis of a quantity of beans greater than the one which could potentially be present in the chamber 24 and on the basis of the current flow rate FR of the grinding device 13, it is possible to keep the grinders 25 active for the necessary time but at the same time to keep the noise to a minimum.

[0107] According to some embodiments, in order to determine the flow rate FR, the method provides to determine the volume of the coffee powder obtained by activating the grinding device 13 for a grinding time tm* set on the basis of a certain quantity of powder Qc to be obtained, measuring the effective grinding time tm during which the grinders 25 are kept active and calculating the ratio between the volume determined and the effective grinding time tm.

[0108] According to some embodiments, in order to determine the flow rate FR of the grinding device 13, the method according to the invention provides to measure or determine a weight of the coffee powder obtained by keeping the grinders 25 active for a certain set grinding time tm* and to measure the effective grinding time tm during which the grinders 25 are kept active.

[0109] According to some embodiments, the method provides to determine the weight of the powder obtained on the basis of a volume Vol of a tablet P of compressed powder, which can be measured or calculated at each preparation of a dose of coffee powder, or according to a defined frequency.

[0110] According to one aspect of the invention, the method provides to detect the height H of the tablet P obtained by means of an encoder 36, or other suitable sensor. In the case of a machine 40, this measurement can be carried out, for example, when the brewing unit 41 is disposed in the operating configuration of fig. 4a. In the case of a stand-alone apparatus 10, an encoder 36 or similar sensor associated with coffee powder compression means, for example suitable to cooperate with a filter-holder, can also be provided.

[0111] In the case of a stand-alone apparatus 10, it can be provided that the weight of the powder obtained is measured by means of load cells or similar weight sensors, for example associated with a powder collection element.

[0112] According to another aspect of the invention, the method provides to detect the effective grinding time tm by means of a time meter 37 which can be for example inside the control unit 30. According to some embodiments, the method provides to determine the flow rate FR on the basis of the ratio between the volume Vol of the tablet, calculated on the basis of the detected height H, multiplied by a density D of the coffee powder, and the measured grinding time tm.

[0113] According to some embodiments, the flow rate FR can be calculated based on the following formula:

[0114] According to some embodiments, the density D can be considered as a constant value, defined in the design phase and stored in the memory unit 35.

[0115] According to possible variants, the density D can be determined as a function of information relating at least to the roasting level of the coffee beans, for example supplied by the user through the user interface 27.

[0116] According to such variants, it can be provided that a plurality of different density values D of the powder are stored in the memory unit 35, each associated with a roasting level RL of the beans, or possibly also with their origin / variety, and the method can provide to select on each occasion the density value D to be considered to determine the flow rate FR based on the information on the beans received through the user interface 27.

[0117] According to some embodiments, the method according to the invention can provide to execute the emptying procedure based on the reception of a specific command from the user through the interface 27.

[0118] According to other variants, it can be provided that the emptying procedure is performed at each beverage preparation. It is clear that, in any case, whenever the emptying procedure needs to be carried out, the emptying time interval Ats will be updated in real time based on the effective flow rate FR for the current operation of the grinding device 13.

[0119] According to some embodiments, the method can comprise a step of receiving information relating to at least the roasting level RL of the beans, or possibly their origin / variety, and on the basis of this information selecting one or more of either the value of the maximum quantity Qmax, of the reference bean quantity Qref and / or of the density D to be used from a plurality of values stored in a memory unit. According to some embodiments, it can be provided that the flow rate calculation also takes into account the granulometry level GL set for the grinding device.

[0120] It is clear that modifications and / or additions of parts may be made to the grinding apparatus 10, to the beverage preparation machine 20 and to the operating method as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0121] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of grinding apparatus 10, machine 20 and operating method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0122] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Method of operation of a grinding apparatus (10) comprising a grinding device (13) provided with a chamber (24) in which bean grinding members (25) are disposed, which is able to carry out at least one procedure for the complete emptying of said chamber (24), characterized in that it comprises: a step of determining a current grinding flow rate (FR) of said grinding device (13), a processing step in which there is calculated, on the basis of said current flow rate (FR) determined, an emptying time interval (Ats) necessary to grind a predefined reference bean quantity (Qref), correlated to a maximum bean quantity (Qmax) that can be accumulated in said chamber (24), and an emptying step in which said grinding members (25) are activated for a duration corresponding to said emptying time interval (Ats) calculated.

2. Method as in claim 1, characterized in that said reference quantity (Qref) is comprised between 1.01 and 2 times said maximum quantity (Qmax).

3. Method as in any claim hereinbefore, characterized in that said predefined reference bean quantity (Qref) is comprised between 1.1 and 1.3 times said maximum quantity (Qmax).

4. Method as in any previous claim from 1 to 3, characterized in that in order to determine said flow rate (FR) it provides to determine the volume of the powdered substance obtained through the activation of the grinding device (13) for a grinding time (tm*) set on the basis of a determinate quantity of powder (Qc), and calculate the ratio between said volume and an effective grinding time (tm) measured during the operation of said grinding device (13).

5. Method as in any previous claim from 1 to 3, characterized in that in order to determine said flow rate (FR) it provides to activate the grinding device (13) for a grinding time (tm*) set on the basis of a determinate quantity of powder (Qc) and to measure an effective grinding time (tm) in which said grinding members (25) were driven to obtain said quantity of powder (Qc) and, at the end of said grinding time (tm*), determine a weight of the quantity of powder effectively ground and calculate the ratio between said determined weight and said effective grinding time (tm).

6. Method as in claim 5, characterized in that in order to determine said weight it provides to compress said quantity of ground powder into the form of a tablet(P), measure its height (H) on the basis of which to determine its volume (Vol) to be multiplied by a density value (D) stored in a memory unit (35) or determined on the basis of information supplied by means of a user interface (27) and correlated to a type of beans to be used.

7. Method as in any claim hereinbefore, characterized in that it comprises a step of receiving information relating to at least one roasting level (RL) of the beans or their origin / variety, and it provides to calculate the current flow rate (FR) also on the basis of this information.

8. Method as in any claim hereinbefore, characterized in that it provides to start said emptying procedure following receipt of a specific execution command received from a user through a user interface (27).

9. Method as in any claim hereinbefore, characterized in that it provides to detect whether a lower aperture (17) of a hopper (12) connected to said grinding device (13) is open or closed, and if a closed position is detected, display on a user interface (27) of said grinding apparatus (10) at least one selectable option to proceed with emptying the grinding device (13).

10. Grinding apparatus (10), comprising a container (11) for coffee beans, a grinding device (13) configured to grind beans and obtain a dose of powder and provided with a chamber (24) configured to contain beans to be ground and in which grinding means (25) are disposed, flow rate determination means (51) configured to determine a current grinding flow rate (FR) of said grinding device (13) and a control unit (30) configured and programmed to carry out an operating method as in any claim hereinbefore.

11. Apparatus (10) as in claim 10, characterized in that said flow rate determination means (51) comprise one or more sensors (36) configured to measure and / or determine a weight of the coffee powder ground by said grinding means (25) and a time meter (37) configured to measure an effective grinding time (tm) during the operation of said grinding device (13).

12. Apparatus (10) as in claim 11, characterized in that said one or more sensors (36) comprise an encoder configured to measure a height (H) of a tablet(P) formed by said ground coffee powder and said control unit (30) is configured to determine the volume (Vol) of said powder as a function of said height (H) and multiply it by a density value (D) stored in a memory unit (35) or determined onthe basis of information supplied by means of a user interface (27) and correlated to a type of beans to be used in order to obtain the weight of said coffee powder.

13. Machine (40) for preparing beverages comprising a grinding apparatus (10) as in one of the claims from 10 to 12, a brewing unit (41) configured to prepare a beverage starting from a powdered substance, a delivery unit (42) fluidically connected to said brewing unit (41), and a user interface (27).

14. Machine (40) as in claim 13, characterized in that it comprises detection means (38) configured to verify whether a lower aperture (17) of said hopper (12) is open or closed and send a signal to the control unit (30), and said control unit (30) is configured to suggest to the user, through an interface (27), at least one selectable option to proceed with emptying said grinding device (13).

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