Milling apparatus and method for adjusting the milling of said apparatus

Abstract

Described is an apparatus (1) for milling bean products or grains, comprising: - a first motor-driven milling roller (3) extending along a first axis (X1) and rotatable about the first axis (X1); - a second motor-driven milling roller (4) extending along a second axis (X2) and rotatable about the second axis (X2), - a milling adjustment unit (30) comprising a kinematic mechanism (5) configured for moving the second roller (4) away from and towards the first roller (3), the apparatus (1) being characterised in that it comprises: a sensor (18, 18') associated with said kinematic mechanism (5) and configured to provide a milling gap null signal when the second roller (4) reaches and comes into contact with the first roller (3); a command-and- control unit (14) configured to derive from the signal of the sensor (18, 18') a position (PZ) for null-setting the kinematic mechanism (5).

Description

[0001] DESCRIPTION

[0002] MILLING APPARATUS AND METHOD FOR ADJUSTING THE MILLING OF SAID APPARATUS

[0003] Technical field

[0004] This invention relates to a milling apparatus and a method for adjusting the milling of said apparatus, which can advantageously be used for milling bean products or grains, in particular coffee grains.

[0005] Background art

[0006] Commonly used in the coffee milling sector are milling apparatuses which use two or more pairs of milling rollers arranged in series.

[0007] The basic structure of these apparatuses therefore comprises a plurality of milling stages, each of which consists of a pair of milling rollers. Each pair of milling rollers is characterised by a different set of teeth positioned on the surface of the rollers.

[0008] More precisely, the first pair of milling rollers, with respect to the flow of product, has a coarser set of teeth, whilst the last pair of milling rollers has a finer set of teeth.

[0009] This allows the coffee to be subjected to a coarser initial grinding, followed by a subsequent gradually finer processing, as the product passes through the various pairs of rollers. This configuration allows a gradual reduction in the grain size of the product, obtaining an extremely fine and homogeneous end result, suitable for various applications, such as the preparation of espresso coffee.

[0010] It should also be noted that the rollers of each pair are also positioned at a specific distance from each other.

[0011] The first set of rollers is designed to perform an initial grinding of the coffee.

[0012] During this step, the whole grains are reduced to a still relatively high grain size, allowing a finer processing in the subsequent stages. As mentioned above, the rollers of the first stage have a coarser set of tooth compared with the successive pairs, which allows the product to be treated without applying an excessive pressure which could adversely affect the quality of the coffee.

[0013] The last pair of milling rollers (that is, the one of the last milling stage) is the pair which operates with a finer set of teeth, thus obtaining the finer milling. This final stage is therefore of fundamental importance as it determines the final quality of the product.

[0014] It should be noted that any inaccuracies in the control of the distance during this step may result in an inequality in the size of the particles, with a negative impact on the overall quality of the coffee, in particular in applications in which the precision of the milling is essential, as in espresso coffee.

[0015] A critical aspect in the design and operation of such apparatuses is therefore that of controlling the distance between the rollers of each pair of milling rollers, in particular the distance of the final rollers, which directly determines the grain size of the end product and consequently affects the finish, that is, the quality, of the end product.

[0016] Thus, the need is particularly felt in the relevant sector for a milling apparatus provided with a system for adjusting the position of the milling rollers which is particularly precise, that is to say, which allows the distance between the rollers to be adjusted with extreme precision, in such a way as to guarantee the optimum distance between the rollers during the entire milling process, thus guaranteeing a rigorous control on the quality of the end product.

[0017] Patent document JPH02258073 describes a system for controlling the gap between rollers, wherein a pair of opposite rollers is provided, with one of the rollers movable relative to the other for adjusting the degree of milling. The relative position of the rollers is detected and compared, in a control unit, with a predetermined value of the gap; the resulting difference is emitted as a control signal towards a unit for adjusting the gap. In that way it is possible to obtain a precise adjustment of the gap without having to rely on the experience or on the subjective perception of the operator.

[0018] Disclosure of the Invention

[0019] The aim of this invention is therefore to provide an apparatus for milling bean products or grains, in particular coffee, and a method for adjusting the milling, which satisfies the need expressed in the introduction.

[0020] In particular, an aim of this invention is to provide an apparatus for milling bean products or grains, in particular coffee, and a method for adjusting the milling, which can allow the milling of the product to be controlled in an extremely simple, accurate and effective manner.

[0021] These aims are fully achieved by the milling apparatus, in particular for coffee, and by a method for regulating the milling apparatus, according to the appended claims.

[0022] Brief description of the drawings

[0023] The features of the invention will become more apparent from the following detailed description of a preferred, non-limiting embodiment of it, illustrated by way of example in the accompanying drawings, in which:

[0024] - Figure 1 is a perspective view of the milling apparatus according to this invention;

[0025] - Figure 2 is a side view of certain details of the milling apparatus according to Figure 1 ;

[0026] - Figures 3 to 6 are respective side views of certain details of the milling apparatus in different operating configurations.

[0027] Detailed description of preferred embodiments of the invention

[0028] With reference to the accompanying drawings, in particular Figures 1 -6, the reference numeral 1 denotes a milling apparatus according to this invention.

[0029] Preferably, the milling apparatus 1 is suitable for milling bean products or grains, in particular coffee beans.

[0030] The milling apparatus 1 comprises, according to one aspect, a frame 2 (illustrated for simplicity only in Figure 2).

[0031] Further, according to another aspect, the milling apparatus 1 comprises a first (motor-driven) milling roller 3 which is rotatable about a first axis X1 , relative to the frame 2, about the first axis X1 .

[0032] According to another aspect, the first milling roller 3 extends along the first axis X1 .

[0033] It should be noted the first roller 3 is a cylindrical roller.

[0034] As clearly shown in Figure 1 , the first roller 3 has an outer lateral milling surface 3A.

[0035] According to another aspect, the first roller 3 is provided with a plurality of milling teeth, arranged on the outer lateral milling surface 3A.

[0036] According to another aspect, the apparatus 1 comprises a first motor 8 for driving the first roller 3 in rotation about the first axis X1 .

[0037] It should be noted that the first roller 3 has been defined above as “motor- driven” since it is connected, in use, to the first motor 8.

[0038] Preferably, the apparatus 1 comprises an articulated joint 10 (preferably a cardan joint) connecting the first motor 8 to the first roller 3.

[0039] Advantageously, this articulated joint 10 allows the first motor 8 to be connected to the first roller 3 even in the absence of a perfect alignment between the axis of the first motor 8 and the first axis X1 of the first roller 3.

[0040] Further, according to another aspect, the milling apparatus 1 comprises a second (motor-driven) milling roller 4 rotatable about a second axis X2, relative to the frame 2, about the second axis X2.

[0041] According to another aspect, the second milling roller 4 extends along the second axis X2.

[0042] According to the invention, the second roller 4 is configured to be movable, away from and towards, the first roller 3.

[0043] Basically, the mobility of the second roller 4 relative to the first roller 3 means that it is possible, advantageously, to vary a distance K between the two rollers, first roller 3 and second roller 4, so as to be able to adjust the milling of the beans.

[0044] As clearly shown in Figure 1 , the second roller 4 has an outer lateral milling surface 4A.

[0045] According to another aspect, the second roller 4 is provided with a plurality of milling teeth, located on the outer lateral milling surface 4A.

[0046] According to another aspect, the apparatus 1 comprises a second motor 7 for driving the second roller 4 in rotation about the second axis X2.

[0047] It should be noted that the second roller 4 has been defined above as “motor-driven” since it is connected, in use, to the second motor 7. Preferably, the apparatus 1 comprises an articulated joint 9 (preferably a cardan joint) connecting the second motor 7 to the second roller 4.

[0048] Advantageously, the articulated joint 9 allows the second motor 7 to be connected to the second roller 4 even in the absence of a perfect alignment between the axis of the second motor 7 and the second axis X2 of the second roller 4.

[0049] This is extremely advantageous because the second motor 7, thanks to the articulated joint 9, is able to correctly transmit the motion to the second roller 4 irrespective of the position of the second roller 4 relative to the frame 2, that is, relative to the first roller 3.

[0050] Preferably, according to an embodiment, the first motor 8 (in particular its housing, that is, the stator) is fixed to the frame 2.

[0051] Preferably, according to an embodiment, the second motor 7 (in particular its housing, that is, the stator) is fixed to the frame 2.

[0052] According to another aspect, the milling apparatus 1 comprises a milling adjustment unit 30 comprising a kinematic mechanism 5 configured to move the second roller 4 away from and towards the first roller 3.

[0053] It should be noted that said kinematic mechanism 5 comprises a first portion P1 , PT and a second portion P2, P2’ operatively connected to each other and configured to move relative to each other. Hereinafter, double references are indicated for some of the elements of the kinematic mechanism 5, for example the double reference numerals P1 and P1 ’ will be used for the first portion.

[0054] In effect, advantageously, according to one aspect, the first kinematic mechanism 5 comprises a first group of elements (described in more detail below), associated with a first end E1 of the second cylinder 4, and a second group of elements, associated with another end E2, opposite the first end, of the second cylinder 4.

[0055] Thus, the double reference for certain elements of the kinematic mechanism 5 is due to the fact that, in the embodiment illustrated, at the two ends E1 , E2 of the second roller 4 there are two identical elements, with two different numerical references.

[0056] It should be noted, therefore, that the first kinematic mechanism 5, according to the particular embodiment illustrated in the accompanying drawings, is bilaterally associated with the second cylinder 4, that is, it is coupled to both ends E1 , E2 of the second cylinder 4.

[0057] According to an embodiment not illustrated, the first kinematic mechanism 5 is associated only with one end of the second cylinder 4 and the second cylinder 4 is configured in such a way that the other end of the second cylinder 4 comprises mechanical movement and / or constraint means to allow the second cylinder 4 to “passively” follow the motion imparted by the first kinematic mechanism 5 associated with the opposite end.

[0058] According to another aspect, the first portion P1 , PT is configured to induce the movement of the second portion P2, P2’ of the kinematic mechanism 5.

[0059] It should be noted that the second portion P2, P2’ of the kinematic mechanism 5 is operatively connected to the second roller 4 to allow the movement of the second roller 4, towards and away from the first roller 3. According to another aspect, the apparatus 1 comprises a sensor 18, 18’ associated with said kinematic mechanism 5 and configured to provide a milling gap null signal when the second roller 4 reaches and comes into contact with the first roller 3.

[0060] According to yet another aspect, the apparatus 1 comprises a command- and-control unit 14.

[0061] It should be noted that according to one aspect, the command-and-control unit 14 is configured to receive the milling gap null signal received from the sensor 18,18’.

[0062] According to yet another aspect, the apparatus 1 also comprises a rotating element 5D, 5D’ positioned between the first portion P1 , P1 ’ and the second portion P2, P2’ of the kinematic mechanism 5.

[0063] According to another aspect, the rotating element 5D, 5D’ is kept in constant contact with the first portion P1 , P1 ’ and operatively associated with the sensor 18, 18’ in such a way that, when the second roller 4 moves towards the first roller 3, the contact between the second roller 4 and the first roller 3 causes the activation of the sensor 18, 18’ by the rotating element 5D, 5D’ to send the null gap signal to the command-and-control unit 14.

[0064] It should be noted that according to another aspect, the command-and- control unit 14 is configured to derive a nulling gap position PZ of the first portion P1 , P1 ’ of the kinematic mechanism 5 on the basis of the milling gap null signal, said position PZ corresponding to the position of the first portion P1 , P1 ’ reached upon contact between the second roller 4 and the first roller 3.

[0065] It should also be noted that the rotating element 5D, 5D’ is configured in such a way as to be movable, preferably rotatable, relative to the second portion P2, P2’ of the kinematic mechanism 5.

[0066] More specifically, the rotating element 5D, 5D' is interposed between the adjusting cam 5C, 5C and the lever 5A, 5A'.

[0067] Preferably, the rotating element 5D, 5D’ is movable relative to the lever 5A, 5A’.

[0068] Preferably, the rotating element 5D, 5D’ is movable relative to the adjusting cam 5C, 5C’. According to another aspect, the command-and-control unit 14 (made as a single unit or distributed between several units) is connected to said sensor 18, 18’ and configured to derive, in the contact position of the second roller 4 with the first roller 3, on the basis of the signal provided by the sensor 18, 18’, a predetermined null position PZ of the kinematic mechanism 5, corresponding to a predetermined position of the first portion P1 , P1 ’ relative to the second portion P2, P2’ of the kinematic mechanism 5.

[0069] In other words, it should be noted that the apparatus 1 according to the invention, as described in more detail below, allows adjusting the position of the second milling roller 4 and of the first milling roller 3 relative to each other so as to adjust the amplitude K which is defined between the milling rollers 3, 4, thus adjusting the finish which can be obtained in the processing of the product.

[0070] According to another aspect, the second portion P2, P2’ of the kinematic mechanism 5 comprises at least one lever 5A, 5A’ rotatably movable relative to the frame 2 about a hinge point 6 not incident on (different from, and preferably parallel to) the second axis X2.

[0071] It should be noted that, preferably, the first axis X1 and the second axis X2 are horizontal axes.

[0072] According to one aspect, the first portion P1 , P1 ’ of the kinematic mechanism 5 comprises a movable cam 5C, 5C’ which is configured to adjust the position of the second portion P2, P2’ of the kinematic mechanism 5.

[0073] It should be noted that the adjusting cam 5C, 5C’ comprises a rotary cam body 12 having an edge 13 with a predetermined profile.

[0074] It should be noted that, according to one aspect, the rotary cam body 12 has a predetermined cam profile 13.

[0075] The cam body 12 rotates about a hinge point 22.

[0076] It should be noted that the predetermined profile of the edge 13 defines a curvilinear shape, not circular relative to the hinge point 22 (so as to vary the distance of the point of contact of the cam body 12 on the lever 5A relative to the hinge point 22, and consequently vary the position of the lever 5A that is, the angle of rotation of the lever 5A about its hinge point 6).

[0077] The cam body 12 is connected to an actuator 20, preferably an electric motor.

[0078] Preferably, the actuator 20 is connected to the command-and-control unit 4 for being controlled.

[0079] For this reason, the command-and-control unit 4 is configured to control the movement of the cam body 12.

[0080] According to another aspect, the apparatus 1 comprises a shaft 21 for connecting the actuator 20 to the cam body 12.

[0081] It should be noted that, according to the particular embodiment illustrated in Figure 1 , wherein the kinematic mechanism 5 is active on both sides on the second cylinder 4, the apparatus 1 comprises a first cam body and a second cam body, respectively positioned at opposite ends E1 , E2 of the second cylinder 4; the connecting shaft 21 is connected both to the first cam body and to the second cam body.

[0082] According to another aspect, the command-and-control unit 14 is configured to rotate the rotating cam body 12 of the adjusting cam 5C, 5C’, and derive, from the milling gap null signal received from the sensor 18, 18’, an angular position of the cam 5C, 5C’ corresponding to the nulling gap position PZ of the kinematic mechanism 5.

[0083] According to another aspect, the command-and-control unit 14 is configured to rotate the rotating cam body 12 of the adjusting cam 5C, 5C’ according to a predetermined direction of rotation W1 (anti-clockwise). Described in more detail below is the procedure for null-setting the actuating kinematic mechanism 5, starting from a position in which the first

[0084] 3 and the second 4 milling rollers are spaced from each other by an arbitrary distance, different from zero. In order to bring the milling rollers 3,

[0085] 4 to the predetermined relative position, that is to say, the milling position, to the desired distance K, the procedure is as follows.

[0086] Due to the command imparted by the command-and-control unit 14, the rotary cam body 12 of the adjusting cam 5C, 5C’ is rotated (according to a predetermined anticlockwise direction of rotation W1 ). It should be noted that, due to this rotation, the second roller 4 comes into contact with the first roller 3.

[0087] In this condition of contact between the second roller 4 and the first roller 3, the lever 5A, 5A’ (moved by the second roller 4) is prevented from rotating.

[0088] In effect, it should be noted that, in this condition, the second roller 4 is in contact with the first roller 3, which is fixed relative to the frame of the apparatus 1 (that is to say, without the possibility of movement, apart from its rotation about the axis of rotation X1 ).

[0089] The continuation of the anticlockwise rotation of the rotating cam body 12 of the adjusting cam 5C, 5C’ does not produce any movement of the lever 5A, 5A’, since it is locked by the first roller 3. Therefore, the lever 5A, 5A’ can no longer follow the profile of the rotary cam body 12 of the adjusting cam 5C, 5C’.

[0090] It should also be noted that the rotating element 5D, 5D’ is free to rotate relative to the lever 5A, 5A’.

[0091] The rotating element 5D, 5D’ is kept in contact with the rotary cam body 12 of the adjusting cam 5C, 5C’ by means of the spring 5E.

[0092] In order to complete the nulling procedure, the rotary cam body 12 of the adjusting cam 5C, 5C’ continues the rotation: in these conditions, the rotating element 5D, 5D’ rotates relative to the lever 5A, 5A’, pushed by the spring 5E, to follow the profile of the cam body 12. The sensor 18 measures the rotation of the rotating element 5D, 5D’ relative to the lever 5A, 5A’.

[0093] In particular, the sensor 18 detects the detachment of the rotating element 5D, 5D’ from the sensor 18 mounted on the lever 5A, 5A’.

[0094] The command-and-control unit 14 receives this information from the sensor 18 and is configured to stop the rotation (anticlockwise) of the rotary cam body 12.

[0095] The position of the cam body 12 corresponding to the start of the detachment of the rotating element 5D, 5D’ from the lever 5A, 5A’ is defined as a zero gap position or as a null-setting position PZ.

[0096] This operation creates a reference point between the first milling roller 3 and the second milling roller 4, corresponding to the contact between the two milling rollers 3, 4, that is to say, at null distance from each other. The subsequent rotation of the cam body 12 (in a clockwise direction) causes the second roller 4 to detach from the first roller 3.

[0097] In that way, the second roller 4 is brought to a desired distance K relative to the first roller 3.

[0098] It should be noted that the rotating element 5D,5D’ is rotatable, relative to the lever 5A, 5A’, about a hinge point 23 (integral with the lever).

[0099] It should be noted that the sensor 18,18’ is preferably mounted on (integrally associated with) the lever 5A, 5A’.

[0100] According to another aspect, the milling apparatus 1 also comprises a pushing element 5E configured to keep the rotating element 5D, 5D’ constantly in contact with the adjusting cam 5C, 5C’.

[0101] According to one aspect, the pushing element 5E is interposed between the rotating element 5D, 5D’ and the lever 5A, 5A’.

[0102] Preferably, the pushing element 5E comprises a spring.

[0103] It should be noted that the pushing element 5E is configured to apply on the rotating element 5D, 5D’ a pushing force directed to detach the rotating element 5D, 5D’ from the lever 5A.

[0104] According to another aspect, the sensor 18, 18’ is configured to detect a movement, in particular a detachment, of the rotating element 5D, 5D’ relative to the sensor 18, 18’ itself (that is, relative to the lever 5A to which the sensor 18, 18’ is associated).

[0105] According to another aspect, the command-and-control unit 14 is configured to derive, in the contact position of the second roller 4 with the first roller 3, said predetermined null-setting position PZ of the kinematic mechanism 5 at the milling distance signal received from the sensor 18, 18’ representing a movement, in particular a detachment, of the rotating element 5D, 5D’ relative to the sensor 18, 18’.

[0106] According to a yet further aspect, the apparatus 1 also comprises an actuator 5B, 5B’ operatively connected to the second portion P2, P2’ of the kinematic mechanism 5 and configured to apply a force on the second portion P2, P2’ of the kinematic mechanism 5 for pushing it against the first portion P1 , P1 ’ of the kinematic mechanism 5.

[0107] Preferably, the actuator 5B, 5B’ is connected to the command-and-control unit 14, to be commanded and / or controlled by it.

[0108] In particular, the actuator 5B, 5B’ is operatively connected to the lever 5A of the kinematic mechanism 5 to apply a force for pushing it against the cam body 12.

[0109] In other words, the actuator 5B, 5B’ is operatively configured to keep the lever 5A of the kinematic mechanism 5 in contact with the cam body 12. Preferably, the actuator 5B,5B’ is a pneumatic type of actuator.

[0110] According to another aspect, the actuator 5B, 5B’ is also configured to interrupt the action of applying the force on the second portion P2, P2’ of the kinematic mechanism 5, so as to allow the moving away of the second milling roller 4 from the first milling roller 3, if the force needed to maintain the contact between the second portion P2, P2’ of the kinematic mechanism 5 and the first portion P1 , P1 ’ of the kinematic mechanism 5 exceeds a predetermined limit value.

[0111] It should be noted that this condition, wherein the force needed to maintain the contact between the second portion P2, P2’ of the kinematic mechanism 5 and the first portion P1 , P1 ’ of the kinematic mechanism 5 exceeds a predetermined limit value, corresponds to an abnormal operation (overload) of the milling apparatus 1 .

[0112] The abnormal operation could be caused by a plurality of different causes potentially dangerous for the operation of the apparatus 1 (for example, the entry into contact of an extraneous object with a considerable hardness between the first and the second milling rollers, which could cause the kinematic mechanism 5 to break).

[0113] For this reason, the above-mentioned operation of the actuator 5B, 5B’ advantageously has a protection against mechanical overload of the set of teeth of the rollers 3, 4, and, moreover, of the kinematic mechanism 5.

[0114] According to another aspect, a method is defined for adjusting the milling (advantageously applicable to the apparatus 1 described above and which is the object of the appended claims) comprising the following steps:

[0115] - bringing into contact with each other the second roller 4 and the first roller 3 actuating the first portion R1 , R1 ’ of the kinematic mechanism 5;

[0116] - providing a milling gap null signal, using a sensor 18, 18’ associated with said kinematic mechanism 5, when the second roller 4 reaches and comes into contact with the first roller 3;

[0117] - deriving from the milling gap null signal provided by the sensor 18, 18’, in the position of contact of the second roller 4 with the first roller 3, a predetermined null position PZ of the kinematic mechanism 5, corresponding to a predetermined position of the first portion P1 , P1 ’ relative to the second portion P2, P2’ of the kinematic mechanism 5.

[0118] According to another aspect, the milling gap null signal is obtained by a movement, in particular a detachment, of the rotating element 5D, 5D’ relative to the sensor 18,18’.

[0119] According to yet another aspect, the method comprises a step of nullsetting the sensor 18,18, comprising the following steps:

[0120] - positioning the first roller 3 and the second roller 4 spaced apart from each other;

[0121] - placing the rotating element 5D, 5D’ in contact with the sensor 18, 18’.

[0122] The step of null-setting the sensor 18, 18’ is illustrated in Figure 6, even though in Figure 6 the rotating element 5D, 5D’ is still not positioned in the actual position of contact with the sensor 18, 18’.

[0123] It should be noted that said (optional) process of null-setting the sensor 18, 18’ is therefore carried out before moving the first roller 3 and the second roller 4 into contact with each other.

[0124] The procedure for null-setting the sensor 18,18’ makes it possible to bring the rotating element 5D, 5D’ into contact with the sensor 18, 18’ (in such a way that it is then possible, advantageously, to detect the detachment in the condition of contact between the first roller 3 and the second roller 4, as described in more detail below, that is, during the procedure for nullsetting the kinematic mechanism 5).

[0125] According to another aspect, the method comprises the following steps:

[0126] - storing, in the memory 15, motion information relative to a law of motion of the adjusting cam 5C, 5C’ with respect to the lever 5A, 5A’;

[0127] - sending, by means of a user interface 16, a parameter representing a desired distance K between the first milling roller 3 and the second milling roller 4;

[0128] - retrieving the motion information from the memory 15 by means of a command-and-control unit 14 connected to the memory 15;

[0129] - calculating, by means of the command-and-control unit 14 and based on the motion information, an angle of rotation of the adjusting cam 5C, 5C’ wherein the first milling roller 3 and the second milling roller 4 are located at the desired distance K;

[0130] - sending, by means of the command-and-control unit 14, a rotation control to the cam 5C,5C’ to bring the cam 5C,5C’ to the calculated angle of rotation, thereby positioning the second milling roller 4 at the desired distance K from the first milling roller 3.

[0131] It should be noted that the user interface 16 may be any type of electronic interface / software, whether or not provided with commands and / or a display unit, which allows sending, to the command-and-control unit 14, the parameter representing a desired distance K between the first roller 3 and the second roller 4.

[0132] It should be noted that the steps described above allow the distance between the first roller 3 and the second roller 4 to be controlled in a particularly accurate manner, thus guaranteeing perfect milling.

[0133] The adjustment method described above is particularly advantageous when applied to a pair of rollers 3, 4 forming part of a group of rollers positioned in series and positioned in the final position relative to the flow of milling products, that is, the rollers of the last milling stage.

[0134] The operation of the apparatus 1 is described below.

[0135] Starting from the position illustrated in Figure 6, with the rotary element 5C, 5C’ in contact with the sensor 18, 18’, that is, the lever 5A, 5A’, the rotary cam body 12 is rotated (preferably according to the anticlockwise direction of rotation W1 ), by the motion transmitted by the actuator 20 to the shaft 21 .

[0136] The rotation of the cam body 12, acting on the lever 5A, causes the lever 5A, 5A’ itself to rotate (in a clockwise direction W2) relative to its hinge point 6, so as to bring the second roller 4 (integral with the lever 5A, 5A’) into contact with the first roller 3.

[0137] During this rotation, the actuator 5B,5B’ applies a force on the lever 5A, 5A’ such as to keep the lever 5A, 5A’ in contact with the cam body 12 (more precisely, the lever 5A, 5A’ is pushed towards the cam body 12).

[0138] In these circumstances, it should be noted that the rotary element 5C, 5C’, which is interposed between the lever 5A, 5A’ and the cam body 12, is in contact both with the lever 5A and with the cam body 12.

[0139] It should be noted that following the rotation of the cam body 12 described above, the second roller 4 is brought into contact with the first roller 3.

[0140] When the contact, between the second roller 4 and the first roller 3 (this condition is illustrated in Figure 3) has been established, the lever 5A is prevented - due to the locking constraint exerted by the first roller 3 (the position of which is fixed relative to the frame 2) on the second roller 4 - from rotating further in the clockwise direction, labelled W2.

[0141] In this situation, the command-and-control unit 14 commands the actuator 20 to further rotate the cam body 12 in an anticlockwise direction W1. It should be noted that, as mentioned above, during this further rotation of the cam body 12, the lever 5A, 5A’ is always positioned in a predetermined position (that is to say, it does not undergo any modification of its position). The rotation of the cam body 12 in an anticlockwise direction W1 is such that, for a certain position of the cam body 12 relative to the sensor 18, 18’ I lever 5A, 5A’, the rotary element 5C, 5C’ detaches from the sensor 18, 18’ I lever 5A, 5A’ (configuration illustrated in Figure 4).

[0142] In this situation, the command-and-control unit 14 receives, from the sensor 18, 18’, a milling gap null signal the value of which represents the detachment of the rotary element 5C, 5C’ from the sensor 18, 18’ / lever 5A, 5A’.

[0143] According to another aspect, it should be noted that the sensor 18, 18’ may be configured to release one of the following types of signals:

[0144] - an analogue signal;

[0145] - a digital signal;

[0146] - a signal of the on-off type, representing the contact or absence of contact of the rotary element 5C, 5C’ relative to the sensor.

[0147] The command-and-control unit 4, on the basis of the signal of the sensor 18, 18’, derives the predetermined position (PZ, indicated in Figure 4) for null-setting the kinematic mechanism 5, corresponding to a predetermined position of the cam body 12 relative to the sensor 18, 18’ (that is, to the lever 5A, 5A’) with the second roller 4 in contact with the first roller 3 (that is, with the lever 5A, 5A’ located in a predetermined position).

[0148] The predetermined position PZ may therefore be used, by the command- and-control unit 4, for adjusting the predetermined distance K between the second roller 4 and the first roller 3. In effect, starting from the predetermined position PZ identified, by giving the command for the rotation of the cam body 12 in the opposite direction to the anticlockwise direction W1 , that is to say, in a clockwise direction W2, it is possible to move the second roller 4 away from the first roller 3, until reaching the predetermined distance K between the milling rollers, which is able to guarantee the desired milling of the grains fed to the rollers. The operating position of the rollers 3, 4 is illustrated in Figure 5.

[0149] The profile of the edge 13 of the cam body 12 may be suitably shaped to allow the reaching also of predetermined distances K of particularly small size, so, for example, the cam body 12 may be shaped in such a way that for small angles of rotation of the cam body 12 the movement of the lever 5A, 5A’ is extremely limited.

[0150] The knowledge of the motion relationship between the cam 12, lever 5A, 5A’, and movement of the second roller 4 (with the storage of information relating to that motion relationship in the memory 15) means that it is possible, by means of the command-and-control unit 4, to control in an exact manner the predetermined distance K.

[0151] In effect, the fact of having identified the null-setting position PZ means that the movements performed, by rotation, by the cam body 12, starting from the null-setting position are particularly precise. The precision and accuracy of the milling adjustment which can be reached by means of the apparatus 1 , and the method according to the invention, are immediately evident.

Claims

CLAIMS1. An apparatus for milling (1 ) bean products or grains, in particular coffee beans, comprising:- a first milling roller (3) rotatable about a first axis (X1 );- a second milling roller (4) rotatable about a second axis (X2) parallel to the first axis (X1),- a milling adjustment unit (30) comprising a driving kinematic mechanism (5) configured to move the second milling roller (4) towards and away from the first milling roller (3): wherein said driving kinematic mechanism (5) comprises a first portion (P1 ,P1 ’) and a second portion (P2,P2’) operatively coupled and configured to move relative to each other, the first portion (P1 ,P1 ’) being configured to induce movement of said second portion (P2,P2’), said second portion (P2,P2’) being operatively connected to said second milling roller (4) to allow the second roller (4) to be moved towards and away from the first roller (3),- a sensor (18,18') associated with said driving kinematic mechanism (5) and configured to provide a zero milling gap signal when the second roller (4) reaches and contacts the first roller (3);- a command-and-control unit (14) communicatively connected to said sensor (18,18') and configured to receive the zero milling gap signal, said apparatus (1 ) being characterized by further comprising a trigger element (5D,5D’) positioned between the first portion (P1 ,P1 ’) and the second portion (P2,P2’) of the driving kinematic mechanism (5), the trigger element (5D,5D’) being maintained in constant abutment against the first portion (P1 ,P1 ’), and operatively associated with the sensor (18,18’) such that, when the second milling roller (4) is moved towards the first milling roller (3), contact between the second milling roller (4) and first milling roller (3) causes the trigger element (5D,5D’) to trigger the sensor (18, 18’) to send the zero milling gap signal to the command-and-control unit (14); wherein the command-and-control unit (14) is configured to determine a zero gap position (PZ) of the first portion (P1 ,P1 ’) of the driving kinematicmechanism (5) based on the zero milling gap signal, the zero gap position corresponding to the position of the first portion (P1 ,P1 ’) reached upon contact between the second milling roller (4) and the first milling roller (3).

2. The milling apparatus (1 ) according to claim 1 , wherein the second portion (P2,P2’) of the driving kinematic mechanism (5) comprises at least one lever (5A,5A’) pivotally movable about a hinge point (6), the hinge point (6) being disposed not incident on the second axis (X2).

3. The milling apparatus (1 ) according to claim 1 or 2, wherein the first portion (P1 ,PT) of the driving kinematic mechanism (5) comprises an adjusting cam (5C,5C’) configured to adjust the position of the second portion (P2,P2’), the adjusting cam (5C,5C’) comprising a rotating cam body (12) having a predefined cam profile (13).

4. The milling apparatus (1 ) according to claim 3, wherein the command-and-control unit (14) is configured to control rotation of the rotating cam body (12) of the adjusting cam (5C,5C’) and to determine, based on the zero milling gap signal received from the sensor (18,18’), an angular position of the adjusting cam (5C,5C’) corresponding to the zero gap position (PZ) of the driving kinematic mechanism (5).

5. The milling apparatus (1 ) according to any of the preceding claims, wherein the trigger element (5D,5D’) is movable mounted on the second portion (P2,P2’) of the driving kinematic mechanism (5) so as to be movable by the first portion (P1 ,PT) upon contact between the second milling roller (4) and the first milling roller (3); and wherein said sensor (18, 18’) is configured to send the zero milling gap signal to the command-and- control unit (14) upon detecting the movement of the trigger element (5D,5D’) relative to the second portion (P2,P2’) of the driving kinematic mechanism (5).

6. The milling apparatus (1 ) according to any of the preceding claims, further comprising a pushing element (5E) configured to maintain the trigger element (5D,5D’) in constant contact with the first portion (P1 ,P1 ’) of the driving kinematic mechanism (5).

7. The milling apparatus (1 ) according to claim 6, wherein said trigger element (5D, 5D’) is pivotably mounted on the second portion (P2, P2’) of the driving kinematic mechanism (5), and wherein the first portion (P1 , P1 ’) of the driving kinematic mechanism (5) is configured to allow the pushing element (5E) to rotate the trigger element (5D, 5D’) away from the second portion (P2, P2’) of the driving kinematic mechanism (5) upon contact between the second milling roller (4) and the first milling roller (3).

8. The milling apparatus (1 ) according to any of the preceding claims, further comprising an actuator (5B,5B’) operatively connected to the second portion (P2,P2’) of the driving kinematic mechanism (5) and configured to apply a force on the second portion (P2,P2’) to push it against the first portion (P1 ,P1 ’) of the driving kinematic mechanism (5).

9. The milling apparatus (1 ) according to claim 8, wherein the actuator (5B,5B’) is further configured to cease applying the force on the second portion (P2,P2’) of the driving kinematic mechanism (5), when a counter force exceeding a predetermined threshold is exerted on the first (3) and second (4) milling rollers.

10. The milling apparatus (1 ) according to any of the preceding claims, wherein said first (3) and second (4) milling rollers are respectively driven by a first driving motor (8) and a second driving motor (7); and wherein a first articulated joint (10), preferably a universal joint, connects the first milling roller (3) to the first driving motor (8) and / or a second articulatedjoint (9), preferably a universal joint, connects the second milling roller (4) to the second driving motor (7).

11. A method for mill setting of a milling apparatus (1 ) for milling bean products or grains, in particular coffee beans, said milling apparatus comprising a first milling roller (3) and a second milling roller (4) rotating about respective first (X1) and second (X2) axes of rotation parallel to each other, and a driving kinematic mechanism (5) comprising a first portion (P1 , P1 ’) and a second portion (P2,P2’) connected to each other, the first portion (P1 ,P1 ’) being configured to move the second portion (P2,P2’) towards and away from the first milling roller (3), said method comprising the steps of:- actuating the first portion (P1 , P1 ') of the driving kinematic mechanism (5) to bring the second milling roller (4) into contact with the first milling roller (3);- providing a zero milling gap signal by means of a sensor (18,18') when the second milling roller (4) reaches and contacts the first milling roller (3); characterized in that said method further comprises the steps of:- providing a trigger element (5D, 5D’) positioned between the first portion (P1 , P1 ’) and the second portion (P2, P2’) of the driving kinematic mechanism (5), said trigger element (5D, 5D’) being maintained in constant abutment against the first portion (P1 , P1 ’), and being operatively associated with the sensor (18, 18’),- triggering the sensor (18, 18’) by the trigger element (5D, 5D’) upon contact between the second milling roller (4) and the first milling roller (3) to provide the zero milling gap signal;- determining, based on the zero milling gap signal provided by the sensor (18,18’), a zero gap position (PZ) of the first portion (P1 ,P1 ’) of the driving kinematic mechanism (5) corresponding to the position of the first portion (P1 ,P1 ’) when the second milling roller (4) contacts the first milling roller12. The method according to claim 11 , further comprising the steps of:- arranging the trigger element (5D, 5D’) to be movable mounted, preferably rotatably, relative to the second portion (P2, P2’) of the driving kinematic mechanism (5),- providing the zero milling gap signal upon detecting the movement of the trigger element (5D,5D’) relative to the second portion (P2, P2’) of the driving kinematic mechanism (5).

13. The method according to the claim 12, further comprising the steps of:- arranging at least one lever (5A,5A’) pivotally movable about a hinge point (6) not incident on the second axis (X2), said at least one lever (5A,5A’) being part of the second portion (P2,P2’) of the driving kinematic mechanism (5);- providing at least one adjusting cam (5C,5C’) comprising a rotating cam body (12) having a predetermined cam profile (13), and the adjusting cam (5C, 5C’) being part of the first portion (P1 ,PT) of the driving kinematic mechanism (5);- pushing the trigger element (5D, 5D’) against the adjusting cam (5C, 50);- detecting movement of the trigger element (5D, 5D’) relative to the lever (5A, 5A’) by means of the sensor (18, 18') upon contact between the second milling roller (4) and the first milling roller (3).

14. The method according to any of the claims 11 to 13, further comprising, prior to bringing the second milling roller (4) and the first milling roller (3) into contact, a reset of the sensor (18.18') comprising the steps of:- arranging the first milling roller (3) and the second milling roller (4) spaced apart;- arranging the trigger element (5D,5D’) in contact with the second portion (P2,P2’) of the driving kinematic mechanism (5).

15. The method according to claim 13 or 14, comprising the steps of: providing a memory (15) configured to store information;- storing, within the memory (15), motion information relating to a law of motion of the adjusting cam (5C,5C’) relative to the lever (5A,5A’);- inputting, via a user interface (16), a parameter representing a desired distance (K) between the first roller (3) and the second roller (4);- retrieving the motion information from the memory (15) by a command- and-control unit (14) connected to the memory (15);- calculating, by the command-and-control unit (14) based on the motion information, a rotation angle of the adjusting cam (5C,5C) at which the first milling roller (3) and the second milling roller (4) are arranged at the desired distance (K);- sending, by the command and control unit (14), a rotation command to the adjusting cam (5C,5C’) to bring the adjusting cam (5C,5C’) to the calculated rotation angle, thereby arranging the second roller (4) at the desired distance (K) from the first milling roller (3).

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