Technical Field

The present invention relates to a mill for the production of food for animals. Background Art

Several mills as known for the production of food for animals that are widely used in the animal feed industry for the purpose of grinding one or more raw materials so as to obtain an animal food in granular form, such as feed.

Generally, the mills of known type comprise a support frame, on which is mounted a grinding chamber adapted to grind the raw materials necessary for the production of one or more foods for animals.

In particular, the grinding of the raw materials introduced into the grinding chamber is carried out by means of a crushing rotor placed inside the grinding chamber and lock in rotation together with a driving shaft adapted to rotate around a horizontal axis of rotation extending inside the grinding chamber itself. Moreover, the grinding chamber comprises a loading port for the raw material to be ground arranged on top of the crushing rotor, and an unloading grid arranged below the crushing rotor, and through which the ground raw material is extracted once it has reached a predefined grain size.

This way, the raw material remains inside the grinding chamber until, through the grinding process, it reaches a grain size which enables it to pass through the unloading grid and then to be collected inside a suitable container.

Generally, the crushing rotors used by mills of this type comprise a fixed body locked in rotation together with the driving shaft and a plurality of crusher elements kinematically coupled idle to the fixed body and movable in rotation around a hinging axis substantially parallel to the horizontal axis of rotation.

This way, when the driving shaft is made to rotate at a constant speed, the crusher elements arrange themselves in a radial pattern with respect to the horizontal axis of rotation to occupy substantially the entire volume of the grinding chamber, so as to grind the raw material contained inside it.

In particular, the fixed body generally comprises a series of retaining plates arranged parallel to each other along the horizontal axis of rotation and between which one or more of the crusher elements are pivoted free to rotate. This way, worn or damaged crusher elements, e.g. as a result of continuous grinding processes, can be replaced with new crusher elements without any need to replace the fixed body.

Moreover, this solution makes it possible to limit the negative effects which act on the crushing rotor as a result of the impact of the crusher elements on the raw material to be ground.

In fact, the type of coupling between the crusher elements and the fixed body permits converting and dissipating the energy generated by the impact of the crusher elements on the raw material into kinetic rotational energy from the crusher elements themselves, reducing the energy absorbed by the fixed body. These solutions significantly reduce the wear of the crushing rotor, thus cutting the maintenance costs of the mill itself.

However, the mills of this type are subject to further upgrades linked to their structural characteristics.

In particular, in the mills of known type, the driving shaft is provided with two ends associated movable in rotation with the inner walls of the grinding chamber and with the support frame, so as to keep the crushing rotor suspended inside the chamber itself and free to rotate around the horizontal axis of rotation.

Consequently, replacing a crushing rotor component or the rotor itself requires the driving shaft to be disassembled from the support frame and taken out of the grinding chamber.

Moreover, with particular reference to the stopping phase of the driving shaft, the crushing rotor is particularly affected by the inertia of the crusher elements, on which it operates, in addition to the centrifugal force generated by the rotation of the driving shaft, the weight force.

In fact, during the stopping phase, some of the crusher elements, which are generally very heavy to ensure the grinding of the raw material, tend to stop their stroke and strike the fixed body with fairly substantial force.

Consequently, following the succession of the grinding processes, it often happens that the center of gravity of the crushing rotor is off-centered with respect to the horizontal axis of rotation due to the repeated impacts between the fixed body and the crusher elements.

This phenomenon negatively affects the rotation of the driving shaft, which does not rotate perfectly in axis with the horizontal axis of rotation, significantly increasing the mechanical stress affecting the structure of the mill.

The above mentioned drawbacks significantly contribute to increasing the wear phenomena of the mechanical parts of the mill, in this case of the driving shaft and the crushing rotor, and at the same time make their maintenance operations difficult and complicated with a significant increase in maintenance costs.

A further drawback of the mills of known type lies in the fact that the production of animal food is particularly limited by the reduced extension of the unloading grid.

In fact, in this type of mill the extension of the unloading grid is limited to defining the bottom wall of the grinding chamber, i.e. the wall oriented towards the ground, where the raw material tends to accumulate naturally due to gravity. However, in this way, the unloading grid acts as a bottleneck which limits the output of the ground raw material, thus significantly reducing the amount of food produced in a predefined time.

Description of the Invention

The main aim of the present invention is to devise a mill for the production of food for animals which allows performing the driving shaft and the crushing rotor maintenance operations in a practical and speedy way.

A further object of the present invention is to devise a mill for the production of food for animals which permits drastically reducing the wear of the crushing rotor.

An additional object of the present invention is to devise a mill for the production of food for animals which, the grinding chamber and the crushing rotor size being equal, permits increasing the amount of animal food produced in a predefined time compared to the mills of known type.

Another object of the present invention is to devise a mill for the production of food for animals which allows overcoming the aforementioned drawbacks of the prior art in the ambit of a simple, rational, easy, effective to use and low cost solution. The aforementioned objects are achieved by the present mill for the production of food for animals having the characteristics of claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will be more evident from the description of a preferred, but not exclusive, embodiment of a mill for the production of food for animals, illustrated by way of a non-limiting example in the accompanying tables of drawing in which:

Figure 1 is a schematic axonometric view of the mill according to the invention; Figure 2 is a schematic detail view of some elements of the mill according to the invention;

Figure 3 is a schematic exploded view of the mill according to the invention; Figure 4 is a schematic cross-sectional view of some elements of the mill according to the invention.

Embodiments of the Invention

With particular reference to these illustrations, reference numeral 1 globally indicates a mill for the production of food for animals.

The mill 1 for the production of food for animals comprises:

at least one support frame 2;

at least one grinding assembly 3, 4, 5, 16 mounted on the support frame 2 and provided with:

at least one grinding chamber 3 of at least one raw material to obtain granular food;

at least one driving shaft 4 inserted at least partly in the grinding chamber 3 and operable in rotation around an axis of rotation A;

at least one crushing rotor 5 housed inside the grinding chamber 3 and associable integral in rotation with the driving shaft 4.

In particular, the axis of rotation A is vertical.

In the continuation of the present treatise, the term “vertical” used with reference to one or more parts of the mill 1, means the disposition in space of such parts in the conditions of normal use of the mill 1, i.e., as shown in the illustrations, the conditions in which the driving shaft 4 is arranged substantially vertical with respect to the ground on which the support frame 2 rests in use. In addition, the terms“above”,“below” and the terms derived therefrom used to refer to one or more elements of the mill 1 mean the mutual position of such elements in relation to the ground.

In other words, the intention is to indicate that a first element is arranged above or below a second one when the first element is placed at a height, referred with respect to the ground, which is higher or lower respectively than the height at which the second element is arranged.

Advantageously, the grinding assembly 3, 4, 5, 16 comprises removable fixing means 6, 7, 40a, 40b, 41, 42a, 42b of the crushing rotor 5 to the driving shaft 4. In particular, the fixing means 6, 7, 40a, 40b, 41, 42a, 42b comprise:

at least a first fixing body 6 made on one of either the crushing rotor 5 or the driving shaft 4;

at least a second fixing body 7 made on the other of either the crushing rotor 5 and the driving shaft 4 and which can be coupled integral in rotation to the first fixing body 6, the first fixing body 6 and the second fixing body 7 being longitudinally movable with respect to each other along the axis of rotation A to allow disassembling the crushing rotor 5 from the support frame 2;

removable locking means 40a, 40b, 41, 42a, 42b of the first fixing body 6 to the second fixing body 7 which are adapted to fix their mutual position longitudinally along the axis of rotation A.

According to the embodiment of the mill 1 shown in the figures, the first fixing body 6 is preferably made in a single body piece with the driving shaft 4 and coincides with the lower end 8 thereof, that is the end of the driving shaft 4 facing the ground, as shown in Figure 3.

In fact, the driving shaft 4 advantageously comprises an upper end substantially opposite the lower end 8 and associated movable in rotation around the axis of rotation A to the support frame 2.

The second fixing body 7, on the other hand, is preferably a hollow body associated with the crushing rotor 5 and defining a housing 45 which extends, in use, along the axis of rotation A.

Preferably, the first and the second fixing body 6, 7 have a transverse section, defined with respect to the axis of rotation A, of a substantially circular shape and have substantially complementary shapes so as to provide a cylindrical type kinematic pair.

Conveniently, the fixing means 6, 7, 40a, 40b, 41, 42a, 42b comprise removable block means (not shown in the figure) of the mutual rotation of the elements of the aforementioned kinematic pair which are adapted to couple the same integral in rotation with each other.

This way, the block means prevent the first and second fixing body 6, 7 from mutually rotating and the locking means 40a, 40b, 41, 42a, 42b lock the mutual sliding thereof along the axis of rotation A.

In other words, the block means and the locking means 40a, 40b, 41, 42a, 42b operate in conjunction with each other so as to allow the driving shaft 4 to be coupled in a removable manner to the crushing rotor 5, which, in use, is suitably accommodated in the center of the grinding chamber 3.

In particular, the grinding chamber 3 comprises at least one base body 10 associable in a removable manner with the support frame 2 and arranged substantially parallel to the ground to delimit the grinding chamber 3 inferiorly. Preferably, the support frame 2 comprises a flange body 11 arranged above the base body 10 and substantially opposite it, thus delimiting the grinding chamber 3 at the top and defining an inlet for the entry of the raw material into the grinding chamber itself.

In particular, the mill 1 preferably comprises a loading assembly 43 defining at least one loading mouth for the raw material to be ground and provided with at least one channel for conveying the raw material from the loading mouth to the inlet.

According to the invention, the mill 1 comprises at least a pair of lateral support elements 12 arranged substantially parallel to each other and associated with the flange body 11, from which they extend vertically overhanging towards the ground until they engage with the base body 10, as shown in Figure 1.

Advantageously, the flange body 11 and the base body 10 are provided with at least one perimeter profile 14 arranged outside the grinding chamber 3 and with which the lateral support elements 12 are associated, which in turn are thus arranged outside the grinding chamber 3, as shown in Figures 1 and 2.

This way, the lateral support elements 12 do not interfere with the crushing rotor 5.

Furthermore, the mill 1 comprises removable fastening/release means 13 for fastening/releasing the base body 10 to/from the support frame 2.

According to the embodiment of the mill 1 shown in the illustrations, the fastening/release means 13 comprise at least one pair of recesses made opposite each other on the perimeter profile 14 of the base body 10 and at least a fixing element made on the end portion facing the ground of each of the support elements 12.

In particular, each of the fixing elements is adapted to operate in conjunction with a corresponding recess to fix the position of the base body 10 in a removable manner, as shown in Figure 2.

Conveniently, the grinding chamber 3 comprises at least one lateral grid 15 associated in a removable manner between the base body 10 and the support frame 2 to laterally surround the crushing rotor 5 by 360°.

More precisely, the lateral grid 15 is placed resting on the perimeter profile 14 of the base body 10 and abuts against the perimeter profile 14 of the flange body 11 to delimit the grinding chamber 3 laterally, as shown in Figure 2.

Advantageously, the lateral grid 15 comprises a plurality of transit holes adapted to define the grain size of the food for animals that comes out of the grinding chamber 3.

Actually, the raw material ground inside the grinding chamber 3 is able to cross the lateral grid 15 only when the grains which make it up reach a grain size having an extension comparable to that of the transit holes.

Moreover, the mill 1 conveniently comprises a plurality of lateral grids 15 provided with transit holes having different extensions.

This way, it is possible to vary the grain size of the produced food for animals depending on the lateral grid mounted on the mill 1.

According to the embodiment of the mill 1 shown in the illustrations, the lateral grid 15 has a substantially cylindrical hollow shape and the flange body 11 and the base body 10 have a substantially circular shape, so as to seal the lateral grid 15 above and below respectively, defining with the latter a grinding chamber 3 with a substantially cylindrical shape which surrounds the crushing rotor 5, as shown in the Figure 2.

Conveniently, the grinding assembly 3, 4, 5, 16 comprises at least one lateral retaining body 16 associated with the support frame 2, which is arranged, in use, around the lateral grid 15 and spaced apart from the latter to define an unloading interspace of the ground raw material which passes through the lateral grid 15.

Preferably, the lateral retaining body 16 is substantially cylindrical in shape and is arranged, in use, concentric with the grinding chamber 3.

In particular, the lateral retaining body 16 comprises at least one pair of containment walls 19, 20, 21 associated with the support frame 2 in a movable manner between at least a first working configuration, wherein the containment walls 19, 20, 21 are moved away from each other and the lateral grid 15 is accessible from the outside, and at least a second working configuration, wherein the containment walls 19, 20, 21 are moved close to each other to surround the lateral grid 15, thus defining the unloading interspace and making the lateral grid 15 inaccessible from the outside.

According to the embodiment of the mill 1 shown in the figures, each of the containment walls 19, 20, 21 comprises:

at least a first end portion 19 hinged to the support frame 2 and movable in rotation around a hinging axis D arranged substantially parallel to the axis of rotation A to allow the movement of the containment wall 18 between the first and the second working configuration;

at least a second end portion 20 adapted to abut against the second end portion 20 of the other of the containment walls 19, 20, 21 in the second working configuration;

removable coupling means 21 of the second end portions 20 adapted to fasten the pair of containment walls 19, 20, 21 in a removable manner in the second working configuration.

Advantageously, the containment walls 19, 20, 21 comprise at least one substantially curved plate-shaped abutment side 22 and placed between the first and the second end portion 19, 20.

In particular, in the second working configuration, the abutment side 22 is arranged facing the lateral grid 15, with which it delimits the unloading interspace laterally, and abuts the flange body 11 at its perimeter profile 14, with which it delimits the unloading interspace at the top.

Moreover, in the working configuration, the abutment side 22 is spaced apart from the perimeter profile 14 of the base body 10, with which it defines an unloading mouth for the ground raw material.

Preferably, the coupling means 21 are made at the second end portions 20.

Optionally, the grinding assembly 3, 4, 5, 16 can comprise at least one collecting body which is associated with the grinding chamber 3 in a removable manner below the unloading interspace in order to collect the ground raw material, e.g., a bucket.

Advantageously, the crushing rotor 5 comprises at least one fixed body 25, 26, 27 associable integral in rotation with the driving shaft 4 and at least one crusher element 24 kinematically coupled idle in rotation to the fixed body 25, 26, 27.

Preferably, the fixed body 25, 26, 27 comprises a series of retaining plates 25 positioned opposite and parallel to each other and centered, in use, along the horizontal axis of rotation, where one or more of the crusher elements 24 are interposed and pivoted free to rotate between the retaining plates 25.

Furthermore, each of the retaining plates 25 is centrally drilled to make at least part of the housing 45 for the driving shaft 4.

Preferably, the retaining plates 25 are circular discs made of metal.

The crusher elements 24, on the other hand, are preferably hammers made of metal and adapted to crush the raw material introduced into the grinding chamber 3.

Advantageously, the fixed body 25, 26, 27 comprises alignment means 26 of the retaining plates 25 adapted to keep the latter aligned to each other along the axis of rotation A.

According to the embodiment of the mill 1 shown in the illustrations, the alignment means 26 comprise at least one pair of through holes (not shown in the illustrations) made on each retaining plate 25 in an off-centre position with respect to the center of the retaining plate 25.

Moreover, the alignment means 26 comprise at least one pair of containment pins 28 adapted to pass through the holes of each retaining plate 25, keeping the latter centered along the axis of rotation A.

This solution permits making use of the crusher elements 24 pivoted movable in rotation along the containment pins 28 between the retaining plates 25, as shown in Figure 4.

In particular, the containment pins 28 extend longitudinally centered along a corresponding pivoting axis B positioned, in use, substantially parallel to the axis of rotation A and around which the crusher elements 24 rotate.

Moreover, the holes are aligned, transversally with respect to the pivoting axis B, and equidistant with respect to the center of the retaining plate 25, in such a way as to position the crusher elements 24 opposite each other, giving the crushing rotor 5 a structure substantially symmetrical with respect to the axis of rotation A.

Preferably, according to the embodiment of the mill 1 shown in the illustrations, the alignment means 26 comprise two pairs of holes and two pairs of containment pins 28, where each pair of holes and each pair of containment pins 28 is arranged rotated by 90° with respect to the other pair of holes and to the other pair of containment pins 28.

Furthermore, the crusher elements 24 pivoted on different pairs of containment pins 28 are arranged, in use, at different heights.

In particular, the fixed body 25, 26, 27 comprises spacer elements 27 interposed between the crusher elements 24 and at least a corresponding retaining plate 25, and adapted to define the difference in height between the crusher elements 24 pivoted on pairs of different containment pins 28.

Such solution enables the crusher elements 24 pivoted on pairs of containment pins 28 to never collide with each other, e.g. during the start and stop phases of the crushing rotor 5.

According to the embodiment of the mill 1 shown in the illustrations, the crushing rotor 5 comprises at least one upper retaining body 29 and at least one lower retaining body positioned opposite each other at the extremal retaining plates 25 of the fixed body 25, 26, 27, thus delimiting the longitudinal extension of the same along the axis of rotation A.

In particular, the upper retaining body 29 and the lower retention body are adapted to operate in conjunction with each other to fix the position of the retaining plates 25 and of the corresponding crusher elements 24 longitudinally along the axis of rotation A, in order to make a crushing rotor 5 with a compact and balanced structure.

Preferably, the upper retaining body 29, the lower retaining body and the retaining plates 25 coincide with the second fixing body 7 and define the housing 45 of the driving shaft 4, in this case of the first fixing body 6, as shown in Figure 4.

In fact, according to the embodiment of the mill 1 shown in the illustrations, the lower retaining body comprises a bottom plate 30 centered along the axis of rotation A and associated with the containment pins 28 in a removable manner at their end portions, so as to delimit the housing 45 inferiorly, as shown in Figure 4.

In particular, the locking means 40a, 40b, 41, 42a, 42b lock the bottom plate 30 to the first fixing body 6 in a removable manner.

In addition, the locking means 40a, 40b, 41, 42a, 42b preferably comprise at least a first through opening 40a, 40b made centrally with respect to the bottom plate 30 and at least a second opening 41 made centrally to the first fixing body 6 and positioned, in use, coaxially to the first opening 40a, 40b.

In addition, the locking means 40a, 40b, 41, 42a, 42b also comprise a block element 42a, 42b associable with the first and with the second fixing body 6, 7 in a removable manner through the first and second opening 40a, 40b, 41, blocking their mutual position longitudinally along the axis of rotation A.

In particular, the block element 42a, 42b comprises at least one elongated portion 42a insertable through the first and second opening 40a, 40b, 41 and at least one expanded portion 42b which is larger in size than the elongated portion 42a and adapted to abut against the outer surface of the bottom plate 30 when the elongated portion 42a is inserted through the first and the second opening 40a, 40b, 41.

Moreover, the first opening 40a, 40b comprises at least one first and one second section 40a, 40b with a conformation substantially complementary to the elongated portion 42a and to the expanded portion 42b respectively.

This way, in use, the expanded portion 42b is positioned inside the second section 40b in abutment against the bottom plate 30 at the mouth of the first section 40a, so that the outer surface of the bottom plate 30 is substantially flat and has no protuberances, as shown in Figure 4.

Advantageously, the crushing rotor 5 comprises at least one creeping body 32 kinematically coupled idle in rotation to the fixed body 25, 26, 27 and arranged in creeping contact on the base body 10.

In particular, the crushing rotor 5 comprises a pair of creeping bodies 32 pivoted along the corresponding containment pins 28 and placed between the bottom plate 30 and one of the retaining plates 25.

Conveniently, the creeping bodies 32 comprise at least one horizontal flat face and at least one inclined flat face which extend radially with respect to the axis of rotation A.

In particular, the horizontal flat face and the inclined flat face are continuous to define at least one wedge-shaped profile positioned in support on the base body 10 and adapted to scrape the surface thereof, removing any remains of raw material that may deposit on it.

In fact, very frequently, because of the heat which develops inside the grinding chamber 3 during the operation of the mill 1 and because of the ambient humidity, a part of the raw material can stick to the base body 10.

Conveniently, the mill 1 comprises movement means 33, 34, 35, 36 of the driving shaft 4 mounted on the support frame 2 and comprising:

at least one motor assembly 33, 34;

transmission means 35, 36 interposed between the motor assembly 33, 34 and the driving shaft 4 and adapted to transmit the motion generated by the motor assembly 33, 34 to the driving shaft 4;

adjustment means for adjusting the transmission ratio between the motor assembly 33, 34 and the driving shaft 4 interposed between the transmission means 35, 36 and at least one of the motor assembly 33, 34 and the driving shaft 4.

Preferably, the motor assembly 33, 34 comprises at least one support body 33 associated with the support frame 2 and one rotating shaft element 34 associated with the support body 33 and rotating with respect to the latter around a central axis C positioned substantially parallel to the axis of rotation A.

In particular, the transmission means 35, 36 comprise at least one flexible member 35 closed on itself in a loop and wrapped at least partly around two pulleys 36, one of which is associated with the motor assembly 33, 34 and the other associated with the driving shaft 4.

The adjustment means, on the other hand, comprise a plurality of grooves 37 for housing the flexible member 35 formed on at least one of the pulleys 36 and having different diameters from each other.

Advantageously, a pulley 36 is locked in rotation together with the shaft element 34 and is centered along the central axis C, and the other pulley 36 is locked in rotation together with the driving shaft 4 at the upper end and is centered along the axis of rotation A.

In particular, the grooves 37 of the pulley 36 associated with the driving shaft 4 are made with increasing diameter starting from the upper end.

On the contrary, the grooves 37 of the pulley 36 associated with the motor assembly 33, 34 are made with decreasing diameter starting from the shaft element 34.

Moreover, the pulleys 36 suitably comprise the same number of grooves 37, where each groove 37 of a pulley 36 is positioned at the same height as a groove 37 of the other pulley 36 having different diameter, as shown in Figure

3.

In other words, the groove 37 having minimum diameter of a pulley 36 is positioned at the same height as the groove 37 having maximum diameter of the other pulley 36 and vice versa.

Advantageously, the support frame 2 comprises at least a containment compartment 38 for containing at least part of the movement means 33, 34, 35, 36 and is provided with at least one opening/closing door 39 adapted to permit or prevent respectively access to the movement means 33, 34, 35, 36, e.g. with the purpose of protecting them from foreign bodies which could be accidentally introduced inside the compartment 38 and which could compromise the operation of the mill 1.

More in detail, the compartment 38 contains the upper end, at least part of the shaft element 34, the respective pulleys 36 and the flexible member 35, as shown in Figure 3.

Advantageously, the support frame 2 also comprises a plurality of wheels 44 for the support and movement to the ground, as shown in Figures 1 and 3.

In particular, according to the embodiment of the mill 1 shown in the illustrations and according to the previously described structure of the mill 1, the characteristics of the components that delimit and define the grinding chamber 3, as well as the characteristics of the driving shaft 4 and of the crushing rotor 5 and the arrangement of the axis of rotation A, permit making a particularly lightweight mill 1 and positioning the grinding chamber at a particularly high level above the ground compared to the mills of known type.

In fact, thanks to such characteristics, the grinding chamber can be arranged above the pelvis of a person of medium build, further facilitating the maintenance operations of the mill and the collection of the ground raw material.

The operation of the mill 1 according to the invention is as follows.

Initially, the raw material to be ground must be inserted into the grinding chamber 3 through the loading assembly 43.

Subsequently, the driving shaft 4 is made to rotate by means of the movement means 33, 34, 35, 36.

In particular, the speed of rotation of the driving shaft 4, and consequently of the crushing rotor 5, depends on the diameter of the grooves 37 to which the flexible member 35 is wound.

In fact, the speed of rotation of the driving shaft 4 increases along with the increase in the diameter of the groove 37 of the pulley 36 associated with the driving shaft 4 compared to the diameter of the groove 37 of the pulley 36 associated with the shaft element 34. In other words, the maximum speed of rotation of the driving shaft 4 is reached when the flexible member 35 is wound to the groove 37 of the pulley 36 associated with the driving shaft 4 having the maximum diameter and with the groove 37 of the pulley associated with the shaft element 34 having the minimum diameter.

Advantageously, the speed of the driving shaft 4 can be varied by opening the compartment 38 and winding the flexible member 35 to a pair of different grooves 37.

Appropriately, the rotation of the driving shaft 4 causes the rotation of the crushing rotor 5 positioned inside the grinding chamber 3.

During the rotation of the crushing rotor 5, the crusher elements 24, subjected to the action of centrifugal force, rotate around the respective containment pins 28 and are positioned in a radial pattern with respect to the axis of rotation A to occupy substantially the entire volume of the grinding chamber 3.

Similarly to what has just been described with reference to the crusher elements 24, the creeping bodies 32 are also positioned in a radial pattern with respect to the axis of rotation A, brushing substantially the entire surface of the base body 10 on which they creep.

Moreover, the centrifugal force exerted on the crusher elements 24 and on the creeping bodies 32, as a result of the rotation of the crushing rotor 5, is decoupled from the weight force acting on them.

In fact, the centrifugal force operates on the crusher elements 24 and on the creeping bodies 32 radially with respect to the axis of rotation A and the weight force operates on them longitudinally along the axis of rotation A.

This way, unlike the mills of known type with a horizontal axis of rotation, the weight force does not push the crusher elements 24 and the creeping bodies 32 to strike the fixed body 25, 26, 27, for example during the start and stop phases of the rotation of the crushing rotor 5.

During the rotation of the crushing rotor 5, the raw material contained in the grinding chamber 3 is crushed by the crusher elements 24 until a raw material is obtained with a grain size such as to cross the lateral grid 15.

In particular, the raw material that crosses the lateral grid 15 is poured into the unloading interspace along which it is conveyed by the lateral retaining body 16 until it reaches the unloading mouth.

Advantageously, during the period of inactivity of the mill 1, it is possible to carry out the maintenance of the grinding assembly 3, 4, 5, 16.

In particular, through the coupling means, it is possible to decouple the second end portions 20 and move the containment walls 19, 20, 21 in the first working configuration.

In this configuration, it is possible to remove the base body 10 through the fastening/release means 13.

At the same time, it is possible to remove the lateral grid 15, e.g. to replace it with one having transit holes different in size or to access the crushing rotor 5.

In fact, in this configuration, it is possible to release the crushing rotor 5 from the driving shaft 4 without releasing the latter from the support frame 2.

In particular, the first and second fixing body 6, 7 can be decoupled by means of the locking means 40a, 40b, 41, 42a, 42b, i.e. it is possible to take the block element 42a, 42b out of the first and the second opening 41, so as to allow the sliding of the second fixing body 7 with respect to the first fixing body 6.

It has in practice been ascertained that the described invention achieves the intended objects.

In particular, the fact is underlined that the vertical axis of rotation allows decoupling the crushing rotor and the driving shaft without disassembling the latter from the mill, thus speeding up and simplifying the maintenance jobs on the crushing rotor.

Moreover, the vertical axis of rotation allows decoupling the centrifugal force exerted on the crusher elements, as a result of the rotation of the crushing rotor, and the weight force operating on them.

What is more, the vertical axis of rotation allows using a lateral grid that surrounds the grinding chamber by 360°.

This way, the volume of the grinding chamber and of the size of the crushing rotor being equal, the quantity of food for animals produced in a predefined period of time is much higher than in known mills, i.e. mills that use a horizontal axis of rotation. Moreover, the base body, the lateral grid and the lateral retaining body, allow easy access to the grinding chamber and to the crushing rotor.

In addition, the adjustment means make it possible to easily adjust the speed of the driving shaft according to the need of the user of the mill.