DESCRIPTION

The present invention relates to a centrifugal spreader for fertilizers and manures, in particular in granular form, of the type comprising a hopper for collecting the material in granular form, a dispensing container which receives the material from the hopper, and a distribution disc for distributing the material in granular form .

In the relevant technical field there are known centrifugal spreaders for fertilizers, each comprising a hopper which collects the material in granular form to be distributed, a container placed under the hopper, into which the amount of material to be distributed is dispensed, and a rotating distribution disc, which receives the material dispensed via an outlet from the container in order to distribute it by means of a centrifugal force.

Typically, an agitator is present inside the dispensing container, this agitator being formed by a rotating body provided with a series of prongs, and mixing the material within the container before it is sent to an outlet opening, in order to prevent the compaction of the material and, more generally, to provide a more uniform outflow.

The agitator may be driven by a dedicated motor, such as that described in International Patent Application WO 2011/113529, or may be driven by the system used to propel the distribution disc, which typically receives its motion from the power take-off of a tractor.

In the latter case, the agitator may be directly connected to the rotation shaft of the distribution disc, as described in EP 784 917 for example, or may be driven via a separate shaft, which also receives its motion from the power take-off via a further distribution unit, as disclosed in EP 1 707 042.

However, the known solutions have a number of drawbacks. If a dedicated motor is used, it is evident that, although this allows the greatest flexibility in the geometry and functional characteristics of the agitator, it implies additional costs due to the presence of supplementary components.

The solution based on a dedicated transmission running from the power takeoff also allows a degree of flexibility in the functional characteristics of the agitator, but results in larger overall dimensions and a degree of complexity in mechanical terms.

The use of an agitator driven by the same shaft as the distribution disc, as described in DE 2818227 for example, is the simplest solution in terms of construction, but gives rise to problems in the assembly and maintenance of the spreader.

The reason for this is that it may be necessary to detach the distribution disc for maintenance, for periodic replacement, or for the purpose of changing the operating width, and the last-mentioned design solution gives rise to considerable problems in the performance of this operation, since it is also necessary to detach the dispensing container or other components which are not easily accessible, in order to carry out this operation.

The technical problem underlying the present invention is that of providing a centrifugal spreader of manures, fertilizers and granular material in general which is structurally and functionally designed to overcome the aforementioned difficulty.

This problem is resolved by the present invention by means of a centrifugal spreader of manures, fertilizers and granular material in general, constructed according to Claim 1.

Preferred characteristics of the invention are defined in the dependent claims. The object of the present invention makes it possible to simplify the operations of detaching the distribution disc, using a solution which is simple and economical in terms of construction.

The characteristics and further advantages of the invention will be more clearly apparent from the following detailed description of a preferred, but non-exclusive, exemplary embodiment of the invention, illustrated, for guidance and in a non-limiting way, with reference to the attached drawings, in which :

- Figure 1 is a perspective view of a centrifugal spreader for manures, fertilizers and granular material in general, constructed according to the present invention;

- Figures 2A and 2B are, respectively, a front view and a perspective view of a dispensing container, a distribution disc and a transmission assembly, which are components of the spreader of Figure 1;

- Figures 3A and 3B are, respectively, a front view and a perspective view of the components of Figures 2A and 2B, in a step of detachment; and

- Figures 4A and 4B are, respectively, a front view and a perspective view of the components of Figures 2A and 2B, in a detached configuration.

With reference to Figure 1 initially, the number 100 indicates the whole of a centrifugal spreader for manures, fertilizers and granular materials in general, constructed according to the present invention.

The spreader 100 is, for example, of the type suitable for fastening to a three- point linkage of a tractor, and comprises a pair of hoppers 1 to contain the granular material for distribution . Preferably, the spreader 100 also comprises an upper bin 11, to the bottom of which the two hoppers 1 are connected. According to a preferred embodiment, the bin 11 comprises a covering element 12, which controls the movement of a cover sheet, not shown in the figure.

As will be more apparent below, the hoppers 1 have symmetrical characteristics, and therefore reference will be made to only one of the two hoppers below, on the understanding that the same details are applicable to the other hopper. It is also to be understood that the principles described below can also be applied in an equivalent manner to spreaders using a single hopper.

The spreader 100 further comprises a dispensing container 2, located in a lower area of each hopper 1.

The dispensing container 2 receives the granular material from the hopper 1, and comprises at least one outlet opening 20 for the controlled exit of the granular material. In the context of the present invention, the term "controlled exit" indicates that the material is made to flow out of the container 2 while its amount is controlled, this amount being regulated by suitable regulating means not shown in the figure. These regulating means are of a known type, and are therefore not described in greater detail below.

The spreader according to the present invention further comprises a distribution disc 3, placed under the dispensing container 2, which receives the material for distribution by the falling of the material through the outlet opening.

The distribution disc 3 is rotated by means of a suitable transmission assembly 4. Thus the material that has fallen on to the distribution disc 3 can be distributed radially by a centrifugal force produced by the rotation of the disc 3.

According to a preferred embodiment, the transmission assembly 4 receives its motion from a power take-off of the tractor, not shown in the figure, and transmits a rotary motion to the distribution disc 3, via a series of shafts only partially illustrated in Figures 2A to 4B.

With reference now to Figures 2A and 2B, the transmission assembly 4 comprises, in particular, a rotation shaft 5 which extends between the distribution disc 3, causing it to rotate, and the dispensing container 2.

According to a preferred embodiment, the rotary motion is transmitted from a transmission shaft 41 to the rotation shaft 5 via a bevel gear drive 40, of which only an outer casing is illustrated in the figure. Thus the axis of rotation 5 extends substantially vertically in use, and the rotation of the distribution disc 3 imparts an acceleration to the granular material away from the shaft 5. The rotation shaft 5 is divided into a first part 51 and a second part 52, connected or connectable by connecting means 6. In particular, in Figures 2A and 2B the two parts 51 and 52 are shown as being connected to one another by the connecting means 6, while in Figures 4A and 4B the two parts are separated.

Figures 3A and 3B show the two parts in an intermediate configuration, in which the connecting element 6 is placed in a release position, by procedures illustrated in greater detail below.

With reference again to Figures 2A and 2B, according to a preferred embodiment, the spreader 100 further comprises an agitator, not shown in the figure, housed inside the dispensing container 2 upstream of the outlet opening 20. In this case, the first part 51 is fixed to the agitator and the second part 52 is fixed to the distribution disc 3, and the connection between the two parts 51 and 52 is such that they are fixed with respect to rotation, so that the agitator is also driven by means of the rotation shaft 5.

In this case, therefore, the part 51 is supported rotatably on the dispensing container 2, by means of a bearing for example.

According to a preferred embodiment, the connection element 6 comprises a locking device 60 which can slide along the rotation shaft 5. Preferably, the locking device 60 is formed by a block slidably associated with the first and second parts 51, 52 so that it can engage simultaneously with the first and second part 51, 52, as shown in Figures 2A and 2B, or with only one of the parts, as in Figures 3 and 4.

Thus, when the block engages both parts simultaneously, respective ends 51A, 52A of the first and second parts 51, 52 are fixed so that they cannot be moved away from one another, and so that the two parts are kept fixed with respect to rotation.

As shown in Figures 3A and 3B, the locking device 60 can be made to slide axially along the shaft 5 so as to free the area of connection between the two ends. In particular, in the present embodiment, the locking device 60 can be moved upwards, remaining associated solely with the part 51 supported by the dispensing container 2. Additionally, according to a preferred embodiment, a threaded coupling can be provided between the locking device and one of the two parts of the shaft 5, so that the axial movement is produced by rotating the locking device 60 on the thread formed on the shaft 5. Furthermore, preferably, a safety device can also be provided to prevent the accidental movement of the locking device 60, using a pin that can be inserted into a corresponding hole, for example. Alternatively, it is possible to provide for the use of right- and left-hand threads, so as to prevent unintentional unscrewing during the movement of the discs.

For the purpose of separating the two ends away, according to a preferred embodiment, one of the two ends 51A, 52A is formed in an articulated portion 55, rotatably connected to one of the two parts 51, 52. Thus, when the locking device 60 is moved so as to release the two ends, the end 51A can be separated from the other end by rotating the articulated portion 55, as shown in Figures 4A and 4B.

Preferably, the threaded portion is formed in the part 52, while it can slide freely on the articulated portion 55.

According to a preferred embodiment, the two ends 51A and 52A are shaped so that, when aligned and positioned near one another, they engage with one another in such a way that the two parts 51 and 52 are fixed with respect to rotation about the axis defined by the shaft 5.

Preferably, the coupling between the ends is provided by means of a socket 54 and a respective extension 53 whose shapes are complementary to one another.

According to a preferred embodiment, the extension 53 takes the form of a strip extending parallel to an axis of extension of the rotation shaft 5. In this case, the extension 53 can easily be inserted into the socket 54 or extracted therefrom, by rotating the articulated portion 55.

More generally, however, the respective ends 51A, 52A and the connecting element 6 are associated with one another for operation by a shape coupling, so as to prevent the separation of the ends and keep the two parts 51 and 52 of the shaft 5 fixed with respect to rotation.

Thus the invention resolves the problem which was proposed, while providing a number of advantages. The principal advantage offered by the invention lies in the fact that dividing the shaft into two parts which are connectable to one another makes it possible to remove the distribution disc without the need to detach the dispensing container.

Additionally, the presence of an articulated portion and the configuration described above make it possible to separate the locking device from the distribution disc, thus facilitating the operations of detaching the latter.

The discovery according to the present invention is also particularly suitable, in terms of reliability and robustness, for use in dusty environments, which is typically the case during operations of manuring and fertilizer distribution.