D e s c r i p t i o n

The present invention relates to a portable device for distribution of granular material, such as various types of corn or manure/fertilisers in a state of heterogeneous aggregation.

It is known that in the agricultural field operations for spreading and/or distributing different types of materials or substances (on the ground or the cultivated areas, also of the arboreal type) are required; let us think about, for example, the pesticides, the reinforcing treatments, the manuring/fertilising operations or also about sowing on very wide areas .

An important aid for execution of these works is given by suitable portable powered devices, that operators moving on foot usually carry on their shoulder; these devices, generally known in the art as "atomisers" are usually based on a propulsory apparatus that in turn drives a blowing fan; this fan generates an air flow into which the material to be distributed/spread is introduced (which material is conveniently housed in a holding tank) and the air flow entraining the suspended material is routed towards a flexible tube.

While the above mentioned known art is widely used, it has some non-negligible drawbacks .

First of all, the atomisers of known type, based on this structural architecture have some "uniqueness" in use since, due to the particular nature of the material to be distributed/spread, construction details specifically sized and designed for the material itself are required; in other words, the atomisers of known type conceived for granular materials cannot be used for spreading materials having different aggregation states (fine powders, liquids and others) .

At the same time, atomisers for granular materials of known type can be subjected to phenomena involving irregularities in the material emission, which are mostly due to the highly heterogeneous nature of the material particle size; actually, clogging phenomena can occur, when too much material is accumulated at the entrance of the flexible tube or, on the contrary, discontinuous or too weak emissions can occur when the blowing action of the fan generates an insufficient power and/or a material suction in a region of the holding tank that is particularly "empty".

Accordingly, the .present invention aims at conceiving a portable device for granular material distribution capable of obviating the above mentioned limits.

Mainly, the present invention aims at conceiving a device that can offer a high efficiency in the distribution/spreading of granular materials (seeds, rice, manure and any other substance or material having a "macroscopic" particle size and a certain difference and/or randomness degree in the average conformation/size of the granular particles) , thus avoiding irregularities in operation and ensuring high homogeneity in the material flow coming out of the device.

Another aim of the present invention is to conceive a device that can be adjusted in a reduced period of time and at low costs, so that it can work as a distributor/spreader of products and substances in aggregation states different from that defined above as a "granular" state (i.e. fine powders, liquids and others) .

Therefore the present invention aims at conceiving a device offering a great ease of use and control for an operator and that can be dismantled and examined/checked in a very simple and quick manner.

The technical task mentioned and the aims specified are substantially achieved by a portable device for granular material distribution having the features set out in one or more of the appended claims.

Description of a preferred but not exclusive embodiment of a portable device for granular material distribution in accordance with the present invention is now given by way of non-limiting example, with reference to the accompanying drawings, in which: - Figs. 1 and 2 show perspective views of a device according to the invention; and - Figs. 3 and 4 are perspective views of structural/operating details of the devices seen in Fig. 1 or 2.

With reference to the drawings, in the portable device for granular material distribution in accordance with the present invention and generally identified by reference numeral 1, there is a holding body 2 (adapted to house a predetermined amount of granular material M) and, denoted at 3, suitable conveying means connected to said holding body 2 and adapted to eject the granular material M in at least one outflow direction 3a (which typically can be the exit direction defined by a flexible tube, as described in more detail in the following) ; also present is propulsion means 4 acting on the conveying means 3 and adapted to transport the granular material M being mixed with, and entrained by an air mass.

Advantageously, the present invention contemplates the presence of selective loading means 5 for the granular material M, which means can be reversibly configured between a lock condition (at which entry of the granular material M into the conveying means 3 is inhibited) and a suction condition (at which, on the contrary, admission of the granular material M into the conveying means is caused) .

Unlike the known art, in which "selective loading" of the granular material does not occur (which material therefore invades the conveying means even when ejection of said granular material is not required) , the present invention is capable of directing and loading the granular material only when the true ejection conditions exist (for instance, when according to the operator's opinion, at that moment distribution/spreading of the material M is necessary) ; this enables clogging (and also insufficient or discontinuous flows) to be avoided, which is typical of known devices, the corresponding "conveying means" of which can be filled with the granular material without however the existence of an appropriate air mass in movement keeping them suspended and without the presence of a dynamic mixing.

In more detail in terms of operation of the present invention, it is possible to see that the propulsion means 4 can be reversibly configured between a "slow- running" condition at which the flow of the granular material M through the conveying means 3 is practically zero, and at least one thrust condition at which on the contrary said granular material M flow takes a non-zero value; in co-ordination with these possible operating conditions (that are practically decided by the operator by a command varying the mechanical power sent to the propulsion means 4, for example), the selective loading means 5 can be advantageously (and reversibly) configured between the lock condition (in co-ordination with the corresponding "slow-running" condition of the propulsion means 4) and the suction condition (in co-ordination with the corresponding "thrust" condition of the propulsion means 4).

From a structural point of view, and in order to enable the selective loading means 5 to be configured as above described, said means comprises at least one hollow lead-in or guide body 5a, which is disposed internally of the holding body 2 and defines a loading direction 5b for the granular material M; the selective loading means 5 further comprises at least one propulsor 5c adapted to determine a thrust on the granular material M (and in particular on the granular material M housed in the holding body 2) in a direction having at least one component coincident with the loading direction 5b. In other words, the selective loading means 5 according to the present invention is able to cause entry of the granular material M into the conveying means only under some operating conditions of the device 1 (and more particularly, only when a turbulence in the material M is generated that routes said material in a movement direction that is compatible with the geometry of the hollow lead-in body 5a) .

According to an embodiment shown in the figures, propulsor 5c comprises a nozzle 5d disposed internally of the holding body and facing the hollow lead-in body 5a; should the current requirements need it (for instance, in order to generate a suitable distribution of turbulence inside the granular material M) , the propulsor can conveniently comprise a plurality of nozzles 5d turned towards the hollow lead-in body 5a.

In order to conveniently route or guide an air mass inside the granular material M, propulsor 5c further comprises an axial duct 5e extending along an extension axis oriented towards the hollow lead-in body 5a; this axial duct 5e practically conveys pressurised air (or more generally a turbulence-promoting agent) into the holding body 2 and preferably into a portion of the holding body 2 in which the material M is gathered; injection of air into the material M gives rise to a turbulent movement of same and therefore promotes entry of the material M into the hollow lead-in body 5a.

At this point, it is important to notice that within the scope of the present invention, the hollow lead-in body 5a is such shaped that movement of the granular material M inside it is only enabled when this material is made sufficiently "turbulent" and preferably only when movement of the granular material M in its "turbulent" state has a direction (and a kinetic energy) compatible with the geometry of the hollow lead-in body 5a (or in other words, when the movement direction of the granular material M is substantially coincident with the load (5b) direction) . — ^" 1 —

For achieving the above aim, the hollow lead-in body 5a comprises an inlet portion (defining a passage section facing at least one nozzle 5d) , a loading portion connected to the inlet portion (and adapted to impart an increase in the potential energy of a granular material M passing through the loading portion) and finally an admission portion connected to the loading portion (and adapted to admit the granular material M into the conveying means 3) .

Division of the hollow lead-in body 5a practically involves the presence of an inlet opening (corresponding to the inlet portion) the front section of which is directly proportional to a maximum admissible flow rate of granular material M and at the same time also involves a suitable type of "intermediate pipeline" (corresponding to the loading portion) the conformation of which allows the kinetic energy imparted to the turbulent flow of the granular material M (that entered said inlet opening successfully, due to its vectorial speed and its scalar kinetic energy from propulsor 5c) to be converted into potential energy; this conversion is the result of a level increase of the granular material M that in this manner can overcome an "inlet threshold" (corresponding to the admission portion) introducing it into the conveying means 3.

Due to this mechanism for conversion of the "mechanical" energy linked to the granular material 3, it is important to notice that in a "slow-running" condition of the propulsion means, propulsor 5c does not energise the granular material M that therefore has no possibility of stepping over the "barrier of potential energy" consisting of the loading portion; in 000110

this manner clogging of the conveying means is prevented.

The optimal treatment of the granular material M and in particular a suitable energising of same are ensured by an appropriate positioning of the hollow lead-in body 5a and of propulsor 5c; in particular, the holding body 2 has a gathering portion in which the granular material M has a minimum potential energy (under conditions of normal use of device 1, this portion substantially corresponds to the "bottom" of the holding body 2) ; specifically, propulsor 5c and/or the hollow lead-in body 5a are positioned close to and/or at this gathering portion.

As to the conveying means 3, it comprises a tubular element (preferably of the flexible type or at all events that can be freely and rotatably handled by an operator) , which in turn has an inlet connected to the holding body 2 (and preferably connected to the hollow lead-in body 5a) and an outlet opposite to said inlet.

At the same time, the propulsion means 4 comprises:

- an air flow source 4a connected to a motor and adapted to generate, preferably through a fan or similar blowing device, an air flow to be at least contained in the conveying means 3;

- a bypass unit 4b positioned in the tubular element and adapted to draw a portion of this air flow (that practically travels within the conveying means 3 or more correctly is contained inside the conveying means 3) and send it at least towards propulsor 5c, through a suitable branch pipe 4d; and

- choking means 4c operatively acting on the bypass unit 4b to selectively choke said air flow portion Q

towards propulsor 5c (still through the branch pipe 4d shown in the figures) .

In order to exert a more accurate control of the kinetic energy and/or the turbulence to be imparted to the granular material M, this choking means 4c can be actuated by an operator (co-ordinately with a power command on the motor of the propulsion means, or also independently of any other operating parameter) and in a particularly appreciated embodiment of the present invention it comprises a throttle valve; this throttle valve can be conveniently configured in a closed position (which position can be taken in co-ordination with the "slow-running" condition of the propulsion means 4) or in a plurality of open positions (partly or fully open conditions, depending on current requirements) .

For the purpose of enabling an appropriate ejection of the granular material M from the conveying means 3, the bypass unit 4b can further comprise a Venturi-effect choke (or similar fluid-operated device) adapted to impart an acceleration to the air flow entraining the suspended granular material M.

The features herein described and claimed in the following can be implemented on a device specifically conceived and assembled for operating on granular materials or can also be mounted on similar portable devices (atomisers or others) that have not been originally conceived for granular materials; to this aim, the present invention can contemplate the presence of new-configuration means 6 which is adapted to enable reversible dismantling of the selective loading means 5. Structurally, this new-configuration means 6 can comprise suitable closure members which can be removably positioned in the bypass unit 4b and/or at a connection between the conveying means 3 and the admission portion of the hollow lead-in body 5a (and can thus enable dismantling of propulsor 5c and/or of the hollow lead-in body 5a, or also closure of the branch pipe 4d) ; in addition, the new-configuration means 6 can also comprise an extension to be connected to the tubular element of the conveying means 3 (and more particularly, to the inlet of the flexible tube when it is fitted into the holding body 2, so as to enable operation with liquid or powdered materials) .

The invention achieves many advantages.

In fact, due to the particular construction architecture of the present device, drawing of the granular material can take place in the most appropriate manner, and a regular (in terms of flow rate) and uniform (in terms of distribution of the material in the passage section) entry of same can be ensured, so that the material is sent to the flexible tube in the best outflow conditions; due to this, the quality of the spreading/distribution work is improved and therefore the working time is reduced, so that the operator's work conditions are made less heavy (the device is to be carried on the operators' shoulder).

In addition, the structural features enabling the present device to be newly configured for operating on different kinds of materials, also of the non-granular type - in other words, the possibility of removing (in a quick and simple manner) the structural elements intended for selective routing of the granular material into the conveying means and replacing them with other components adapted to work on different materials - give the device a wide operating flexibility, therefore allowing the work resources to be better utilised.

In addition, it is to be noted that the present invention can be implemented on already existing atomising devices, i.e. it can allow a retrofit operation, which will further increase the operating capability of the device with reduced costs and ease of intervention.

Finally, thanks to the present invention, low manufacturing costs of the device (or even only of those structural/operating parts enabling the device to operate on granular materials) are ensured and particular adaptations and changes or modifications are not required even when use of devices of known type is contemplated, which is advantageous in terms of global production economy and final price of the product.