DESCRIPTION

[01] The present invention refers the technical field of agricultural machines and the subject of the invention is a machine for harvesting leaf vegetables farmed in a plot of land.

[02] As is known, in the field of intensive cultivation special automatic or semiautomatic machines are used, which are designed to collect the vegetables farmed in a relatively large plot of land.

[03] Specifically, in the cultivation of special categories of leaf vegetables, commonly referred to as baby leaves, harvesting machines comprise a cutting head equipped with a blade which is designed to cut the vegetable leaves and a conveyor belt designed to promote the movement of the leaves along a predetermined advance direction.

[04] Downstream of the conveyor belt there is often placed a platform which is intended to accommodate an operator in charge with the manual collection of the cut leaves.

[05] In this case, in fact, the operator manually collects the leaves deposited on the conveyor belt and stores them in suitable tanks or containers.

[06] The main limitation of this configuration lies in that during the collection step it is not possible to separate the vegetable leaves from any foreign bodies present in the soil and accidentally collected by the cutting head.

[07] These foreign bodies can be organic such as, for example, soil, pieces of wood or very small animals, or can be constituted by various waste products thrown on the ground such as, for example, paper, cigarette stubs, etc.

[08] Furthermore, the operator must separate manually the suitable leaves from the leaves that need to be rejected because of defects or alterations in terms of shape or consistency.

[09] Some technical solutions have been developed for the removal of the foreign bodies and are used in the most advanced machines.

[010] Specifically, downstream of the conveyor belt there is a selection station which is designed to promote the separation of the leaves from all the foreign bodies gathered during the vegetable cutting step.

[01 1 ] For example, this sorting station can be obtained using a vibrating belt provided with a metallic net whose meshes cannot be larger than the leaves.

[012] The vibration transmitted to the metallic belt makes the foreign bodies fall through the meshes and consequently the leaves conveyed out of the station are cleaner than they were in the moment of collection.

[013] Possible alternatives to the vibrating system are blowing or suction systems, even if the yield of the latter is substantially similar to that of the system just described above.

[014] In the selection machines used for processing tomatoes, some artificial viewers are installed in addition to the systems for eliminating foreign bodies, wherein said viewers are designed to sort the produce according to the colour of the leaves.

[015] These viewers, however, are not capable of identifying all the flaws and alterations that may affect the leaves and therefore their use does not guarantee the optimal selection of the harvested produce.

[016] The main drawback posed by the solutions described above is thus represented by the fact that they cannot guarantee high precision and reliability in the evaluation of the waste contained among the vegetable leaves collected from the ground.

[017] This limitation can be overcome by making a further manual selection of the leaves and this processing step can negatively affect the quality of the product, as it subjects the latter to increased bacterial contamination and involves longer processing times. Consequently, the life cycle of the product will be shorter, too.

[018] Furthermore, this sorting step makes it more difficult to maintain the product in the cold chain and, in addition to shortening the life cycle of the leaves, reduces also the geographical distances from the sales points that can be reached from the production plants.

[019] The patent documents US2003/182920, US5964081 and US2004/216441 describe machines for harvesting leaf vegetables which, however, pose all the drawbacks listed above.

[020] The present invention intends to solve the technical problems described above, thus making it possible to provide a machine for harvesting leaf vegetables farmed in a plot of land which allows the produce selection process to be improved.

[021 ] It is a further object of the present invention to provide a machine for harvesting leaf vegetables which makes it possible to precisely and efficiently separate the unsuitable leaves or the foreign bodies present among said leaf vegetables. [022] It is another object of the present invention to provide a machine for harvesting leaf vegetables which makes it possible to reduce the bacterial contamination to which the produce may be subjected during the successive processing or packaging steps.

[023] It is a further object of the present invention to provide a machine for harvesting leaf vegetables which makes it possible to extend the life cycle of the packaged produce.

[024] It is another object of the present invention to provide a machine for harvesting leaf vegetables which makes it possible to reduce the need to handle the produce once it has been harvested.

[025] It is a further object of the present invention to provide a machine for harvesting leaf vegetables which makes it easier to maintain the packaged produce in the cold chain, thus allowing it to be sold in geographical areas that are located relatively far from the processing plant.

[026] It is another, yet not the least object of the present invention to provide a machine for harvesting leaf vegetables which makes it possible to reduce labour, processing and packaging costs.

[027] These objects are achieved by a machine for harvesting leaf vegetables of the type according to claim 1 .

[028] Other objects which are described in greater detail below are achieved by a machine for harvesting leaf vegetables according to the dependent claims.

[029] The advantages and characteristics of the present invention are clearly illustrated in the following detailed description of some preferred non-limiting embodiments of a machine for harvesting leaf vegetables, with special reference to the following drawings:

Figures 1 -3 are respectively a side view, a top view and a rear view of a machine for harvesting leaf vegetables according to the invention;

- Figure 4 is an enlarged side view of a first detail of Figure 1 ;

Figures 5-6 are respectively a perspective view and a side view of a second detail of Figure 1.

[030] The subject of the present invention is a machine for harvesting leaf vegetables.

[031 ] This machine, hereinafter indicated by the reference number 1 , can be used especially for harvesting baby leaves F farmed in a plot of land and having a relatively large size.

[032] As can be better observed in Figures 1-4, the machine 1 comprises a support frame 2 defining a longitudinal extention axis L and a plurality of wheels 3 3"' rotatably mounted on said frame 2 and designed to come into contact with the ground T.

[033] The frame 2 can be substantially reticulated, and a pair of front wheels 3, 3' and a pair of rear wheels 3", 3"' can be anchored to its ends 4, 5.

[034] Furthermore, steering means not visible in the figures can be provided, wherein said steering means are anchored to the frame 2 and designed to promote the simultaneous rotation of the pair of front wheels 3, 3' and/or of the pair of rear wheels 3", 3"'.

[035] In an alternative embodiment of the invention, not illustrated in the figures, at least one pair of tracks can be used instead of the wheels 3 3"', wherein said tracks are rotatably anchored to the frame 2 and if necessary can be steering tracks.

[036] The machine 1 may also comprise drive means 6 anchored to the frame 2 and operatively connected to one or more wheels 3 3"' or to one or more tracks.

[037] The drive means 6 are designed to promote the selective rotation of the wheels 3 3"' or the tracks to which they are connected, in such a way as to allow the machine

1 to move on the ground T.

[038] For example, the drive means 6 may comprise an internal combustion engine, not illustrated herein, connected to a drive member, not shown in the figures, either, which is designed to transfer the rotary motion to the wheels 3 3"' or to the tracks.

[039] As an alternative to the internal combustion engine, it is possible to use one or more electric motors powered by a plurality of accumulators which are anchored to the frame 1 , too.

[040] The machine 1 , furthermore, comprises collecting means 7 operatively associated with the frame 1 and designed to cut the leaves F of the vegetables while the machine 1 moves.

[041 ] Specifically, the collecting means 7 comprise a cutting head 8 placed in the proximity of the front end 4 of the frame 2.

[042] This head 8 may comprise a belt blade 9 which can be positioned on a substantially vertical plane ττ, orthogonal to the direction of advance of the machine 1.

[043] Furthermore, the collecting means 7 comprise a first conveyor belt 10 located downstream of the blade 9 and designed to collect the cut vegetable leaves F and convey them towards the rear portion 5 of the frame 2 along a substantially longitudinal advance direction A.

[044] As best shown in Figure 1 , the frame 2 may comprise a centre portion 1 1 and a front projection 12 having two substantially parallel longitudinal arms 13.

[045] Said arms 13 have one end 14 hinged to the centre portion 1 1 , and a free opposite end 15 to which the belt blade 9 is anchored.

[046] The first conveyor belt 10 is inserted in the transverse space that separates the two arms 13 of the projection 12 and the free end 15 of the latter is movable between a lower position, substantially level with the ground, in which the blade 9 interacts with the vegetable leaves F, and a raised position, in which the blade 9 does not cut the vegetables.

[047] The machine 1 may conveniently comprise also selection means 16 operatively associated with the frame 1 and designed to separate the unsuitable leaves F' or the foreign bodies C collected by the machine from the leaves F which, on the contrary, are suitable for use and do not have any foreign body among them.

[048] The expression "unsuitable leaves" used in the preceding paragraph and throughout the text below refers to those leaves which, for example, present alterations in terms of shape and/or composition or damages caused by the presence of insects or parasites.

[049] In the embodiment of the invention illustrated in the figures, the selection means 16 comprise a net belt 17 located downstream of the first conveyor belt 10, substantially at the level of the centre portion 1 1 of the frame 2.

[050] This belt 17 comprises a metallic net 18 constituted by meshes whose size does not exceed the size of the leaves F and designed to collect all the produce released by the first belt 10 promoting its movement along the advance direction A.

[051 ] In the machine shown in the figures, the advance direction A is substantially longitudinal and parallel to the axis of development L of the frame 1.

[052] However, in further embodiments of the machine, different from the one shown herein, the advance direction A of the cut leaves F may be not completely longitudinal and may comprise also transverse or inclined sections, according to the position of the various components of the machine with respect to the frame.

[053] The net belt 17 can be selected into the group comprising the vibrating belts to promote oscillation of the collected product F and any relatively large foreign bodies C such as, for example, soil, stones or similar objects fall through the meshes of the belt.

[054] The selection means 16 furthermore comprise at least one sensor 19 designed to irradiate the cut leaves F with electromagnetic radiation having a predetermined wavelength and, at the same time, to detect the electromagnetic radiation reflected by the same leaves following the previous irradiation cycle.

[055] The sensor 19, furthermore, is configured to generate an electric signal s associated with the electromagnetic radiation reflected by the leaves F and is connected to an electronic control unit 20 designed to receive and process this electric signal s.

[056] Specifically, the electronic control unit 20 is designed to process the electric signal s emitted by the sensor 19 to determine its frequency spectrum and compare it with one or more previously stored reference frequency spectra.

[057] To operate with these functions, the electronic control unit 20 uses a programmable microprocessor and a memory portion, neither of which is shown in the drawings.

[058] The memory portion is designed to temporarily or permanently store digital data generated during the processing cycle carried out by the processor or associated with the reference frequency spectrum.

[059] According to a specific aspect of the invention, the frequency spectrum of the electric signal s processed by the electronic control unit 20 is selected into the infrared and/or in the ultraviolet region.

[060] Specifically, a spectrum analysis of the electric signal s limited within the ultraviolet band will make it possible to identify all the foreign bodies which do not contain chlorophyll, and which therefore are not of plant origin.

[061 ] Chlorophyll, in fact, has high capacity of absorbing the electromagnetic radiation in the ultraviolet band and therefore the reference frequency spectrum for this specific band will show relatively low values.

[062] The spectrum analysis of the electric signal s in the infrared band, instead, will make it possible to identify the unsuitable leaves F or the foreign bodies which contain chlorophyll but are of a different nature compared to the collected vegetable leaves.

[063] In this case, therefore, the reference frequency spectrum in this specific band will substantially correspond to that of a vegetable leaf.

[064] The electronic control unit 20 is therefore configured to carry out a spectrum analysis in bands which do not include the visible spectrum, which is generally included between 400nm and 700nm.

[065] Preferably, the electronic control unit 20 is programmed in such a way that it simultaneously carries out the spectrum analysis of the electric signal s in the ultraviolet band and in the infrared band.

[066] In this way, in order to establish the degree of suitability of the leaves F, F, the electronic control unit 20 will process the information associated with both of these bands, respectively the ultraviolet band and the infrared band.

[067] Furthermore, the sensor 19 can be made in such a way as to exclude or filter the emission or the reception of the electromagnetic waves within the visible band.

[068] The sensors 19, therefore, in addition to detecting the unsuitable leaves F', make it possible to identify all the foreign bodies C which have been collected by the machine but have not been eliminated by the net belt 17.

[069] From the operational point of view, each sensor 19 may comprise a box-shaped casing 21 made of a metallic material and extending over the entire width h of the belt 10, 17 placed upstream.

[070] There is also one pair of supports 22 connected to the casing 21 and having one end 23 suited to be anchored to a corresponding strap 24 which is integral with the frame.

[071 ] In this way, the casing 21 will be fixed to the frame in a position which is substantially orthogonal to the direction of advance A of the cut leaves F, F\

[072] Furthermore, the casing 21 can be selectively rotated with respect to the supports 22 and comprises a screen 25 facing inwards and substantially transparent to the electromagnetic radiation emitted by the sensor 19 and reflected by the leaves F.

[073] The casing 21 can house one or more electronic boards, not visible in the figures, which are designed to support series of transmitting/receiving members designed to transmit and receive a corresponding electromagnetic wave in the ultraviolet spectrum and/or the infrared spectrum.

[074] Preferably, the sensor 19 may comprise a first series of receiving/transmitting members, not shown herein, arranged side by side along a direction which is orthogonal to the advance direction of the leaves F and suited to transmit electromagnetic radiation in the ultraviolet band.

[075] Furthermore, the sensor 19 may comprise also a second series of receiving/transmitting members, not shown herein, arranged side by side along a direction which is orthogonal to the advance direction of the leaves F and suited to transmit electromagnetic radiation in the infrared band.

[076] In addition to the above, both series can have a length not shorter than the width h, l ₂ of the first belt 10 or the net belt 17.

[077] The machine may conveniently comprise distinct collection areas 26, 27 for the suitable leaves F and the unsuitable leaves F or the foreign bodies C.

[078] These collection areas 26, 27 are respectively positioned downstream of the first conveyor belt 10 or the net belt 17, if the latter is installed in the machine.

[079] As best shown in Figures 4-6, the collection areas 26, 27 can be positioned side by side or be staggered longitudinally.

[080] Furthermore, in the proximity of the collection areas 26, 27 there may be a second conveyor belt 28 and a third conveyor belt 29 adapted to convey the suitable leaves F, the unsuitable leaves F' and the foreign bodies C towards two distinct containers.

[081 ] Specifically, the second conveyor belt 28 and the third conveyor belt 29 can be substantially positioned transversely and there may be a fourth conveyor belt 30, positioned transversely, too, and suited to convey the suitable leaves F or the unsuitable leaves F' into a container located outside the machine 1 , for example a bin or a similar container.

[082] As best shown in greater detail in Figures 1 and 4-6, the collection areas 26, 27 can be positioned under the first conveyor belt 10 or under the net belt 17, if the latter is installed in the machine.

[083] In this way, the leaves F, F' released by one of the belts 10, 17 reach the corresponding collection area after falling in the air along a substantially vertical or slightly tilted plane ττ'.

[084] One collection area 26 can be aligned longitudinally with the fall-down plane ττ', while the other collection area 27 can be longitudinally staggered with respect to said plane ττ'.

[085] Consequently, also the second conveyor belt 28 and the third conveyor belt 29 can be respectively aligned or staggered with respect to the fall-down plane ττ'.

[086] Advantageously, the sensor 19 is positioned between the corresponding belt 10, 17 and the collection areas 26, 27, in such a way as to irradiate the leaves F with the respective electromagnetic radiation while they fall along the plane ττ'.

[087] To increase the efficiency of the selection means 16, it is possible to install a pair of sensors 19 arranged on opposite sides with respect to the fall-down plane ττ', so as to irradiate the cut leaves F with respective electromagnetic radiation propagating along opposing propagation directions Y, Y'.

[088] In this way, it will be possible to irradiate the leaves F from above and from below while the fall towards the collection areas 26, 27.

[089] In the embodiment of the machine shown in Figures 4-6, the selection means comprise a diverting member 31 positioned under the sensor 19 in order to selectively divert the leaves F while they fall and to collect them in the respective area 26, 27.

[090] The diverting member 31 is connected to the electronic control unit 20 in such a way that it is activated according to the result of the comparison between the frequency spectrum of the electric signal s and the reference frequency spectrum.

[091 ] The diverting member 31 conveniently comprises a plurality of shafts 32 positioned transversely side by side and selectively movable between a first end position and a second end position.

[092] In the first end position the shafts 32 do not intersect the fall-down plane ττ' while in the second end position they intersect the fall-down plane ττ' and interact with the leaves F, F'.

[093] In this way, when the shafts 32 are in the first end position the leaves F are deposited in the first collection area 26 while when the shafts 32 are in the second end position the leaves F' are diverted from their falling trajectory and are deposited in the second collection area 27.

[094] The diverting member may conveniently comprise a plurality of actuators, not visible in the drawings, which are designed to selectively move the shafts 32 between the two end positions.

[095] Each actuator can be connected to the electronic control unit 20 which in turn can independently activate one or more actuators according to the result of the comparison between the frequency of the electric signal s and the reference spectrum.

[096] Preferably, as can be better observed in Figures 5 and 6, the selection means 16 may comprise also a shaped surface, indicated by the reference number 33, positioned under the sensor 19 and in front of the shafts 32 of the diverting member 31. [097] The shaped surface 33 is adapted to come into contact with the produce and the leaves F' hit too energetically by the shafts 32, in such a way as to accompany them while they fall down and allow them to be collected in the corresponding area.

[098] Furthermore, the selection means 16 may comprise a plane surface 34 located upstream of the sensor 19 and suited to receive the leaves F, F' coming from the first conveyor belt 10 or from the net belt 17.

[099] This surface 34, visible in Figures 1 , 3 and 4, conveys the cut leaves F, F' in a substantially uniform manner along the advance direction A, correctly accompanying them before they start falling, so as to guide them along the predefined fall-down plane ττ'.

[0100] In the embodiment of the machine shown in the figures there is a further conveyor belt 35 provided with a mat which is suited to define this plane surface 33.

[0101] Preferably, the conveyor belt 35 will rotate at a higher rotation speed compared to that transmitted to the first conveyor belt 10 or the net belt 17.

[0102] Alternatively, this surface can be made in other ways, for example using a flat or shaped metal sheet anchored to the frame 2 of the machine 1.

[0103] The present invention can be carried out according to other variant embodiments, all of which fall within the scope of the inventive features claimed and described herein; these technical characteristics can be obtained by means of different but technically equivalent components and materials; the invention can be carried out in any shape and size, provided that they are compatible with its intended use.

[0104] The reference numbers and signs added in the claims and the description are intended to make the text clearer to understand and must not be considered as elements intended to limit the technical scope of application of the objects or processes they are meant to identify.