ITBO20090141A1 - MACHINE FOR THE AUTOMATIC DEFOGLIATURA OF BULB VEGETABLES, IN PARTICULAR OF ONIONS, AND ITS RELATED METHOD OF DEFOGLIATION OF THESE VEGETABLES - Google Patents

Description

DESCRIPTION

Field of application

The present invention refers to a defoliator machine, or to a machine intended for the automatic defoliation of bulb vegetables, in particular onions; the invention also refers to a method for the defoliation of said vegetables.

The defoliation operation belongs to the traditional cycle of transformation of onions and related vegetables, and consists in the elimination of the leaves of the plant to keep only the edible bulb.

The described invention therefore finds useful application in the technological process of food processing.

Known art

In the current state of the art, the aforementioned defoliation operation is carried out in special machines by means of a large suction fan located underneath a grate for collecting the onions. Once the onions have been loaded on the machine, the mechanical action of the fan sucks the leaves to be expelled through the appropriately sized meshes of the grid, thus operating the desired defoliation. Such a solution, while substantially achieving the predetermined purpose of transforming the vegetable, nevertheless has some obvious disadvantages.

First of all, the continuous operation of the suction fan causes a high noise level in the system, with consequent degradation of the acoustic well-being of the operators supervising and controlling the devices.

Furthermore, since the defoliation operation is generally carried out on onions that have not yet been processed, they are deposited on the collection grid still contaminated by earth, dust, stones and any other types of debris.

This circumstance has a double negative consequence. On the one hand, the action of the fan on the product tends to promote a constant dispersion of dust in the surrounding air, causing problems related to the healthiness and cleanliness of the workplace.

At the same time, the coarser granulometry residues, such as stones, fall between the meshes of the collection grid causing damage and wear to the underlying fan, which must consequently be replaced very frequently.

In order to try to obviate the drawbacks described above, machines have recently been proposed with a completely different mechanical conception from those described above, ie based on the movement of the onions by means of a rotating roller, which has a helical profile projecting onto its surface.

This roller is flanked by an idle check roller, so that the rotation of the helical profile tends to press the onion against this check roller. The resulting mechanical action promotes the removal of the leaves of the vegetable, which are dragged downwards through the gap that divides the two rollers; the onions, on the other hand, remain above the two cylindrical rollers and are transported up to an unloading end thanks to the presence of the helical profile, which performs the function of the helix of a screw conveyor.

Machines of this new type, of foreign design, if on the one hand they solve the problem of the noise typical of fan devices, however in practice they have shown disappointing mechanical performances, at least when used in the processing of products grown in clayey soil, such as à This is the case of the Italian peninsula.

In particular, in addition to problems of vibration and rapid wear of the mechanical components, frequent blockages of the idle roller caused by earthy deposits accumulated during the defoliation operations, with consequent degradation of the performance of the machine, were noted.

The technical problem underlying the present invention is, therefore, that of devising a defoliator machine and a relative defoliation method which do not have any of the drawbacks described above with reference to the known art.

Summary of the invention

The aforesaid technical problem is solved by a defoliator machine according to the wording of claim 1 and by a defoliation method according to the wording of claim 10.

Further characteristics and advantages of the machine and of the method according to the present invention will emerge from the description, given below, of a preferred embodiment given by way of non-limiting example with reference to the attached drawings.

Brief description of the drawings

Figure 1 represents a perspective view of the defoliator machine according to the present invention;

Figure 2 is a rear view of the leaf remover machine of Figure 1, with the transmission protective casing removed to allow viewing of the internal components.

Detailed description

With reference to the accompanying figures, we identify with 1 a defoliator machine for bulb vegetables, and in particular for onions, according to the present invention.

This machine 1 comprises a support frame 10 to which at least one main roller 2 and at least one stop roller 3 are rotatably associated, preferably of equal size - or having substantially the same diameter and length - and longitudinally side by side to define above a collection channel 4 for the onions to be defoliated.

In particular, the collection channel 4 is defined by the recess that forms in the upper part of the two side-by-side rollers; consequently the distance between the two rollers 2, 3, although preferably variable as will be discussed below, must in any case always be less than the minimum size of the vegetable to be processed, in order to prevent these from falling under the rollers 2, 3 We define as the interstitial opening 4c the gap that divides the two rollers 2, 3 side by side.

The defoliator machine 1 comprises, in the preferred embodiment, a plurality of main rollers 2 and abutment rollers 3; in this case the machine represented in the accompanying figures exhibits four pairs of rollers, which define four distinct collection channels 4, arranged parallel on the same horizontal plane. It should be noted that, in the present description, the homologous elements relating to pairs of different rollers have been identified with the same numeral.

The collection channels 4 extend between a loading end 4a and an unloading end 4b of the leaf remover machine 1. In fact, as will be discussed below, the opposite rollers 2, 3 perform, in addition to an action defoliation of the supported vegetables, also a movement of these along the collection channels 4 between the two ends of the device.

At the unloading end 4b the defoliator machine 1 can comprise, as shown in Figure 1, an unloading chute 20 for the products already processed by the device.

The defoliator machine also comprises motor means 5, arranged to move the two rollers, main 2 and abutment 3, of each single pair of rollers separately in counter-rotation. With the adverb separately it is meant that the motor means 5 are directly connected to both rollers 2, 3 and set them in rotation independently, that is, neither of the two rollers 2, 3 is idle and driven in rotation only from the movement of the other. The direction of rotation of each pair of rollers is such that their tangential speeds are directed downwards at the interstitial opening 4c which divides them.

The counter-rotation movement of the pairs of rollers 2, 3 allows first of all to keep the processed onions in the bed of the collection channel 4 defined by them. Furthermore, the mechanical action transmitted to the vegetables arranged along the channel 4 causes the removal, as will be described below, through the interstitial opening 4c, of the leaves of these. These leaves are collected with suitable means below the horizontal plane of the rollers.

The main roller 2 has a peripheral helical profile 2a designed to promote, by virtue of the rotation imparted to the roller, the movement of the onions along the collection channel 4, acting as a transport screw. The presence of the helical profile 2a also contributes to forcing the processed products towards the interstitial opening 4c, playing an active role in the defoliation process itself.

The defoliation operation therefore takes place by virtue of the dragging forces transmitted by the rollers 2, 3 to the onions present on the collection channel 4. The rollers 2, 3 in fact, moving in counter-rotation, tend to press the onions in the direction of the interstitial opening 4c, both by friction with the smooth surface of the check roller 3 and by the dragging action carried out by the helical profile 2a of the main roller 2. On the other hand, given that the size of the interstitial opening 4c is ̈ such as not to allow the onion bulb to pass through it, it remains confined above the collection channel 4; however, the mechanical action due to the rotation of the rollers 2, 3 leads to the removal by tearing of all the small leaf appendages, which are easily removable from the rest of the vegetable.

It should be noted that, unlike what happens in all devices of the known art, in the defoliator machine 1 according to the present invention both rollers 2, 3 contribute to the removal of the leaves.

In the preferred embodiments, the helical profile 2a consists of at least one metal spiral, preferably made of stainless steel, integrally wound around a cylindrical core of the main roller 2 having dimensions equal to the abutment roller 3. In particular, in the defoliator machine 1 illustrated in the accompanying figures, each main roller 2 has a helical profile 2a with two principles, each of these principles being constituted by a separate metal spiral. From a constructive point of view, the metal spirals can be applied on the cylindrical core by means of welding points, or in any other suitable way.

As mentioned above, the relative position of the main roller 2 and the check roller 3 is not fixed, but the gap between them can adapt, within certain limits, to the resistant action of the processed products, to favor in particular the ™ removal of leaves.

In each pair of rollers, the main roll 2 and the abutment roll 3 are therefore relatively movable according to a direction transversal to their rotation axes; the defoliator machine also comprises elastic means 12 whose action opposes the relative removal of said rollers.

To grant the aforesaid degree of transversal freedom to the rollers, at least one of the main rollers 2 or abutment rollers 3 is rotatably associated, at its opposite ends, with an upper arm of a respective rocker arm 11a, 11b hinged in one of its points intermediate to the support frame 10; the elastic means 12, which take the form of helical springs, are associated with the other arm, ie the lower one.

In the specific embodiment illustrated in the accompanying figures, the check rollers 3 are rotatably mounted, at their opposite ends, on the upper arm of a pair of vertical rockers 11a, 11b, hinged by means of a bushing on the two opposite sides. of the support frame 10; the main rollers 2 are instead mounted on vertically projecting elements integral with the frame 10 and their rotation axes are therefore fixed with respect to the structure.

The helical spring constituting the elastic means 12, which can be suitably pre-tensioned by means of an adjustment nut, is compressed between the lower ends of two rocker arms 11a, 11b associated with two distinct abutment rollers 3, belonging to two pairs of adjacent rollers.

To allow this mounting solution, the position of the main roller 2 and the check roller 3 is reversed in the successive pairs of rollers, so that the four pairs of rollers previously mentioned form two groups of two pairs. In practice, for each of these groups, we have two adjacent main rollers 2, sideways to which the two feedback rollers 3 are placed. by the action of the underlying helical spring.

Each roller, be it a main roller 2 or a check roller 3, is supported at its opposite ends preferably by means of oscillating ball or roller bearings, associated with the upper end of the rockers 11a, 11b in the case of check rollers 3, to the vertically projecting elements 16a, 16b integral with the support frame 10 in the case of the main roller 2.

In particular, by virtue of the conformation outlined above where the main rollers 2 are placed side by side in groups of two, said vertically projecting elements 16a, 16b take the form of fixed plates 16a or planar forks 16b, the latter only partially visible in the attached figure 1 , which have two holes side by side for the insertion of the support bearings of the two main rollers 2 side by side.

In the illustrated embodiment, the fixed plates 16a are used in correspondence with the loading end 4a of the machine, while the forks 16b are adopted in correspondence with the unloading end, where the overall dimensions must be limited in order not to hinder the access of the onions to the unloading chute 20.

Likewise, the rocker arms 11a, 11b also have a different shape depending on their mounting position near the loading 4a and 4b unloading ends of the leaf stripper 1. Thus, we will have rod-shaped rockers 11b, less bulky, at the end of machine unloading 4b and flat rocker arms 11a at the opposite end. Of the rod-shaped rockers 11b, only the upper arm is visible in the attached figure 1.

The plate-like rocker arms 11a, used at the loading end 4a of the machine, are designed to abut against the fixed plates 16a at a position of minimum gap between the main rollers 2 and the abutment rollers 3 to which the elements themselves are Associates.

Always in correspondence with the load end 4a of the machine, at least one transmission pinion 13 is associated with the terminal end of the rollers 2, 3, associated with the motor means 5 by means of a transmission chain 14.

In alternative embodiments not illustrated, the transmission chain 14 can be replaced by a belt or other suitable means for transmitting the rotary motion.

The transmission pinions 13 associated with the different rollers 2, 3 are aligned along the horizontal plane of the rollers; to allow the counter-rotating movement of the adjacent rollers, the transmission chain 14 must pass alternately above and below the successive pinions 13.

It should therefore be noted that, despite their close position, the transmission pinions 13 respectively associated with two coupled rollers do not constitute gears, but must rather be sufficiently spaced from each other, even in correspondence with the position of minimum deviation, so as to allow transit between them of the transmission chain 14.

This constructive constraint requires the adoption of toothed wheels with limited diameters; possibly the diameter of the head circumference must not exceed that of the associated roller. To prevent such a dimensional limitation from compromising the transmission of high torques to the rollers of the machine, in the preferred embodiment each roll 2, 3 is provided with a plurality of successive transmission pinions keyed onto the roll shaft; three in the case illustrated in the accompanying figures.

As clearly visible in Figure 2, the transmission chain 14 winds over a drive pinion 17 connected to the drive means 5, then is stretched over a first idle pinion 18, then passes alternately above and below the transmission pinions 13 aligned and integral with the rollers 2, 3 of the device, finally passes below two other idle pinions 18 arranged below the previous ones. One of the lower idler sprockets 18 is mounted on a chain tensioning device 19, the other, like the upper one, directly on the support frame 10.

The entire transmission device described above is preferably fixed by a cover casing 21, the representation of which has been omitted in Figure 2 for reasons of clarity of the drawing.

Similarly, the collection channels 4 of the device are covered by a protective cage 22, consisting of two side walls and an upper grid, open at its opposite ends for loading 4a and unloading 4b; furthermore, the pairs of rollers 2, 3 constituting the collection channel 4 are separated from each other by means of longitudinal partitions 23.

The motor means 5, however of a known type, preferably comprise an electric motor connected, by means of a gearmotor assembly, to the motor pinion 17.

The electric motor and the associated gearmotor unit in series are arranged laterally with respect to the leaf remover machine 1; for this purpose the support frame 10 has a lateral support shelf. Thanks to this location of the motor unit, the motor pinion 17 is horizontally aligned with the transmission pinions 13.

The use of an electric motor allows the adoption of an inverter to easily modify the rotation speed of the rollers, thus allowing to adapt this operating parameter of the machine according to the type of onions to be processed.

The leaf remover machine 1 object of the present invention can be integrated with a cleaning device, not shown in the accompanying figures.

Such a cleaning device comprises a carriage, transversal with respect to the axis of rotation of the rollers 2, 3, arranged to be mounted above said rollers 2, 3, equipped with rotating brushes with respect to an axis transversal to the axis rotation of the rollers 2, 3 and intended to contact the upper part of the rollers 2, 3. The carriage is movable longitudinally, i.e. according to a direction parallel to the rotation axis of the rollers 2, 3, between the load ends 4a and discharge 4b of the defoliator machine 1, and is connected to its own motor means which allow the movement and rotation of the brushes.

Said own motor means are constituted by two distinct motors, even if the possibility of using a single motor responsible for both the movement of the trolley and that of the brushes is not excluded.

The cleaning device is used with the machine running, but unloads of onions, to remove processing residues that could obstruct the collection channels 4; automatically, the brushes are started in rotation and moved along the entire extension of the defoliator 1.

The defoliator 1 described above allows to implement a method of defoliation of bulb vegetables, and in particular of onions, comprising the following steps: feeding the loading end 4a of the collection channels 4 with the onions to be defoliated; move the rollers 2, 3 of the machine separately in counter-rotation forcing the onions towards the interstitial opening 4c, also thanks to the action of the peripheral helical profile 2a of the main roller 2, and thus causing the removal, through this opening, of their leaves; at the same time, again by rotating the main roller 2, move the onions along the collection channel 4 up to a discharge end 4b by means of the helical profile 2a.

The method also provides for the possibility of varying the rotation speed of the rollers, by acting on a control board of the inverter associated with the electric motor, according to the type and quantity of onions processed.

From practical experiments, it has been shown that an optimal reference speed for the rollers of the defoliator 1 is close to 300 revolutions per minute.

In addition, an indicative sizing of the machine that guarantees good efficiency of the method described above provides for main rollers 2 and abutment rollers 3 with a diameter of 70 mm and a pitch of the helical profile 2a of 100 mm (i.e. two starts with a pitch of 200 mm).

The numerical values reported above, although they identify a particularly functional configuration of the device, must not however be construed as limiting the invention in question.

The main advantage of the defoliator machine described above derives from its mechanical reliability in operation, which is particularly improved with respect to that of machines of similar design of the known art.

Another obvious advantage of the machine concerns the limited noise and the low lifting of dust due to the absence of a suction fan used for defoliation operations.

Another advantage lies in the adaptability of the device to the processing of different types of onions, grown in soils with different characteristics. In particular, the machine is particularly suitable for processing onions coming from the typical Italian production areas.

A further advantage derives from the possibility of carrying out routine maintenance of the machine in an effective and automated way, by means of a cleaning device associated with it.

Yet another advantage of the machine resides in its relatively limited manufacturing cost, ie not exceeding that of the devices already on the market.

The advantages of the defoliation method according to the present invention result from its unusual speed and efficiency. Furthermore, all the advantages described above in relation to the machine obviously also refer to the defoliation method.

Obviously, in order to satisfy contingent and specific needs, a person skilled in the art can make numerous modifications and variations to the invention described above, all of which are contained within the scope of protection of the invention as defined by the following claims.

Claims (10)

CLAIMS 1. Defoliator machine (1) for bulb vegetables, comprising: a support frame (10); at least one main roller (2) and at least one abutment roller (3) rotatably associated with said support frame (10), said rollers (2, 3) being longitudinally side by side to define a collection channel (4) at the top for bulb vegetables to be defoliated, said collection channel (4) extending between a loading end (4a) and an unloading end (4b) of the defoliator machine (1); and motor means (5) designed to move said two rollers (2, 3) separately in counter-rotation causing the removal, through an interstitial opening (4c) that divides the two rollers (2, 3), of the leaves of the vegetables from bulb arranged along the collection channel (4); said main roller (2) having a peripheral helical profile (2a) designed to promote the movement of said bulb vegetables along said collection channel (4) and at the same time helping to force said bulb vegetables towards the interstitial opening (4c) favoring said removal of the leaves. 2. Defoliator machine (1) according to claim 1, in which the main roller (2) and the abutment roller (3) are relatively movable according to a direction transversal to their axes of rotation, said defoliator machine comprising elastic means (12) whose action opposes the relative removal of said main (2) and abutment (3) rollers. 3. Defoliator machine (1) according to claim 2, in which the opposite ends of at least one of said main (2) or abutment (3) rollers are rotatably associated with an arm of a respective rocker arms (11a, 11b), hinged at an intermediate point thereof to the support frame (10), the elastic means (12) being associated with the other arm of said rocker arm (11a, 11b). 4. Defoliator machine (1) according to one of the preceding claims, in which, at one of the loading (4a) or unloading (4b) ends of the device, at each of the terminal ends of the main (2) and abutment ( 3) At least one transmission pinion (13) is associated with the motor means (5) by means of a transmission chain (14). 5. Defoliator machine (1) according to claim 4, in which the terminal ends to which the transmission pinions (13) are associated correspond to the loading end (4a) of the defoliator machine (1). 6. Defoliator machine (1) according to claim 5, in which the drive pinions (13) associated with the different rollers (2, 3) are horizontally aligned, the drive chain (14) passing alternately above and below the pinions transmission (13) subsequent. 7. Defoliator machine (1) according to one of the preceding claims, in which the main roller (2) and the abutment roller (3) have substantially the same diameter and length. 8. Defoliator machine according to one of the preceding claims, in which the helical profile (2a) consists of at least one metal spiral integrally wound around a cylindrical core of the main roller (2). 9. Defoliator machine (1) according to one of the preceding claims, comprising an upper cleaning device comprising in turn: a carriage transversal to the axis of rotation of the main (2) and abutment (3) rollers arranged to be mounted on the above said rollers (2, 3) and equipped with rotating brushes designed to contact the upper part of said rollers (2, 3); own motor means connected to said trolley and intended to move the brushes in rotation and to move in translation, along a direction parallel to the rotation axis of said rollers (2, 3), the trolley itself between the loading ends (4a) and unloading (4b) of the defoliator machine (1). 10. Method for the defoliation of bulb vegetables comprising the following phases: feeding with bulb vegetables to be defoliated a loading end (4a) of at least one collection channel (4) defined above by a main roller (2) and by a check roller (3) longitudinally placed side by side and divided by an interstitial opening (4c); move the two rollers (2, 3) separately in counter-rotation forcing, also by means of a helical profile (2a) peripheral of the main roller (2), the bulb vegetables arranged along the collection channel (4) towards the opening interstitial (4c) and causing the removal of their leaves through it; moving said bulb vegetables along said collection channel (4) up to an unloading end (4b) by means of the peripheral helical profile (2a) of the main roller (2).