ES2640663T3 - Dusting machine for cleaning skins - Google Patents

Abstract

Improved dusting machine (1) for cleaning skins (P) comprising: - a supporting frame (2) suitable for resting on a reference surface (S); - a conveyor belt (3), coupled with said supporting frame (2), provided with an upper surface (3a) suitable for receiving skins (P) of various sizes in an extended position and operatively connected with first driving means suitable for moving said belt conveyor (3) for positioning said skins (P) advancing along a predetermined longitudinal direction (X); - cleaning means (4), associated with said conveyor belt (3), suitable for cooperating by contact with said skins (P) extended on said conveyor belt (3) to remove impurities, dust and / or shreds (B) present on the front (Sa) and / or back (Sp) surface of said skins (P), said cleaning means (4) comprising a surface coating (5) made of suitable adhesive material to remove it by detachment of said skins (P) and retaining said impurities, dust and / or shreds (B), characterized in that it comprises grinding means (6), operatively connected with said cleaning means (4) and actuated so as to define a resting position, in which said grinding means (6) are far from said cleaning means (4), and a working position in which said grinding means (6) are arranged adjacent to said surface coating (5) of said cleaning means (4) ) with which they cooperate by contact c in order to remove by abrasion a part of the material of said surface coating (5) of said cleaning means (4) restoring the cleaning capacity of said cleaning means (4).

Description

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DESCRIPTION

Dusting machine for cleaning skins

The present invention relates to an improved dusting machine for cleaning skins that will be used in the skin industry in order to remove residual impurities, such as small shreds, fibers or extraneous skin fragments to the surface of the skin itself.

In the field of the tannery, these residual impurities remain superficially on the skin even after the usual cleaning operations, carried out, for example with dusting or vacuuming machines, before the finishing operation such as pigmentation or color spraying.

It is known that the industrial processing of animal skins includes a series of mechanical operations with which it is possible, for example, to cut, divide, shave or stack the skins.

These operations are carried out by special machines and take place in subsequent and mutually consecutive phases of the entire skin treatment production process.

During the usual processing to which the skins are subjected in the tannery industry it often happens that impurities or dusts of various types, as well as small pieces of fiber, are deposited on the lateral faces of the skins themselves and adhere strongly on them , creating substantial surface defects.

This can be seen especially after the "polishing" processing of the skins in machines commonly known as drums, or after their processing in machines known as stacking machines and designed to soften the skins after proper drying and conditioning.

The polishing processing causes, in fact, a natural accumulation of electrostatic charges on the front face, the most valuable ("grain side"), of the skins, favoring the adhesion on that of foreign particles, especially the fibers that break especially from the "side of the flesh" of the skins themselves, as the posterior and less valuable layer of the dermis of animal skin is known.

For its part, the stacking processing, with which skins are worked in order to soften them, causes the partial or complete removal of shreds from the side of the meat.

In addition, the development of superficial defects in the lateral faces ("grain side" and "meat side") of animal skins also arises from the fact that, due to production requirements between one processing and the next, usually they stack on top of each other, generally placing the "meat side" of the upper skin in contact with the "grain side", as the most valuable one has said, of the lower skin.

With the skins pressed on each other, it is inevitable that the shreds or impurities present on the flesh side of a skin are transmitted and adhere permanently to the side of the adjacent skin grain, compromising their quality with the consequent Negative need for degradation but even reduction of the usable surface of the skin.

It seems, therefore, essential to eliminate impurities and dusts from processed animal skins in the animal tannery industry in order to avoid the qualitative degradation of the finished product or, as a result of trimming the defective area, the net loss on the part of the useful surface of the skins.

The removal of impurities and / or powders must take place before the execution of the finishing operations that normally include the deposit of chemical substances such as dyes, pigments, solvents or binders.

More generally, impurities must be removed before semi-finished skins undergo further processing.

In fact, the processing of skins that have impurities and / or dusts creates or amplifies any surface defects present, which considerably degrades the finished product and are removable only by cutting the defective areas.

According to a technology established in the field of the tannery, the cleaning of flexible laminar surfaces of impurities, particles, fragments or foreign fibers is confided to machines known in the industry as "dusters" and "planers", used in any phase of the processing cycle

The operation of the dusters consists primarily of blowing air on the skin, in order to lift dusts, impurities or other foreign particles, and then in the aspiration of these.

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However, such dusters of known type used in the tannery industry in order to clean animal skins or the like have the limitation of not being able to completely remove the impurities present in them, especially those that remain adhered as a result of static electricity .

The adverse effects of this situation are accentuated in the subsequent spraying and varnishing operations that compact the impurities with the laminar surface, highlighting them in this way and creating surface defects that, being sporadically dispersed, are harmful, according to what is already has indicated above.

It follows that, in order to eliminate surface defects, under similar circumstances it is customary to perform additional work, always unwanted in the tannery industry, such as trimming the affected area of the laminar surface, which generate waste from Inadequate production and prolong processing time.

The alternative is the inevitable degradation of the overall quality of the finished product, with the unfavorable economic losses that this entails.

A newly designed machine, available in the skin sector, allows to eliminate the remaining impurities, which remain fixed to the skin even after being treated with dusting or brushing machines, and includes, as essential technical characteristics:

• a supporting frame that rests on a support structure and is provided with a conveyor belt that receives the animal skin to be cleaned on the upper surface;

• cleaning means, for example a series of rollers or a closed-loop conveyor belt, facing the supporting frame and provided with a surface coating made of adhesive material that, cooperating by contact with the skin, removes impurities, dusts or tatters of any nature (see document EP2037037). On the one hand, this machine produces in a very effective way the cleaning of the animal skin, eliminating even the impurities, tatters or smaller powders of difficult removal.

On the other hand, the cleaning means, thanks to which said result is achieved, effectively contain the impurities removed from the surface of the skin, without losing in any case its cleaning capacity due to the regeneration means provided in the dusting machine and operating on cleaning means so that they also remove impurities, tatters and / or dusts that have come off the surface of the skin.

For example, the regeneration means comprise at least one longitudinal brush that cooperates by contact with the cleaning means which, in turn, extends substantially along the entire width of the cleaning means themselves, which generally consist of rollers. rotary defining linear axes mutually parallel and orthogonal to the longitudinal direction along which the skin advances on the conveyor belt.

In such a case, the regeneration means often also comprise a shaped receptacle fixed to the supporting frame and which contains in its interior a detergent bath that permanently retains impurities, tatters and / or dusts captured by the bristles of the longitudinal brush which, when the own broken brush, they are partially submerged in it.

In other embodiments, the regeneration means may comprise, alternatively or in addition, at least one longitudinal finishing arm, arranged downstream of the longitudinal brush and suitable for removing the residual film from the detergent bath that remains on the cleaning means after contact with the bristles of the longitudinal brush.

Even these dusting machines of recent conception are not, in any case, free of some recognized technical drawbacks.

In fact, in fact, after a few cycles of work or operation (the duration of which can be estimated at approximately 15-20 days), the adhesive material that constitutes the surface coating of the cleaning means has a bright appearance and is no longer viscous and sticky: in practice, said adhesive material loses, over time and with use, its own capacity of adhesion, grip, retention or elasticity, de facto limiting, but also compromising, the actual operational efficiency of the cleaning means.

The reason for this is based on the fact that the continuous contact of the surface coating with skins inevitably causes a progressive loss of the adhesion capacity of the adhesive material from which said surface coating of the cleaning means is made.

In addition, the surface coating directly contacts the carpet of the conveyor belt at its own ends and not the skins supported by the belt itself as in its central part; On the other hand, due to the fact that each skin is different from another in shape and area, direct contact between the conveyor belt and the surface coating of the cleaning means does not always occur at the same points of these components.

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This factor compromises the flatness of the surface coating of the cleaning means in its end areas.

In order to overcome these obvious negative situations, it is currently necessary to replace, at best, the surface coating (if removable) or, in the worst case, the entire conveyor belt (if the surface coating it is integrated in it), with the obvious economic disadvantages that this entails both in relation to the spare parts and in relation to the machine downtimes.

The present invention aims to overcome the drawbacks of the known technique considered in this document and just mentioned.

In detail, the main purpose of the present invention is to provide an improved dusting machine for cleaning skins that allows restoring the capacity in the line of tension, engagement, extraction or detachment of the surface coating belonging to the cleaning means, without the need to carry out onerous maintenance interventions and / or replacement of these machine construction details, as is the case with current technology.

In other words, the main purpose of the invention is to make available an improved dusting machine for cleaning skins that restores the original level of effectiveness of the clamping function of the surface coating of the cleaning means more quickly and easily than the case of The prior art.

Within the cognitive sphere of these purposes, it is the task of the invention to minimize, if not clarify, the actual manual intervention that an operator of the tannery industry must perform in order to restore (or recover) the effective cleaning power of the cleaning means of the adhesive surface coating type, in a dusting machine for cleaning animal skins.

It is a further purpose of the present invention to conceive of an improved dusting machine for cleaning skins that has an efficiency greater than that of equivalent machines of known type.

It is a last but no less important purpose of the invention to implement an improved dusting machine for cleaning skins whose duration of downtime is shorter than those that can be verified on equivalent machines of known type.

Said purposes are achieved by means of an improved dusting machine for cleaning skins according to claim 1, as will be referred to hereafter for the sake of short exposure.

Other detailed technical features of the improved dusting machine of the present invention are reported in the corresponding dependent claims.

The claims mentioned above, defined specifically and specifically hereinafter, shall be considered an integral part of the present description.

Advantageously, the improved dusting machine of the invention makes it possible to restore the adhesive capacity (or even adhesion or viscosity) and the flatness of the surface coating of the cleaning means that act on the skins more easily, quickly and immediately than the known machines.

This is due to the fact that the improved dusting machine of the invention includes grinding means operatively connected with the cleaning means and actuated so as to define a resting position in which the grinding means are far from the grinding means. cleaning, and a working position in which the grinding means are arranged adjacent to the surface coating of the cleaning means with which they cooperate by contact in order to wear away part of the surface coating material of the cleaning means, restoring the original adhesiveness which allows impurities, powders and / or tatters present in the skin to be captured, cleaning them.

Equally advantageously, the improved dust removal machine for cleaning skins of the invention makes it possible to limit, with respect to the prior art, repair, replacement and / or maintenance interventions for cleaning means, in particular the adhesive surface coating belonging to them, with consequent reduction of related costs, with respect to those that currently have to be covered.

Advantageously, the improved dusting machine for cleaning skins of the invention reduces the efforts and operations that an operator of the tannery industry must perform in order to pass the surface coating of the return cleaning means by grinding means. to the original state, restoring its cleaning capacity.

Equally advantageously, thanks to the invention it is possible that the operators of the tannery field greatly reduce, in comparison with similar known machines, the downtime of operation.

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of a dusting machine for cleaning skins, evidently favored by the presence in the machine of the invention of the grinding means that are periodically actuated in the working position in order to restore the cleaning capacity of the cleaning means in a short time and in a simple way, without the need to perform normal and laborious operations to replace the current state of the art.

Such purposes and advantages will appear to a large extent from the description of a preferred embodiment of the improved dusting machine for cleaning skins of the invention, provided by way of illustration and indicative, but not limiting, with reference to the attached drawing sheets, in which:

- Figure 1 is a simplified and schematic side view of the improved dusting machine of the invention;

- Figure 2 is an enlargement of a first constructive assembly of Figure 1, comprising the grinding means in the rest position;

- figure 3 is the increase of the construction set of figure 2 but with the grinding means in the working position;

- Figure 4 is an enlargement of a second construction set of Figure 1.

The improved dusting machine for cleaning skins of the invention is illustrated in Figure 1 where it is numbered globally with 1.

As can be seen, the improved dusting machine 1 comprises:

- a supporting frame 2 adapted to rest on a reference surface S, such as the pavement of a factory manufacturing the tannery industry;

- a conveyor belt, numbered as a whole with 3, coupled with the supporting frame 2, provided with an upper surface 3a adapted to receive P skins of various sizes in extended position and operatively connected with first driving means (not shown for simplicity of the explanation) that move the conveyor belt 3 to place the skins P advancing along a direction X in general substantially horizontal, predetermined longitudinal;

- cleaning means, generally indicated with 4 and associated with the conveyor belt 3, suitable for cooperating by contact with the skins P extended on the conveyor belt 3 so as to remove impurities, powders and / or shreds B present on the front surface Sa and / or subsequent Sp of the skins P, including the cleaning means 4 a surface coating 5 made of adhesive material and suitable for removing it by detaching the skins P and retaining the impurities, powders and / or shreds B.

According to the invention, the dusting machine 1 comprises grinding means, indicated globally with 6, operatively connected with the cleaning means 4 and operated so as to define a resting position in which the grinding means 6 are far away. of the cleaning means 4, and a working position in which the grinding means 6 are arranged adjacent to the surface coating 5 of the cleaning means 4 with which they tend to cooperate by contact in order to abrasively remove a part of the surface coating material 5 of the cleaning means 4 restoring the cleaning capacity of the cleaning means 4 themselves.

Particularly but not binding, the grinding means 6 are coupled with the supporting frame 2 through support means, indicated globally with 7, and also extend over the entire width of the cleaning means 4, as will be clear more ahead.

Preferably but not necessarily, the grinding means 6 comprises:

- a transverse roller 8 defining a longitudinal axis Y which, for a first aspect, is orthogonal to the longitudinal direction of advance X of the skins P on the conveyor belt 3 and around which, for a second aspect, the transverse roller 8 it is driven in rotation by second driving means, indicated as a whole with 9, when the grinding means 6 assume the working position;

- abrasion means, generally indicated with 10, arranged on the external surface 8a of the cross roller 8, which cooperate by contact, touching it, with the surface coating 5 of the cleaning means 4 again when the grinding means 6 assume the work position.

In particular, the abrasion means 10 mentioned above are any of the folded abrasive systems selected from the group consisting of abrasive paper 11, abrasive cloth with interchangeable weft and / or similar grooved, rough or folded surfaces.

By way of preferred but not limiting title, in this case the abrasion means 10 are detachably coupled with the transverse roller 8, thus allowing any replacement of only the abrasion means 10, for example in case of excessive wear , deterioration or breakage at a focal point, although it is still understood that, in other embodiments of the grinding means of the improved dusting machine of the invention, the abrasion means may be stably and definitively coupled with the transverse roller.

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In addition, the grinding means 6 are operated between the resting position and the previously defined working position by means of actuation, numbered as a whole with 12, associated with the supporting frame 2 and managed by the operator to which they are easily accessible. from a location adjacent to the supporting frame itself 2.

To move the grinding means 6 between the rest position and the working position, the actuation means 12 act directly on a lever arm l3 which is operatively connected with a central shaft 14 belonging to the cross roller 8 and defines a rotation fulcrum 15 around which the lever arm 13 is rotatably actuated by actuation means 12 in such a way as to define the resting position mentioned above and the work position mentioned above for grinding means 6.

More specifically, the rotation fulcrum 15 defines the point at which the support means 7 are arranged, with which the grinding means 6 are attached (or pivoted) to the supporting frame 2, with which the actuating means 12 also They are connected.

In this regard, the latter are, in this case, purely preferential, of the manual type, which preferably comprise an endless screw 16 arranged in contact with the lower section 17 of the lever arm 13, and an adjusting nut 18 that engages in the worm 16 and which, when driven in rotation by the operator, causes the advance or retraction of the worm itself 16 and the corresponding rotation of the lever arm 13 (and with this of the grinding means 6 which they constitute a piece with it) around the rotation fulcrum 15 in order to place the grinding means 6 in the rest position and in the working position respectively, as obtained well by observing figures 2 and 3.

The figures mentioned so far show that, adequately but not necessarily, the improved dusting machine 1 of the invention also includes end-of-travel means, indicated as a whole with 19, which have the function of stopping the movement of the grinding means 6 in the resting position and in the working position.

In accordance with the preferred embodiment described herein of the invention, the end-of-travel means 19 are operatively connected with the lever arm 13 of the actuating means 12 with which they interfere in such a way that they define the position at rest and the working position of the grinding means 6: specifically, the end-of-travel means 19 cooperate with the lower end 13a of the lever arm 13 in each of the two relevant positions defined above of the grinding means 6 .

It should be noted that the end-of-travel means 19 are any of the technical components selected from the group consisting of position sensors 20 (as in the case being examined and described), mechanical stops and / or the like.

In relation to the cleaning means 4, in this case the cleaning means 4 are partially different and independent of the conveyor belt 3 and partially integrated (or of one piece) with the conveyor belt 3 in order to allow the cleaning of the front surface Sa and simultaneously of the rear surface Sp of the skins P.

Preferably but not exclusively, the cleaning means 4 comprise a first closed loop belt 21, arranged above the conveyor belt 3 and supported between rotating rollers 22, 23 parallel and separated from each other and between which the first one extends closed loop tape 21.

These rotary rollers 22, 23 are driven in rotation by third driving means, not shown for presentation convenience, such that consecutive sections of the outer surface 21a of the first closed loop tape 21 cooperate by contact with the front surface Sa ( grain side) of the skins P to remove impurities, powders and / or shreds B from them.

Still preferably but not in a binding manner, the cleaning means 4 also comprise a second closed loop belt 24, which belongs to the conveyor belt 3 that receives the skins P to be cleaned: the second closed loop belt 24 is supported and extends between respective rotating rollers 25, 26 separated parallel to each other that are driven in rotation by fourth driving means, although not illustrated by simplicity, such that consecutive sections of the outer surface 24a of the second closed loop tape 24 cooperate by contact with the rear surface Sp of the skins P in order to remove from them the impurities, powders and / or shreds B relative: in practice, therefore, also the conveyor belt 3 that receives the skins P to be cleaned integrates, in this In this case, a part of the cleaning means 4 with which the improved dusting machine 1 of the invention is equipped.

Thus, the cleaning action of the skins P carried out by the improved dusting machine 1 of the invention is complete and detailed, such as to allow a possible but frequent subsequent stacking of the newly cleaned skins P to occur without involving risks. of degradation and / or trimming of the P skins, necessary in their

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place if the side of the meat (or the side of the scab) had minimal residues of shreds, dusts and / or impurities that adhere stably, also due to the pressure exerted by the various skins stacked on each other, on the side of the underlying skin pimple.

When the grinding means 6 assume the working position, the third driving means rotate the closed-loop belts 25, 26 of the cleaning means 4 in rotation at a reduced speed, lower than the speed at which the cleaning means 4 cooperate by contact with the P skins, touching them; furthermore, in said working position of the grinding means 6, the transverse roller 8 of the grinding means 6 rotates, for approximately ten minutes, in the opposite direction to that of the respective closed loop belt 25, 26.

Recovering a technical feature described above, according to which the grinding means 6 extend over the entire width of the cleaning means 4, it is first highlighted as the longitudinal axis Y of the transverse roller 8 is parallel to the linear axes Y 'parallel and separated from each other of the rotary rollers 22, 23, 25 and 26 and, in addition, as the width (or front) of the transverse roller 8 is substantially equal to the width (or front) of the rotary rollers 22 themselves, 23, 25 and 26.

As regards the adhesive material of the surface coating 5, this is any of the materials selected from a self-adhesive paper, a layer of natural or synthetic glue, a layer of soft polymer such as polyurethane gel, silicone or other elastomers and / or natural and synthetic rubbers.

Preferably but not necessarily, the improved dusting machine 1 of the present invention comprises regeneration means, indicated as a whole with 27, operatively connected with the cleaning means 4, suitable for continuously removing the cleaning means 4, the impurities, powders and / or shreds B that the surface coating 5 has previously collected from the skins themselves P.

More specifically, the regeneration means 27 are preferably coupled with the bearing frame 2 and, in this case, are covered by a pair of protective covers, not indicated with a reference number in the attached figures, rotatably coupled one with the upper part and the other part with the lower part of the supporting frame 2 so as to allow inspection, maintenance, repair and / or replacement by the operator of the regeneration means 27.

In particular, the regeneration means 27 comprise a first operating group, indicated globally by 28, which cooperates with the first closed loop tape 21 of the cleaning means 4, and a second operating group, numbered as a whole with 29, which cooperates with the second closed loop tape 24 of the cleaning means 4.

According to the description just provided on the construction details of the regeneration means 27, it is derived that the first and the second operating group 28, 29 of the regeneration means 27 are covered by a respective protective cover.

Furthermore, it is emphasized that, preferably but not exclusively, the regeneration means 27 include any (or an appropriate combination of) cleaning devices selected from the group consisting of:

- two longitudinal brushes 30, each of which cooperates continuously by contact with the surface coating 5 of the cleaning means 4 and extends substantially the entire width of the cleaning means 4, and two shaped containers 31, each of which it is fixed to the supporting frame 2 and containing inside it a detergent bath (illustrated only in Figure 1 where indicated with D) in which the bristles 32 of the respective longitudinal brush 30 are at least partially submerged, such as shown in particular by figure 4;

- two longitudinal finishing arms (or blades) 33, better visible in the magnification of Figure 4, each of which is arranged downstream of the longitudinal brush 30, suitable for removing the residual veil from the cleaning bath D that remains on the cleaning means 4 after contact with the respective longitudinal brush 30;

- at least one longitudinal roller coated with a sheet layer made of a porous material selected from sponge, felt, fabric, rubber and the like;

- a plurality of cleaning liquid jets, suitable for interfering with said rotating closed loop tape, which exit a plurality of through holes in a longitudinal tubular element facing said closed tape.

Preferably but not necessarily, the improved dusting machine 1 of the present invention also includes a mechanical insertion and distension assembly of the skins P, numbered globally with 34 in Figure 1: said mechanical assembly 34 is disposed upstream of the conveyor belt 3 and is suitable for stretching the skins P in such a way that they reach the conveyor belt 3 and the cleaning means 4 in the correct position, perfectly stretched and without wrinkles.

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The mechanical insertion and distension assembly 34 of the skins P includes, purely as an example, two transport mats 35, 36 suitably mounted on top of each other, which allows the distension and correct insertion of the skins P between the two belts in closed loop 21 and 24 which in the case in question define the cleaning means 4 of the dusting machine 1 of the invention.

In operation, the skins P reach, one at a time, the conveyor belt 3 after having been stretched by the mechanical insertion and distension assembly 34, and are positioned in advance by the first driving means along the longitudinal direction X until reaching the first closed loop tape 2l of the cleaning means 4 and contacting or touching its surface coating 5.

With continuous contact, the viscosity or adhesive force of the surface coating 5 (for example made of silicone) of the first closed loop tape 21 allows impurities, powders and / or shreds B present on the side of the grain to be removed by shedding ( the front surface Sa) of the skins P.

It should be noted that the first closed loop belt 21 rotates in the same direction (indicated by the arrow Z) along which the skins P advance on the conveyor belt 3 (indicated by the arrow X), such that the removal action of impurities, powders and / or tatters B occurs with complete and effective efficiency.

Consecutive sections of the outer surface 21a of the first closed loop tape 21 that have already cooperated progressively by contact with the skins P, in particular with the grain side (more noble) of the latter, are subjected to the action of the brush longitudinal 30 of the regeneration means 27 which makes it possible to retain (or remove) from the adhesive surface coating 5 impurities, powders and / or shreds B, while the longitudinal finishing arm 33 removes the residual veil from the detergent bath D which remains on the surface coating 5 after contact with the longitudinal brush 30: the consecutive sections of the outer surface 21a of the first closed loop tape 21 (in particular of its surface coating 5) are thus totally clean, ready for perform a new cleaning action of an additional section of the same skin P freshly cleaned or of the subsequent skin P, in this constructive example of the mechanical set of introduction and relaxation 34.

At the same time and without continuity solution, the skins P, in their advance along the longitudinal direction X, meet the second closed loop tape 24 of the cleaning means 4 where the cleaning of the side of the flesh or side of the scab (the posterior surface Sp, the least valuable) of the P skins, to perform a thorough and thorough cleaning that also takes into account the risks, in order to eliminate or minimize them, which may result from the subsequent state in which the skins P are arranged, ie stacked.

As has been said, over time and with the continuous cycles of processing and use, the adhesive material of the surface coating 5 of the cleaning means 4 loses its clamping capacity and, therefore, it is necessary to reactivate it: it is at this point when the operator temporarily stops the load of skins P on the conveyor belt 3 through the mechanical insertion and distension assembly 34, it stops the operation of the first driving means and drives the actuating means 12 in order to place the means of grinding 6 from the resting position of figure 2 to the working position of figure 3 where the light but effective contact between the surface coating 5 and the abrasion means 10 takes place (which in this case consist of the abrasive paper 11 ).

In said position (maintained for an appropriate and predetermined time, for example, ten minutes), the cross roller 8, and with the abrasion means 10, of the grinding means 6 is rotatably driven by the second driving means 9 around of the longitudinal axis Y in an angular direction, indicated by the arrow G in figure 3, contrary to the angular direction Z which is moved with the first closed loop tape 21: in this phase, the first closed loop tape 21 rotates to a speed lower than that at which it rotates to clean the skins P of dusts, impurities and / or tatters B.

In this way, the abrasion means 10 are rubbed against the surface coating 5 of the first closed loop tape 21, restoring the clamping capacity of the adhesive material from which the surface coating 5 itself is made.

After the grinding stage of the surface coating 5 of the cleaning means 4 has finished, the operator intervenes again on the actuating means 12, driving them in the opposite direction to the previous one so that they move the grinding means 6 from the cleaning means 4 and bringing them back to the rest position of Figure 2, due to the counterclockwise rotation of the lever arm 13 around the rotation fulcrum 15.

Based on the description just provided, it is understood, therefore, that the improved dusting machine for cleaning skins, object of the invention, achieves the ends and achieves the above-mentioned advantages.

At the time of execution, changes may be made to the improved dusting machine to clean skins

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animals in the field of the tannery, object of the invention, which are constituted, for example, in a supporting framework that has a constructive composition different from that detectable, in the case schematically, from the attached figures.

In addition, in other embodiments of the invention, not shown, the improved dusting machine for cleaning skins could comprise a conveyor belt of constructive design different from that described above and based on the attached figures.

In addition, additional embodiments of the present invention, again not illustrated, could allow the improved dusting machine for cleaning skins to include cleaning means of constructive composition and articulation different from those described above: in particular, the cleaning means of the dusting machine improved to clean skins of the invention could comprise, in a first alternative, only a closed loop belt, which forms a separate element and separated from the conveyor belt and arranged generally superior to this in order to clean the grain side (or valuable upper side) of animal skins.

In a second alternative, although not shown in the accompanying drawings, the cleaning means of the improved dusting machine for cleaning skins of the invention may belong to and be integrated or be a part with the conveyor belt in order to clean the side of the meat (or side of the scab or lower side) of animal skins.

In both cases just mentioned, the construction of the regeneration means (although optional elements in the innovative dusting machine of the invention) could vary accordingly.

On the other hand, in alternative embodiments of the present invention, although not shown in the attached figures, the improved dusting machine for cleaning skins of the invention could comprise grinding means associated with both the first set of cleaning means and the second set of cleaning means and not only the first set of cleaning means, as can be deduced by observing the attached figures.

Finally, the drive means may be of the automatic type (for example hydraulic or pneumatic linear actuators operated by a central processing and control unit) in alternative embodiments of the improved dust cleaning machine that is claimed herein exclusively. , which does not affect the advantage provided by the present invention.

Finally, it is clear that several more changes could be made to the improved dusting machine in question, without departing from the principle of intimate novelty in the idea of the invention expressed in this document, since it is clear that, in the practical implementation of the invention , materials, shapes and sizes of the details illustrated may be changed, as necessary, and replaced with other technically equivalent ones.

Where the constructive and technical characteristics mentioned in the following claims are followed by numbers or reference signs, those reference signs have been introduced with the sole objective of increasing the intelligibility of the claims themselves and, therefore, have no limiting effect. on the interpretation of each identified element, by way of example only, by these reference signs.

Claims (18)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. Improved dusting machine (1) for cleaning skins (P) comprising: - a supporting frame (2) suitable for resting on a reference surface (S); - a conveyor belt (3), coupled with said supporting frame (2), provided with an upper surface (3a) suitable for receiving skins (P) of various sizes in an extended position and operatively connected with first driving means suitable for moving said belt conveyor (3) for positioning said skins (P) advancing along a predetermined longitudinal direction (X); - cleaning means (4), associated with said conveyor belt (3), suitable for cooperating by contact with said skins (P) extended on said conveyor belt (3) to remove impurities, dust and / or shreds (B) present on the front (Sa) and / or back (Sp) surface of said skins (P), said cleaning means (4) comprising a surface coating (5) made of suitable adhesive material to remove it by detachment of said skins (P) and retain said impurities, dust and / or tatters (B), characterized in that it comprises grinding means (6), operatively connected with said cleaning means (4) and operated so as to define a resting position, in which said grinding means (6) are far from said means of cleaning (4), and a working position in which said grinding means (6) are arranged adjacent to said surface coating (5) of said cleaning means (4) with which they cooperate by contact in order to remove by abrasion a part of the material of said surface coating (5) of said cleaning means (4) restoring the cleaning capacity of said cleaning means (4). 2. Dusting machine (1) according to claim 1), characterized in that said grinding means (6) are coupled with said supporting frame (2) through support means (7). 3. Dusting machine (1) according to claim 1) or 2), characterized in that said grinding means (6) comprise: - a transverse roller (8) defining a longitudinal axis (Y) that is orthogonal to said longitudinal direction of advance (X) of said skins (P) and around which said transverse roller (8) is rotated by second means impellers (9) when said grinding means (6) assume said working position; - abrasion means (10), arranged on the outer surface (8a) of said transverse roller (8) and suitable for cooperating by contact with said surface coating (5) of said cleaning means (4) when said grinding means ( 6) assume this working position. 4. Dusting machine (1) according to claim 3), characterized in that said abrasion means (10) are any of folded abrasive systems selected from the group consisting of abrasive paper (11), abrasive pan with interchangeable weft and / or fluted, rough or similar folded surfaces. 5. Dusting machine (1) according to claim 3) or 4), characterized in that said abrasion means (10) are removably coupled with said transverse roller (8). 6. Dusting machine (1) according to any one of the preceding claims, characterized in that said grinding means (6) are driven between said resting position and said working position by actuating means (12) operated by the operator and associated with said bearing framework (2). 7. Dusting machine (1) according to claim 6), characterized in that, to move said grinding means (6) between said resting position and said working position, said driving means (12) operate directly on a lever arm (13) which is operatively connected with a central shaft (14) that belongs to said transverse roller (8) and defines a rotation fulcrum (15) around which said lever arm (13) is actuated in rotation by said drive means (12) so as to define said rest position and said work position for said grinding means (6). 8. Dusting machine (1) according to any of the preceding claims, characterized in that it comprises end-of-travel means (19), applied to said bearing frame (2) and suitable for stopping the movement of said grinding means (6 ) in said resting position and in said working position. 9. Dusting machine (1) according to claim 8) and 7), characterized in that said end-of-travel means (19) are operatively connected with said lever arm (13) of said drive means (12 ) with which it interferes so as to define said resting position and said working position of said grinding means (6). 10. Dusting machine (1) according to claim 8) or 9), characterized in that said end-of-travel means (19) are any of the technical components selected from the group consisting of position sensors (20), mechanical and / or similar stops. 5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 11. Dusting machine (1) according to any of the preceding claims, characterized in that said cleaning means (4) are independent and distinct from said conveyor belt (3) and / or belong to said conveyor belt (3) with the in order to allow cleaning of only said front surface (Sa) of said skins (P), of only said rear surface (Sp) of said skins (P) or simultaneously of said front surface (Sa) and said rear surface (Sp) of said skins (P). 12. Dusting machine (1) according to any of the preceding claims, characterized in that said cleaning means (4) comprise a first closed loop belt (21), arranged above said conveyor belt (3) and supported between Rotary rollers (22, 23) parallel and separated from each other and between which said first closed-loop tape (21) extends, suitable to be driven in rotation by third driving means such that consecutive sections of the external surface (21a ) of said first closed loop tape (21) cooperate by contacting said front surface (Sa) of said skins (P) to remove said impurities, dust and / or shreds (B) from them. 13. Dusting machine (1) according to any of the preceding claims, characterized in that said cleaning means (4) comprise a second closed loop belt (24), which belongs to said conveyor belt (3) receiving said skins (P) to be cleaned, said second tape being in a closed loop (24) supported and extending between rotating rollers (25, 26) parallel and separated from each other suitable for being driven in rotation by fourth driving means such that consecutive sections of the outer surface (24a) of said second closed loop tape (24) cooperate by contacting said rear surface (Sp) of said skins (P) to remove said impurities, dust and / or shreds (B) from them. 14. Dusting machine (1) according to any of the preceding claims, characterized in that it comprises regeneration means (27) operatively connected with said cleaning means (4), suitable for removing said cleaning means (4) said impurities, dust and / or shreds (B) that said surface coating (5) has previously captured from said skins (P). 15. Dusting machine (1) according to claim 14), characterized in that said regeneration means (27) are coupled with said bearing frame (2) and are covered by at least one protective cover rotatably coupled with the part upper and / or lower of said bearing framework (2) in a way that allows the operator to inspect, maintain, repair and / or replace said regeneration means (27). 16. Dusting machine (1) according to claim 14) or 15) and claim 11), characterized in that said regeneration means (27) comprise a first operating group (28), which cooperates with said first set (22) ) of said cleaning means (4), and a second operating group (29), which cooperates with said second set (23) of said cleaning means (4). 17. Dusting machine (1) according to any of claims 14) to 16), characterized in that said regeneration means (27) comprise any, or a suitable combination, of the cleaning devices selected from the group consisting of : - at least one longitudinal brush (30) cooperating by contact with said surface coating (5) of said cleaning means (4) and extending substantially over the entire width of said cleaning means (4), and a shaped container ( 31), fixed to said bearing frame (2) and containing inside a cleaning bath (D) in which the bristles (32) of said longitudinal brush (30) are at least partially submerged; - at least one longitudinal finishing arm (33), disposed downstream of said longitudinal brush (30), suitable for removing the residual veil from said cleaning bath (D) that remains on said cleaning means (4) after contact with said longitudinal brush (30); - at least one longitudinal roller coated with a sheet layer made of a porous material selected from sponge, felt, fabric, rubber and the like; - a plurality of cleaning liquid jets, suitable for interfering with said rotating closed loop tape, which exit a plurality of through holes made in a longitudinal tubular element facing said closed tape. 18. Dusting machine (1) according to any of the preceding claims, characterized in that it comprises a mechanical assembly for the introduction and distension (34) of said skins (P), arranged upstream of said conveyor belt (3), suitable to stretch said skins (P) such that said skins (P) reach said conveyor belt (3) and subsequently said cleaning means (4) in the correct position, perfectly extended.