DESCRIPTION

The present invention generally relates to a spray booth for tannery leathers treatment by means of cover products, such as paints, pigments, resins, oils, paraffins, glues, and so on. As known, in the industrial sector of the tanning of leathers spray equipment or machines, commonly known as "booths", are available suitable to be used to spray on the leathers various covering products, such as paints, pigments, resins, oils, paraffins, glues or similar natural and/or chemical products.

As also known, spray coating is, among the finishing operations of the leathers of the tanning industry, one of the most important of the processing cycle, which requires wide space availability in the factory, in view of the extent of the plants which it is performed with.

In substance, the coating of the leathers consists in covering the grain side with one or more layers of covering and colorant material, in the form of elastic, thin and uniform film applied by spraying and in more or less high amount, as a function of the covering capacity that it is desired to get.

The main risk also associated with the coating of the leathers is obviously the environmental pollution that it causes in the workplace; in order to eliminate or at least reduce such a risk suitable spray booths must be used that can be essentially of two types:

• open spray booths, with open surface on one or more sides;

• closed, watertight, spraying booths, with closed surface on all sides, with the exception of "technical" openings which can be closed by means of shutters or sluice gates, suitable to allow the entry of leathers concerned by the spraying operations.

Further classification of spray booths used in the field of tanning derives from the type of spraying carried out, which may be manual (always less widespread) or automatic (without the personnel intervention).

A typical spray booth of known type basically and essentially comprises a bearing framework, such as a box-shaped casing in case it is closed, suitable to rest on a reference surface (the paving of a plant) and in which a spraying area (or chamber) is defined where leathers treatment takes place by means of spraying in a nebulized form of natural and/or chemical products partly identified above. A traditional spray booth of the prior art also includes a support structure - such as typically a conveyor belt for example of the type with parallel and spaced apart strands - associated with the bearing framework and suitable to receive the leathers to be treated, by spraying on them natural and/or chemical products, as well as an operating group in turn including: · a movable element coupled with the bearing framework and facing the spraying area (or chamber);

• a distribution shaft removably but firmly coupled with the movable element through fixing means and defining a vertical longitudinal axis;

• a plurality of support arms, each of which is connected with the movable element according to a radial direction relative to the distribution shaft and provided with dispensing means which spray in a nebulized form natural and/or chemical products on the leathers.

In particular, the distribution shaft communicates through hydraulic connection means with the dispensing means and with containment means (industrial tanks) housing the natural and/or chemical products to be sprayed on the leathers.

Typically, a known type spray booth also includes a fumes suction and abatement system, placed laterally to the bearing framework of the spray booth and having the function of sucking and filtering the fumes of chemical covering products which are deposited on the leathers.

The spray booths of the tanning industry are available in various constructive and operative types: traditionally, in any case, the spray booths are of alternative type having a single support arm or of the circular rotary or elliptical rotary type, for example with eight, twelve, sixteen support arms.

In case of rotary spraying booths, the operating group introduced above comprises, for instance, a rotating carousel arranged inside the spraying area and surrounding the distribution shaft, while the dispensing means associated with each of the support arms comprise one or more spray guns through which the deposition of the covering products of the grain side of the leathers takes place.

In such a constructive solution, the support arms radially protrude from the rotary body which are coupled with and usually are in number of eight, twelve or sixteen: they have various length and are arranged slightly inclined downward starting from the rotary body around which they are evenly distributed. In this type of spray booth, the diameter described by the automatic spray guns in their rotation around the vertical longitudinal axis defined by the distribution shaft is greater than the width of the support structure (such as a conveyor belt).

Both in case of use of rotary spray booths and in case of use of elliptical spray booths, the deposition process of covering products on the tannery leathers and, in particular, the spraying paint process of the leathers themselves includes the following phases, which follow one another during the daily work:

• preparation of the covering product (i.e. the paint to be used) and start of the appliance with relative speed, plants and spray guns adjustment;

· spraying of the covering product (paint and/or colour) on the various prefixed batches of tannery leathers and simultaneous preparation of the next product and/or colour for the subsequent batches;

• cleaning of the spraying plant used and of the spray guns;

• speed, plants and spray guns readjustment;

· repetition of the spraying phase of the coating product (paint and/or colour) and cleaning phase the deposition and/or spraying plants as in the previous points, up to the end of processing.

In particular, the cleaning operations of the spraying plant include the delicate and important maintenance of the distribution shaft which, in general, is positioned in the central part of the spraying area or chamber: in order that the cleaning of such a component is effective and complete, the distribution shaft has to be removed from the applicative position and therefore decoupled from the movable rotating element which it is attached to.

It follows that, in order to perform the ordinary and periodic maintenance (but, if necessary, repair and/or replacement) operations of the distribution shaft, indispensable to preserve the structural and functional integrity of its components (in particular, the seals contained into it), the operator must access inside the spraying area, by physically climbing on the support structure (normally, a flexible surface which is that one of any conveyor belt), disassembling in that position the distribution shaft from the movable element supporting it and, finally, manually bring the distribution shaft outside the spraying area (or chamber) where only then he can comfortably perform all the operations required by the case.

It is therefore clear that such an operative situation leads at the current state of the art to a series of recognized drawbacks for the spray booths of the leathers tanning sector. A first important drawback of the known technique, concerning the disassembling operations of the distribution shaft from its applicative position, comes, indeed, from the fact that these operations are somewhat laborious, complicated and hard for the operator, given the considerable weight of the component concerned, the uncomfortable, almost cramped, position from which the operator is obliged to operate assuming forced and stressful postures for his own body, although it should be noted that such an arguing refers to a workplace.

The difficulties are such that, currently, in order to effectively perform the operation of disassembly and assembly of the distribution shaft from/in a spray booth at least two operators are employed.

Further induced drawbacks inevitably accompany to this, such as times and costs of disassembly and subsequent assembly of the distribution shaft which are of high impact and relevant, also in consideration of the fact that, if at least one auxiliary distribution shaft (although quite expensive) is not available at stocks, the shutdown time of the spray booth is nowadays rather long, to all the detriment of the whole production efficiency.

A further drawback of the known technique herewith concerned refers to the fact that the health of same operator who performs the operation of disassembly of the distribution shaft from the spray booth is to some extent subject to risks since the operator, in such a phase, inevitably gets into contact with the residues of chemical products used in the spraying treatment of the leathers and still present in the spraying area (or chamber) and/or in the distribution shaft, exhaling them, with all the consequent risks.

Without neglecting the fact that, always negatively even if these are working purviews, the operator, especially in the phase of separation of the distribution shaft from the movable element of the operating group, is often affected by accidental and uncontrolled falling of the residues of the products sprayed on the leathers still present inside the distribution shaft, with the obvious drawbacks and disadvantages that this involves, not only from the operator's health point of view.

A last but not least drawback associated with the spray booth for leathers treatment of the prior art is represented by the fact that, during the disassembly and assembly manoeuvres of the distribution shaft of spray booths, it can happen that the operator (or much more often, the operators, as said) accidentally tramples, for example due to loss of balance, the support structure (typically a conveyor belt), with the risk of damaging it even in a serious manner. Starting, therefore, from the awareness of the drawbacks of the current state of the art presented above, the present invention intends to fully remedy them.

In particular, main purpose of the invention is to provide a spray booth for leathers treatment which compared to the prior art simplifies the disassembly and subsequent assembly manoeuvres of the distribution shaft that the operator must carry out.

In other words, primary purpose of the present invention is to implement a spray booth for leathers treatment in which the distribution shaft is removable/applicable from/to the movable element of the operating group - typically a rotating carousel - in a manner easier than what is allowed by equivalent booths of known type.

Within this purpose, it is task of the present invention to create a spray booth for leathers treatment in which the simplification of the extraction/introduction manoeuvres of the distribution shaft to/from the spraying area (or chamber) is such that to also enable a single operator to perform these manoeuvres.

It is another task of the invention to develop a spray booth for leathers treatment which allows to reduce the physical efforts, and the negative consequences deriving from them, which also a single operator must perform in order to carry out the disassembly/assembly operations of the distribution shaft.

It is a further task of the present invention to provide a spray booth for leathers treatment which allows to reduce, compared to similar known spraying booths, the contact by the operator (employee to the removal/extraction or introduction of the distribution shaft respectively from the spraying chamber, starting from its applicative position, or into the spraying chamber, starting from its non-operative position) with the residues, present in the spraying area, of the products used for spraying of the leathers and, in return, the risks to same operator's health.

It is, also, task of the invention to give substance to a spray booth for leathers treatment which, in general line, involves shutdown (or stationary) times of the machine, due to maintenance, repair and/or replacement of the distribution shaft, largely lower than those ones associated with the known spray booths.

It is another purpose of the present invention to indicate a spray booth for leathers treatment which allows to keep unchanged the structural and functional integrity of the support structure which receives the leathers - typically though not exclusively a conveyor belt - as long as compared to what occurs in the prior art. It is a last but not least purpose of the present invention to make available a spray booth for leathers treatment which, ultimately, presents an efficiency better than that one of similar prior art spray booths.

The foregoing purposes are achieved through a spray booth for leathers treatment according to claim 1 attached hereto, as hereinafter referred for the sake of brevity of exposure.

Additional constructional features of detail of the spray booth of the invention are contained in the corresponding dependent claims.

The above-mentioned claims, in the following specifically and concretely defined, shall mean an integral part of the present description.

Advantageously, the spray booth for leathers treatment of the invention simplifies the operations that even a single operator, for example with the aid of an equipped carriage, must perform firstly in order to extract the distribution shaft from the spraying area, separating it from the operating, preferably rotary, group and subsequently in order to place it again in the stable applicative position inside the spraying area.

This is about the fixing means with which the distribution shaft is coupled with the movable element of the operating group, which are originally of the quick coupling type and thus allow the operator to disassemble/assemble, by means of an industrial mechanized mechanical arm, the distribution shaft from its applicative position in order to carry out its maintenance more quickly, easily and conveniently than what occurs with the spray booths of known type.

In essence, therefore, the distribution shaft is removable from the spraying area - a closed chamber or an open chamber, depending on the type of spray booth installed in the plant - as it already happens in the prior art, but with operations that, by means of the invention, are markedly more simple and more rapid, and less laborious and less hard than those ones currently carry out in order to do the same operation.

Still advantageously, what just said allows to reach the purposes and fulfill the tasks before highlighted, such as an increased safety for the operator performing disassembly/assembly of the distribution shaft, a greater protection of the structural/functional integrity of the support structure and, ultimately, an improved efficiency of the spray booth thanks to the decjection of the duration of the shutdown times of the machine.

The foregoing objects and advantages, as well as other ones which will emerge later, will result to a greater extent from the description which follows, relating to a preferred embodiment of the spray booth for leathers treatment of the invention, given by indicative and illustrative, but not limitative, way with the help of the attached tables of drawings in which:

- figure 1 is a schematic and simplified assonometric view of the spray booth for leathers treatment of the invention, in non-operative condition, with the distribution shaft totally extracted from the spraying area and separated from the bearing framework;

figure la is an enlarged detail of figure 1;

- figure 2 is a schematic, simplified and truncated side view of the spray booth of the invention, still in non-operative condition, with the distribution shaft in extraction or introduction phase from/in the spraying area but always separated from the bearing framework;

figure 2a is a first enlarged detail of figure 2;

figure 2b is a second enlarged detail of figure 2;

- figure 3 is a schematic, simplified and truncated side view of the spray booth of the invention in operative conditions, with the distribution shaft in the applicative position; figure 3a is a first enlarged detail of figure 3;

figure 3b is a second enlarged detail of figure 3.

The spray booth for leathers treatment, object of the present invention, is illustrated in figure 1 where it is globally numbered with 1.

As it can be observed, such a spray booth 1 comprises, as already acquired to the state of the art of the field:

- a bearing framework, indicated as a whole with 2, suitable to rest on a reference surface (such as the paving of a production plant) and in which a spraying area 3 is defined where leathers treatment properly and effectively takes place by spraying in nebulized form natural and/or chemical products;

a support structure, only schematically identified in the attached figures where it is indicated as a whole with 4, associated with the bearing framework 2 and adapted to receive, resting on its upper surface, the leathers to be treated by means of spraying of natural and/or chemical products;

- an operative group, which is numbered as a whole with 5 and includes:

• a movable element 6 coupled with the bearing framework 2 and facing the spraying area 3; • a distribution shaft 7 removably coupled with the movable element 6 through fixing means, indicated as a whole with 8, and defining a vertical longitudinal axis Y;

• a plurality of support arms 9, each of which is connected with the movable element 6 (in this specific case, in a radial direction relative to the distribution shaft 7) and provided with dispensing means, numbered on the whole with 10, suitable to spray in a nebulized form natural and/or chemical products on the leathers,

the distribution shaft 7 communicating through hydraulic connection means, numbered on the whole with 11, with the dispensing means 10 and with containment means, not shown for the sake of simplicity, which house the natural and/or chemical products to be sprayed on the leathers.

In accordance with the invention, the fixing means 8 comprise quick coupling means, indicated as a whole with 12, which make the distribution shaft 7 easily and automatically removable from the spraying area 3, in such a way as to define for the distribution shaft 7 itself an applicative position in which the distribution shaft 7 is stably coupled with the bearing framework 2 to exert its distributing function, and a non-applicative position in which the distribution shaft 7 is completely separated from the bearing framework 2 and from the support arms 9, extracted from the spraying area 3 in order to be easily subjected to maintenance, repair and/or replacement by employees of the field.

It should be noted first of all that the spray booth 1 visible in the accompanying figures (related, it is stressed, to a preferred but not binding embodiment) is of the open type, that is the spraying area 3 defined by the bearing framework 2, habitually and normally, communicates with the outside without being isolated from this by means of panels, bulkheads and/or the like as in the case of closed spray booths, not represented in the drawings that follow, which, however, the inventive technical concept of the invention described herein extends to.

In these closed spray booths, the spraying area is properly set up as a watertight spraying chamber, isolated from the outside and accessible only through the operation of one or more shutters which are rotatably coupled with the bearing framework at respective through openings which, in operating conditions, are hermetically closed by the shutters themselves. As it is best derived from figure 2 and from its two enlargements of figures 2a and 2b, the quick coupling means 12 are arranged partly on the distribution shaft 7, partly on the bearing framework 2 and partly on the movable element 6 which, in particular, is connected with first motorization means, as a whole numbered with 13, placed above the bearing framework 2 and adapted to move it within the spraying area 3 in such a way as to allow an as much homogeneous and uniform as possible spraying of the natural and/or chemical products on the leathers resting on the support structure 4 below.

Figures 1 and 2 show that the distribution shaft 7 is placed in the non-applicative position, starting from the applicative position in which it is however stably coupled with the movable element 6, by means of grip of the distribution shaft 7 with self-propelled equipped mechanized arm M, available at the factory and operable by the operator from a position external to the spraying area.

The distribution shaft 7 is likewise placed in the applicative position, starting from the aforesaid non-applicative position in which it is separated from the movable element 6 and external to the spraying area 3, always by means of grip of the distribution shaft 7 with the equipped mechanized arm M from the external position.

The distribution shaft 7, also, has a mostly and substantially longitudinal development and is contained, together with the movable element 6, inside the spraying area 3.

Suitably, the equipped mechanized arm M is automatically managed by the operator, through a central processing and control unit, not shown, integral with the equipped arm M. From what has been said the innovative scope of the invention arises and how it achieves its intended purposes, bringing a significant novelty in the tanning industry.

In other embodiments of the invention, not represented in the attached drawings, the spray booth could comprise moving means coupled with the bearing framework and/or with the support structure and adapted to be operated by the operator, preferably through a central processing and control unit at his disposal, in order to extract/introduce the distribution shaft from/into the spraying area and place it alternately between the aforesaid applicative position and the aforesaid non-applicative position: these moving means, therefore, have the same function of the equipped mechanized arm described above and visible in the accompanying figures relating, however, only to the preferred embodiment of the invention. In advantageous but not binding way, the spray booth 1 comprises guide means, numbered on the whole with 14, arranged inside the spraying area 3, suitable to favour the correct and safe extraction/introduction of the distribution shaft 7 from/in the spraying area 3 itself.

More in detail, the guide means 14 comprise a shaped bracket 15 fixed to the bearing framework 2, arranged above the support structure 4 which receives the leathers to be treated and contained in the spraying area 3: the shaped bracket 15 receives in stable and safe sliding an end of the distribution shaft 7, in this case the lower end 7a.

Preferably but not necessarily, the shaped bracket 15 has a longitudinal extension and substantially extends for the entire width of the spraying area 3 in such a way as to guide the distribution shaft 7 until the almost complete extraction or introduction from or in the spraying area 3 and to ward off that its possible, albeit very remote, accidental fall from the equipped mechanized arm M causes irreparable damages not only to the distribution shaft 7 itself but also to the components below - the support structure 4 and the bearing framework 2 -.

It is understood that in other embodiments of the spray booth of the present invention, not shown in the attached drawings, the guide means could include more than one shaped bracket, for example, two shaped brackets distinct and vertically spaced apart each other, each of which able to receive by sliding a respective end of the distribution shaft.

In addition, further embodiments of the spray booth of the invention, yet not illustrated in the attached figures, could provide that the (at least one) shaped bracket of the guide means (which preferably could have a plane or U-shaped laminar profile in cross section) extends only for a part of the width (understood as the longitudinal direction Z orthogonal to the main development direction X of the spraying area and, as it will be better clarified soon, of the advancement direction of the leathers inside it) or the length of the spraying area.

According to the preferred embodiment described herein of the invention, the distribution shaft 7 comprises a tubular body 16 inside which independent auxiliary pipes 17 are housed which, when the distribution shaft 7 takes said applicative position and quick coupling means 12 are coupled each other (see in this regard figure 3), communicate with main pipes or ducts 18, distinct from the auxiliary piping 17, belonging to the hydraulic connection means 11, as the enlarged details of figures 3a and 3b well show.

Since, as previously stated, the solution of spray booth 1 chosen for the description of the preferred embodiment of the invention is of the open type, the bearing framework 2 suitably defines a series of through, preferably lateral, through each of which the distribution shaft 7 passes from the applicative position to the non-applicative position and vice versa.

In function of this, in particular, the equipped mechanized arm M accesses the distribution shaft 7 to take it from the applicative position and, also, places it in such a position by passing, in both stages, through these through openings 19. It is understood, also in this case, that in other embodiments of the open spray booth of the invention, not shown in the enclosed drawings, the bearing framework could only provide a single lateral through opening through which the operator accesses the distribution shaft through the equipped mechanized arm in order to extract it from the spraying area.

As regards the support structure 4, in this case it includes, in preferred but not exclusive title, a conveyor belt, for example of the strands or threads type and not shown, adapted to be moved by second motorization means, yet not illustrated, along a longitudinal direction X (coincident with the main development direction of the spraying area 3) orthogonal to the vertical longitudinal axis Y in order to determine the entry of the leathers into the spraying area 3, the progressive advance of the leathers in the spraying area while undergoing the treatment by means of the natural and/or chemical products, and the exit of the leathers from the spraying area 3 and their removal from the bearing framework 2 in order to be then dried and stored.

With specific reference to the operating group 5, it preferably comprises a rotating carrousel 20 in which the movable element 6 is constituted by a rotary body 21 which is adapted to be set in rotation around the vertical longitudinal axis Y by the first motorization means 13, surrounds the distribution shaft 7 and on which the support arms 9 are uniformly distributed, for example along a circle or an ellipse.

As far as the dispensing means 10 are concerned, they comprise, by preferred but not exclusive way, one or more spray guns, not represented, arranged at the free end 9a of each of the support arms 9, as established constructive customary in the machinery sector for the tanning industry considered herein - i.e. spray booth -.

In general, the spray guns are in maximum number of three for each of the support arms 9 which rotate integrally with the rotary body 21 around the vertical longitudinal axis Y.

The operational phases of extraction and introduction of the distribution shaft 7 in the spraying area 3 in order to, respectively, separate it by the movable element 6 of the operating group 5 and coupled it with the same (performed obviously when the spray booth 1 is in downtime conditions in order to perform maintenance of its component members and, if necessary, even repair or replace them) appear thus in clear evidence from the detail of the technical features just mentioned of the spray booth 1 of the invention, as well as the operative simplification which matches these phases compared to the present state of the art, with the obvious significant advantages (already underlined) deriving from that. On the basis of the description just given, it is understood, therefore, that the spray booth for leathers treatment of the present invention achieves the purpose and reaches the advantages yet mentioned.

Upon implementation, changes could be made to the spray booth for leathers treatment of the present invention, consisting, for example, in a bearing framework integrated and monolithic with the support structure, rather than distinct and separate from it as in the embodiment described above and illustrated in the accompanying figures.

Moreover, other embodiments of the invention, not accompanied herewith by reference drawings, could provide that the spray booth comprises a support structure provided with support surface of the leathers not necessarily of mobile or movable type, as in the case previously described, but purely fixed and receiving the leathers automatically or manually loaded.

In addition, other embodiments of the spray booth herewith claimed as exclusive right, always not shown in the accompanying drawing tables, could exist in which the operating group has, although in the necessary essential features indicated in the independent claim which follows, a constructive conception different from that one obtainable from the description just given and from the attached figures, which does not affect the advantage brought by the present invention.

In such a case, for example, in spray booths better known in the field concerned as "booth with flat roof" - i.e. cabins with flat roof - the operating group could include, as movable element, a classic central disc of high dimension, put in rotation by the first motorization means around the vertical longitudinal axis defined by the distribution shaft, and a plurality of substantially vertical support arms, protruding downwardly from the perimetrical edge of such a rotatable disc on which they are generally uniformly distributed.

Beyond that, in further embodiments of the invention, yet not shown, the quick coupling means could be of a different type from that one described above and shown in the accompanying figures (protrusions of the distribution shaft which stably but removably snap-engage, bayonet-engage and so on in seats of the rotary body and the bearing framework), such as for example magnetic coupling means, interlocking coupling means and the like.

It is, finally, clear that several other changes could be made to the spray booth concerned, without departing from the principle of novelty intrinsic in the inventive idea expressed herein, as it is clear that, in the practical implementation of the invention, materials, shapes and sizes of the illustrated details could be changed, as needed, and replaced with others technically equivalent.

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