DESCRIPTION

The present invention relates to a plant for painting manufactured products, comprising at least one heat treatment section for said manufactured products, and having improved characteristics with regard to the separation and isolation of said heat treatment section from the other sections of the plant.

As is known, industrial painting systems for manufactured products generally comprise at least one product pre-treatment section, at least one painting section and at least one polymerization/drying section for the painted products. The manufactured products to be painted, for example metallic pieces with a high aspect ratio, such as straight bars with different cross sections, or metal sheets or plates, are advanced between the various sections after being suspended from an overhead transporter. Depending on the configuration of the system, there may be one or more overhead transporter lines, with corresponding transfer means which transfer the manufactured products from one line to another. To achieve the maximum productivity and the maximum possible quality of painting, these systems normally function continuously. Usually, at least the pre-treatment section and the painted product polymerization/drying section provide temperature conditions above ambient temperature. By way of example, the simplest working cycle usually involves the following steps:

attaching the pieces vertically to an overhead transporter with predominantly horizontal movement,

pre-treating the pieces as they advance continuously through specific tunnels using special acid or alkaline liquids, followed by cold washing with mains and/or demineralised water;

drip drying of any liquid remaining on the surface of the pieces, followed by low- temperature drying in special ovens;

spray painting of the pieces in special cabins;

polymerization (baking) of the paint in continuous ovens kept at a constant, uniform temperature (for example, for powder paints, around 195°-200°C) for an amount of time that can vary according to the type of paint (for example, for powder paints, 25-30 min.);

unloading of painted pieces from the system.

Currently, the necessary continuous movement of the pieces suspended vertically from the transporter requires the entrances and exits to the pre-treatment tunnel and ovens to be kept constantly open, which can result in considerable problems in terms of quality, production and energy consumption, as described below.

The problems encountered in the tunnel are substantially due to the phenomenon of leakage of hot vapours, mist, and drops of chemically corrosive and polluting hot liquids, particularly from the open entrance and exit to the tunnel.

This results in problems such as environmental pollution both inside and outside the working environment (which can be harmful to the health of operators), or the formation of corrosive (or at the very least hazardous or inappropriate from the point of view of safety) puddles on the floor around the openings, energy loss, and similar problems.

Currently, these problems are partially solved by the use of special suction fans whose function is to remove to the outside at least part of these vapours either directly or through special drip trays.

The problems encountered with ovens, even ovens fitted with special forced-air "veils" intended to contain losses of hot air, involve the well-known phenomenon known as the "chimney effect", whereby large quantities of cold ambient air naturally continuously enter the oven openings from the bottom, compensated by the simultaneous escape of equal quantities of hot air from the top.

In summary, current oven problems include:

the escape of hot air which is irretrievably lost (energy loss);

the entry of cold air which must be heated (energy consumption);

the entry of pollutants (mainly dust) pulled in by said cold air;

the free, uncontrolled meeting of cold air with hot air and vice- versa in the areas around the openings, generating uncontrollable vortices which can, for example, cause the powder paint just applied to partially peel off and contaminate adjacent (or even distant) pieces of a different colour inside the polymerization ovens, thereby compromising production quality; to tackle this problem, it is often necessary to install additional ovens between the painting cabins and the polymerization ovens. These additional ovens are smaller but have very high energy consumption, and they are usually infra-red radiant panels whose purpose is to bind the paint onto the piece through gelification, thereby preventing particles of paint from being dispersed in the ovens and contamination between different colours;

uncontrolled and uncontrollable oscillations between freshly-painted pieces, which can result in pieces sticking together, thereby resulting in production losses and the risk of blockages due to interference with individual pieces or with fixed structural components of the oven; this problem is only partially resolved by using piece-holder chains or adhesives, requiring full-time use of personnel with a consequent increase in labour costs;

the creation, with certain types of powder paint, of the phenomenon known as "snow" which also leads to increased costs due to the need for regular cleaning of any filters or of the entire oven.

Given these considerations, there is an evident need to provide a painting system that will make it possible to eliminate of minimise the problems described above.

The aim of the present invention, therefore, is to provide a painting system that will overcome, or minimise, known system problems.

In particular, given this aim, an object of the present invention is to provide a painting system that allows to avoid a direct connection between the inside and outside of the heat treatment sections (for example the pre-treatment tunnel and/or ovens), through the entrances and exits thereof, while keeping the pieces entering and exiting said sections moving continuously. Another object of the present invention is to provide a painting system that enables the exchange of hot and cold air between the inside and outside of the heat treatment sections (for example the pre-treatment tunnel and/or ovens) to be minimized, thereby reducing energy consumption.

A further object of the present invention is to provide a painting system that prevents or minimises the leakage of substances, such as drops of water, chemically corrosive vapours, paint dust and similar, from the heat treatment sections.

Yet another object of the present invention is to provide a painting system in which the movement and bumping of pieces due to air convection phenomena are reduced.

Another object of the present invention is to eliminate the need to place gelification ovens ahead of the polymerization ovens in order to bind the paint particles onto the pieces to prevent contamination between different colours.

Another object of the present invention is to provide a painting system that does not require the use of labour or devices such as piece-holder chains or adhesives to prevent or minimise bumping of pieces due to air convection phenomena.

Yet another object of the present invention is to provide a painting system that enables measures intended to contain substances exiting the heat treatment sections, for example from the pre-treatment tunnel, to be reduced.

A further object of the present invention is to provide a painting system that enables the heat treatment sections to be separated or isolated, while keeping the products continuously moving. Yet another object of the present invention is to provide a painting system where it is possible to have the heat treatment sections separated or isolated from the rest of the system, regardless of the geometric conformation of the pieces to be treated, whether they be profiles with a predominantly mono-directional shape or sheets with a two-directional form.

A further, yet not final, object of the present invention is to provide a painting system which is easy to build at a competitive cost.

The present invention therefore relates to a plant for painting manufactured products comprising overhead transport means for said products along a direction of advancement and at least one heat treatment station for said products; the painting plant according to the invention is characterized in that it comprises support means for said products which are operationally coupled to said overhead transport means and first opening/closing means for said heat treatment section. In the plant according to the invention, said support means rotate between at least one first position and at least one second position and said first opening/closing means are able to move between a closed position and an open position. Furthermore, in the system according to the invention, first actuator means are positioned, with respect to said direction of advancement, upstream of said first opening/closing means and determine the rotation of said support means between said first position and said second position.

In this manner, as described in more detail below, the presence of the first opening/closing means enables separation and isolation between said heat treatment station and the rest of the plant. Furthermore, the presence of the rotating support means and the corresponding first actuator means makes it possible to keep the products moving continuously, regardless of their dimensions and the frequency with which they are positioned on said overhead transport means.

Preferably, said support means comprise a first portion operationally coupled to said overhead transport means and a second portion operationally coupled to said first portion and able to be operationally coupled to said products, said second portion being free to rotate with respect to said first portion.

Advantageously, the angle of rotation between said first position and said second position is around 90°.

Preferably, said first opening/closing means comprise one or more door means, consisting for example of doors with one or two panels, either sliding or rotating (with panels).

In this case, the plant according to the invention may comprise a plurality of doors separated by one or more intermediate chambers. For example, the first opening/closing means may comprise first door means, a first intermediate chamber, and second door means, or said first opening/closing means may comprise first door means, a first intermediate chamber, second door means, a second intermediate chamber, and third door means.

A particularly preferred embodiment of the painting plant according to the present invention is characterised in that it comprises second opening/closing means for said heat treatment section, said first and second opening/closing means being positioned respectively upstream and downstream of said heat treatment section.

Advantageously, in a particularly preferred embodiment of the painting plant according to the present invention, said first and second opening/closing means are physically positioned side by side. For the purposes of the present invention, with the term "positioned side by side" it is meant that the first and second opening/closing means are positioned contiguous to each other. In other words, in this embodiment the overhead transport means enter and exit the heat treatment section in the same area and in two substantially parallel and opposite directions. In such a case, said first and second opening/closing means can advantageously comprise one or more doors shared among them, i.e. one or more doors that can be used for alternatively opening/closing said first or second opening/closing means.

Preferably, said one or more doors are driven by driving means, e.g. a chain, synchronised with said overhead transport means.

Also, when first and second opening/closing are present, the plant according to the invention advantageously comprises second actuator means positioned, with respect to said direction of advancement, downstream of said second opening/closing means, these second actuator means determining the rotation of said support means between said second position and said first position.

A preferred embodiment of the painting plant according to the invention, provides for the presence of third actuator means positioned, with respect to said direction of advancement, downstream of said first opening/closing means, and the presence of fourth actuator means positioned, with respect to said direction of advancement, upstream of said second opening/closing means and downstream of said third actuator means, said third actuator means determining the rotation of said support means between said second position and said first position, and said fourth actuator means determining the rotation of said support means between said first position and said second position.

Further characteristics and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof, which are illustrated by no way of limitation in the accompanying drawings, in which: figure 1 shows a schematic plan view of a painting plant according to the present invention;

figure 2 shows a side view of a first embodiment of rotating support means and of a related actuator in a painting plant according to the present invention;

figure 3 shows a side view of a second embodiment of rotating support means and of a related actuator in a painting plant according to the present invention;

figure 4 shows a top view of the embodiments shown in figure 2 and 3;

figure 5 shows a side view of an embodiment of a painting plant according to the present invention with a first type of manufactured product;

figure 6 shows a side view of an embodiment of a painting plant according to the present invention with a second type of manufactured product;

figure 7 shows the opening and closing operational sequence for a first embodiment of the opening/closing means on a painting plant according to the present invention; figure 8 shows the opening and closing operational sequence for a second embodiment of the opening/closing means on a painting plant according to the present invention; figure 9 shows a particular embodiment of the opening/closing means of a painting plant according to the present invention;

figure 10 shows a further particular embodiment of the opening/closing means of a painting plant according to the present invention;

figure 11 shows a further particular embodiment of the opening/closing means of a painting plant according to the present invention;

figure 12 shows a particular embodiment of the opening/closing means of a painting plant according to the present invention.

With reference to figure 1, a painting plant for manufactured products according to the present invention, designated with the reference number 1, in its most general embodiment comprises means 2 for the overhead transport of manufactured products along a direction of advancement, which carries said products through a plurality of treatment stations/areas, generally starting from a loading station 9 and finishing at an unloading station 8.

In particular, the plant according to the present invention comprises at least one station for the heat treatment of said products. For example, the heat treatment section may consist of a drying/polymerization section 7 placed downstream of a paint application zone 6, consisting for example of a dust painting cabin. Other heat treatment zones may consist of a product pre- treatment tunnel 3 and/or a product drying oven 5 placed downstream of said tunnel 3, possibly with an interposed drip zone 4. With reference also to figures 2 to 6, one of the peculiar characteristics of the painting plant 1 according to the present invention is that is comprises support means 20 for said manufactured products 10,100 which are operationally coupled to said overhead transport means 2. The products can for example be pieces with a mainly longitudinal form, for example profiles/bars 10 with a mainly mono-directional form, or pieces with a two- directional form, such as sheets 100.

As can be noted from the accompanying figures 5 and 6, in order to maximise system productivity, these manufactured products are generally suspended from support means 20 with the greatest possible density, i.e. leaving the minimum possible distance between the different pieces (whether they are sheets 100 or profiles/bars 10).

Another peculiar characteristic of the painting plant 1 according to the present invention is that it comprises first opening/closing means for said heat treatment section, said first opening/closing means being able to move between a closed position and an open position. For example, these opening/closing means 11 may be positioned upstream of the drying/polymerization section 7, and/or upstream of the pre-treatment tunnel 3 (block 14), and/or downstream of the drying oven 5 (block 13).

As illustrated in figures 2-4, said support means 20 rotate between at least one first position and at least one second position, this rotation being determined by first actuator means 25 positioned, with respect to the direction of advancement of the products as indicated by the arrow 50, upstream of said first opening/closing means 11, 13, 14.

The actuator means 25 can be mechanical, acting for example by interfering with the support means 20 and causing them to rotate while they advance, or electro-mechanical, possibly with remote control.

Preferably, with reference to figures 2-4, said support means 20 comprise a first portion 21 operationally coupled to said overhead transport means and substantially rigidly coupled thereto, and a second portion 22 operationally coupled to said first portion 21 and able to be operationally coupled to said products, and free to rotate with respect to said first portion 21. The second portion 22, for example, may comprise a first plate 222 connected to the first portion 21 so as to be free to rotate. A plurality of second plates 223, to which the manufactured products are attached, is operationally connected to said first plate 222. This embodiment is particularly useful when the overhead transport means 2 comprise two or more transport chains and the products need to be transferred between these chains. Using known transfer means, the plates 223 can be transferred from one chain to another using known methods. Alternatively, the second portion 22 may comprise a third plate 224 connected to the first portion 21 so as to be free to rotate. The manufactured products 10, 100 can then be attached to said third plate 224.

With reference to figures 5 and 6, the positioning of the products on the various support means 20 along the direction of advancement can be done using all or only part of said means, depending on the horizontal length of the products. For example, with reference to figure 5, in the case of sheets 100 with a long horizontal length (i.e. along the direction of advancement), it may be advisable/necessary to use alternate support means 20; conversely, with reference to figure 6, in the case of bars/profiles with a long vertical length (i.e. perpendicular to the direction of advancement), it is generally advantageous to use all the support means 20.

With reference to figure 4, advantageously the angle of rotation between said first position and said second position is around 90°. In this way, the free space created along the direction of advancement when the support means 20 are in the second position is maximised.

In practice, with reference to figures 2-4, during continuous movement of the manufactured products by the overhead transport means 2, driven by the actuator means 25, the support means 20 rotate from a first position (in particular, with reference to the direction of advancement indicated by the arrow 50, namely that of the first two support assemblies 201 and 202 shown in figure 4) to a second position (in particular, with reference to figure 4, that of the last two support assemblies 203 and 204). In the example shown in figure 4, the actuator means 25 engage the arm 225 of the second portion 22 causing it to rotate through 90°.

In this way, the free space created along the direction of transport is no longer given by the distance between the suspended products, but by the distance between the support means 20 connected to the overhead transport means 2 (or multiple means), since the latter is larger than the former. As is better illustrated below, this free space enables the opening/closing means to be opened immediately prior to the arrival of the products suspended from the rotated support means 20, and to be closed again immediately after the passage of the products.

Preferably, said first opening/closing means comprise door means, comprising for example a door with one or two panels, which can be opened or closed by sliding in a direction perpendicular to the direction of advancement or by rotating on a vertical axis.

A further advantage given by the use of doors means derives from the fact that in this way it is possible to keep the transporter moving in a straight line as it enters and exits the heat treatment station.

In particular, it is preferable that the opening/closing means comprise a plurality of doors separated by one or more intermediate chambers. In this way, by correctly regulating the opening and closing of the doors, it is possible to minimize the exchange of air between the inside and the outside of the heat treatment station, by keeping at least one of said doors closed.

An embodiment of this type, illustrated in figure 7, is such that the first opening/closing means 11 comprise first door means 111, for example a sliding door or two guillotine doors, a first intermediate chamber 115, and second door means 112, for example a sliding door or two guillotine doors. Immediately upstream of the first opening/closing means 11, with reference to the direction of advancement indicated by the arrow 50, the support means 20 are at the second position rotated through 90° by effect of the first actuator means 25 with respect to the first position in which they are kept during the other transport stages. Taking as a reference the group of products highlighted in bold type and designated with the reference number 60, at a given time taken as a reference T=0, the first door means 11 1 open to allow the passage of the support means 20 with the relative products, and remain open until the time T=12, at which point they are closed. Immediately afterwards, at the time T=13, the second door means 112 are opened to allow the entry of the support means 20 with the relative products into the heat treatment station, and are closed at the time T=24. Immediately afterwards, the same sequence begins again for the successive support means 20 with the relative products. After exiting the heat treatment station (not illustrated), the support means 20 can be rotated from the second position to the first position by effect of the second actuator means 55.

If we take as an example a distance of 600 mm between the support means 20 and a speed of 1.5 m/min for the overhead transport means 2, the times T correspond to seconds. In this way, the cycle is repeated every 24 seconds, while at the same time closing/isolating conditions between the inside and outside of the heat treatment station are always maintained, since one of the door means 111 or 112 is always closed.

Alternatively, with reference to figure 8, it is possible to have first door means 11 1, a first intermediate chamber 115, second door means 112, a second intermediate chamber 116, ad third door means 113. Also in this case, the door means 111, 112, and 113 may advantageously consist of a sliding door or two guillotine doors.

As in the previous case, at a given time taken as a reference T=0, the first door means 1 11 open to allow the passage of the first support means 20 with the relative products, and remain open until the time T=18, at which point they are closed. Immediately afterwards, at the time T=19, the second door means 112 are opened to allow the entry of the first support means 20 with the relative products into the second intermediate chamber 116. At the time T=25, the first door means 111 open again to allow the entry of the second support means 20, immediately following the first support means 20, into the first intermediate chamber 115, and are closed at the time T=36. Immediately afterwards, at the time T=37, the third door means 113 are opened to allow the entry of the first support means 20 with the relative products into the heat treatment station, and are closed at the time T=47. At the time T=48, the first door means 111 open again to allow the entry of the third support means 20, immediately following the second support means 20, into the first intermediate chamber 115, followed by the immediate closure of the second door means 112.

Also in this case, if we take as an example a distance of 600 mm between the support means 20 and a speed of 1.5 m/min for the overhead transport means 2, the times T correspond to seconds. In this way, the cycle is repeated every 48 seconds, while at the same time closing/isolating conditions between the inside and outside of the heat treatment station are always maintained, since one of the door means 111, 112 or 113 is always closed, the isolation being greater than in the previous case due to the presence of the two intermediate chambers 115 and 116.

A particularly preferred embodiment provides for the presence of second opening/closing means 12 for said heat treatment section, said first 11 and second 12 opening/closing means being positioned respectively upstream and downstream of said heat treatment section. In practice, it is preferable, particularly for the drying/polymerization sections 7, to have a closure both upstream and downstream of the station. These considerations can obviously also be applied to other sections of the system, such as the tunnel 3 or the drying station 5, for example.

In such a shown in figures 9-12, said first and second opening/closing means are physically positioned side by side. In other words, as better explained in the detailed description of the embodiments of figures 9-12, the entrance and exit of the products to and from the heat treatment station take place in the same area of the plant, with the transport line 2 moving parallelely and in opposite directions in the entrance and exit zones.

As shown in figures 9-12, preferably said first and second opening/closing can advantageously comprise one or more doors 91, 92; 503; 521; 551 shared among them, i.e. one or more doors that can be used for alternatively opening/closing said first or second opening/closing means. Preferably, said one or more doors 91, 92; 503; 521; 551 are driven by a chain 501; 520; 550 or equivalent means, which is synchronised with said overhead transport means 2. In general, when said second opening/closing means 12 are present, the plant according to the present invention advantageously provides for the presence of second actuator means positioned, with reference to the direction of advancement, downstream of said second opening/closing means 12, said second actuator means determining the rotation of said support means 20 between said second position and said first position.

Although a further rotation is possible, for example a 90° rotation of the support means 20, it is in fact preferable to return said support means and the relative products to the starting configuration and disposition, corresponding of course to the first position.

In order to reduce the lateral dimensions of the heat treatment stations, the plant according to the invention preferably provides for the presence of third actuator means positioned, with respect to said direction of advancement, downstream of said first opening/closing means, and of fourth actuator means positioned, with respect to said direction of advancement, upstream of said second opening/closing means and downstream of said third actuator means; said third actuator means determine the rotation of the support means between said second position and said first position, while said fourth actuator means determine the rotation of said support means between said first position and said second position.

In practice, inside the heat treatment station, the third actuator means restore the original configuration, with the minimum distance between the various manufactured products and the minimum lateral dimensions. Immediately before the exit, the fourth actuator means return the support means and the related products to a position of maximum distance between them along the direction of advancement, to enable them to pass through the second opening/closing means.

A particular embodiment of the painting system according to the present invention, illustrated in Figure 9, provides for the presence of first 11 and second 12 opening/closing means for the heat treatment section, for example on the drying/polymerization oven 7. Said first 11 and second 12 opening/closing means are positioned respectively upstream and downstream of the heat treatment station 7, with respect to the direction of travel of the overhead transport line 2, and said first 11 and second 12 opening/closing means are physically side by side. This can be achieved e.g. by proper configuration of the path of the transport line 2. In this way, the doors 91 and 92, sliding at right angles to the overhead transporter 2, alternately close the intermediate chamber 93 of the first opening/closing means 11 and the chamber 94 of the second opening/closing means 12. In practice, with reference to the situation illustrated in figure 9, by synchronising the transporter 2 with the door opening and closing control, when the door 91 slides to the left, the intermediate chamber 93 is closed at the entrance (i.e. from the outside of the oven 7) and the chamber 94 is open at the exit (i.e. towards the outside of the oven 7); at the same time, the door 92 slides to the right, opening the exit to the intermediate chamber 93 towards the inside of the oven 7, while the entrance to the chamber 94 from the oven 7 is closed by the door 92.

A further embodiment is shown in figure 10, where first 11 and second 12 opening/closing means are respectively positioned, side by side, upstream and downstream a heat treatment section 7 with respect to the direction of travel of the overhead transport line 2 indicated by the arrows 50.

A plurality of doors 503 are interposed between the entrance and exit area of the heat treatment section 7 and rotate counterclockwise, suspended from and guided by the chain 501 and the rail 502. The movement of the doors 503 (and the chain 501) is synchronised with the movement of the transporter 2, through, e.g., mechanical linking, so that the doors 503 do not interfere with the products 10. In this way, the doors 503 are brought in correspondence of the entrance area, where they create the intermediate chamber 115 which is always closed on either side, and in correspondence of the exit area, where they create the intermediate chamber 515 which is always closed on either side.

A still further embodiment is shown in figure 11, where first 11 and second 12 opening/closing means are again positioned side by side, respectively upstream and downstream a heat treatment section 7 with respect to the direction of travel of the overhead transport line 2 indicated by the arrows 50.

A first plurality of doors 511 are suspended on a first ring-forming chain 510 rotating counterclockwise; a second plurality of doors 521 are suspended on a second ring-forming chain 520 rotating clockwise; a third plurality of doors 531 are suspended on a third ring- forming chain 530 rotating counterclockwise. The chain 510 and the corresponding doors 511 are dedicated to the first opening/closing means 11; the chain 530 and the corresponding doors 531 are dedicated to the second opening/closing means 12; the chain 520 and the corresponding doors 521 are shared between the first opening/closing means 11 and the second opening/closing means 12. The three chains 510, 520 and 530 are synchronised with the movement of the transporter 2 so that the doors 511, 521 and 531 do not interfere with the products 10; the three chains 510, 520 and 530 are also synchronised among them so that the doors 511 are 521 are brought simultaneously in correspondence of the entrance zone thereby determining opening/closing of the first opening/closing means 11 while the doors 531 are 521 are brought simultaneously in correspondence of the exit zone thereby determining opening/closing of the second opening/closing means 12. In other words, in this way one of the doors 511 together with one of the doors 521 keep closed the entrance of the heat treatment section 7, while one of the doors 531 together with one of the doors 521 keep closed the exit of the heat treatment section 7. A mechanical linking between the overhead transport line 2 and the chains 510, 520 and 530 can be used to keep synchronisation among them; alternatively, the overhead transport line 2 can be linked and synchronised with one of the chains 510, 520 and 530, which in turn can be linked and synchronised with the remaining two chains.

A preferred embodiment is shown in figure 12, where first 11 and second 12 opening/closing means are again positioned side by side, respectively upstream and downstream a heat treatment section 7 with respect to the direction of travel of the overhead transport line 2 indicated by the arrows 50.

A plurality of doors 551 are suspended on a chain 550 which enter and exit the heat treatment section 7 through the same entrance and exit areas of the overhead transport line 2.

The movement of the chain 550 is synchronised with the movement of the transporter 2 so that the doors 551 do not interfere with the products hanging from the transporter. Preferably, the movement of the chain 550 can be driven by the movement of the overhead transport line 2. For example, the chain 550 can be conveniently mounted on a first 555 and a second wheel 556. A transmission chain or belt 560, mounted on one or more wheels 570, 571, is mechanically coupled with one of said first 555 or second 556 wheels, for example the first wheel 555 as indicated in figure 12. The transmission chain or belt 560 is also mechanically coupled to the overhead transport line 2 through e.g., the wheels 570, 571, as indicated in figure 12. In this way it is possible to keep the whole system always synchronised and, as shown in figure 12, the chain 550, rotating clockwise, brings the doors 551 at the entrance and exit zone in correspondence of a free space between two consecutive products (or groups of products). In other words, the chain 550 and the corresponding doors 551 are shared between the first opening/closing means 11 and the second opening/closing means 12, said doors 551 being alternatively used for opening/closing said first or second opening/closing means.

As can be noted from the description given, the technical solutions adopted for the painting machine according to the present invention fully achieve the set objects and aims.

The painting system thus conceived can be produced in several possible variants, without departing from the scope of the present invention. In practice, the materials used, the dimensions and contingent forms may vary according to requirements and the state of the art.