ITVR20110242A1 - PAINTING EQUIPMENT - Google Patents

Description

DESCRIPTION

Attached to a patent application for INDUSTRIAL INVENTION having the title

"Painting equipment"

The present invention relates to a painting apparatus. Preferably, the present invention refers to an apparatus for painting hides.

In particular, this equipment is normally used in tanning processes for the production and finishing of hides.

Even more particularly, these tanning processes are carried out by means of painting plants (also called "painting booths") having a support structure defining a tunnel. In correspondence with this tunnel are mounted conveyor belts (on which the hides to be painted are placed) and a rotating carousel on which spray guns of paint are mounted. In detail, this carousel is rotatably mounted on the support structure and faces the conveyor belts. Precisely, the conveyor belts are mounted on a lower part of the tunnel, while the carousel is mounted on the tunnel ceiling.

In this way, the spray guns spray the paint from top to bottom on the advancing hides. In addition, the rotation of the carousel allows the guns to be moved along a substantially circumferential path so as to paint the entire surface of the advancing hides.

In particular, such guns form part of the painting equipment.

In accordance with the known art, the painting apparatus also comprises a plurality of paint supply circuits connected to the guns. A paint with a predetermined color circulates in each of these circuits; for example, a red paint circulates in a first circuit, while a green paint circulates in a second circuit. Furthermore, each circuit normally comprises a distribution duct which extends along a closed path, and a suction duct connected to a paint tank. In detail, the function of the suction duct is to transport the paint from the tank to the distribution duct.

According to the known art, the painting apparatus comprises a plurality of spray guns for each supply circuit. In particular, the same number of guns is associated with each power supply circuit.

In other words, the circuit that feeds the red paint will have, for example, seven guns and the circuit that feeds the green paint will always have seven guns.

In fact, in this way, each circuit has its own guns and it is possible to switch from dispensing the red paint to dispensing the paint simply by activating the green paint supply circuit and deactivating the red paint supply circuit.

However, this known technique has some drawbacks.

In fact, each power supply circuit needs its own guns. For example, if seven guns are required for each circuit (the number of guns is determined by the surface extension of the leathers to be painted) and if the equipment includes three circuits, the equipment will comprise totally twenty-one guns.

Such a number of guns, in addition to increasing the overall dimensions of the equipment and increasing its weight, causes an increase in costs relating to the equipment itself (the cost of a gun must be multiplied by the number of guns needed for each circuit and by the number of circuits of the painting equipment).

In addition to this, it must be considered that after the realization of the equipment it is necessary to carry out periodic maintenance for each gun. Therefore, the maintenance costs for each gun must be multiplied by the total number of guns.

In this situation, the object of the present invention is to provide a painting apparatus which remedies the aforementioned drawbacks.

In particular, the object of the present invention is to provide a painting apparatus which has a simplified structure with respect to the known art.

Finally, it is an object of the present invention to provide a painting apparatus which has lower manufacturing and maintenance costs than the known art.

The indicated aims are substantially achieved by a painting apparatus according to what is described in the attached claims.

Further characteristics and advantages of the present invention will become more apparent from the detailed description of a preferred, but not exclusive, embodiment of a painting apparatus illustrated in the accompanying drawings, in which:

Figure 1 is a schematic view of a painting apparatus according to the present invention;

Figure 2 is a sectional view of a detail of the apparatus of Figure 1;

Figure 3 is a sectional view of a further detail of the apparatus of Figure 1; - figure 4 shows, in front view and in partial section, a painting plant according to the present invention.

With reference to the aforementioned figures, the reference number 1 globally indicates a painting apparatus according to the present invention.

In particular, the painting apparatus 1 comprises at least one paint dispensing member 2 and a first paint supply circuit C1 operatively connected to the dispensing member 2 to bring said first paint to the dispensing member 2 itself. .

Preferably, the first supply circuit Ci comprises its own paint distribution duct 3 placed in fluid communication with the dispensing member 2. Furthermore, the distribution duct 3 of the first supply circuit Ci extends along a closed circuit.

In addition, the first supply circuit Ci comprises its own intake duct 4 connected to the distribution duct 3 and placed in fluid communication with the latter. In particular, the intake duct 4 is connected to the distribution duct 3 by means of a three-way tubular element.

In addition, the apparatus 1 comprises at least one paint container 5 operatively associated with the first supply circuit Ci to contain the first paint to be dispensed. In detail, the intake duct 4 is, at least in part, inserted into the paint container 5 so that it can be sucked in during the operating phase.

Furthermore, a pump 6 of the hydraulic type is associated with the first supply circuit C1 for sucking the paint from the container 5. Preferably, this pump 6 is connected to the intake duct 4 and is operative in the latter.

In practice, the drawing duct 4 carries the paint into the distribution duct 3 so as to maintain this latter load of paint in the operating phase.

Furthermore, the apparatus 1 comprises a supply circuit CL of a washing liquid for washing the first supply circuit Ci when a paint change is carried out. In other words, when the paint of the container 5 of the first circuit is changed (for example replaced with a paint of a different color), a washing of the first supply circuit C1 is carried out.

In particular, the washing liquid supply circuit CL is connected between its own container 28 of a washing liquid and the first supply circuit Ci. Even more particularly, the washing liquid supply circuit CL comprises its own pump 6 for bringing the washing liquid into the first supply circuit Ci.

Preferably, the washing liquid supply circuit CL comprises an auxiliary duct 7 connected between the washing liquid container 28 and the suction duct 4 of each paint supply circuit to bring the washing liquid into the washing liquid supply circuit. paint. In particular, the pump 6 of the supply circuit CL operates in the auxiliary duct 7.

In addition, the supply circuit CL of a washing liquid comprises an inlet valve 8 interposed between the auxiliary duct 7 and the intake duct 4 of the first supply circuit Ci and configurable between an inlet condition in which the auxiliary duct 7 it is in fluid communication with the intake duct 4, and a locking condition in which said inlet valve 8 blocks the communication between the auxiliary duct 7 and the intake duct 4.

In particular, during the inlet condition, the inlet valve 8 blocks the fluid communication of the auxiliary duct 7 with the part of the intake duct 4 extending from the inlet valve 8 to the container 5. In this way, the washing liquid passes from the container 28 of the washing liquid to the first feed circuit C1 of the first paint without entering the container 5 of the first paint.

Practically, when it becomes necessary to change the color of the first paint contained in the relative container 5 and therefore it becomes necessary to wash the first supply circuit Cl, it is sufficient to configure the inlet valve 8 from the locking configuration to the inlet condition, deactivate pump 6 of the first supply circuit Cl and activate pump 6 of the washing liquid supply circuit CL.

Furthermore, the apparatus 1 comprises at least a second supply circuit C2 for a second paint operatively connected to the same dispensing member 2 of the first supply circuit Cl to bring the second paint to the dispensing member 2. Said second supply circuit C2 is distinct from the first Cl and comprises, similarly to the first supply circuit Cl, its own distribution duct 3 and its own intake duct 4. Preferably, the paint distribution duct 3 of the second supply circuit C2 is placed in communication with fluid with the dispensing member 2. Furthermore, this paint distribution duct 3 of the second supply circuit C2 extends along a closed circuit.

Preferably, the second supply circuit C2 comprises its own intake duct 4 in fluid communication with the distribution duct 3. In particular, the intake duct 4 is connected to the distribution duct 3 by means of a three-way tubular element.

In addition, the auxiliary duct 7 of the supply circuit CL of a washing liquid is connected between the container 28 of the washing liquid and the suction duct 4 of the second supply circuit C2 of the paint to bring the washing liquid into the second circuit. supply C2 of the paint.

In addition, the supply circuit CL of a washing liquid comprises a further inlet valve 29 interposed between the auxiliary duct 7 and the intake duct 4 of the second supply circuit C2 and configurable between an inlet condition in which the duct auxiliary 7 is in fluid communication with the intake duct 4, and a blocking condition in which the further inlet valve 29 blocks the communication between the auxiliary duct 7 and the intake duct 4.

In particular, during the inlet condition, the further inlet valve 29 blocks the fluid communication of the auxiliary duct 7 with the part of the intake duct 4 extending from the further inlet valve 29 to the container 5.

As can be seen in Figure 1, the apparatus 1 can also comprise further supply circuits for other paints. In fact, the apparatus 1, in general, has three power supply circuits for paints having different colors. However, for the sake of simplicity but without limiting effect, reference will be made hereinafter to only the first power supply circuit C1 and the second power supply circuit C2.

According to the present invention, the supply circuit CL of a washing liquid is connected to the dispensing member 2 to bring the washing liquid to the dispensing member 2. The apparatus 1 further comprises a valve body 9 of paint selection operatively interposed between each supply circuit Cl, C2, CL and the paint dispensing member 2 to selectively deliver the first paint or the second paint or the washing liquid. In other words, the paint selection valve body 9 is interposed between each circuit and the dispensing member 2 to select the paint or washing liquid to be dispensed.

It should be noted that the washing liquid supply circuit CL is connected both to the intake duct 4 (via the inlet valve 8, 29) and to the valve body 9 so as to be able to wash the entire supply circuit respectively (in the case of a paint change by activating the inlet valve 8, 29) or the valve body 9 and the dispensing member 8 (in the case of a selection of one of the paint already present in the supply circuits by activating the valve body 9).

Advantageously, the valve body 9 allows to select the dispensing of the first paint or of the second paint and, between one paint and the other, it allows to select the dispensing of the washing liquid so as to wash the dispensing member 2 first dispensing of the new paint.

It should be noted that the paint selection operation is different from the paint change operation. In fact, the operation of selecting a paint is carried out by means of the valve body 9 and allows to select one of the paints already loaded in the respective circuits. On the other hand, the paint change operation refers to the replacement of one paint with another (for example purple paint instead of red paint) contained in a container 5 and loaded into the relative supply circuit.

In particular, the valve body 9 has three inputs 10: a first input 10a for the first supply circuit Cl, a second input 10b for the second supply circuit C2 and a third input 10c for the supply circuit CL of a liquid wash.

Furthermore, the valve body 9 has an outlet 11 placed in fluid communication with the delivery member 2. In detail, the apparatus 1 comprises an outlet duct 17 extending from the outlet 11 of the valve body 9 to the delivery member. dispensing 2 to put the valve body 9 in fluid communication with the dispensing member 2 so as to bring a paint or washing liquid to the dispensing member 2.

In addition, each inlet 10 of the valve body 9 is in selective fluid communication with the outlet 11 for the passage of the first paint or second paint or washing liquid towards the dispensing member 2.

In particular, the valve body 9 comprises a plurality of movable elements 12, each of which interposed between a respective inlet 10 and the outlet 11. Each movable element 12 is movable between a stop position in which it blocks the fluid communication between the inlet 10 and outlet 11 and a passage position in which it allows fluid communication between inlet 10 and outlet 11.

In Figure 2, it is possible to see a part of the valve body 9 and, precisely, it is possible to see two inlets 10a, 10b and the outlet 11. In detail, the valve body 9 comprises a plurality of connection ducts 13 each associated with a respective inlet 10. Even more in detail, each connection duct 13 connects the respective inlet 10 to the outlet 11. Each movable element 12 is operative in the connection duct 13 to allow the passage of the paint or washing liquid from the inlet 10 to the outlet 11 (passage position) or to block the passage of paint or washing liquid from inlet 10 to outlet 11 (stop position). Precisely, during the stop position the movable element 12 occupies the entire section of the respective connection duct 13.

Preferably, the valve body 9 comprises actuation means 14 associated with each movable element 12 to bring it from the stop position to the passage position. These actuation means 14, together with the respective movable element 12 constitute a known type solenoid valve.

Preferably, the valve body internally has a plurality of seats 30, each arranged in correspondence with a connecting duct 13 and in fluid communication therewith. In other words, each seat 30 is an extension of a respective connection duct 13. The actuation means 14 are inserted into the seats 30, and each movable element 12 during the stop position is inserted into the connection duct 13 and occupies the same the entire section, while during the passage position the movable element 12 is arranged in the respective seat 30. According to the present invention, the dispensing member 2 has a spray nozzle 15 (Figure 3) for spraying a paint or liquid and a drain hole 16 having a passage section greater than the passage section of the spray nozzle 15 for discharging the paint or washing liquid.

Preferably, as can be seen in Figure 3, the delivery member 2 has an internal discharge duct 18 and a spraying duct 19.

The discharge duct 18 and the spraying duct 19 are in fluid communication with the outlet duct 17. It should be noted that the outlet duct 17 extends, at least partially, into the delivery member 2 itself. In other words, the part of the outlet duct 17 positioned inside the dispensing member 2 divides into the discharge duct 18 and the spraying duct 19.

In addition, the dispensing member 2 comprises a drain valve 20 operatively associated with the drain hole 16 to allow or block the discharge of the paint or washing liquid through the drain hole 16. In particular, the drain valve 20 it is arranged between the discharge duct 18 and the spraying duct 19 to divert the paint or the washing liquid selectively towards the discharge hole 16 or towards the spray nozzle 15.

In this way, during the delivery of a paint, the discharge valve 20 blocks the communication of fluid between the outlet pipe 17 and the discharge pipe 18 and allows the communication of fluid between the outlet pipe 17 and the spray pipe. 19 so that the paint is sprayed from the spray nozzle 15 to the outside. During the dispensing of the washing liquid, the discharge valve 20 blocks the communication of fluid between the outlet pipe 17 and the spray pipe 19 and allows the communication of fluid between the outlet pipe 17 and the discharge pipe 18 in so that the liquid is discharged to the outside through the discharge hole 16. It should be noted that, during the paint selection operations, the discharge valve 20 is configured in the condition in which it blocks the communication of fluid between the outlet pipe 17 and the discharge duct 18 and allows the communication of fluid between the outlet duct 17 and the spraying duct 19 so that the nozzle 15 is also washed.

In an alternative embodiment, the discharge valve 20 has its own configuration of complete opening during which it allows simultaneous fluid communication between the outlet pipe 17 and the discharge pipe 18 and spraying pipe 19.

In Figure 3, the discharge valve 20 has been represented symbolically as it is of a type known in the hydraulic sector.

In the preferred embodiment, illustrated in the attached figures, the painting apparatus 1 comprises a plurality of dispensing members 2 each of which is connected to the first supply circuit Cl, to the second supply circuit C2 and to the liquid supply circuit CL washing. In addition, the apparatus 1 comprises a plurality of valve bodies 9 each associated with a respective delivery member 2.

Advantageously, the paint supply circuits are connected to each dispensing member 2. Preferably, the valve bodies 9 are connected in series along the supply circuits.

In particular, each valve body 9 comprises a plurality of passage ducts 21 each associated with a respective supply circuit. Even more particularly, each passage duct 21 is part of the relative supply circuit and is in fluid communication with the relative inlet 10 of the valve body 9.

In detail, with reference to Figure 2, it is possible to see two passage ducts 21. Preferably, each passage duct 21 extends between its own inlet end 22 defining the inlet 10 and its own outlet end 23. In this way , each distribution duct 3 also extends between an outlet end 23 of a passage duct 21 of a valve body 9 and an inlet end 22 of the passage duct 21 of the subsequent valve body 9.

Furthermore, each connecting duct 13 extends from the passage duct 21 to the outlet duct 17 and places these ducts in fluid communication with each other.

As already explained, each supply circuit comprises its own distribution duct 3 extending along a closed path along which the delivery members 2 and the valve bodies 9 are arranged, and a suction duct 4 extending from a container 5, containing a paint or washing liquid, to the distribution duct 3 to take a paint or the washing liquid and bring it into the distribution duct 3.

In addition, the first and second supply circuits C2 each comprise a return duct 24 extending from the distribution duct 3 to the container 5 to return the paint to the respective container 5. In other words, the return duct 24 provides a return path for the paint being unloaded from the distribution duct 3. In fact, during the paint change phase of a supply circuit, the return duct 24 allows to recover (returning it to the respective container 5) the paint present inside the distribution duct 3 before washing this distribution duct 3.

It should be noted that the intake duct 4 and the return duct 24 relating to a paint supply circuit are distinct from each other.

In addition, each first and second supply circuit C2 comprises a return valve 25 interposed between the distribution duct 3 and the return duct 24 and configurable between an open condition in which the distribution duct 3 is in fluid communication with the return conduit 24, and a closed condition in which the return valve 25 blocks the communication of fluid between the distribution conduit 3 and the return conduit 24.

Furthermore, during the open condition, the return valve 25 interrupts the circulation of paint inside the distribution duct 3; while during the closed condition the return valve 25 allows the circulation of paint inside the entire distribution duct 3.

Preferably, the return valve 25 is positioned in proximity to the connection between the distribution duct 3 and the intake duct 4.

As already partially defined, the valve bodies 9, the discharge valves 20, the return valves 25 and the inlet valves 8 comprise solenoid valves.

In addition to the foregoing, each paint supply circuit comprises a device 26 for measuring the quantity of circulating paint. Preferably, this paint measuring device 26 is arranged along each pick-up duct 4 and is operative inside said duct. Furthermore, the painting apparatus 1 comprises a control unit 27 operatively connected to the valve bodies 9, to the discharge valves 20, to the return valves 25, to the inlet valves 8 and to the pumps 6 to control them.

In particular, in Figure 1, the control unit 27 comprises three control units where a first control unit is configured to manage the valve bodies 9, a second control unit is configured to manage the exhaust valves 20 and a third unit control valve is configured to manage the inlet 8 and return valves and the pumps 6.

Advantageously, the three control units are connected to each other so as to coordinate the management of the valves and of the valve bodies 9 according to a predefined sequence.

More precisely, to perform a color selection operation (selection of a paint already loaded in the power supply circuits of the equipment 1), the control unit 27 is configured for:

- commanding each valve body 9 to bring the movable elements 12 relating to the paint supply circuits to the stop position;

- commanding each valve body 9 to bring the movable element 12 relative to the supply circuit CL of a washing liquid into the passage position;

- activating the pump 6 of the supply circuit CL of a washing liquid so that the washing liquid reaches the delivery member 2;

- commanding each discharge valve 20 to allow the paint to be discharged through the discharge hole 16;

- deactivate the pump 6 of the supply circuit CL of a washing liquid after a predefined time interval;

- commanding each valve body 9 to bring the movable element 12 relating to the supply circuit CL of a washing liquid to the stop position;

- commanding each valve body 9 to bring the movable elements 12 relating to the paint supply circuits of interest into a passage position.

On the other hand, for the execution of a paint change operation of a power supply circuit, the control unit 27 is configured for:

- commanding the return valve 25 to move to the open condition so as to return the paint present in the circuit inside the container 5;

deactivate the pump 6 of the paint supply circuit, command the return valve 25 to move to the closed condition and command the inlet valve 8 to move to the inlet condition;

- activate the pump 6 of the supply circuit CL of a washing liquid so as to bring the washing liquid into the supply circuit of the paint to be washed;

- managing the discharge valves 20 of the dispensing members 2 so as to efficiently wash both the supply circuit and the spray nozzle 15;

- deactivate the pump 6 of the supply circuit CL of a washing liquid after a predefined time interval;

- activate pump 6 of the paint supply circuit as soon as the paint change has been made.

It should be noted that the step of managing the discharge valves 20 of the dispensing members 2 provides a first sub-phase in which each discharge valve 20 allows the washing liquid to be discharged through the washing hole and a second sub-step in which each discharge valve 20 allows the washing liquid to be discharged through the spray nozzle 15. Advantageously, during the first sub-phase the washing liquid exits at a first speed from the drain hole 16 so as to optimally wash the supply circuit. While, during the second sub-phase, the washing liquid exits at a second speed, lower than the first, from the spray nozzle 15 so as to optimally wash the spray nozzle 15.

In fact, the discharge hole 16 has a larger diameter than the diameter of the spray nozzle 15 so as to allow the washing liquid to exit at a higher speed (second speed) from the discharge hole 16 than the outlet speed 11 (first speed) of the washing liquid from the spray nozzle 15.

The present invention also relates to a painting system 100 (Figure 4) comprising a support structure 101 having a lower portion 102 and an upper portion 103 mutually facing each other and defining between them a passage area 104 in which they can be inserted of the products to be painted (preferably leather). In other words, the support structure 101 is shaped like a tunnel.

Furthermore, the painting plant 100 comprises advancement means 105 mounted on the lower portion 102 of the support structure 101 for advancing the products to be painted. In particular, the advancement means 105 comprise a conveyor belt 106 (preferably perforated) defining its own direction of advancement. In other words, the conveyor belt 106 runs through the tunnel.

In addition, the painting plant 100 comprises a carousel 107 rotatably mounted on the upper portion 103 of the support structure 101 and rotatable with respect to a main axis of rotation 108. This main axis of rotation 108 is substantially transverse to the direction of advancement of the conveyor belt 106.

More precisely, the carousel 107 comprises a plurality of arms 109 extending substantially radially with respect to the rotation axis 108. Each arm 109 extends between its own connection end 110, close to the rotation axis 108, and its own projecting operating end 111 cantilevered with respect to the axis of rotation 108.

In particular, the arms 109 of the carousel 107 are inserted in the passage area 104.

In accordance with the present invention, the painting plant 100 comprises the previously described painting apparatus 1 in which the dispensing member 2 is inserted in the passage area 104 and is connected to the periphery of the rotating carousel 107 for dispensing the paint towards the products to be painted.

In detail, each rotation member is connected at the operating end 111 of each arm 109.

In this way, during the use of the plant 100, the rotation of the carousel 107 causes the dispensing members 2 to rotate along a substantially circular path so as to strike the product to be painted advancing on the conveyor belt 106.

In particular, at least part of the distribution ducts 3 of the supply circuits are mounted on the rotating carousel 107 and, in use, rotate around the main rotation axis 108. The remaining part of each power supply circuit is mounted on the support structure 101 and is, in use, fixed with respect to the carousel 107.

In detail, the system 100 comprises a rotating hydraulic joint 112 interposed between the support structure 101 and the rotating carousel 107 to put the part of the distribution ducts 3 mounted on the support structure 101 in fluid communication with the rest of the distribution circuits. Power supply.

This rotating hydraulic joint 112 is of a known type and, therefore, will not be described further in detail.

In particular, the painting plant 100 comprises a covering structure 113 connected to the support structure 101 at the hydraulic joint 112 and extending away from the latter to cover the distribution ducts 3 and the dispensing members 2 from the rest. power supply circuits in order to prevent the paints dispensed from coming into contact with the remaining parts of the power supply circuits.

The present invention achieves the intended purposes.

In particular, the present invention has a simplified structure with respect to the known art. In fact, the painting apparatus according to the present invention allows to have a single delivery member connected to several paint supply circuits thanks to the presence of the valve body. Furthermore, the washing liquid supply circuit allows washing the dispensing member before selecting a new paint (already loaded in a supply circuit) to be dispensed. In particular, the washing liquid supply circuit is connected directly to the valve body so that only the delivery member can be washed.

It should also be noted that the present invention allows a reduction in the number of dispensing members necessary, thus lowering the cost connected to the implementation of the invention.

Claims (19)

CLAIMS Painting apparatus (1) comprising: at least one paint dispensing member (2); a first supply circuit (Cl) of a first paint operatively connected to the dispensing member (2) to bring said first paint to the dispensing member (2); characterized in that it comprises at least a second supply circuit (C2) for a second paint operatively connected to the dispensing member (2) to bring said second paint to the dispensing member (2); said apparatus (1) further comprising a feeding circuit (CL) of a washing liquid operatively connected to the dispensing member (2) to bring said washing liquid to the dispensing member (2); said apparatus (1) comprising a paint selection valve body (9) operatively interposed between each supply circuit and the paint dispensing member (2) to selectively deliver the first paint or the second paint or the washing liquid. 2. Painting apparatus (1) according to claim 1 characterized in that the valve body (9) has at least three inlets (10); each supply circuit being connected to a respective inlet (10) of the valve body (9); said valve body (9) also having an outlet (11) placed in fluid communication with the delivery member (2); each inlet (10) of the valve body (9) being in selective fluid communication with the outlet (11) for the passage of the first paint or second paint or washing liquid towards the dispensing member (2). 3. Painting apparatus (1) according to claim 2 characterized in that said valve body (9) comprises a plurality of movable elements (12) each of which interposed between a respective inlet (10) and outlet (11) and being movable between a stop position which blocks the fluid communication between the inlet (10) and the outlet (11) and a passage position in which it allows the fluid communication between the inlet (10) and the exit (the)· 4. Painting apparatus (1) according to claim 3 characterized in that the valve body (9) comprises actuation means (14) associated with each movable element (12) to bring it from the stop position to the passage position. Painting apparatus (1) according to any one of the preceding claims characterized in that the dispensing member (2) has a spray nozzle (15) for spraying a paint or washing liquid and a drain hole (16) having a passage section greater than the passage section of the spray nozzle (15) for discharging the paint or washing liquid; said dispensing member (2) comprising a drain valve (20) operatively associated with the drain hole (16) to allow or block the discharge of the paint or washing liquid through the drain hole (16). 6. Painting apparatus (1) according to any one of the preceding claims characterized in that it comprises a plurality of delivery members (2) each of which is connected to the first power supply circuit (Cl), to the second power supply circuit (C2) and to the washing liquid feeding circuit; said apparatus (1) comprising a plurality of valve bodies (9) each associated with a respective delivery member (2). 7. Painting apparatus (1) according to claim 6 characterized in that the valve bodies (9) are connected in series along the power supply circuits. 8. Painting apparatus (1) according to claim 7 characterized in that each valve body (9) comprises a plurality of passage ducts (21) each associated with a respective supply circuit; each passage duct (21) being part of the relative supply circuit and being in fluid communication with the relative inlet (10) of the valve body (9). Painting apparatus (1) according to any one of the preceding claims characterized in that each supply circuit comprises a distribution duct (3) extending along a closed path along which the dispensing members (2) and the bodies are arranged valves (9); said supply circuit comprising a suction duct (4) extending from a container (5), containing a paint or washing liquid, to the distribution duct (3) to take a paint or the washing liquid and carry it into the distribution duct (3). 10. Painting apparatus (1) according to claim 9 characterized in that the first and second supply circuits (C2) each comprise a return pipe (24) extending from the distribution pipe (3) to the container (5) for return the paint or washing liquid to the container (5); each first and second supply circuit (C2) comprising a return valve (25) interposed between the distribution conduit (3) and the return conduit (24) and configurable between an open condition in which the distribution conduit (3 ) is in fluid communication with the return conduit (24), and a closed condition in which said return valve (25) blocks the fluid communication between the distribution conduit (3) and the return conduit (24) . Painting apparatus (1) according to any one of claims 9 to 10 characterized in that the supply circuit (CL) of a washing liquid comprises an auxiliary duct (7) connected between the tank (5) of washing liquid washing and the suction duct (4) of each paint feed circuit to bring the washing liquid into the paint feed circuit; said supply circuit (CL) of a washing liquid comprising an inlet valve (8) interposed between the auxiliary duct (7) and the intake duct (4) and configurable between an inlet condition in which the auxiliary duct (7 ) is in fluid communication with the intake duct (4), and a blocking condition in which said inlet valve (8) blocks the communication between the auxiliary duct (7) and the intake duct (4). Painting apparatus (1) according to any one of the preceding claims characterized in that the valve body (9), the discharge valve (20), the return valve (25) and the inlet valve (8) comprise solenoid valves . 13. Painting apparatus (1) according to claim 12 characterized in that it comprises a control unit (27) operatively connected to the valve body (9), to the discharge valve (20), to the return valve (25), to the inlet valve (8) to control them. Painting apparatus (1) according to any one of the preceding claims characterized in that each supply circuit comprises its own pump (6) for bringing the paint or washing liquid to the dispensing members (2). Painting apparatus (1) according to any one of the preceding claims characterized in that the first paint has a color different from the color of the second paint. Painting apparatus (1) according to any one of the preceding claims characterized in that it comprises each paint supply circuit comprises a device (26) for measuring the quantity of circulating paint. 17. Painting plant (100) comprising: a support structure (101) having a lower portion (102) and an upper portion (103) mutually facing each other and defining between them a passage area (104) in which products to be painted can be inserted; advancement means (105) mounted on the lower portion (102) of the support structure (101) for advancing the products to be painted; a carousel (107) rotatably mounted on the upper portion (103) of the support structure (101) and rotatable with respect to a main axis of rotation (108); said carousel (107) being, at least in part, inserted in the passage area (104); characterized in that it comprises the painting apparatus (1) according to any one of claims 1 to 16 in which the dispensing member (2) is inserted in the passage area (104) and is connected to the periphery of the carousel ( 107) rotating to deliver the paint to the products to be painted. Painting plant (100) according to claim 17 characterized in that at least part of the distribution ducts (3) of the supply circuits are mounted on the rotating carousel (107) and, in use, rotate around the axis of rotation ( 108) main; the remaining part of each power supply circuit being mounted on the support structure (101) and, in use, fixed with respect to the carousel (107); said system (100) comprising a rotating hydraulic joint (112) interposed between the support structure (101) and the rotating carousel (107) to put said part of the distribution ducts (3) in fluid communication with the rest of the Power supply . 19. Painting plant (100) according to claim 18 characterized in that it comprises a covering structure (113) connected to the support structure (101) at the hydraulic joint (112) to cover the distribution ducts (3) and the dispensing members (2) from the rest of the supply circuits so as to prevent the paints dispensed from coming into contact with the remaining parts of the supply circuits.