DEVICE FOR COATING AND METHOD THEREOF

Abstract

 The present invention concerns a machine (1) for the treatment, such as painting, of workpieces (P), such as panels (P), made of wood, plastic, fiberglass, glass, metal and the like, comprising means for the treatment (23, 24) of at least one of said workpieces (P) to be treated, and a dragging system (5), for dragging a paper band (6), wherein the dragging system (5) comprises a winding roller (51) and a winding/unwinding roller (52), wherein said machine (1) is characterized in that the winding roller (51) wind the dirty paper (62), which has been dirtied by the treatment of at least one workpiece (P) by means of said treatment means (23, 24), in that said winding/unwinding roller (52) wind or unwind the clean paper (61), wherein the clean paper (61) is intended to support at least one workpiece (P) to be treated by means of said treatment means (23, 24) and to absorb or collect the waste of the treatment of said treatment means (23, 24), becoming dirty paper (62), and in that said machine (1) includes return movable means (54), movable from a rest position to an operating position, wherein said return movable means (54) pass from said rest position to said operating position to change the path of the paper (6) unwound or wound by said winding/unwinding roller (52) for a section sufficient to support said at least one workpiece (P) without unwinding the dirty paper (62), and wherein said return movable means (54) pass from said operating position to said rest position to provide clean paper (61) to support said at least one workpiece (P), which is wound by said winding/unwinding roller (52), without unwinding said dirty paper (62).
The present invention also concerns a method of treating at least one piece (P), a computer program and a storage medium.

Description

[0001] The present invention relates to a machine for painting pieces and method thereof.

[0002] More specifically, the invention relates to a machine and relative method for conveying pieces, such as panels and the like, to be subjected to treatment or processing, and in particular to be painted, designed and manufactured to reduce the consumption of the absorbent paper necessary to carry out the painting step.

[0003] In the following the description will be directed to machines for painting panels, but it is quite clear that the same should not be considered limited to this specific use.

[0004] As is well known, currently there are machines for painting panels, for example panels made of wood, fiberglass, plastic and the like, which can be used for example in the field of the furniture manufacturing, which mainly comprise an input transport section, which can include a first roller table, on which the panel can be arranged by an operator or an automatic loading/handling system, such as a handling robot and the like, a painting station, having a conveyor belt unit, internally arranged for the passage of the panel to be painted, an inlet opening, for the entry of the panel to be processed, in correspondence of which said input transport section is arranged an outlet opening, for the exit of the painted panel, in which said painting station comprises means for spraying the paint on the surface of the panel, and a second exit transport section, which can include a second roller plane, in which the painted panel can be taken by an operator or a generic automatic unloading/handling system, such as a robot, arranged in correspondence of said outlet opening.

[0005] Said painting machines for panels also comprise a unwinding reel, arranged in correspondence of said inlet opening, on which the paper is wound, typically absorbent paper, or plastic films in general, on which the panels to be painted are arranged on, and a winding roller, arranged in correspondence of said outlet opening, on which the paper can be re-wound after its use.

[0006] In particular, the paper (or the plastic film) is placed on the conveyor belt, sliding on it in a coordinated fashion, while the panel slides inside the painting station.

[0007] The paint sprayed in excess, which does not paint the panel, also called "overspray", is collected by the absorbent paper on which the panel is placed, which is then wound on the second winding reel.

[0008] This solution implies that the panel P must be loaded onto said inlet transport section and picked up from said outlet transport section. Therefore, in order for the painting process to be completed, it is necessary to provide an operator or an automatic loading system, at the inlet of the machine, and an operator, or a pickup plant, at the machine outlet. This obviously implies a considerable operating cost of the plant.

[0009] Alternatively, it is possible to envisage a single operator, that is the generic automatic loading/unloading system, at the machine inlet, painting and arranging the painted piece directly on the input transport section, so that it can be picked up by the same operator or unloading/automatic handling system directly from the first inlet section, which in its turn may further load a new piece to be painted, to be placed always on the same first transport section.

[0010] In this case, however, the absorbent paper underlying the painted workpiece or panel, now dirty because of the excess paint, must be at least partially re-wound on itself. This, as is known, causes considerable problems due to the fact that said dirty paper tends to be sticky, sticking on itself, and often tearing. This slows down or interrupts the production process several times.

[0011] This can also imply considerable paper consumption, which is a very expensive consumable.

[0012] It is apparent that the solutions according to the prior art are expensive in economic terms. Furthermore, the possibility of unwinding dirty paper is not applicable.

[0013] In light of the above, it is therefore an object of the present invention to propose a method and a machine for painting parts, such as panels and the like, which allows a saving in terms of process as well as of absorbent paper, maintaining a high production efficiency.

[0014] It is specific object of the present invention a machine for the treatment, such as painting, of workpieces, such as panels, made of wood, plastic, fiberglass, glass, metal and the like, comprising means for the treatment of at least one of said workpieces to be treated, and a dragging system, for dragging a paper band, wherein the dragging system comprises a winding roller and a winding/unwinding roller, wherein said machine is characterized in that the winding roller wind the dirty paper, which has been dirtied by the treatment of at least one workpiece by means of said treatment means, in that said winding/unwinding roller wind or unwind the clean paper, wherein the clean paper is intended to support at least one workpiece to be treated by means of said treatment means and to absorb or collect the waste of the treatment of said treatment means, becoming dirty paper, and in that said machine includes return movable means, movable from a rest position to an operating position, wherein said return movable means pass from said rest position to said operating position to change the path of the paper unwound or wound by said winding/unwinding roller for a section sufficient to support said at least one workpiece without unwinding the dirty paper, and wherein said return movable means pass from said operating position to said rest position to provide clean paper to support said at least one workpiece, which is wound by said winding/unwinding roller, without unwinding said dirty paper.

[0015] Always according to the invention, said return movable means may comprise a tensioning roller.

[0016] Still according to the invention, said machine may comprise a main conveyor for loading and removing at least one of the said workpieces to be treated or painted.

[0017] Advantageously according to the invention, said winding roller may be arranged in correspondence of said main conveyor.

[0018] Further according to the invention, said machine may comprise a painting station, having a support base, on which the workpiece to be painted is placed during the treatment, and an inlet opening for the introduction of said workpiece to be painted in said painting station, wherein said main conveyor is placed in correspondence of said inlet opening.

[0019] Preferably according to the invention, said dragging system may comprise a dragging belt, arranged within said painting station substantially in correspondence of said support base, wherein the paper rests and is dragged during the advancement, for supporting the workpiece to be painted.

[0020] Always according to the invention, said treatment means may comprise a painting robot of anthropomorphic, Cartesian and similar type.

[0021] Still according to the invention, said machine may comprise an auxiliary conveyor, to support said workpiece to allow the variation of said path of the paper unwound or wound by said winding/unwinding roller, and in that said painting station has an outlet opening, wherein said auxiliary conveyor is arranged in correspondence of said outlet opening.

[0022] Advantageously according to the invention, said winding/unwinding roller is arranged in correspondence of said auxiliary conveyor.

[0023] Further, according to the invention, said treatment means may comprise a reciprocating spraying arm.

[0024] Preferably according to the invention, said winding roller may be arranged in correspondence of said auxiliary conveyor and said winding/unwinding roller is arranged in correspondence of said main conveyor.

[0025] Always according to the invention, said machine may comprise a logic control unit for the operating coordination of said machine.

[0026] It is further object of the present invention a method of treating at least one workpiece, such as a panel made of wood, plastic, fiberglass, rubber and the like, wherein a paper band is used to transport said at least one workpiece, comprising the following steps: A. positioning said workpiece to be treated on clean paper, wherein said clean paper is intended to support said at least one workpiece to be treated and to absorb or collect the treatment wastes, wherein the path of the clean paper is varied for a section sufficient to support said at least one workpiece without unwinding dirty paper; B. treating said at least one workpiece on a support base; and C. extracting said workpiece to be treated, wherein the clean paper to support at least one workpiece to be treated in a subsequent treatment cycle is fed or re-wound without unwinding the dirty paper, dirtied during one treatment cycle of said at least one workpiece.

[0027] Always according to the invention, in said step A may comprise the following substeps: A1. winding said clean paper; and A2. gradually reducing the path of said clean paper.

[0028] Still according to the invention, in said steps A1 and A2 said clean paper is wound for a section equal to at least the length of said at least one workpiece to be treated and of the support base.

[0029] Further according to the invention, step C may comprise the following substeps: C1. unwinding said clean paper; C2. winding up said dirty paper; and C3. gradually increasing the path of said paper.

[0030] Advantageously according to the invention, in said step C1 and C3 said clean paper may be unwound for a section equal to at least the length of said at least one workpiece to be treated and of the support base.

[0031] Preferably according to the invention, said step A may comprise the following substeps: A3. unwinding said clean paper; and A4. gradually increasing of the path of said paper; and A5. wrapping said dirty paper.

[0032] Always according to the invention, in said steps A3 and A4 said clean paper may be unwound for a section equal to at least the length of said at least one workpiece to be treated and of the supporting base.

[0033] Still according to the invention, said step C may comprise the following substeps: C4. wrapping said clean paper; and C5. gradually reducing the path of said paper.

[0034] Further according to the invention, in said steps C4 and C5 said clean paper may be wound for a section equal to at least the length of said at least one workpiece to be treated and of the support base.

[0035] Advantageously according to the invention, said step B may comprise the painting of said piece.

[0036] Preferably, according to the invention, said method may provide for at least one winding roller, for winding said dirty paper, at least one winding/unwinding roller for unwinding and rewinding said clean paper, and return movable means, such as a return roller, movable from a rest position to an operating position and vice-versa.

[0037] It is also object of the present invention a computer program including instructions, which, when the program is executed by a computer, cause the computer to execute the steps and the respective substeps A, B and/or C of the method described above.

[0038] It is further object of the present invention a computer-readable storage medium containing instructions, which, when executed by a computer, cause the computer to execute the method steps described above.

[0039] The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 illustrates a first embodiment of a painting machine according to the present invention;

figure 2A illustrates the first step of a first embodiment of an operating method of the machine according to figure 1;

figure 2B illustrates the second step of the operating method of of the machine according to figure 2A;

figure 2C illustrates the third step of the operating method of the machine according to figure 2A;

figure 2D illustrates the fourth step of the operating method of the machine according to figure 2A;

figure 2E shows the fifth step of the operating method of the machine according to figure 2A;

figure 3A illustrates the first step of a second embodiment of an operating method of a machine according to the present invention;

figure 3B illustrates the second step of the operating method of the machine according to figure 3A;

figure 3C illustrates the third step of the operating method of the machine according to figure 3A;

figure 3D illustrates the fourth step of the operating method of the machine according to figure 3A;

figure 3E illustrates the fifth step of the operating method of the machine according to figure 3A;

figure 4A illustrates the first step of a third embodiment of an operating method of a machine according to the present invention;

figure 4B illustrates the second step of the operating method of the machine according to figure 4A;

figure 4C illustrates the third step of the operating method of the machine according to figure 4A;

figure 4D illustrates the fourth step of the operating method of the machine according to figure 4A; and

figure 4E illustrates the fifth step of the operating method of the machine according to figure 4A.

[0040] In the various figures, similar parts will be indicated by the same reference numbers.

[0041] With reference to figure 1, a painting machine 1 according to the present invention can be seen.

[0042] Said machine 1 essentially comprises a main conveyor 3, which can comprise a roller table, in which the panel P to be processed is arranged by an operator U or by a loading robot or any automatic loading/handling system, a painting station 2, an auxiliary conveyor 4, which also in this case may possibly comprise a roller table, and a dragging system 5, for dragging absorbent paper 6.

[0043] The painting station 2 comprises a chassis 21, having an inlet opening 211 and an outlet opening 212.

[0044] Inside said chassis there is installed and movable a dragging belt 55 (better described below), which also forms a support base 22, on which the paper rests and is dragged during the advancement, and a reciprocating spraying arm 23, to paint the panel P when it passes under it.

[0045] The main conveyor 3 comprises, in the embodiment, a rollers plane having a plurality of idle or motorized rollers, on which the panel P to be painted can slide. Of course, different conveyor variants according to the prior art can be possible, such as those of belt type and the like.

[0046] Said main conveyor 3 is arranged at said inlet opening 211 of said chassis 21.

[0047] The auxiliary conveyor 4, structurally analogous to said main conveyor 3, is arranged at said outlet opening 212 of said chassis 21.

[0048] The dragging system 5 comprises a winding roller 51, capable of winding, shown in the embodiment arranged in correspondence of or near said inlet opening 211, on which a reel of absorbent paper 6 is wound, intended to be placed underneath the piece (the panel P) to be painted during the painting phases to absorb the overspray.

[0049] Said dragging system 5 also comprises a winding/unwinding roller 52, capable of both winding and unwinding the absorbent paper 6, which in the embodiment shown is arranged substantially in correspondence of said outlet opening 212. On the winding/unwinding roller 52, the absorbent paper 6 can be rewound, owing to the retraction of the tensioning roller 54.

[0050] The dragging system 5 further comprises said dragging belt 55 moved by dragging rollers 53, possibly motorized, to allow the sliding of the absorbent paper 6 on said dragging belt 55 and then on said support base 22.

[0051] Furthermore, said dragging system 5 comprises transmission means, as in the present case, a tensioning roller 54, arranged near said winding roller 51, capable of assuming a rest position and one or more extracted positions, in which it is moved away from said winding roller 51. In particular, when said tensioning roller 54 is extracted, it extends the path, during the unwinding of paper from said winding/unwinding roller 52 and shortens it during winding, always winding on a winding/unwinding roller 52. Said tensioning roller 54 is a possible embodiment of the movable transmission means, which can possibly also be realized in further configurations and with other members.

[0052] The operation of the painting machine 1 according to the present invention is coordinated by a logic control unit 7, which executes an appropriate program that is the treatment method of the workpiece to be machined, installed in it. In particular, said control logic unit 7 comprises a processor.

[0053] The operation of the transport and painting machine 1 described above can be carried out according to different methods and processes, as described in the following.

[0054] A first embodiment or operating mode of the painting machine 1 is shown in figures 2A-2E.

[0055] In particular, in figure 2A an operator U or an automatic loading system (e.g. a robot) positions the panel P or even a load or a plurality of panels P (in the figure for the sake of simplicity a single panel P is shown) on the main conveyor 3.

[0056] The absorbing paper 6 has a section of dirty paper 62, which has already been used in a previous activity of painting a previous piece or panel P, mainly wound on said winding roller 51, and a section of clean paper 61, not yet used and which is mainly wound on said winding/unwinding roller 52.

[0057] In the figures, the separation line separating the dirty paper portion 62 from the clean paper portion 61 is indicated with 63.

[0058] Still with reference to the indicated figures, the length of the panel P is indicated by the letter L, while the support base 22 has a lateral length indicated with the letter B.

[0059] In figures 2A-2E, L is greater than B, in particular it is assumed that L is equal to 3000 mm, while B is equal to 2000 mm, as reported directly in the figures. Different dimensions and proportions can be used both for the length L of the workpiece P and for the lateral length B of the support base 22 of the painting station 2.

[0060] In the configuration shown in figure 2A, said winding roller 51 and said winding/unwinding roller 52 are stationary, said tensioning roller 54 is in the operative position, thus allowing to have a section of clean absorbent paper 61 of a length equal to L (in the indicated example 3000 mm) below the main conveyor 3 such as to allow the subsequent passage through the machine of the panel P onto the clean absorbent paper 61 up to the auxiliary conveyor 4, without unwinding the dirty paper 62 wound on said winding roller 51.

[0061] In figure 2B the panel P advances on the main conveyor 3 in the direction indicated with the arrow A, enters the painting station 2, resting on the clean paper 61 as it advances, owing to the dragging rollers 53 which drag the dragging belt 55.

[0062] The reciprocating spraying arm 23 does not spray, i.e. it does not paint the panel P, while said winding/unwinding roller 52 winds the clean paper 61, which is arranged below the panel P and is dragged by means of a driving dragging belt 55 from said dragging rollers 53.

[0063] The tensioning roller 54 is gradually brought to the rest position, thus making sufficient dirty paper 62 (or already used in previous spraying steps) such as to cover the entire support base 22, inside the painting station 2 available. This avoids wasting clean paper 61 unnecessarily.

[0064] In particular, as it can be seen, the separation line 63 which separates the clean paper 61 from the dirty paper 62 is substantially in correspondence with said outlet opening 212.

[0065] Said winding roller 51 is therefore stationary, so that the dirty paper is not carried out 62.

[0066] With reference to figure 2C, the panel P returns moving on the transport systems, re-entering the painting station 2, resting on clean paper 61. In particular, the panel P moves in the direction indicated with the arrow R, contrary to that of the arrow A.

[0067] The spraying arm 23 is active and the panel P is thus subjected to painting.

[0068] The spraying arm 23 paints the panel moving transversely with respect to the advance direction of the same, in other words, the spraying arm 23 moves in a direction perpendicular to the table, in which figures 2A-2E are shown.

[0069] The winding/unwinding roller 52 unwinds clean paper 61, while the roller 51 wraps dirty paper 62.

[0070] The tensioning roller 54 is in rest position, in order to move forward thereafter to avoid winding up dirty paper 62, which would then have to be unwound, which would cause the risk of breaking the absorbent paper tape 6.

[0071] With reference now to figure 2D, it can be seen that the tensioning roller 54 is extracted so as to maintain a portion of dirty paper 62 of sufficient length below the main conveyor 3 to be able to return covering the transport of the painting station 2 in the subsequent working steps.

[0072] The panel P has gone out from the inlet opening 211 of the painting station, on the main conveyor 3 and the winding/unwinding roller 52 unwound clean paper 61, to allow the advancement of the panels P.

[0073] With reference now to figure 2E, the tensioning roller 54 is observed, which is further extracted so as to recover the clean paper 61, necessary to arrange, in correspondence with said main conveyor 3, sufficient clean paper 61, to allow a new painting cycle without unwinding dirty paper 62, so as to avoid risks of breaking the absorbent paper band 6, often due, as mentioned, to unwinding dirty paper 62 previously wound on a reel.

[0074] The winding/unwinding roller 52 thus unwinds clean paper 61, while the winding roller 51 is stationary, due to the action of said tensioning roller 54, which recovers said clean paper 61.

[0075] The operator U, or any automatic loading and unloading system, picks up the painted panel P from the main conveyor 3 and replaces it with a new panel P to be painted.

[0076] With reference now to figures 3A-3E, a second embodiment of a painting machine and the relevant operating method can be observed, as controlled and coordinated by said logic control unit 7.

[0077] In this embodiment, the reciprocator spraying arm 23 is replaced in the embodiment in question by an anthropomorphic robot 24, which is able to move and orientate the paint spraying nozzle in space to carry out the painting of a piece inside the painting station 2. In other variants, instead of the anthropomorphic robot 24 a Cartesian robot or generic robot can be installed.

[0078] Moreover, said painting machine 1 does not provide the auxiliary conveyor 4.

[0079] With reference to figure 3A, an operator U or an automatic loading system (not shown in the figures) positions the panel P or the load of panels P on the main conveyor 3.

[0080] In the initial configuration, said winding roller 51 and said winding/unwinding roller 52 are stationary.

[0081] The tensioning roller 54 is in the operating position and this allows to have a sufficient length of clean paper 61 under the main conveyor 3 without having to unwind the dirty paper 62 from the winding roller 51, to allow the subsequent advancement of the panel P (or loading of panels P) up to the inside of the painting station 2 on clean paper 61, without having to unwind from the roll arranged on said roller 51 of dirty paper 62. In particular, a quantity of clean paper 61 is provided, substantially of the length L of the panel P. In practice, a further portion of paper is generally provided before and after the panel P to allow it to be painted.

[0082] With reference to figure 3B, the piece advances on the main conveyor 3 along the direction A, entering the painting station 2, and is placed on the clean paper 61, advanced by said dragging belt 55 moved by said dragging rollers 53, while the winding/unwinding roller 52 winds said clean paper 61.

[0083] As can be seen, when the panel P is completely inserted inside the painting station 2, the separation line 63, which separates the clean paper 61 from the dirty paper 62 is substantially in correspondence of the inlet opening 211.

[0084] The panel P thus stops inside the painting station 2, arranged on the clean paper 61 on said support base 22.

[0085] During the advancement of the panel, P, inside the painting station 2, said winding/unwinding roller 52 then winds the clean paper 61. The tensioning roller 54 is gradually arranged towards said rest position, thus making the clean paper 61 wind, as said above, from said winding/unwinding roller 52 thus making available sufficient clean paper to house the whole panel P (or the load of panels P) inside the painting station 2.

[0086] The roller 51 is stationary and dirty paper 62 is thus not carried out, preventing the risks of breaking it.

[0087] Referring now to figure 3C, the anthropomorphic robot 24, positioned inside the painting station 2, completes the painting cycle. The panel P or the panels P arranged inside the painting station 2 are painted while they are still inside the painting station 2.

[0088] Both said winding roller 51 and said winding/unwinding roller 52 are stationary, while the tensioning roller 54 is arranged in a rest position.

[0089] With reference to the figure 3D, the panel P or the load of panels P is moved along the direction of the arrow R by means of the dragging rollers 53, thus coming out from the painting station 2 by arranging itself on the main conveyor 3.

[0090] The winding/unwinding roller 52 unwinds clean paper 61, while the winding roller 51 winds the dirty paper 62.

[0091] The tensioning roller 54 is in its rest position, but it can then advance so as to recover clean paper 61, to be unwound from said winding/unwinding roller 52, to prevent winding and then unwinding dirty paper 62.

[0092] With reference now to the figure 3E, it can be observed that the tensioning roller 54 is moved from said rest position towards said operating position, so as to ensure sufficient clean paper 61 below the main conveyor 3, such as to allow the painting cycle to be performed again, i.e. to arrange sufficient clean paper 61 to be placed under panel P or panels P to be painted without unloading the dirty paper 62.

[0093] As far as the dragging system is concerned, said winding/unwinding roller 52 unwinds clean paper 61 and said winding roller 51 is stationary.

[0094] The operator U or an automatic loading and unloading system removes the panel P or the panels P painted from the main roller table and replaces them with new panels P to be painted.

[0095] With reference now to figures 4A-4E, a third embodiment of the painting machine 1 and relevant operating method can be observed, which also in this case is managed by a computer program processed by said logic control unit 7.

[0096] In the case at issue, a reciprocating spraying arm 23 is provided inside the painting station 2.

[0097] Furthermore, the winding/unwinding roller 52 is arranged in correspondence of the main conveyor 3.

[0098] With reference to figure 4A, the operator U or an automatic loading system positions the panel P or the load of panels P on the main conveyor 3 of the device 1.

[0099] Said winding roller 51 and said second winding/unwinding roller 52 are stationary. The tensioning roller 54 is in rest position and the dirty paper 62 is arranged on said support base. The separation line 63, which separates the clean paper 61 from the dirty paper 62, is substantially in correspondence with said outlet opening 212.

[0100] With reference now to figure 4B, it can be observed that the panel P (or the load of panels P) advances by means of the dragging rollers 53, entering a painting station 2 resting on clean paper 61, which comes from the winding/unwinding roller 52.

[0101] In this case, the spraying arm is active, so that the panel P is painted.

[0102] Therefore, the winding/unwinding roller 52 unwraps clean paper 61, while the winding roller 51 wraps dirty paper 62.

[0103] The tensioning roller 54 is in the rest position, to be extracted subsequently, so as to prevent winding dirty paper 62, which would otherwise subsequently be necessary to unwound.

[0104] Referring now to figure 4C, the tensioning roller 54, moving into the operating position, has allowed the maintenance under the auxiliary conveyor 4 of a length of dirty paper 62 sufficient to cover the transport of the station during the return of the piece (see figure 4E), without having to unwind dirty paper 62 and avoid wasting clean paper 61.

[0105] The panel P has come out painted on the auxiliary conveyor 4, while the winding/unwinding roller 52 unwinds clean paper 61 to allow the advancement of the panel P.

[0106] With reference to figure 4D, the tensioning roller 54 has been further extracted, thus recovering sufficient clean paper 61 under the auxiliary conveyor 4, such as to allow the execution of a new cycle without ever unwinding dirty paper 62 on said winding roller 51.

[0107] The panel P thus returns following the direction R, re-entering the painting station 2 obviously resting on clean paper 61.

[0108] Said winding/unwinding roller 52 winds clean paper 61 while said winding roller 51 is stationary. The tensioning roller 54 is gradually retracted, so that the dirty paper is not carried out by said winding roller 51.

[0109] At this point, referring to figure 4E, panel P comes out by positioning itself on the main conveyor 3. Said winding/unwinding roller 52 winds the clean paper 61.

[0110] The tensioning roller 54 is retracted, making available a sufficient length of dirty paper 62 to cover the entire support base 22 inside said painting station 2 before the entrance of a new panel P to be painted. This avoids wasting clean paper 61.

[0111] The winding roller 51 is stationary, so that dirty paper 62 is not wound.

[0112] The operator U or the automatic loading and unloading system removes the painted panel P (or the painted panels P) from the main conveyor 3 and replaces them with new panels P to be painted.

[0113] An advantage of the present invention is that of avoiding unwinding the roller, on which the dirty paper is wound.

[0114] Another advantage of the present invention is that it allows a saving of paper for painting operations.

[0115] A further advantage of the present invention is also that of operating both with reciprocator spray arms and with robotic arms.

[0116] The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. Machine (1) for the treatment, such as painting, of workpieces (P), such as panels (P), made of wood, plastic, fiberglass, glass, metal and the like, comprising
means for the treatment (23, 24) of at least one of said workpieces (P) to be treated, and
a dragging system (5), for dragging a paper band (6), wherein the dragging system (5) comprises a winding roller (51) and a winding/unwinding roller (52),
wherein said machine (1) is characterized
in that the winding roller (51) wind the dirty paper (62), which has been dirtied by the treatment of at least one workpiece (P) by means of said treatment means (23, 24),
in that said winding/unwinding roller (52) wind or unwind the clean paper (61), wherein the clean paper (61) is intended to support at least one workpiece (P) to be treated by means of said treatment means (23, 24) and to absorb or collect the waste of the treatment of said treatment means (23, 24), becoming dirty paper (62), and
in that said machine (1) includes return movable means (54), movable from a rest position to an operating position,

wherein said return movable means (54) pass from said rest position to said operating position to change the path of the paper (6) unwound or wound by said winding/unwinding roller (52) for a section sufficient to support said at least one workpiece (P) without unwinding the dirty paper (62), and

wherein said return movable means (54) pass from said operating position to said rest position to provide clean paper (61) to support said at least one workpiece (P), which is wound by said winding/unwinding roller (52), without unwinding said dirty paper (62).

2. Machine (1) according to the preceding claim, characterized in that said return movable means (54) comprise a tensioning roller (54).

3. Machine (1) according to any one of the preceding claims, characterized in that it comprises a main conveyor (3) for loading and removing at least one of the said workpieces (P) to be treated or painted.

4. Machine (1) according to the preceding claim, characterized in that said winding roller (51) is arranged in correspondence of said main conveyor (3).

5. Machine (1) according to any one of the preceding claims, characterized in that it comprises a painting station (2), having a support base (22), on which the workpiece (P) to be painted is placed during the treatment, and an inlet opening (211) for the introduction of said workpiece (P) to be painted in said painting station (2), wherein said main conveyor (3) is placed in correspondence of said inlet opening (211).

6. Machine (1) according to the preceding claim, characterized in that said dragging system (5) comprises a dragging belt (55), arranged within said painting station (2) substantially in correspondence of said support base (22), wherein the paper (6) rests and is dragged during the advancement, for supporting the workpiece (P) to be painted.

7. Machine (1) according to any one of the preceding claims, characterized in that said treatment means comprise a painting robot (24) of anthropomorphic, Cartesian and similar type.

8. Machine (1) according to any one of the preceding claims, characterized in that it comprises an auxiliary conveyor (4), to support said workpiece (P) to allow the variation of said path of the paper (6) unwound or wound by said winding/unwinding roller (52), and in that said painting station (2) has an outlet opening (212), wherein said auxiliary conveyor (4) is arranged in correspondence of said outlet opening (212).

9. Machine (1) according to the preceding claim, characterized in that the said winding/unwinding roller (52) is arranged in correspondence of said auxiliary conveyor (4).

10. Machine (1) according to any one of the preceding claims, characterized in that said treatment means comprise a reciprocating spraying arm (23).

11. Machine (1) according to any one of claims 8-10, when not dependent on claims 4 and 9, characterized in that said winding roller (51) is arranged in correspondence of said auxiliary conveyor (4) and said winding/unwinding roller (52) is arranged in correspondence of said main conveyor (3).

12. Machine (1) according to any one of the preceding claims, characterized in that it comprises a logic control unit (7) for the operating coordination of said machine (1).

13. Method of treating at least one workpiece (P), such as a panel (P) made of wood, plastic, fiberglass, rubber and the like, wherein a paper band (6) is used to transport said at least one workpiece (P), comprising the following steps:

A. positioning said workpiece (P) to be treated on clean paper (61), wherein said clean paper (61) is intended to support said at least one workpiece (P) to be treated and to absorb or collect the treatment wastes, wherein the path of the clean paper (61) is varied for a section sufficient to support said at least one workpiece (P) without unwinding dirty paper (62);

B. treating said at least one workpiece (P) on a support base (22); and

C. extracting said workpiece (P) to be treated, wherein the clean paper (61) to support at least one workpiece (P) to be treated in a subsequent treatment cycle is fed or re-wound without unwinding the dirty paper (62), dirtied during one treatment cycle of said at least one workpiece (P).

14. Method according to the preceding claim, characterized in that said step A comprises the following substeps:

A1. winding said clean paper (61); and

A2. gradually reducing the path of said clean paper (61).

15. Method according to the preceding claim, characterized in that said steps A1 and A2 said clean paper (61) is wound for a section equal to at least the length of said at least one workpiece to be treated and of the support base (22).

16. Method according to any one of the claims 13-15, characterized in that said step C comprises the following substeps:

C1. unwinding said clean paper (61);

C2. winding up said dirty paper (62); and

C3. gradually increasing the path of said paper (6).

17. Method according to the preceding claim, characterized in that in said step C1 and C3 said clean paper (61) is unwound for a section equal to at least the length of said at least one workpiece to be treated and of the support base (22).

18. Method according to claim 13, characterized in that said step A comprises the following substeps:

A3. unwinding said clean paper (61); and

A4. gradually increasing of the path of said paper (6); and

A5. wrapping said dirty paper (62).

19. Method according to the preceding claim, characterized in that in said steps A3 and A4 said clean paper (61) is unwound for a section equal to at least the length of said at least one workpiece to be treated and of the supporting base (22).

20. Method according to any one of claims 18 or 19, characterized in that said step C comprises the following substeps:

C4. wrapping said clean paper (61); and

C5. gradually reducing the path of said paper (6).

21. Method according to the preceding claim, characterized in that in said steps C4 and C5 said clean paper (61) is wound for a section equal to at least the length of said at least one workpiece to be treated and of the support base (22).

22. Method according to any one of claims 13-21, characterized in that said step B comprises the painting of said piece (P).

23. Method according to any one of claims 13-22, characterized in that it provides for at least one winding roller (51), for winding said dirty paper (62), at least one winding/unwinding roller (52) for unwinding and rewinding said clean paper (61), and return movable means (54), such as a return roller (54), movable from a rest position to an operating position and vice-versa.

24. Computer program including instructions which, when the program is executed by a computer, cause the computer to execute the steps and the respective substeps A, B and/or C of the method according to any one of claims 13-23.

25. Computer-readable storage medium containing instructions which, when executed by a computer, cause the computer to execute the method steps according to any one of claims 13-23.

Drawing