AN INDUSTRIAL PLANT FOR HEAT TREATMENT OF PIECES

Description

[0001] The scope of the invention relates to the field of heat treatment of pieces, and in particular but not limited to industrial furnaces for polymerizing liquid or dust paints, applied to extruded pieces or metal profiles, and with a pre-treatment tunnel in order to prepare the extruded pieces or metal profile to a painting process with dusts or liquids.

[0002] At the present state of the technical and technological knowledge, the liquid and dust paints applied on metal surfaces just after their application must be submitted to a cooking or polymerizing phase, which can be actuated by keeping the painted artefacts in a suitable furnace, maintained for a certain time at a given temperature. The time and temperature are depending on the characteristics of the applied paints.

[0003] For example only, in order to polymerize the dust paints applied on certain extruded bars of aluminium alloy, a constant and uniform temperature in a furnace at 195°-200° C for a time of 25-30 minutes is needed.

[0004] The used furnaces can be either "static" or "continuous". In the static furnace, the painted pieces are introduced and closed by means of simple sliding doors or shutter doors. Such types of furnaces are suitable for batch artefacts, are simple and do not have functional problems.

[0005] The "continuous" furnaces are on the other hand characterized in that the pieces are continuously moving, as they enter in the furnace proceeding inside it and exit without interruptions. They are suitable for a continuous production of industrial kind, with high productivity results but with power energy consumption and serious defects that negatively affect the quality of the finished products. Therefore the need exists of eliminating the serious defects until now unsolved of the "continuous" industrial furnaces, in particular of the furnaces suitable for the polymerization of the dust paints applied on the extruded bars of aluminium alloy. In painting plants of the bars painted in vertical, in order to reach maximum results in productivity a continuous movement is required, by means of an air conveyor on which the pieces are hanged in vertical, in a consecutive way and with the least affordable pitch, according to the sizes of the produced pieces.

[0006] Once having ended the painting, the conveyor loaded with hanged pieces enters in the polymerization furnace and follows a longitudinal path corresponding with the time needed by the polymerization, and then exits and proceeds towards the discharge at the end of the process.

[0007] Internally, the continuous furnaces must have a free height able to contain the air conveyor, the hanging hooks, the hangers, the pieces in vertical with a suitable lower safety margin. Normally, their internal height is equal approximately to 9-10 m or more.

[0008] The continuous proceeding of the air conveyor, and also the minimum hanging pitch of the pieces which do not permit any kind of static closure of the inlet and outlet ports, and this physical limitation cause two serious not yet solved defects, i.e. the continuous heat losses and the harmful oscillations of the pieces entering and exiting the furnace.

[0009] Concerning the continuous heat losses, they are caused by the relevant but necessary difference of the air temperature between the inside of the furnace (195°-200°C) and the outside (ambient). This difference inevitably generates the known "chimney effect" consisting in the natural entry of a great quantity of ambient air (therefore at a low temperature) from the lower part of the port and the contemporary natural exit of the same quantity of hot air from the upper part of the port.

[0010] Fig. 1 represents the phenomenon with an empiric graph in which 1 indicates the entry threshold, and 2 indicates the inner room of the furnace. It is known that the air speed and therefore its entry flow rate is maximum in the lower portion 3, and they practically go to zero at a half height of the port 4, whereas at the same time the exit air speed is maximum in the upper portion 5. It is also known that the thermal energy losses from the open ports represent the highest percentage of the global power balance of the lost energy in the continuous furnaces.

[0011] At the present state of the art, a more efficient system as other possible is applied, the so called "air curtain", in any case able to limit very partially the output of hot air. Such system requires the expensive creation of one or more forced aeration tunnels, realized through the further application of one or more fans, capable to generate a continuous vertical movement of air, with a rather rapid speed, with the scope of blocking the output of hot air as in the case of the entrances of some supermarkets, airports, etc. On the other hand, such system requires the occupation of a certain layout area, a greater investment and also a further request for electric energy for the actuation of the fans.

[0012] For a better clarity and as an example, Fig. 2 represents in section the actuation layout of the known system.

[0013] The fans 6 suck air in the upper portion from suitable tunnels 7 and 8, open in the inlet and outlet ports and which force the same air for being vertically conveyed upwards (arrows 9). Today neither less expensive, nor more efficient systems exist of the "air curtain" for limiting the losses from the open ports for which they are greatly used.

[0014] Concerning the resulting harmful oscillations of the inlet and outlet pieces from the furnace, they are directly due to the directions and ways (5 and 3 in fig. 1) of the air moving in the inlet and outlet tunnels. Such directions with mutually opposed ways are useful to trigger longitudinal oscillations, in many cases disturbed by the vertical movement of the forced air of the "air curtain". Finally, the various natural or forced air flows are absolutely not controllable, are varying in time and also depend from the weight and the geometric form of the pieces.

[0015] These fluctuating oscillations create a first quality damage as the pieces just painted often hit other contiguous pieces, until sometimes being mutually glued because of the fresh and not yet polymerized paint. It is clear that a relevant damage derives from the needs of the final selection and the consequent disposal of the waste. Furthermore the air movement of the forced ventilation, before the polymerization occurs, sometimes is able to detach surface particles of paint in the fresh dust, these particles being directed from the air itself and inevitably falling on the surface of other batches, painted with a different colour, so contaminating the same and subjecting them to a final quality waste.

[0016] An empirical device, oriented to avoid the hitting of the pieces hanging in vertical, is known and normally applied. It concerns the manual application of rigid, semirigid or flexible connections among contiguous pieces, so avoiding that each piece freely and disorderly oscillates until hitting against other ones near to it.

[0017] Fig.3 represents one among different and similar systems, nowadays adopted.

[0018] The pressing pinches 10, before the entry of the pieces in the furnace, are applied in the lower part of each piece in movement and being integral with a small chain 11, which connects the pieces in chain one with the other and does not permit great oscillations, in any case such to reach a mutual hitting.

[0019] The defect is therefore only partially avoided, as the lower end parts of the painted pieces are all inevitably damaged by the pinches so that such parts must be cut and disposed of in the final operation in 12 parts.

[0020] The application of any connection system generates a second negative drawback, referred to the need of a stable use of the pinches 10, by one or two persons in the applicative operations at the entry, and of the removal operations at the exit from the furnace. The pinches in turn must be frequently disposed of, as they smear with paint or break when they are detached from the piece with which they are frequently connected by gluing with the polymerized paint.

[0021] Problems similar to those mentioned for a traditional polymerization furnace occur in a traditional pre-treatment tunnel, placed upwards of the polymerization furnace, and able to prepare the extruded or metal profiles in the painting process with dusts or liquid.

[0022] In particular the pre-treatment is realized with a liquid detergent generally heated at a temperature of 50/55°C, at which it partially evaporates.

[0023] The hot steam creates with a chimney effect a movement of hot, wet and ascending air exiting from the tunnel, through the upper portion of its inlet and outlet ports and at the same time it determines a return of cold air inside the tunnel through the lower portion of its inlet and outlet ports.

[0024] This results in a greater energy consumption for heating the pre-treatment liquid which must be kept at the desired temperature.

[0025] Document DE 963 696 discloses an industrial plant for the heat treatment of pieces having one main overhead transport line for the pieces, one inlet and one outlet, further comprising dynamic closing means for said inlet and outlet, and synchronizing means for synchronizing the dynamic closing means with said main transport line.

[0026] The technical scope of the present invention is to realize an industrial plant for hot treatment of pieces, able to avoid the drawbacks lamented in the known art. Within this technical scope, an aim of the invention is to provide an industrial plant for hot treatment of pieces, able to permit a strong reduction of the heat losses and consequently a relevant energy saving.

[0027] Another aim of the invention is to provide an industrial plant for hot treatment of pieces, able to avoid the harmful oscillations of the pieces at the entry and exit from the plant.

[0028] These and other aims are obtained, according to the invention, with an industrial plant for the hot treatment of pieces according to claim 1.

[0029] Preferably, the permanent dynamic closing means comprise, for each port, at least one rotary means positioned at the inside of two lateral walls, with a cylindrical shape of the port.

[0030] Preferably the synchronization means comprise, for each rotary means, a direct mechanic transmission with the transport line to which it is associated.

[0031] The scope of the finding consists in the invention of a new, double separation system of the pieces hanged on two different conveyor lines with the same direction, with the main scope to realize, when the ports are dynamically closed, the passage from the inlet and outlet ports to small alternate groups of the same size, in any case able to be suitably housed in the hollow spaces of a suitable rotary means, with an automatic synchronism with the speed of the air conveyors. These new features of the system permit to obtain the same results of containing the losses and eliminating the harmful oscillations, also in any plant which functions with a snap system (i.e. step by step) and not due to the fact that the rotary means closure of the plant is always guaranteed for any stopping position of the air conveyor. Prefered embodiments are defined in the dependent claims.

[0032] The present invention is shown with reference to its preferred and exemplary but not limitative embodiment of the more general concept, with reference to the annexed figures in which:

Figures 1, 2 and 3 above described refer as already said, to solutions concerning the known state of the art.

Figure 4 shows a top view of the furnace, according to a preferred way of realization of invention, with the length of the primary and secondary transport lines highlighted;

Figure 5 shows an enlarged detail in Figure 4;

Figure 6 shows the structure of a rotary means of the furnace in Figure 4;

Figure 7 shows a port, provided with the rotary means in Figure 6, and Figure 8 shows a detail of Figure 7.

[0033] With reference to the shown Figures, an exemplary path or double separation of the pieces 41 is shown, with a relative passage through the rotary means with a continuous water tightness. The main air conveyor 13 coming from the painting (arrow 14) moves loaded with painted pieces, hanged one after the other. The minimum hanging pitch is useful for the productivity effects as already said, and in any case it would not permit to introduce suitable hollow spaces of the rotary means without interfering with its blades.

[0034] The exchange station 15, already known due to the fact that it is today used also for other actuation needs of the painting plants, provides for an "air" transfer alternatively of one piece or one group of two or more pieces at the same time, coming from the main line 13 to the secondary line 16. When the exchange has already occurred, downwards of the station 15, the main line 13 and the secondary line 16 are loaded in the same way with alternate groups 40 of pieces 41, with the main result that therefore in both lines the groups 40 of pieces 41 are spaced, leaving both the same hollow length 17 absolutely necessary for the correct housing of the same groups 40 in the spaces 19 of successive rotary means 18.

[0035] The hollow spaces 19 among the blades 20 of the rotary means are placed in such a way, that in any of their angular positions, the blades keep the port always closed, avoiding the continuous entry of cold air and the contemporary exit of hot air.

[0036] The exchange station 21 permits to reconstruct in the main line 13 the pieces 41 or the groups 40 of pieces 41 which continue their movement, consecutively aligned again inside the furnace (arrow 24).

[0037] The actuation of the outlet system of the furnace (arrow 25) can be easily understood between the exchange stations 22 and 23, as it is completely similar to the inlet one which was described above.

[0038] This new system eliminates the "chimney effect" phenomenon, even if a small loss of heat remains as, each time a group of pieces passes, a hollow space of the rotary means slowly draws towards the outlet an equal volume of hot air, whereas its opposed hollow space draws in the inside an equal volume of ambient air.

[0039] For this reason it is necessary to precise that in any case a certain volume of hot air, impregnated with binders of with moving particles of paint must be expelled from the inside of the furnace, so that the hot air losses from the hollow spaces of the rotary means can be advantageously partly or completely substituted, the losses derived from chimneys with natural or forced suction being normally provided in the polymerization furnaces.

[0040] The wall 26 in Fig. 7 acts as separation between the inside of the hot furnace and the outer space. This wall is provided with an inlet (or outlet) port formed by two lateral cylinder-shaped walls 27 realized for the dynamic, permanent closure of the port.

[0041] At the inside of such walls the rotary means 18 is placed, which is shown in detail in Fig. 6. It is formed, in its entirety, by an internal cylinder 28 with three or more blades 20, provided with gaskets 30 apt to be airtight in the dynamic sliding direction on the walls 27.

[0042] The rotary means has its own axis 31 housed at the top and bottom in suitable supports which permit to the same a correct rotation.

[0043] In the upper part, the rotary means is integral with a toothed wheel 32. The air conveyor, here shown for clarity reasons without hanged pieces, is provided with appendices or hooks 34 placed with a constant pitch and necessarily provided on the hanging chain for the translation of pieces.

[0044] Such appendices or hooks 34 engage with suitable means in the hollow spaces of the toothed wheel 32, and pull the same in a slow rotation. The toothed wheel directly engaged in the appendices or hooks 34 of the air conveyor is the simple and known working use of the "rack drive". This simple solution of direct drive permits to obtain the automatic rotation of the rotary means with an absolute mechanic synchronism at the conveyor speed. If the speed of the overhead conveyor varies for any need, the one of the rotary means engaged with the same varies in synchronism. All without neither the use of particular extra transmissions nor of mechanical pneumatic, hydraulic, electrical, electronic and computer equipments, in any case of a relatively simple realization, which would however represent possible variables, which are non-substitute or alternative to the main inventive concept of the above described and illustrated method.

[0045] The description and the drawings have the value of purely indicative examples with the aim to make the original and novel concepts of the finding understood, which finally consist in the invention of a system able to create loaded lengths alternated with empty lengths of pieces on the overhead conveyor, in order to make physically possible the passage of the same from the outside to the inside of a furnace and vice versa through rotary means put in synchronic rotation with the characteristics of the movement of the overhead conveyor, whereas the portal of the furnace remains closed for any angular position assumed by the rotary means.

[0046] The forming of the groups of pieces, the quantity and position of the rotary means, the number of blades, the paths of the conveyor, the shape and position of the exchange stations, etc. lend themselves to endless constructive variations in relation to the various placing needs in the layout of the plants and in relation to the various solutions chosen for the realization of the continuous or stepped furnaces, without prejudice to the original and novel inventive concept of the present finding, as defined in the claims.

[0047] The overall finding realizes following important industrial results:

• dramatic reduction of the heat losses from the furnace with consequent lesser energy consumptions,
  • reduction of the post-combustion emissions,
  • elimination of the harmful oscillations of the painted pieces,
  • constancy of the quality of production,
• reduction of the passive energy costs in relation to the elimination of the today adopted systems for containing the losses based on the application of fans used for producing the "air curtain,"
• elimination of the further manpower costs dedicated to the application of the means impeding the hitting of the pieces, and
• elimination of the costs inherent to the selection and disposal of the working scraps.

[0048] What was said and illustrated with reference to a polymerization furnace can also be applied in the case in which the plant is made by a pre-treating tunnel for preparing metal extruded or profiled parts for a dust or liquid painting process.

[0049] So in particular the production line continues providing both a pre-treatment tunnel according to the invention and a polymerization furnace according to the invention, the advantages obtained with them being still more evident.

Claims

1. An industrial plant for the heat treatment of pieces (41) having a main overhead transport line (13) for the pieces (41), at least one inlet port for the pieces and at least one outlet port for the pieces, comprising a secondary line (16) for the transport of pieces, distribution means (15, 21, 22, 23) for the inlet and outlet pieces between the main transport line (13) and the secondary transport line (16) in order to automatically form hollow lengths (17) alternately on the main and second transport lines (13, 16), permanent dynamic closing means (18-20) of said at least one inlet port and said at least one outlet port, and synchronizing means for synchronizing the movement of the dynamic closing means with the movement of said main transport line (13) and of said secondary transport line (16), said alternate hollow spaces (17) being functional for the passage of pieces (41) through said at least one inlet port and through said at least one outlet port, without interference with said dynamic closing means.

2. The industrial plant according to the preceding claim, characterized in that said permanent dynamic closing means comprise, for each port, at least one rotary means (18) positioned at the inside of two cylinder-shaped side walls (27) of the port.

3. The industrial plant according the preceding claim, characterized in that said rotary means (18) has an inner cylinder (28), coaxial with respect to said two cylinder-shaped side walls (27) of the port, and at least three blades (20) angularly equidistant and radially protruding from said inner cylinder (28).

4. The industrial plant according to the preceding claim, characterized in that said blades (20) are provided with gaskets (30) for air-sealing during dynamic rotation by creeping on said two cylinder-shaped side walls (27) of the port.

5. The industrial plant according to claims 2 and 3, characterized in that said synchronizing means comprise, for each rotary means (13), a mechanical transmission directed to the transport line (13, 16) to which it is associated.

6. The industrial plant according to the preceding claim, characterized in that said mechanical transmission comprises a toothed wheel (32) flush with the rotary means (18) and engaged in suitable hooks (34) of the transport line (13, 16) provided with the hanging and translation of the pieces (41).

7. The industrial plant according to one or more preceding claims, characterized in that the primary and secondary transport lines (13, 16) have means for a continuous movement.

8. The industrial plant according to one or more preceding claims characterized in that the primary and secondary transport lines (13, 16) have means for a step-by-step movement.

9. The industrial plant according to one or more preceding claims, characterized in that the primary and secondary transport lines (13, 16) have means for a constant hanging step of the pieces.

10. The industrial plant according to one or more preceding claims, characterized in that the primary and secondary transport lines (13, 16) have a correspondent advancement direction.

11. The industrial plant according to claims 2 and 3 characterized in that said distribution means of the inlet and outlet pieces between the main transport line (13) and the secondary line (16) are so configurated to automatically create on the primary and secondary transport line (13, 16) said hollow lengths (17) being alternated with the same consistence, and full lengths (40) being alternated with the same consistence, the consistence of the alternated full (40) and hollow lengths being so chosen that the pieces (41) of the full lengths (40) can be simultaneously housed in any of the spaces (19) among the blades (20) of the rotary means (18).

12. The industrial plant according to one or more preceding claims, characterized in that it consists of a polymerization plant of the paint applied to metal extruded or profiled parts.

13. The industrial plant according to one ore more preceding claims, characterized in that it consists of a pre-treatment tunnel preparing metal extruded or profiled parts in a dust or liquid painting process.

Ansprüche

1. Industrieanlage zur Wärmebehandlung von Teilen (41), aufweisend ein Haupthängefördersystem (13) für die Teile (41), mindestens eine Einlauföffnung für die Teile und mindestens eine Auslauföffnung für die Teile, umfassend ein Hilfssystem (16) für die Beförderung von Teilen, Verteilmittel (15, 21, 22, 23) für die Ein- und Auslassteile zwischen dem Hauptfördersystem (13) und dem Hilfsfördersystem (16), um automatisch hohle Längen (17) alternativ auf dem Haupt- und dem Hilfsfördersystem (13, 16) zu bilden, permanente dynamische Verschließmittel (18-20) der mindestens einen Einlassöffnung und der mindestens einen Auslassöffnung sowie Synchronisiermittel zum Synchronisieren der Bewegung der dynamischen Verschließmittel mit der Bewegung des Hauptfördersystems (13) und des Hilfsfördersystems (16), wobei die abwechselnden Hohlräume (17) für das Durchlaufen von Teilen (41) durch die mindestens eine Einlassöffnung und die mindestens eine Auslassöffnung dienen, ohne mit den dynamischen Verschließmitteln zu interferieren.

2. Industrieanlage nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass die permanenten Verschließmittel für jede Öffnung mindestens ein Rotationsmittel (18) umfassen, das an der Innenseite zweier zylinderförmiger Seitenwände (27) der Öffnung positioniert ist.

3. Industrieanlage nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass das Rotationsmittel (18) einen internen Zylinder (28) aufweist, der koaxial zu den zwei zylinderförmigen Seitenwänden (27) der Öffnung angeordnet ist, sowie mindestens drei Messer (20), die winkelig gleichabständig sind und radial aus dem internen Zylinder (28) hervorstehen.

4. Industrieanlage nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass die Messer (20) mit Dichtungen (30) für die Luftabdichtung während der dynamischen Drehung durch Anlegen an die zwei zylinderförmigen Seitenwände (27) der Öffnung versehen sind.

5. Industrieanlage nach Anspruch 2 und 3, dadurch gekennzeichnet, dass die Synchronisiermittel für jedes Rotationsmittel (18) einen mechanischen Antrieb umfassen, der zum Fördersystem (13, 16), mit dem er verbunden ist, gerichtet ist.

6. Industrieanlage nach dem vorhergehenden Anspruch, dadurch gekennzeichnet, dass der mechanische Antrieb ein Zahnrad (32) umfasst, auf gleicher Ebene mit dem Rotationsmittel (18) und im Eingriff in geeignete Haken (34) des Fördersystems (13, 16), versehen mit dem Hängen und Verschieben der Teile (41).

7. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Haupt- und das Hilfsfördersystem (13, 16) Mittel für eine Dauerbewegung aufweisen.

8. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Haupt- und das Hilfsfördersystem (13, 16) Mittel für eine Schrittbewegung aufweisen.

9. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Haupt- und das Hilfsfördersystem (13, 16) Mittel für einen kontinuierlichen Schritt zum Aufhängen der Teile umfassen.

10. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Haupt- und das Hilfsfördersystem (13, 16) eine entsprechende Vorschubrichtung aufweisen.

11. Industrieanlage nach Anspruch 2 und 3, dadurch gekennzeichnet, dass die Verteilmittel der Ein- und Auslassteile zwischen dem Hauptfördersystem (13) und dem Hilfssystem (16) so ausgelegt sind, dass sie auf dem Haupt- und dem Hilfsfördersystem (13, 16) automatisch zwei hohle Längen (17) erzeugen, die mit derselben Folgerichtigkeit abgewechselt werden, sowie volle Längen (40), die mit derselben Folgerichtigkeit abgewechselt werden, wobei die Folgerichtigkeit der abgewechselten vollen (40) und hohlen Längen so gewählt wird, dass die Teile (41) mit vollen Längen (40) gleichzeitig in irgendeinem Raum (19) zwischen den Messern (20) des Rotationsmittels (18) untergebracht werden können.

12. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass sie aus einer Polymerisationsanlage des Lacks besteht, der an stranggepressten Teilen oder Profilteilen aus Metall angebracht wird.

13. Industrieanlage nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass sie aus einem Vorbehandlungstunnel zum Vorbereiten von stranggepressten Teilen oder Profilteilen aus Metall in einem Pulver- oder Flüssiglackierverfahren besteht.

Revendications

1. Etablissement industriel pour le traitement thermique de pièces (41) ayant une courroie transporteuse aérienne principale (13) destinée aux pièces (41), au moins un orifice d'admission des pièces et au moins un orifice de sortie des pièces, comprenant une courroie secondaire (16) destinée au transport des pièces, des moyens de distribution (15, 21, 22, 23) de pièces en entrée et en sortie entre la courroie transporteuse principale (13) et la courroie transporteuse secondaire (16) afin de former automatiquement des longueurs vides (17) alternativement sur les courroies transporteuses principale et secondaire (13, 16), des moyens de fermeture dynamiques (18-20) dudit au moins un orifice d'admission et dudit au moins un orifice de sortie, ainsi que des moyens de synchronisation servant à synchroniser le mouvement des moyens de fermeture dynamiques à celui de ladite courroie transporteuse principale (13) et de ladite courroie transporteuse secondaire (16), lesdits espaces vides alternés (17) servant au passage des pièces (41) à travers ledit au moins un orifice d'admission et à travers ledit au moins un orifice de sortie, sans interférer avec les moyens de fermeture dynamiques.

2. Etablissement industriel selon la revendication précédente, caractérisé en ce que lesdits moyens de fermeture dynamiques comprennent, pour chaque orifice, au moins un moyen de rotation (18) positionné à l'intérieur de deux cloisons latérales, en forme de cylindre (27), de l'orifice.

3. Etablissement industriel selon la revendication précédente, caractérisé en ce que ledit moyen de rotation (18) possède un cylindre interne (28), coaxial par rapport auxdites deux cloisons latérales, en forme de cylindre (27), de l'orifice et au moins trois lames (20) équidistantes angulairement et dépassant radialement dudit cylindre interne (28).

4. Etablissement industriel selon la revendication précédente, caractérisé en ce que lesdites lames (20) sont pourvues de joints d'étanchéité (30) à l'air lors de la rotation dynamique par fluage sur lesdites deux cloisons latérales, en forme de cylindre (27), de l'orifice.

5. Etablissement industriel selon les revendications 2 et 3, caractérisé en ce que les moyens de synchronisation comprennent, pour chaque moyen de rotation (18), une transmission mécanique dirigée vers la courroie transporteuse (13, 16) à laquelle elle est associée.

6. Etablissement industriel selon la revendication précédente, caractérisé en ce que ladite transmission mécanique comprend une roue dentée (32) alignée avec le moyen de rotation (18) et engagée dans des crochets (34) appropriés de la courroie transporteuse (13, 16) pourvue de la suspension et de la translation des pièces (41).

7. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que les courroies transporteuses principale et secondaire (13, 16) possèdent des moyens permettant un mouvement continu.

8. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que les courroies transporteuses principale et secondaire (13, 16) possèdent des moyens permettant un mouvement pas à pas.

9. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que les courroies transporteuses principale et secondaire (13, 16) possèdent des moyens permettant une étape de suspension permanente des pièces.

10. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que les courroies transporteuses principale et secondaire (13, 16) possèdent une direction de progression correspondante.

11. Etablissement industriel selon les revendications 2 et 3, caractérisé en ce que lesdits moyens de distribution des pièces en entrée et en sortie entre la courroie transporteuse principale (13) et la courroie transporteuse secondaire (16) sont configurés de telle manière à créer automatiquement sur les courroies transporteuses principale et secondaire (13, 16) desdites longueurs vides (17) étant alternées avec la même régularité, et des longueurs pleines (40) étant alternées avec la même régularité, la régularité des longueurs pleines (40) et des longueurs vides alternées étant choisie de telle manière que les pièces (41) des longueurs pleines (40) peuvent simultanément être logées dans l'un quelconque des espaces (19) parmi les lames (20) du moyen de rotation (18).

12. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce qu'il consiste en une installation de polymérisation de l'enduit appliqué aux pièces extrudées ou profilées en métal.

13. Etablissement industriel selon l'une ou plusieurs des revendications précédentes, caractérisé en ce qu'il consiste en un tunnel de prétraitement préparant des pièces extrudées ou profilées en métal dans un procédé de peinture liquide ou à la poussière.

Drawing