WO2018055241A1

WO2018055241A1 - A method for increasing a filling factor of a suspension member and/or installation frequency of suspension members of a transport line in an automatic painting line and an automatic painting line

Info

Publication number: WO2018055241A1
Application number: PCT/FI2017/050678
Authority: WO
Inventors: Jukka KIVISTÖ
Original assignee: Coating Tech Oy
Priority date: 2016-09-26
Filing date: 2017-09-26
Publication date: 2018-03-29

Abstract

The invention relates to a method for increasing the suspension-element-specific degree of filling (5) and/or the installation density of suspension elements (3) of a conveyor line (K; K1) on an automated painting line (1) which comprises a conveyor line (K; K1) equipped with a drive mechanism and having an adjustable conveying speed (v; v1), and a painting station (M) and a baking oven (U), through which the conveyor line (K; K1) runs. The method comprises at least the following steps: - assembling a group of articles (2) to be painted on a suspension element (3), said suspension element being suspended from a filling line (K; K2), the conveying speed (v; v2) of the filling line (K; K2) being adjustable irrespective of the conveying speed (v; v1) of the conveyor line; - conveying the suspension element (3), loaded with the group of articles (2) to be painted, along the filling line (K; K2) to the side of the transfer line (K; K1); - transferring the suspension element (3), loaded with the group of articles (2) to be painted, from the filing line (K; K2, 7) to the conveyor line (K; K1) via a filling station (6; 61 ) between the filling line (K; K2) and the conveyor line (K; K1), wherein the same vertical plane extends through the filling line (K; K2) and the conveyor line (K; K1); however, the filing line (K; K2) and the conveyor line (K; K1) being at least partly one above the other at said filling station (6; 61).

Description

A method for increasing the suspension-element-specific degree of filling and/or the density of installing suspension elements on a conveyor line of an automated painting line, and an automated painting line

The invention relates to a method according to the preamble of claim 1 for increas- ing the suspension-element-specific degree of filling and/or the installation density (number) of suspension elements on a conveyor line of an automated painting line.

The invention also relates to an automated painting line comprising a conveyor line equipped with a drive mechanism. Furthermore, the invention relates to a coupling element for transferring a suspension element from a filling line to a conveyor line of an automated painting line as defined in the claims.

Automated powder painting lines {i.e. so-called paint baking or powder coating lines) are normally endless painting lines by which articles to be painted, connected by suspension elements to a conveyor line connected to a ceiling or ceiling structures, are first conveyed to a washing machine and thereafter dried in a drying oven placed downstream of the washing machine. After the drying oven, the articles to be painted are conveyed by the conveying means of the conveyor line to a painting station for the actual coating with paint. The painted articles are introduced in a baking oven for baking, where the coat of paint is fixed on the surface of the articles by baking. For the time of the whole cycle described above, the articles to be painted or painted articles are fastened to a conveying backing in the form of a suspension element which is, in turn, suspended from said (overhead) conveyor. Depending on the size and shape of the articles, a variable number of articles to be painted may be loaded on one suspension element. The maximum number of articles to be painted per suspension element will depend, among other things, on the size of the machinery, particularly the size of the oven, but in a normal situation the maximum loading capacity is far from being in full use, and significantly fewer articles to be painted are loaded, and less densely, than would be possible. If the maximum capacity of a suspension element is represented by a given article-type-specific maximum degree of filling of the suspension element, less than 50% of the article-type-specific maximum degree of filling is in use under normal operation. The suspension-element-specific degree of filling is a measure of the extent of the area formed by a three-dimensional vertical plane extending through a given suspension element and the articles loaded on it, i.e. the assembling plane, and how much empty space is left on this assembling plane when said assembling plane is seen in a transverse direction from the front, i.e. from a direction perpendicular to the assembling plane.

A low suspension-element-specific degree of filling, and a too sparse suspension of the suspension elements per length unit of the conveyor line (conveyor), i.e. the low installation density of the suspension elements, have the following disadvantages which reduce the efficiency of e.g. the baking oven, the washer, the drying oven, and the painting station.

- Contrary to what is commonly believed, the quality of the paint coating is, on average, improved when the degree of filling of the suspension elements is increased. This is due, among other things, to facts relating to the quality of the paint and the circulation.

- The efficiency of the baking oven downstream of the painting, and the efficiency of the drying oven downstream of the washer will depend on the number of articles painted/to be painted can be fitted in the baking oven or drying oven, to be baked in a unit of time. - In washers upstream of the painting station, considerable amounts of washing liquid are used; if there are fewer articles to be washed per unit of time, the consumption of washing liquid per article to be washed is naturally increased, and the efficiency of the washer is decreased.

The efficiency of such an automated painting line, comprising the consumption of energy and washing liquid per article to be painted and passing through the conveyor line, as well as the article-specific quality of the paint coat are thus quite essentially dependent on how many articles to be painted can be loaded on each suspension element, and how densely the suspension elements can be installed on the conveyor, per unit in the travel direction of the conveyor. Figure 1 shows an example of an automated, endless and continuous paint baking line 1 , conventional as such, comprising a conveyor line K; K1 installed overhead or on ceiling structures, for conveying articles 2 suspended from it by a suspension element, via various steps and related machine tools; in this case, articles 32 are conveyed via a washer P, a drying oven D, a painting station M, a quality control station S, and a baking oven U. The velocities of the different sections of the conveyor line may be adjusted to some extent before each machine tool, but the average line velocity has to be maintained such that the baking oven and the painting station operate with as few interruptions as possible.

On such a paint baking line, first of all, it is very difficult to maintain a uniform high suspension-element-specific degree of filling, because articles to be painted can only be loaded on one suspension element at a given maximum constant filling rate depending on the line velocity, resulting in a given maximum standard degree of filling. This standard degree of filling is often merely 20 to 50% of the maximum assembling plane allowed by the suspension element, and of the maximum filling density allowed by said assembling plane for said article to be painted, and it is hardly helpful e.g. to increase the number of workers, because the assembling space around the suspension elements is limited. Secondly, such a paint baking line often results in a number of limitations to the density of installation of suspension elements on the conveyor line; for example in the paint baking line shown in Fig. 1 , the installation density may be limited by various fault situations of the conveyor, the steps and the machine tools, which is why the filling of the conveyor line with suspension elements has to be either stopped completely, or the suspension density of the conveyor line in the travel direction has to be made significantly lower.

A third very important drawback in paint baking lines of prior art relates to the non- ergonomic filling of the suspension elements: filling the suspension elements with articles to be painted is often heavy because it requires lifting the heavy suspension elements and the articles assembled on them onto the hooks of the conveyor line, or alternatively assembling the articles directly onto the suspension elements suspended on the hooks of the conveyor at a rate dictated by the speed of the conveyor. These drawbacks cannot be eliminated by filling the suspension elements outside the conveyor line, because the suspension elements would still have to be lifted onto the hooks of the conveyor line. In practice, using the latter method in painting lines of prior art will result in a significant decrease in the rate of filling the suspension elements and the line speeds, or incomplete filling of the machines. Based on the prior art described above, the primary aim of the invention was to provide a method and an apparatus for substantially increasing the suspension- element-specific degree of filling at a given average line speed of a painting line.

A second main aim of the invention was to provide a method and an automated painting line in which it is possible to increase the installation density of suspension elements on the conveyor line. A third main aim of the invention was to improve the ergonomics of filling the suspension elements, whereby the suspension elements loaded with the articles to be painted could be transferred onto the conveyor means of the conveyor line quickly but without heavy lifting operations.

Yet another aim of the invention was to provide a method and an apparatus for increasing the line speed of the conveyor line.

The above mentioned aims are achieved by the method according to claim 1 for increasing the suspension-element-specific degree of filling and/or the installation density of the suspension elements on the conveyor line of an automated painting line, as well as by the corresponding automated painting line according to claim 17.

To put it more precisely, the method according to the invention for increasing the suspension-element-specific degree of filling and/or the installation density of the suspension elements on the conveyor line of an automated painting line comprises a conveyor line equipped with a drive mechanism and having an adjustable conveying speed, and a painting station and a baking oven, via which the conveyor line runs. The method comprises at least the following steps:

- loading a number of articles to be painted, on a suspension element, said suspension element being arranged on a filling line or in a filling carriage, the conveying speed of the filling line or the conveying speed of the filling carriage being adjustable irrespective of the conveying speed of the conveyor line;

- conveying the suspension element, on which a number of articles to be painted are loaded, next to the conveyor line along a filling line, whereby the same vertical plane extends through the filling line and the conveyor line, or through the filling carriage and the conveyor line, but the filling line and the conveyor line, or the filling carriage and the conveyor line, being still on different horizontal levels at said filling station, at least on a length section of said filling station; and - transferring the suspension element, on which a number of articles to be painted are loaded, either a) from the filling line to the conveyor line via the filling station between the filling line and the conveyor line, by a coupling element of the filling line, the coupling element being constantly coupled to the filling line during the transfer from the filling line to the conveyor line, and the coupling element or the suspension elements suspended from it comes into contact with the conveyor line or the supports of the conveyor line during said transfer, or b) from the filling carriage to the conveyor line via the filling station between the filling carriage and the conveyor line, by a coupling elements of the filling carriage, the coupling elements being constantly coupled to the conveyor line during the transfer from the filling carriage to the conveyor line, and the coupling elements or the suspension elements suspended on it comes into contact with the conveyor line or the brackets of the conveyor line during said transfer, wherein The automated painting line according to the invention, in turn, comprises a conveyor line equipped with a drive mechanism, its travel speed and the speed of conveying suspension elements, depending directly on the travel speed, being adjustable, as well as a painting station and a baking oven, through which said conveyor line travels, wherein the painting line further comprises a filling line and a filling station placed between the filling line and said conveyor line in such a way that the same vertical plane extends via the filling line and said conveyor line at the filling station between them. However, the filling line and the conveyor line, or the support from which the suspension elements are suspended at their upper ends, are on different horizontal levels, at least partly one above the other over the length of said filling station, whereby suspension elements can be suspended from the filling line or its support, to be equipped with articles to be painted, the suspension elements with the articles to be painted being thereafter transferable by gravity onto the conveyor line by means of a coupling element of the filling line, via the filling station between the filling line and the conveyor line. The conveying speed of the suspension elements on the filling line is thus adjustable irrespective of the conveying speed of the suspension elements on the conveyor line, and the coupling element comprises an upper hanger which is constantly supported to the filling line during the transfer, and a lower hanger which touches the conveyor line or its bracket (K1 a) during the transfer when the suspension element (3) is transferred by gravity from the filling line (K; K2) to the conveyor line (K; K1 ) of the painting line.

In an advantageous embodiment of the invention, the upper hanger of the coupling element comprises rollers or sliding elements or the like, for supporting the cou- pling element when it is slid along the slide bar of the conveyor line. The lower hanger of the coupling element preferably comprises a hook-shaped element by which the suspension element can be coupled to the lower end of the coupling element.

The method according to the invention may also be applied in automated and semi-automated wet painting lines in addition to paint baking lines. On a wet painting line, the oven downstream of the painting station is a drying oven having a temperature considerably lower than the temperatures of a baking oven used for paint baking.

First of all, the invention is based on the fact that a higher suspension-element- specific degree of filling is achieved by loading the suspension elements on a separate filling line which is placed entirely outside the conveyor line and whose line speed is adjustable as desired with respect to the line speed (conveying speed) of the conveyor line. From the filling line, the suspension elements are brought directly to the conveyor line at a desired moment of time and at a desired speed.

Using such a separate filling line, the suspension-element-specific degree of filling is no longer determined fully by the average conveying speed of the conveyor line but by the ratio between the travel speed of the filling line and the travel speed of the conveyor line, wherein the conveying speed of the filling line may often be selected irrespective of the travel speed of the conveyor line, and it may be, for example, 0 m/min. In the same way, the suspension elements may also be removed from the conveyor line; the suspension elements on which the painted articles are loaded, are transferred to a discharge line whose line speed is often clearly lower than the speed of the conveyor line. After that, the painted articles may be taken off the suspension elements at one's own pace.

A high installation density on the conveyor line, in turn, is achieved because using a separate filling line makes it possible to fill suspension elements in advance, in case of breakdowns in the conveyor line or failures or interruptions in different steps. The installation density of the conveyor line refers to the number of suspension elements equipped with articles to be painted that can be fitted over a given length of the conveyor line.

Another very important aspect of the invention is the placement of the filling line and the conveyor line on different horizontal levels but on the same vertical plane at the filling station between them. Such a structure of the filling station provides a fluent and ergonomic transfer of the suspension elements from the filling line to the conveyor line by means of a coupling element according to the invention, which is supported or is constantly connected to one of the conveyor lines and is transferred by gravity from the filling line to the conveyor line. Such a method of transferring the suspension elements, equipped with the articles to be painted, by gravity provides the significant ergonomic advantage that there is no need to lift the heavy suspension elements equipped with the articles to be painted, from the filling line to the conveyor line, nor to apply mechanized carrier vehicles for the transfer.

Furthermore, the method of transfer by gravity provides the additional advantage that since the heavily loaded suspension elements no longer have to be lifted from the filling line to the conveyor line but they may be transferred by gravity by means of a coupling element according to the invention, the transfer may thus be implemented so that the suspension element is constantly supported to either the conveyor line or the filling line (or their brackets), whereby there is no longer any risk of falling of the suspension elements during the transfer.

In an advantageous embodiment of the invention, the suspension elements are suspended from the filling line or a conveyor of a filling carriage in such a way that the vertical line extending through them is perpendicular to their transfer direction on the filling line or the conveyor of the filling carriage.

By increasing the suspension-element-specific degree of filling and/or the installation density of the conveyor line in the above described way, the invention thus provides the significant advantage that it is possible to significantly increase the degree of utilization of the machines used in the steps of the painting line, such as the washing machine (washer), the drying oven, the baking oven, and the painting station, as well as the article-specific coverage of articles passing through the painting station, with paint. The step-specific degree of utilization of the machines is significantly increased by the method of the invention, because more articles to be painted can be loaded on the same suspension element, or more densely. Furthermore, line breaks of the conveyor line and step-specific failures can be compensated more efficiently by the invention.

In another preferred embodiment of the invention, the filling line is configured to be movable by connecting it to a movable filling carriage. By means of the filling car- riage, it is possible to further improve the ergonomics and the possibility to compensate for line breaks and step-specific failures. Instead of having to lift the articles to be painted onto suspension elements suspended from a fixed filling line, the articles to be painted may be first loaded on a filling carriage in a flexible way, and the whole filling carriage may then be transferred to a desired location next to the conveyor line.

In this context, the suspension-element-specific degree of filing refers to the same as was defined above; in other words, it measures the extent of the three- dimensional assembling plane of the suspension elements on one hand, and the amount of empty space on said three-dimensional assembling plane. In this context, the conveyor line refers to an overhead conveyor connected to ceiling structures or the ceiling, such as a guide bar, rail or the like, from which or from whose brackets the suspension elements can be suspended. The conveyor line may be equipped with mechanized carrying vehicles, or mechanized and partly manual carrying vehicles for conveying the suspension elements along the conveyor line.

The conveyor line is preferably continuous and endless, and it extends without interruption from one work station of the painting line to another, connecting all the steps and machine tools of the painting line to the same circulation connected by the conveyor line. The conveyor line comprises a guide bar, a rail, or the like. Alternatively, the conveyor line is a guide bar, a rail, or the like, to which a bracket for the conveyor line, extending underneath the conveyor line, is supported in a movable way. The engagement of the bracket to the conveyor rail or the like is preferably implemented by conveyor rollers. The coupling elements can be coupled or supported to the conveyor line, or more preferably to the brackets underneath the conveyor line, either directly or by means of suspension elements.

In this context, the filling line refers to a conveyor connected to the ceiling structures or to a filling carriage, such as a guide bar, a beam, or the like, from which the suspension elements for the articles to be painted can be suspended but from which conveyor line there is no direct connection of transferring the suspension elements to the conveyor line or its brackets. The filling line and the conveyor line run on different height levels, at least at the filling station between the conveyor line and the filling line. The filing line may be operated manually, or it may be equipped with mechanized carrier vehicles for conveying the suspension elements along the filling line.

In an embodiment of the invention, the filling line is a guide bar or rail separate from the conveyor line and having free ends. The filling station refers to a section of the conveyor line in which the filling line and the conveyor line extend in parallel but on different height levels, and in which the the articles to be painted, with the respective suspension elements, are transferred from the filling line to the conveyor line.

In this context, the automated painting line refers to a semi-automated or automated painting line which operates continuously or in cycles.

In this context, the travel speed of the conveyor line, the filling line or the discharge line refers to the line speed of the automated or semi-automated line.

On the other hand, the conveying speed of the conveyor line, the filling line or the discharge line refers to the speed at which suspension elements are conveyed on the line. The suspension elements may have a given conveying speed even if the line speed is zero, for example in the case of manual movement of suspension elements along the filling line.

In a preferred embodiment of the invention, the method further comprises a step in which the suspension element equipped with painted articles is transferred from the conveyor line to a discharge line via a discharge station. The discharge station is placed downstream of the painting station (M) and the baking oven (U) in the travel direction of the conveyor line, and said average speed of said discharge line may be set different from the average speed of the conveyor line, at least at said discharge station. The suspension element is transferred from the conveyor line to the discharge line by a coupling element which is constantly in contact with the conveyor line and/or the discharge line during the transfer. This improves the ergonomics when painted articles are discharged from the conveyor line in the same way as suspension elements and articles to be painted, loaded on them, are transferred from the filling line to the conveyor line. Transferring the articles to a separate discharge line further provides the advantage that the painted articles may be transferred to a storage at a desired pace which is not dependent on the line speed of the conveyor line. In this context, the discharge station refers to a section on the conveyor line in which the discharge line and the conveyor line extend on the same vertical line but at an angle to each other (in other words, they extend on different height levels), and at which discharge station the painted articles with the respective suspension elements are transferred from the conveyor line to the discharge line. In this context, the discharge line refers to a conveyor connected to the ceiling structures or a filling carriage, such as a guide bar, a beam, or the like, from which the suspension elements for the painted articles can be suspended but to which discharge line there is no direct connection of transferring the suspension elements from the conveyor line or the supports of the same. The discharge line and the conveyor line, or the brackets of the conveyor line, extend on different height levels, at least at the discharge station between the conveyor line and the discharge line. The discharge line may be operated manually, or it may be equipped with mechanized conveying vehicles for conveying the suspension elements along the . discharge line. In yet another preferred embodiment of the invention, the suspension-element- specific degree of filling (F) and/or the installation density of the suspension elements is detected by detecting the total number of articles to be painted, passing by it in a given period of time, for drawing conclusions on the suspension- element-specific degree of filling and the installation density of the suspension elements.

In a preferred embodiment of the invention, the method comprises:

- loading a group of articles to be painted, on a suspension element, said suspension element being coupled to a filling line connected to a transferable filling carriage, along which filling line the suspension element is transferable manually or by gravity, wherein its speed is adjustable irrespective of the travel speed of the conveyor line;

- moving the filling line connected to the filling carriage to the vicinity of the conveyor line, whereby a filling station is formed between them, at which filling station the same vertical line extends via the filling line and the conveyor line, the filling line and the conveyor line being, however, on different horizontal levels, one above the other, over at least part of the length of the filling station;

- transferring the suspension element, on which a group of articles to be painted are assembled, from the filling carriage to the conveyor line via the filling station between the filling line and the conveyor line, by a coupling element which is constantly connected to the filling line of the filling carriage or to the conveyor line or to the brackets of the conveyor line during the transfer from the filling carriage to the conveyor line. In a preferred embodiment of the invention, the coupling elements of the filling line remain on the filling line and are not transferred with the articles to be painted, loaded on the suspension elements, to the conveyor line. In this case, the number of suspension elements on the conveyor line is not increased after the transfer although the density of the suspension elements on the conveyor line is increased. In another preferred embodiment of the invention, the coupling elements of the filling line are transferred with the suspension elements to the conveyor line. In this case, the number of coupling elements connected to the suspension elements on the conveyor line is increased after the transfer.

In the following, the invention and the advantages achieved by it will be illustrated in more detail with reference to the appended drawings.

Figures 1 A and 1 B show schematically the transfer of the suspension elements from the filling line to the conveyor line and from the conveyor line to the discharge line, respectively.

Figures 2A and 2B show schematically the degree of filling of the suspension elements, which can be achieved on the conveyor line and the filling line, respectively.

Figure 2C shows the degree of filling of a suspension element that can be achieved with the suspension method of prior art.

Figure 3 shows a typical automated paint baking or powder painting line. Figures 4A, 4B, 4C, 4D, and 4E show schematically a coupling element and the principle of transferring suspension elements by means of it, from the filling line to the conveyor line or from the conveyor line to the discharge line, correspondingly.

Figures 5A and 5B show schematically a filling carriage seen from different direc- tions.

Figures 5C and 5D show schematically another filling carriage in a perspective view, and a detail of the filling carriage.

In the following, we shall first outline the aspects of the invention illustrated by each figure. Figures 1 A and 1 B show schematically how suspension elements 3 and unpainted articles to be painted (not shown in the figures), loaded on them, are transferred from a filling line K; K2 to a conveyor line K; K1 via a filling station 6; 61 between the filling and conveyor lines, and from the conveyor line K; K1 to a discharge line K; K3 via conveyor and discharge lines 6; 62, respectively. The travel directions of the conveyor, filling and discharge lines are indicated by arrows in Figs. 1 A and 1 B.

Figure 2A shows schematically the filling of the suspension element 3 with articles 2 to be painted to a given standard degree of filling F1 on the conveyor line K; K1 having a travel speed v; v1 and an average conveying speed A over a given length of the conveyor line and in a given period of time.

Figure 2B, in turn, shows the filling of suspension elements on a filling line K; K2 running in parallel with the conveyor line K; K1 , with articles 2 to be painted similar to those in Fig. 2A. On the filling line K; K2, the suspension element 3 can be filled to a higher degree of filling F; F2, because, first of all, the assembling plane 3a is larger, and secondly, a larger proportion of the three-dimensional assembling plane 3a is constituted by the articles 2.

Figure 2C shows a typical suspension element 3 of prior art, with only one article 2 assembled on its assembling plane 3a. There is a significant amount of vacant surface space 5 which could be utilized on the assembling plane. Figure 3 shows an automated paint baking line 1 which comprises a conveyor line K; K1 equipped with a drive mechanism and having an adjustable conveying speed v; v1 . The automated painting line is preferably a continuous endless conveyor line.

In the figure, a way of marking is applied, in which articles assembled on a single suspension element being conveyed on the line are indicated with number 2, and the index 2¹, 2², 2³... given as a postfix to the article indicates the following or the preceding step to which the article will be or has been subjected. The groups of articles 20 assembled on several suspension elements before each step are also numbered in a similar way. The automated painting line 1 shown in Fig. 3 comprises various steps for processing the articles to be painted, through which steps the articles 2 are conveyed by the conveyor line K. First of all, the articles 2; 2¹ to be washed and painted are conveyed to a washing step where they are pretreated by removing dirt and fat 2 from their surface in a washing machine (washer) P. The washed articles 2; 2² are conveyed to a drying oven D for drying, from which the dried articles 2; 2³ are conveyed to a painting station M. The painted articles 2; 2⁴ are controlled at a control station S, after which the painted and controlled articles 2; 2⁴ are conveyed to a baking oven U through which the conveyor line K; K1 runs. The actual conveyor means of the conveyor line K; K1 are not shown separately in the figure, and with respect to their implementation, reference is made to prior art. The painted and baked articles 2; 2⁵ are then transferred to a storage by using equipment not presented in this context. Figure 4A shows the conveyor line K; K1 and the filling line K; K2 whose path runs at least partly in parallel with the conveyor line and whose one end is welded to the conveyor line K; K1 and runs in a slanted way downwards towards the conveyor line. The conveyor line is formed of a guide bar or a rail. The suspending member 3, with the articles 2 not shown in the figure, is transferred from the filling line to the conveyor line K; K1 by a coupling element 4; 4A of the filling line, which coupling element 4; 4A is in constant contact with the guide bar or rail forming the filling line K; K2 during the transfer, and is also in contact with the conveyor line K; K1 at the final stage of the transfer.

Figure 4B, in turn, shows the conveyor line K; K1 and the discharge line K; K3 whose path runs at least partly in parallel with the conveyor line and which is welded to the conveyor line K; K1 . The discharge line is formed of a rail or a guide bar, along which the coupling element is transferable by a conveyor roller at its upper end. The suspension element 3 is moved from the conveyor line K; K1 to the discharge line by means of the coupling element 4, the coupling element 4 being in constant contact with at least the conveyor line K; K1 during the transfer and in contact with the discharge line K; K3 at the final stage of the transfer.

Figures 4C and 4D show a side view and a front view of a similar filling line arrangement as that shown in Figs. 4A and 4B, but the coupling element 4 is now supported to both the filling line K; K2 and cogged brackets (K1 a) of the transport line (K; K1 ) which are supported by the conveyor rollers (K1 b) to the rail-formed conveyor line (K; K1 ) connected to the ceiling structures.

Figure 4E shows a side view of the discharge station 6; 62 of the conveyor arrangement comprising the discharge line and the conveyor line. Cogged brackets K1 a are supported at their top by conveyor rollers K1 a to the guide bar forming the conveyor line K; K1 . Both the conveyor line K; K1 and its brackets K1 extend downwards at the discharge station, wherein the brackets K1 a can be moved by gravity on the guide bars of the conveyor line, with the help of said conveyor rollers K1 a. In this case, the coupling means 4 of the discharge line comprises an upper hanger 41 a supported to the guide bar, and a lower hanger 41 b engaging the suspension element 3 supported to the bracket K1 a. Via the upper hangers 41 a provided at its upper end, the coupling element 4 of the discharge line engages the guide bar of the discharge line K; K3 for the time of the transfer. At the discharge station 6; 61 shown in the figure, the travel direction of the conveyor line K; K1 slopes downwards towards the discharge line K; K3. When the vertical position of the conveyor line K; K1 is sufficiently low with respect to the discharge line K; K3, the bracket K1 a connected to the conveyor roller K1 b of the conveyor line has come so far down with respect to the discharge line K; K3 that the suspension element 3 supported to the bracket K1 a automatically engages the discharge line K; K3 and can be carried away along the discharge line. The lower hanger 41 b of the coupling element 4; 4B of the discharge line is identical with the lower hanger 41 b of the coupling element 4A of the filling line shown in Figs. 4C and 4D.

Figures 5A and 5B show a preferred embodiment of the invention; the figures show a filling carriage 7 equipped with a filling line K; K2 and movable by pushing. The filling carriage 7 comprises a horizontal guide bar 71 fastened to the top of a vertical frame 90 and simultaneously used as the filling line. A horizontal platform is mounted on the lower end of the frame, a pair of wheels 91 and a pair of crutches 92 being connected to its lower side. Suspension elements 3 equipped with articles to be painted may be connected to the guide bar K; K2 by coupling elements 4.

Figures 5C and 5D show another preferred embodiment of the invention; Figs. 5C and 5D also show a filling carriage 7 equipped with a filling line 71 , movable by pushing. The filling carriage 7 comprises a horizontal guide bar 71 fastened to the top of a vertical frame 90 and simultaneously used as the filling line. A horizontal platform is connected to the lower end of the frame, two pairs of wheels 91 being connected to its lower side. By means of the coupling elements 4, suspension elements 3 equipped with articles to be painted may be connected to the guide bar 71 , and the direction of the guide bar can be easily changed by means of a turnbuckle. Using this filling carriage 7, it is possible to change the direction of the guide bar and thereby to transfer the suspension elements 3 to several locations of the conveyor line.

In the following, different aspects of the invention will be described with reference to Figs. 1 to 5 and to the brief description of these figures presented above.

Already discussed briefly in connection with the description of prior art, Fig. 3 shows a quite common way of lifting suspension elements 3 onto an automated painting line 1 . Figure 3 shows a section 1 1 of the painting line 1 upstream of a washer or washing machine P, where a group of articles 20; 21 is loaded on their suspension elements 3 and is conveyed towards the washer. Each suspension element 3, loaded with articles 2 to be painted, is lifted onto a hook 40 on the conveyor line K; K1 upstream of the washing machine P, for preparing the articles 2; 21 to be painted and washed. However, this is relatively slow and heavy work in view of ergonomics, because each suspension element 3 loaded with articles 2 has to be first carried alongside the conveyor line K; K1 (normally to a section 1 1 of the conveyor line upstream of the washing machine P, as illustrated in Fig. 3) and then lifted onto hooks 40 installed on the conveyor.

In another method of filling suspension elements 3, commonly in use in power painting plants, the suspension elements are lifted by means of hooks 40 onto the section 1 1 of the conveyor line upstream of the washer, or onto a section 13 of the conveyor line K; K1 placed directly upstream of the painting station M. After this, the suspension elements are loaded with the articles 2 to be painted. At this point, however, the suspension element 3 is easily incompletely filled, because it is necessary to maintain a given average speed A on the conveyor line K; K1 , defined by the baking oven U and the painting stage M, and the speeds of these sections 1 1 , 13 of the conveyor line cannot be adjusted independently.

A prior art known way to fill the suspension elements 3, to the average standard degree of filling F1 determined by the running speed v; v1 of the conveyor line, is shown in Fig. 2A. A worker assembles the articles 2 to be painted onto the suspension elements 3 while the conveyor line K; K1 is running forward in the direction indicated by the arrow, at a travel speed v; v1 and at an average travel speed A. The suspension element 3 may be already fastened to the hooks 40 of the conveyor line K; K1 upstream of the washing machine 3 on the conveyor line, as shown in Fig. 3. In Fig. 2A, two articles 2 are assembled on each suspension element 3, covering a given shared area of the vertical plane extending through them. A relatively large area 5; 5b of the shared vertical plane extending through the front surface of the suspension element and the articles, i.e. the assembling plane 3a; 3a1 , is left vacant, and furthermore, this assembling plane 3a1 is relatively small.

By assembling the same articles 2 to be painted onto a suspension element 3 similar to that shown in Fig. 2A but using a filling line K; K2 according to the invention, illustrated in Fig. 2B, the degree of filling F of the suspension element can be significantly increased from the first degree of filling F; F1 shown in Fig. 2A to the second, higher degree of filling F; F2 shown in Fig. 2B. In Fig. 2B, six articles 2 can be fastened to the front surface of a similar suspension element, covering a larger shared area of the vertical plane extending through them. Thus, the common assembling plane 3a; 3a2 extending through the front surface of the suspension element and the articles becomes large, that is, 3a2 >3a1 ; and moreover, a smaller area 5; 5b of the surface is left vacant. The filling line K; K2 has a speed v; v2, and its average speed is B in the same period of time when the section of the conveyor line running in parallel with the filling line has the average speed A. The speed B is lower than A and makes it possible to fill the suspension element to said higher degree of filling F; F2 and thereafter to transfer the suspension element loaded with articles 2 via the filling station 6; 61 to the main line (conveyor line) K; K1 , as shown in Fig. 1 B.

Figure 4A shows the conveyor line K; K1 as well as the filling line K; K2 running at least partly on the same vertical plane as the conveyor line. At the filling station, the filling line K; K2 extends downwards towards the conveyor line K; K1 as the conveyor line K; K1 extends in the horizontal direction. The filing line K; K2 is configured to converge the conveyor line K; K1 immediately downstream of the filling station 6; 61 between them. Figure 4A shows how the suspension element 3 loaded with a group of articles 2 to be painted is first conveyed along the filling line K; K2 to the immediate vicinity of the conveyor line K; K1 . The transfer area where the filling line K2 and the main line K1 are so close that the suspension element 3 can be transferred from the conveyor line K; K1 to the filling line K; K2 by means of the coupling element 4, is called the filling station, and it is indicated with the reference 6; 61 in Fig. 4A.

As shown by Fig. 4A, the suspension element 3 loaded with a group of articles to be painted (not shown separately in the figure) is moved from the filling line K; K2 to the conveyor line K; K1 via the above-mentioned filling station 6; 61 between the filling line K; K2 and the conveyor line K; K1 . The suspension element 3 is transferred from the filling line K; K2 to the conveyor line by means of the coupling element 4. The coupling element 4 comprises a suspender 41 having a rigid upper hanger 41 a with a hook-like free end. The upper hanger 41 a can be slid by its hook-like end along a smooth guide bar, such as a bar or a beam, of the filling line K; K2. The upper hanger 41 a joins a rigid lower hanger 41 b underneath it, also having a hook-like part, by which the lower hanger 41 b can be slid along the guide bar, such as a smooth bar or beam, of the conveyor line K; K1 , o r it can be conveyed by a cogged bracket coupled to the conveyor line K; K1 (cf. Fig. 4C). The suspension element 3 is suspended from a hook 42 at the end of a rigid vertical arm 41 c connected to the lower hanger 41 b of the coupling element The vertical distance between the upper and lower hangers 41 a, 41 b is such that when the suspension element 3 is conveyed or slid by the coupling element 4 on the filling line K; K2 or brackets supported to it (not shown in the figures), the hook-like part of the lower hanger 41 b does not reach the conveyor line K; K1 , whereby the suspension element is supported by the upper hanger 41 a to the guide bars of the filling line K; K2 first when the conveyor line K; K1 and the filing line K; K2 converge, the filling line running obliquely towards the conveyor line K; K1 at the filling station 6; 61 between them; the lower hanger 41 b extending to the conveyor line K; K1 or the brackets of the conveyor line supported to it, extending further below, thereby supporting the suspension element to the conveyor line. In this way, the suspension element 3 is constantly supported to the conveyor line (K; K1 ) and/or the filling line (K; K2) by means of the upper hanger 41 a or the lower hanger 41 b. At the filling station 6; 61 , the filling line and a virtual vertical plane 8 parallel to the conveyor line extend through the filling line K; K2 and the conveyor line K; K1 . At the filling station 6; 61 , the filling line K; K2 and the conveyor line K; K1 extend partly one above the other on the same vertical plane. Therefore, the conveyor line K; K1 extends at a first vertical distance T; T1 from the ground (Po) in the travel direction of the conveyor line before the painting station M, and the filling line K; K2 extends at a second vertical distance T; T2 from the ground. At the filling station 6; 61 , the distance T; T2 of the filling line from the ground differs from the distance T; T1 of the conveyor line K; K1 from the ground Po in such a way that the distance between the lines K2, K1 decreases and the corresponding distances T2, T1 from the ground Po approach each other.

The suspension element 3 with the articles 2 not shown in the figure is thus transferred from the filling line K; K2 to the conveyor line K; K1 by means of the coupling element 4 which is in constant contact with either the conveyor line K; K1 or the filling line K; K2 during the transfer. The coupling element 4 can be disconnected from the engaging element 31 of the suspension element 3, as shown in Figs. 4C and 4D.

In an embodiment of the invention, illustrated in Figs. 4A to 4B mentioned above, the coupling element 4 may be connected to the engaging element 31 of the suspension element 3, by which the suspension element is engaged with the brackets K1 a of the conveyor line K; K1 . In this case, the coupling element 4 may remain connected to said engaging element 31 when the article 2 is conveyed further along the conveyor line K; K1 to various pretreatments for the painting and to the actual powder coating. In this case, the combination of the engaging element of the suspension element and the coupling element 31 , 4, together with the articles 2 to be painted, is thus brought from the filling line K; K2 to the conveyor line K; K1 . The combination of the engaging element of the suspension element and the coupling element 31 , 4 thus engages the brackets K1 a of the conveyor line K; K1 by means of the engaging element 3; 31 of the suspension element, and the coupling element 4 follows the engaging element 31 to the paint coating and its pretreatments.

The components of the coupling element 4 supporting to the filling and conveyor lines K; K2, K; K1 may be sliding elements, rolling elements or hook-like elements. In the embodiment of the invention shown in Figs. 4C and 4D, the coupling element 4 engages the filling line K; K2 by means of upper hangers 4; 41 a in the form of rolling elements. However, the coupling element 4 does not engage the transfer line K; K1 until later at the final stage of the transfer, indirectly by means of the suspension element 3. The coupling element 4 comprises a lower hanger which has a hook-like engaging part 41 b1 extending towards the suspension element in a direction transverse to the direction of the conveyor line and being detachably engageable to the structures in the upper part of the engaging element 31 of the suspension element 3, such as an opening in the upper part. The engaging element 31 of the suspension element 3, in turn, engages the cogging K1 a of the conveyor line K; K1 by means of the hook-like element 31 a. During the above presented transfer from the filling line to the conveyor line, the suspension element 3 is supported by means of the coupling element 4 which is constantly coupled to either the conveyor line or the filling line, directly or indirectly, by means of the engaging element 31 of the suspension element 3. Such a way of transfer is considerably more secure than if the articles to be painted were lifted by means of the suspension element onto hooks 400 provided ready on the conveyor line.

Figure 4B, in turn, shows the conveyor line K; K1 and the discharge line K; K3 whose path runs at least partly in parallel with the conveyor line and which is welded to the conveyor line K; K1 . At the discharge station 6; 61 , the discharge line K; K3 and the conveyor line K; K1 are on the same virtual vertical plane (not shown in the figure) of the discharge line and the conveyor line again. At the discharge station 6; 63, the discharge line K; K2 and the conveyor line K; K1 extend at least partly one above the other. The conveyor line K; K1 extends at a distance T; T1 from the ground Po, and the discharge line K; K3 extends at a distance T; T3 from the ground. At the filling station 6; 61 , however, the distance T; T3 of the discharge line K; K3 from the ground differs from the distance T; T1 of the conveyor line K; K1 from the ground Po in such a way that the distance between the discharge and conveyor lines K3, K1 decreases and their corresponding distances T3, T1 from the ground approach each other.

The suspension element 3 is transferred from the conveyor line K; K1 to the discharge line by an arrangement similar to that shown in Fig. 4A. Again, the coupling element 4 is constantly supported to the conveyor line K1 or the discharge line during the transfer at the discharge station 6; 62 between the conveyor line K1 and the discharge line K3; i.e. it is, by means of its hook-like elements, in constant contact with either the conveyor line K; K1 or the discharge line K; K3.

In the method according to the invention, the suspension element 3 loaded with the painted articles 2; 24 is transferred from the conveyor line K; K1 to the dis- charge line K; K3 at the discharge station 6; 62 placed downstream of the painting station M and the baking oven U in the travel direction of the conveyor line, cf. Fig. 3. The average speed C of the discharge line K; K3 (Fig. 1 C) is configured to be different from the average speed A of the conveyor line K; K1 . In a preferred embodiment of the invention, articles are moved manually, or preferably by gravity, on the discharge line downstream of the discharge station.

Figures 4A and 4B show a situation in which the suspender 41 begins, at some stage, to rest on the conveyor line K; K1 by means of the lower hanger when the suspender 41 is conveyed along the filling line K; K2 towards the conveyor line K; K1 . In some conveyor lines, the suspension elements 3 do not engage the conveyor line directly by their hook-like upper and lower hangers of the coupling element 4, as shown in Figs. 4A and 4B, but they engage cogged brackets K1 a provided below the conveyor line K; K1 and connected to the conveyor line K; K1 , as shown in Figs. 4C and 4D. The brackets K1 a extend in parallel with the conveyor line, and they are conveyed by rollers K1 b or the like supported to the conveyor line. The indirect way of coupling the suspension elements 3 to the conveyor line is shown in Figs. 4C and 4D. As shown by Figs. 4C and 4D, the lower and upper hangers 41 a, 41 b of the suspender 4 are not necessarily hook-shaped but they may consist of various sliding or conveying elements which may also be simultaneously coupled to the conveyor line K; K1 and its brackets K1 b.

Figures 5A and 5B as well as 5C show a preferred embodiment of the invention, comprising a filling carriage 7 having a frame 90 whose upper part is provided with a filling line 71 . The filling carriage 7 and thereby also the filling line are movable on wheels 91 . A horizontal guide bar 71 fastened to the top of the vertical frame 90 of the filling carriage 9 is simultaneously used as the filling line. Suspension elements 3 loaded with articles 2 to be painted may be suspended from the guide bar K; K2 e.g. by means of the above-presented coupling elements 4. After the suspension elements 3 have been connected by the coupling elements 4 to the filling line 71 provided in the filling carriage 9, the suspension elements are movable, manually or by gravity, on the filling line, at a desired speed, whereby their speed is naturally independent of the line speed v; v1 of the conveyor line. When the suspension elements are to be transferred to the main line, i.e. the conveyor line, the filling line 71 provided in the filling carriage 7 is first moved next to the conveyor line K; K1 so that the same vertical, plane parallel to these lines K1 , 71 extends through the filling line 71 and the conveyor line K; K1 . In this way, a filling station 6; 61 is formed between the conveyor line K; K1 and the movable filling line 71 (cf. Fig. 1 A), at which the movable filling line 71 and the conveyor line K; K1 are one above the other, on different horizontal levels. The filing line 71 is directed obliquely downwards or downwards towards the conveyor line, depending on whether articles to be painted are transferred from it to the conveyor line, or whether painted articles are transferred from the conveyor line to the movable filling line 71 . The suspension element 3 loaded with a group of articles 2 to be painted may be transferred from the guide bar 71 of the filling carriage 7 to the conveyor line K; K1 by gravity, by means of a coupling element 4 and a transfer arrangement similar to those shown in Fig. 2A for transferring suspension elements from the stationary filling line K; K2 to the conveyor line K; K1 . In the embodiment of the invention shown in Fig. 5, the filling line 71 may be rotated in the vertical plane around its end connected to the frame 90, whereby it is articulated by means of a turnbuckle. A method not shown in the figures, for detecting the suspension-element-specific degree of filling F and/or the installation density of the suspension elements 3 on the conveyor line, comprises detecting the average degree of filling F; F1 of articles 2 to be painted, on the suspension elements, and/or the number (density) of suspension elements on the conveyor line K; K1 . The detection of the degree of filling of the suspension elements and/or the number of suspension elements is based on the total number of articles 2 to be painted, as detected by a measuring device, such as an ultrasonic detector, in a given period of time. The information about the degree of filling (F1 ) and/or the installation density is then transmitted to a supervisor in a wireless and automated way. After the detection of the degree of filling and/or the number of the suspension elements, the functions of the painting line 1 can be efficiently adjusted on the basis of this. The adjustment may be based on, for example, a change in the speed v; v1 of the conveyor line K; K1 , or a change in the number of pistols at the painting station M, on the basis of the detected average degree of filling (F1 ) and/or the number of suspension elements 3. List of reference numerals

1 Painting line

2 Article (either to be painted or painted)

20 Group of articles (either to be painted or painted)

20a, 20b Groups of articles

21 , 22, 23,24, 25 Article/group of articles after different steps

3 Suspension element

31 Engaging element for suspension element

31 a Hook of engaging element

3a, 3a1 , 3a2 Assembling plane, vertical plane

30 Group of suspension elements

4 Coupling element for suspension element

4A Coupling element for filling line

4B Coupling element for discharge line

4C Coupling element for filling carriage

41 Suspender

41 a Upper hanger

41 b Lower hanger

41 b1 Engaging part

42 Hook

400 Conventional suspension element (hook)

5 Free surface space on the assembling plane of the suspension element

5a, 5b Free surface space on the assembling plane of the suspension element

6 Transfer station 5; 61 Filling station

6; 62 Discharge station

7 Filling carriage

71 Conveyor for filling carriage

A Average speed of conveyor line

B Average speed of filling line

C Average speed of discharge line

D Dryer

F; F1 Degree of filling of the suspension element

F; F2 Degree of filling of the suspension element

K Conveyor

K; K1 Conveyor line

K1 a Bracket (cogged)

K1 b Conveyor roller

K; K2 Filling line

K; K3 Discharge lineK3b Conveyor roller

L; L1 Vertical plane extending through the filling line and the conveyor line

L; L2 Vertical plane extending through the conveyor line and the discharge line

L10 Longitudinal direction (travel direction) of the filling line

L20 Longitudinal direction (travel direction) of the conveyor line or its bracket

L30 Longitudinal direction (travel direction) of the discharge line

v; v1 Conveying speed of the conveyor line

v; v2 Conveying speed of the filling line

v; v3 Conveying speed of the discharge line M Painting station

P Washing machine

Po Ground

T Distance from the ground

T; T1 Distance of the conveyor line from the ground

T; T2 Distance of the filling line from the ground

T; T3 Distance of the discharge line from the ground

U Baking oven

Claims

1 . A method for increasing the suspension-element-specific degree of filling (F) of a conveyor line (K; K1 ) and/or the installation density of suspension elements (3) on an automated painting line (1 ) comprising a conveyor line (K; K1 ) equipped with a drive mechanism and having an adjustable conveying speed (v; v1 ), and a painting station (M) and a baking oven (U), through which the conveyor line (K; K1 ) extends, wherein the painting line (1 ) further comprises a filling line (K; K2) or a filling carriage (9) as well as a filling station (6; 61 ) between said filling line (K; K2) or filling carriage and said conveyor line (K; K1 ), characterized in that the method comprises at least the following steps:

- loading a group of articles (2) to be painted, on a suspension element (3), said suspension element being suspended from the filling line (K; K2) or a filling carriage (7), the conveying speed (v; v2) of the filling line (K; K2) or the conveying speed of the filling carriage (7) being adjustable irrespective of the conveying speed (v; v1 ) of the conveyor line;

- conveying the suspension element (3), loaded with the group of articles (2) to be painted, along the filling line (K; K2) to the side of the conveyor line (K; K1 ), wherein the same vertical plane extends through the filling line (K; K2) and the conveyor line (K, K1 ) or through the filling carriage (7) and the conveyor line (K; K1 ); however, the filling line (K; K2) and the conveyor line (K; K1 ), or the filling carriage (7) and the conveyor line (K, K1 ) being on different horizontal levels at said filling station (6, 61 ), at least on a section of the length of said filling station (6, 61 ); - transferring the suspension element (3), on which a number of articles (2) to be painted are loaded, either a) from the filling line (K; K2) to the conveyor line (K; K1 ) via the filling station (6; 61 ) between the filling line (K; K2) and the conveyor line (K; K1 ), by means of a coupling element (4; 4a) of the filling line (K; K2), the coupling element (4) being constantly connected to the filling line during the transfer from the filling line (K; K2) to the conveyor line (K; K1 ), and the coupling element (4; 4A) or the suspension element (3) suspended from it coming into contact with the conveyor line (K; K1 ) or the brackets of the conveyor line (K; K1 ) during said transfer, or b) from the filling carriage (7) to the conveyor line (K; K1 ) via the filling station (6; 61 ) between the filling carriage (7) and the conveyor line (K; K1 ), by means of a coupling element of the filling carriage (7), the coupling element being constantly connected to the conveyor line (K; K1 ) during the transfer from the filling carriage (7) to the conveyor line (K; K1 ), and the coupling element (4; 4A) or the suspension element (3) suspended on it coming into contact with the conveyor line (K; K1 ) or the brackets of the conveyor line (K; K1 ) during said transfer, wherein the coupling element, together with the suspension element (3) and the articles to be painted connected to it, is conveyed downwards at said filling station (6; 61 ), by gravity.

2. The method according to claim 1 , characterized in that the method comprises

- loading a group of articles (2) to be painted, on the suspension element (3), said suspension element being connected to a filling line (71 ) connected to a movable filling carriage (7), along which filling line the suspension element is transferable manually or by gravity, whereby its velocity is adjustable independently of the travel speed (v; v1 ) of the conveyor line;

- moving the filling line (71 ) connected to the filling carriage (7) to the side of the conveyor line (K; K1 ), whereby a filling station (6; 61 ) is formed between them, at which the same vertical plane extends through the filling line (71 ) and the conveyor line (K; K1 ); however, the filling line (71 ) and the conveyor line (K; K1 ) being on different horizontal levels, one above the other, on at least a section of the length of the filling station (6; 61 );

- transferring the suspension element (3), loaded with a group of articles (2) to be painted, from the filling carriage (7) to the conveyor line (K; K1 ) via the filling station (6; 61 ) between the filling line (7; 71 ) and the conveyor line (K, K1 ), by means of a coupling element which is constantly connected to the filling line (71 ) of the filling carriage (7) or to the conveyor line (K; K1 ) or to the brackets of the conveyor line (K; K1 ) during the transfer from the filling carriage (7) to the conveyor line (K; K1 ).

3. The method according to claim 1 or 2, characterized in that the coupling elements (4;4A) of the filling line remain on the filling line and are not transferred to the conveyor line (K; K1 ) with the articles to be painted, coupled to the suspension elements (3), whereby the number of coupling elements (4) on the conveyor line is not increased after the transfer.

4. The method according to claim 1 or 2, characterized in that the coupling elements (4) are transferred to the conveyor line (K; K1 ) together with the suspension elements (3) loaded with articles to be painted, whereby the number of coupling elements (4) is increased after the transfer.

5. The method according to any of the preceding claims, characterized in that the longitudinal direction (L10) of the conveyor line (K; K1 ), or the longitudinal direction (L10) of the bracket (K1 a) of the conveyor line (K; K1 ), from which the suspension elements (3) are suspended at their upper ends, differs from the longitudinal direction (L20) of the filling line (K; K2) at the filling station (6; 61 ).

6. The method according to any of the preceding claims, characterized in that the conveyor line (K; K1 ) or the bracket (K1 a) of the conveyor line, from which the suspension elements (3) are suspended after the suspension elements (3) have been transferred from the filling line (K; K2) or the filling carriage (7) to said conveyor line (K; K1 ) or bracket (K1 ) of the conveyor line, extends at a first vertical distance (T; T1 ) from the ground (Po) in the travel direction of the conveyor line upstream of the painting station (M), and the filling line (K; K2) extends at a second vertical distance (T; T2) from the ground, the distance (T; T2) of the filling line from the ground differing from the distance (T; T1 ) of the conveyor line (K; K1 ) from the ground (Po) on at least a section of the length of the filling station (6; 61 ) between the conveyor line (K; K1 ) and the filling line (T; T2), at which filling station (6; 61 ) the suspension element (3) is transferred by gravity from the filling line (K; K2) to the conveyor line (K; K1 ). 7. The method according to any of the preceding claims, characterized in that the method further comprises the following steps:

- loading a group of first articles (2) to be painted on the suspension elements (3) on the conveyor line (K; K1 ) upstream of the filling station (6; 61 ) between the conveyor line (K; K1 ) and the filling line (K; K2); - loading a group of second articles (20) to be painted on the suspension elements (3), said suspension element being connected to the filling line (K; K2), followed by conveying the suspension element (3) along the filling line (K; K2) to the side of the conveyor line (K; K1 ) and transferring it from the filling line (K; K2,

7) to the conveyor line (K; K1 ) by means of the coupling element (4A) of the filling line, via the filling station (6; 61 ) between the filling line (K; K2) and the conveyor line (K; K1 ), for adding the second group of articles (20) to be painted to said conveyor line (K; K1 ); - after the transfer of the suspension element (3) to the conveyor line (K; K1 ), the engaging element (4A) of the filling line either remaining on the filling line or being transferred together with the suspension element (3) from the filling line to the conveyor line (K; K1 ).

8. The method according to any of the preceding claims, characterized in that the conveyor line (K; K1 ) extends at a given first vertical distance (T; T1 ) from the ground downstream of the baking oven (U), and the discharge line (K; K3) extends at a given second vertical distance (T; T3) from the ground, and the first distance (T1 ) differs from the second distance (T3) in at least that section of the conveyor line (K; K1 ) where the discharge station (6; 62) between the discharge line and the conveyor line is located and where painted articles (2; 2⁵) are transferred from the conveyor line (K; K1 ) to the discharge line (K; K3).

9. The method according to any of the preceding claims, characterized in that the suspension element (3) is transferred from the conveyor line (K; K1 ) to the discharge line (K; K3) by means of the coupling element (4) of the discharge line, whose upper hanger (41 a) is constantly in contact with or supported to the conveyor line (K; K1 ) or its brackets during the transfer, and whose lower hanger (41 b) comes into contact with the suspension element (3) suspended from the discharge line (K; K3) during the transfer.

10. The method according to any of the preceding claims, characterized in that the suspension element (3) is transferred from the filling line (K; K2) to the conveyor line (K; K1 ) at the filling station (6; 61 ) located upstream of the painting station (M) in the travel direction of the conveyor line, wherein the average speed (B) of conveying suspension elements (3) on the filling line (K; K2) is adjusted, on the basis of the painting-station-specific or baking-oven-specific speed of the conveyor line, lower or higher than the average speed (A) of conveying suspension elements (3) on the conveyor line (K; K1 ), on the section of the conveyor line located upstream of the filling station (6; 61 ) in the travel direction of the conveyor line.

1 1 . The method according to claim 10, characterized in that the average conveying speed (B) of the filling line (K; K2) is adjusted to be lower than the average conveying speed (A) of the conveyor line (K; K1 ), preferably lower than 50% of the conveying speed (v; v1 ) of that section of the conveyor line (K; K1 ) which is located immediately upstream of the filling station (6; 61 ) in the travel direction of the conveyor line (K; K1 ).

12. The method according to claim 1 1 , characterized in that the conveying speed of the filling line (K; K2) is adjusted to be 0 m/min when the suspension element (3) is being loaded with articles (2) to be painted, and that the suspension element (3) loaded with a group of articles (2) to be painted is conveyed to the filling station (6; 61 ) manually or by gravity.

13. The method according to any of the preceding claims, characterized in an increase in the suspension-element-specific degree of filling (F) by at least 50% in relation to an average standard degree of filling (F1 ) of a suspension element, which is calculated at an average standard filling speed of suspension elements (3) and is obtained by loading articles (2) to be painted, onto suspension elements (3) on a conveyor line (K; K1 ) running to a painting station (M) at a given average travel speed (A) of the conveyor line, and wherein the increase in the degree of filling (F) is obtained by comparing said average standard degree of filling (F1 ) of the conveyor line with an average degree of the filling (F2) of suspension elements, which average degree of filling (F2) of suspension elements is obtained by loading identical articles (2) to be painted, onto suspension elements on a filling line (K; K2) on a conveyor line leading to a painting line and having an average travel speed (B), said filling line being located in such a way with respect to the conveyor line (K; K1 ) that the articles (2) to be painted are transferable, loaded on the suspension elements, from the filling line (K; K2) to the conveyor line (K; K1 ) at a filling station (6; 61 ), wherein different horizontal planes extend through the conveyor line (K; K1 ) and the filling line (K; K2) at least at the filling station (6; 61 ) between them.

14. The method according to any of the preceding claims, characterized in that the method further comprises a step in which the suspension element (3) equipped with painted articles (2; 24) is transferred from the conveyor line (K; K1 ) to a discharge line (K; K3) at a second transfer station (6; 62), i.e. a discharge station, which is located downstream of the painting station (M) and the baking oven (U) in the travel direction of the conveyor line, wherein the average speed (C) of said discharge line (K; K3) is different from the speed (v; v1 ) of the conveyor line (K; K1 ) at least at said discharge station (6; 62).

15. The method according to claim 14, characterized in that the suspension element (3) loaded with painted articles (2; 24) is conveyed along the conveyor line (K; K1 ) to the side of a stationary or movable discharge line (K; K3), and thereafter the suspension element (3) loaded with articles to be painted is transferred from the conveyor line to the discharge line (K; K3) or to a discharge carriage equipped with a movable discharge line (K; K3).

16. The method according to any of the preceding claims, characterized in that the method further comprises a step of detecting the average degree of filling (F;

F1 ) of articles (2) to be painted, on the suspension elements (3), and/or the number (density) of suspension elements on the conveyor line (K; K1 ).

17. An automated painting line (1 ) for increasing the suspension-element-specific degree of filling and/or the installation density of suspension elements on a conveyor line, which painting line comprises a conveyor line (K; K1 ) equipped with a drive mechanism and whose travel speed and speed (v; v1 ) of conveying suspension elements (3), directly dependent on the travel speed, are adjustable, and a painting station (M) and a baking oven (U), through which said conveyor line (K; K1 ) runs, whereby the painting line (1 ) further comprises a filling line (K; K2) and a filling station (6; 61 ) placed between the filling line (K; K2) and said conveyor line (K; K1 ) in such a way that the same vertical plane extends through the filling line (K; K2) and said conveyor line (K; K1 ) at the filling station (6; 61 ) between them, characterized in that the filling line (K; K2) and the conveyor line (K; K1 ) or its bracket, from which the suspension elements are suspended at their upper ends, are, however, on different horizontal levels, at least partly one above the other, over the length of said filling station (6; 61 ), from which filling line (K; K2) or its bracket (K1 a) it is possible to suspend suspension elements (3) which can be equipped with articles (2) to be painted, the suspension elements (3) with the articles (2) to be painted being then transferable by gravity to the conveyor line (K; K1 ) by means of the coupling element (4; 4A) of the filling line, via said filling station (6; 61 ) between the filling line (K; K2) and the conveyor line (K; K1 ), wherein the speed (v; v2) of conveying the suspension elements (3) on the filling line (K; K2) is adjustable irrespective of the speed (v; v1 ) of conveying the suspension elements (3) on the conveyor line (K; K1 ); and the coupling element (4; 4a) comprises an upper hanger (41 a) constantly supported to the filling line (K; K2) during the transfer, and a lower hanger (41 b) which touches the conveyor line (K; K1 ) or its bracket (K1 a) during the transfer of the suspension element (3) from the filling line (K; K2) of the painting line to the conveyor line (K; K1 ) by gravity.

18. The painting line (1 ) according to claim 17, characterized in that the upper hanger (41 a) of the coupling element (4; 4A) of the filling line comprises sliding or rolling elements, by which the coupling element (4) can be transferred by gravity along the downwards extending section of the conveyor line (K; K1 ) at the filling station (6; 61 ).

19. The painting line (1 ) according to claim 17 or 18, characterized in that the conveyor line (K; K1 ) or its bracket (K1 a), to which the suspension element is supported, and the filling line (K; K2) are placed on horizontal levels and their distances (T1 , T2) from the ground (Po) differ from each other, or that the conveyor line (K; K1 ) or its bracket (K1 a), to which the suspension element is supported, and the discharge line (K; K3) are placed on different horizontal levels whose distances (T1 , T3) from the ground (Po) differ from each other, wherein the distances (T1 ) and (T2) or (T1 ) and (T3) converge at the filling station (6; 61 ) or the discharge station (6; 62).

20. The automated painting line (1 ) according to claim 17, characterized in that the filing line (K; K2) is configured to be movable by connecting it to a movable filling carriage (7).

21 . The automated painting line (1 ) according to any of the preceding claims 17 to 20, characterized in that the automated painting line (1 ) further comprises a washer (P) and a drying oven (D) which are placed upstream of the painting station in the travel direction of the conveyor line and through which said conveyor line (K) runs before entering the painting station (M), and that the filling station (6; 61 ) is placed upstream of said washer (P) in the travel direction of the conveyor line (K; K1 ).

22. The automated painting line (1 ) according to any of the preceding claims 17 to 21 , characterized in that the filling station (6; 61 ) between the filling line and the conveyor line is placed upstream of the painting station (M).

23. The automated painting line (1 ) according to any of the preceding claims 17 to 22, characterized in that the painting line (K; K1 ) is a continuous endless conveyor line, such as a guide bar, a rail, or the like, which is possibly equipped with a movable bracket (K1 a), to which the suspension elements can be supported.

24. The painting line (1 ) according to claim 23, characterized in that the filing line (K; K2) is formed of an elongated guide bar, a rail or the like, to which the suspension element can be supported by its upper end, and which filling line is not connected with the conveyor line with direct connection of transferring the suspension element.

25. The painting line (1 ) according to claim 24, characterized in that both ends of the guide bar, rail or the like forming the filling line (K; K2) are free.

26. The automated painting line (1 ) according to any of the preceding claims 16 to 25, characterized in that the average conveying speed (B) of the filling line (K; K2) is configured to be lower than the average speed (A) of that section of the conveyor line (K; K1 ) which is placed immediately upstream of the filling station (6; 61 ) between said filing line and the conveyor line in the travel direction of the conveyor line.

27. The automated painting line (1 ) according to any of the preceding claims 16 to 26, characterized in that the conveyor line (K; K1 ) or its bracket, to which the suspension element can be supported by its upper end (3), extends at a given first vertical distance (T; T1 ) from the ground (Po), and the filling line (K; K2) extends at a given second vertical distance (T; T2) from the ground (Po), and the first distance (T1 ) differs from the second distance (T2) in at least that section of the conveyor line (K; K1 ) in which the filling station (P; P1 ) between the conveyor line and the filling line is placed.

28. The automated painting line (1 ) according to any of the preceding claims 16 to 27, which further comprises a discharge line (K; K3) tangential to or in contact with the conveyor line (K; K1 ), and wherein a discharge station (6; 63) is provided between the discharge line (K; K3) and the conveyor line (K; K1 ), at which suspension elements (3) equipped with painted and then baked articles (2; 2⁵) are transferable from said conveyor line (K; K1 ) to the discharge line by means of a coupling element (4), wherein the discharge line (K; K3) and the conveyor line (K; K1 ) are at least partly one above the other so that the same vertical plane extends through them, and the conveying speed of the discharge line is adjustable irrespective of the speed of the conveyor line.

29. The automated painting line (1 ) according to any of the preceding claims 16 to 27, characterized in that the suspension elements (3) are plate-like and are suspended from the filling line (K; K2) or from the conveyor (71 ) of the filling carriage (7) so that their vertical plane is transverse to their travel direction on the filling line or on the conveyor (71 ) of the filling carriage (7).