EP0506834B1 - Supporting frame for a continuous transport device - Google Patents

Abstract

A support, in particular a profile or wire frame, for a continuous transport device for transporting thin, flexible objects, panels or metal sheets, through a drying tunnel or through a tunnel for heat treatment or the like is characterized by the shape of its surface, which receives the objects to be transported. The purpose of this shape is to bend the panels to be transported forward when receiving them approximately horizontally in order to prevent them from bending vertically under their own weight as soon as they are lifted approximately vertically from the wire frame before or during transport. In the case of this latter deformation, contact points are produced between the panel and the preceding wire frame, which seriously impair the quality of the dried products.

Description

The present invention relates to holding devices which are known under the name of wire frames and which are mounted one behind the other on one or more chains (or similar devices) in a parallel arrangement. In this way, a continuous transport of the sheets or sheets is ensured, so that they are sent through a tunnel for drying or thermal treatment or are only waiting between. two consecutive processes can be in the same production line.

Transport systems of this type are well known and are used frequently. A typical example from the metal packaging industry is shown schematically in FIG. In the metal packaging industry, thin iron sheets or aluminum sheets are required, which are painted, printed or coated for protection or for optical reasons. It is necessary that the metal sheets at temperatures between 120 ° C and 220 ° C about ten Dry or polymerize for minutes so that the paint or the like adheres firmly to the metal and can therefore perform its protective or decorative function. This application form serves only as an example, because the wire frames of the present invention can be used to carry all types of flat, thin objects that are transported in an almost vertical position, the time during which they are subjected to treatment by the length of the Tunnel is limited.

FIG. 1 shows a sheet or sheet metal coating installation a and a belt transport arrangement b for inserting the sheets between the wire frames 1 of a continuous transport device c. An unloading device with a belt transport arrangement d in the direction of a stack e is also shown.

FIG. 2 shows, in plan view, a typical wire frame 1 for a transport device for the transport of metal plates through a drying tunnel. In Figure 3 the same wire frame can be seen in profile. In Figure 2, a sheet of metal of maximum length and maximum width is shown by dashed lines.

The design of this wire frame 1 results from a compromise between two contradicting necessities; namely to provide a large and robust support surface that is suitable for a large number of different sheet or sheet sizes and to provide a minimum mass in order to reduce the energy required for heating up to processing temperature several times per hour. The wire frames are usually made of welded or riveted flat section steel, as shown in Figure 2. On the other hand, it has been kept up to the present day to reinsert their surfaces between two parallel planes in order to easily align them on a roller plate in the event that they are dented or deformed due to a transport incident (FIG. 3).

These wire frames are installed on one or more chains 2 (Figure 4). So that the transported panels lie clearly on the surface that is opposite to the currently printed or coated side, that is, on the back (so that the front does not come into contact with the previous wire frame), the type of fastening of the approximately horizontal wire frame on the or the chains for an angle of 15 degrees between the vertical and the support plane of the wire frame. In well-designed transport systems, U-shaped parts 3, which are attached to the top of the wire frame, serve as cross-connections between two successive wire frames. Due to this cage-like arrangement, the wire frames that move in a row are practically not deformable.

Such designs were completely satisfactory as long as the lengths and heights (dimensions of the quasi-vertical panel during transport) was so related to its thickness that the panels did not bend under their own weight and remained largely straight against the wire frame, as can be seen in FIG. 4, reference number 4.

The search for a more effective use of the metal tends to enlarge the single sheet and reduce its thickness. In conventional transport devices, the large and thin panels bend slightly, as can be seen in FIG. 4 with the reference number 5, so that the undesired contacts between the panel and the back of the preceding wire frame occur more and more frequently. This results in a lack of protection and / or unsightly stains that make the board almost unusable. This tendency can also be found in panels made of light metal, which is less rigid than steel.

From US-A-2 593 415 and from US-A-1 736 866 supports of upper and lower run transport devices are known for transporting flat objects. The supports of these transport devices are flat. The objects are fed in a horizontal position in the support deflection area of the transport device and then erected in an approximately vertical position by further transport of the run.

The aim of the present invention is to eliminate these disadvantages. It is based on the fact that one must exert a great force to bring a flat object made of a material that is resistant in two mutually perpendicular directions into a curved shape. In fact, the deformability of the board is lost due to the shaping that takes place in different directions, and a great effort is therefore required. Thus, in order to prevent a panel from bending around a horizontal axis, as shown in Figure 4, reference number 5, it is sufficient to proceed in such a way that the panel is bent around a vertical axis before it is turned into an almost vertical one Position, in which according to the known device, there is a risk of undesirable deformations. This pre-bending is achieved in a simple manner with the aid of the wire frames which are the subject of the present invention.

Figur 1

eine schematische Seitenansicht einer Transporteinrichtung mit Stützen für flache Transportgegenstände,

Figur 2

eine Draufsicht auf eine Stütze,

Figur 3

eine Stirnansicht auf eine bekannte Stütze,

Figur 4

eine Seitenansicht mehrerer Stützen,

Figur 5,6,7,8,10

Stirnansichten auf verschiedene Ausführungformen erfindungsgemäßer Stützen,

Figur 9

eine Detailansicht einer Stütze,

Figur 11

eine Draufsicht auf eine sich in der Transporteinrichtung befindlichen Stütze.

The invention is explained in more detail with reference to the figures. Show it:

Figure 1

1 shows a schematic side view of a transport device with supports for flat transport objects,

Figure 2

a top view of a prop,

Figure 3

a front view of a known support,

Figure 4

a side view of several supports,

Figure 5,6,7,8,10

End views of different designs of supports according to the invention,

Figure 9

a detailed view of a support,

Figure 11

a plan view of a support located in the transport device.

The most immediate realization of a wire frame (web frame, profile frame) according to the present invention is to bend an ordinary wire frame to give it a shape that corresponds to a section of a cylinder, as shown in Figure 5, or slightly to kink so that an open V-shape is created, as shown in Figure 6. The wire frames according to the invention can have extensions on the side which point upwards (FIG. 7) or downwards (FIG. 8).

In the first three embodiments, the wire frame bends the panel so that the side parts precede the center of the panel in a vertical or almost vertical position during transportation. The opposite is the case in the embodiment of FIG. 8. The wire frames can bend the panels in one way or another, both bending directions are within the scope of the present invention.

In order to facilitate the manufacture of the wire frame according to FIGS. 7 and 8 using conventional tools, The flat steel profiles 6 with a rectangular cross section, which serve to produce the lateral support extensions 7 (arms), can be replaced by trapezoidal profiles. This is shown in Figure 9. In this way, the lateral support extensions 7 automatically form the desired V-shaped angle near approximately 180 degrees during manufacture, with respect to the central part of the wire frame.

If it is not possible to design the panel feeder (belt transport arrangement b) of FIG. 1 in such a way that the panel sides can be raised before they are inserted between two wire frames and if the wire frames are provided with raised side parts, that is to say if they match profiles 5, 6 or 7, the design of the wire frame of FIG. 2 is no longer suitable for the automatic loading of "toothed" panels which have lateral zigzag edges (see dashed line in the middle left of FIG. 11, reference number 8). The side cutouts of these panels, which are found more and more frequently in the metalworking industry, are intended to avoid the metal losses caused by the straight cut when the objects to be produced are assigned to the surface of the panels in a five-way arrangement in order to be painted or printed will. In general, they are round objects, such as lids or can bases, closures, which are manufactured in large quantities and their material costs play a significant role in the cost price.

The representation according to FIG. 2 no longer corresponds to these conditions, because when the panels are loaded automatically, that is to say as soon as they make a translational movement along the wire frame axis, there is a risk that the edges 9 of the toothed sheets 8 collide with the lateral support extensions 7, the latter outer ends are raised beyond the center of the panel.

Figures 10 and 11 show a wire frame which eliminates this disadvantage.

In such a wire frame, the toothed edges are supported by straight and continuous profiles 12¹ and 12², which run parallel to the plane of symmetry of the wire frame and are bent on the outer part, so that, for example, rectangular frames are formed which are welded or riveted to a central part 15. With the help of stiffeners 16, this construction is reinforced.

In a preferred embodiment, the rectilinear profiles 12 1 and 12 2 have an almost trapezoidal cross-section, so that, when assembled, an angled surface is automatically obtained, as shown in section in FIG. 10, the frame or frames 15 and the stiffeners 16 still being made of Flat steel with a rectangular cross-section can be produced.

Figure 11 shows a wire frame having, for example, two side frames 12 1 and 12 2 on each side. This number can be reduced or increased without departing from the scope of the invention. A multiplication of the profiles 12¹, 12², 12 ⁿ leads to the fact that the sides of a large number of panels of different sizes can be better supported, but due to the increased mass of the wire frame there is also an increased energy requirement when heating for the treatment.

Likewise, profiles 12 1, 12 ⁿ with a rectangular cross-section, which are used for the production of the side frames, remain within the scope of this invention if they have a continuous length parallel to the plane of symmetry of the wire frame.

Figure 10 shows that when the profiles 12 have a trapezoidal cross-section, each connection 12 1 - 12 2, 12 2 - 12 ^{n forms} a new oblique angle part which increases the desired curvature of the panel.

On the other hand, the automatic loading devices have devices which slow down and stop each board inserted into the transport device b (FIG. 1). Likewise, the unloading stations d of the same figure are equipped with belts for removal, which are often supported by magnetic or other rollers. The shape of the wire frame must be such that obstacles on its path are avoided.

The wire frames of the present invention have the desired conditions to avoid these obstacles.

On the one hand, the profiles and the outer longitudinal frames 12 2 or 12 ⁿ do not extend over the entire height of the wire frame in order to enable the attachment of a magnetic or pneumatic panel braking device 13, which is only shown by its outline at the bottom right in FIG. 11.

On the other hand, a large arcuate cut-out between the sides 12¹ allows one to get around the horizontal belts and the associated magnetic and pneumatic rollers, the latter pulling out panels which are depressed by the movement of the wire frames at the end of the transport device and passed on to a transport device 18 , according to reference symbol d of FIG. 1.

Moreover, a central bracket 17, which is fixed on the frame 15 in such a way that it passes between two groups of trigger belts 14, prevents the tall and narrow panels, which have been curved by the shape of the wire frame, between the frames 12¹ slip through.

The U-shaped parts, which serve as cross connections between successive wire frames, are on the horizontal sides of the frames 12¹, 12², 12 ⁿ attached, as can be seen from Figure 11.

Such a wire frame (profile frame, web frame) comes into contact with the chains 2 through its two webs which protrude from the sides of the frame 15. These webs extend into the openings of the chain links. The wire frames are held in the classic way by slotted pins.

Such a wire frame, which represents two planes of symmetry before the U-shaped parts 3 are attached, can be used indiscriminately to design a transport arrangement in which the center of the bent metal sheets faces forwards or backwards, the assembly of the cross-connecting pieces 3 (U-shaped parts 3) alone determines how the transport arrangement works.

These wire frames are particularly intended for transport arrangements of drying tunnels, which are installed in printing and painting systems for metal panels, which e.g. for the production of packaging (cans, tin containers, barrels, etc.), bottle caps (capsules, crown caps) or various metal articles that are mass-produced (plates, toys, games, etc.).

Claims (5)

1. A support (1), more particularly a wire-, bar- or section frame for preferably continuous conveying devices (c) conveying flat, thin and flexible objects, preferably provided with a fresh surface coating, such as plates or metal sheets, for instance through a drying tunnel or a tunnel for thermal treatment or through a store for objects between two successive processes, the support being transferable from an approximately horizontal position into an approximately vertical position, characterised in that the surface of the support (1) extends in a curve or bend such that the support (1) holding the object assigned thereto initially in an approximately horizontal position imparts to the object a preliminary curvature about an axis which lies in the vertical, preferably central plane, more particularly the longitudinal plane or the longitudinal central plane of the conveying device (c), so that when the object is erected into the approximately vertical position, the object is prevented from deforming about an axis extending approximately perpendicularly to the said plane before or during conveying.
2. A support according to claim 1, characterised in that it consists of metal sections (6) which are shaped and joined together, in that some sections (6) have a trapezoidal cross-section to produce the curved or bent surface so as to impart the preliminary curvature to the plate.
3. A support according to one of the preceding claims, characterised by exterior sections (sections 12¹, 12², 12ⁿ) which extend parallel to the plane of symmetry of the support and form a continuous underlying support for the complete parts or teeth of the toothing of serrated plates or metal sheets, for example.
4. A support according to one of the preceding claims, characterised by the installation on chains (2) of a continuous conveying device (c), such that the plates or metal sheets are given a preferably cylindrical preliminary curvature, the axis of the cylinder, which lies in the central vertical plane, more particularly the longitudinal central plane of the conveying device (c), lying either in front of or behind the plates during conveying.
5. A support according to one of the preceding claims, characterised by the presence of a central clip (17) which prevents the plate from falling or sliding through between the sides of the support (1).

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