EP0112432B1 - Flat produce, especially a screening belt or a link belt for paper-making machines or the like - Google Patents

Abstract

An endless sieve band or composite band for paper machines and the like, has a plurality of helixes composed of an elastic wire and each having two opposite winding legs and also two head curves connecting the winding legs with one another and having a predetermined wire diameter and wire width, wherein the helixes are arranged so that when the head curve of one of two neighboring helixes is inserted into an intermediate space of another of the two neighboring helixes an overlapping region is formed into which an insertion wire is introduced, and the winding legs of each of the helixes include a supporting winding leg which has flat supporting sufaces with a width exceeding the wire diameter or the wire width of the head curves.

Description

The invention relates to a flat structure, preferably to a screen belt or link belt for paper machines or the like. with a large number of coils made of elastic plastic or metal wire, which consist of opposing winding legs and head arches connecting them, in the spaces between which a head bow of the adjacent coil is inserted so far that an overlap area arises between the two coils, in which a Plug wire made of plastic or metal is arranged.

Such fabrics are described for example in DE-C 2419751 and DE-A 2938221.

In the initially mentioned patent, the wire coils have a tension in the form of a tension spring in such a way that the respectively adjacent wire coils are in contact with one another.

Such a wire link belt is intended to maintain its dimension elastically, in particular in the transverse direction. Furthermore, the technical progress of such a wire link belt is seen in the fact that production is simplified by the fact that the coils necessarily find their place when they are inserted into one another and cling to one another, so that complex devices can be avoided and that the connecting means no longer have to be stiff and heavy .

In the case of the aforementioned publication, it is provided that the coils do not have a tension preload and that the wire of the coils is torsion-free. This is intended to increase the lifespan of the fabric and ensure freedom from marking.

These different, practically contradicting statements lead to fabrics that can be used in many different ways.

Over time, however, it has been shown that these fabrics have peculiarities for which improvements are sought. As a result of the mostly round or slightly oval cross-sections of the wires from which the coils are made, the fabric has an extremely high air permeability. This is sometimes desirable, but in paper making it often causes the paper to flutter.

This helps to ensure that filling elements are also inserted into the coils made of elastic plastic or metal wire - in addition to the connecting means (plug wires). This allows the air permeability to be influenced, but a considerable amount of work has to be accepted in order to insert the parts designed as plug wires or as a cotton-plastic filler into the coils. In addition, material consumption and purchase price increase.

Another peculiarity of previous flat structures is the so-called point contact between the supporting winding legs and, for example, the paper. Depending on the weight and quality of the paper and the contact pressure during manufacture, it leads to pressing of the winding legs on the finished paper. Although these prints are desirable for the production of samples, for example, these prints must be avoided in the production of highly qualified smooth papers.

The only punctiform or edge-shaped contact between the supporting winding legs of the coils and the paper leads to another peculiarity of the known flat structures, namely to the fact that the heat flow between the calender roller and the paper is only weak due to the low contact possibilities and the resulting small contact areas is. As a result, the load-bearing winding legs have larger contact surfaces with the paper, which reduces the risk of marking at the contact points and contact edges and improves the heat flow, but an even higher air permeability of the flat structures must be accepted, since the distance between the individual turns of the coils becomes larger.

In order to reduce this air permeability, sealing rails or sheet metal inserts are also used in the last-mentioned flat structures, which are introduced in the longitudinal direction in the coils or in the spaces between adjacent winding legs.

In contrast, the present invention has for its object to provide a fabric of the type described, which combines the advantages of easy manufacture from round wire coils with the advantages of large contact surfaces and good heat transfer and a limited air permeability.

It has been found that this problem can be solved in a simple manner in that the supporting winding legs of the coils have flat contact surfaces, the width of which is greater than the wire diameter or the wire width of the head bends.

As a result, the coils can be joined together to form flat structures just as easily - often even more easily - than coils made of round wire. Only one spiral size needs to be provided for the automatic production of the flat structures on production (joining) machines. In other words, practically all automatic manufacturing (joining) machines can easily produce flat structures with only one coil size.

In addition, manual production is easier and lighter, since the filaments used are more precise and smoother than previously used filaments.

The gaps between the individual winding legs can be large as required be designed smaller or smaller. Not only are advantageous, large, flat receiving surfaces of the supporting winding legs obtained, but also an air flow of the desired strength, without the disadvantageous use of fillers between the winding legs or within the coils.

The heat transfer, for example from calender rolls through the sheet to the paper, also improves.

Comparable advantages also arise with regard to numerous other possible uses of the flat structures according to the invention, for example as a screen belt.

Due to the width of the turn legs and the dependent size of the gaps in the entire fabric, it is possible to vary the air permeability between that of an almost closed total contact surface and that which is formed from load-bearing turn legs, the width of which is only slightly larger than that Diameter or the width of the head arches.

In one exemplary embodiment of the invention, the new sheet-like structure is designed such that the turns of the spirals opposite the turns of the helixes that have the flat bearing surfaces have a round, oval or triangular cross-section. The air permeability is only influenced by the load-bearing turn legs.

A further variation possibility of the air permeability with a good support for the paper results from the fact that both winding legs of the coils connected to a head bend each have flat contact surfaces. As a result, the air flow is opposed to a greater resistance than in the first embodiment.

According to the invention, it is in the hand that the wires of the head arches of the coils have a substantially round, oval, triangular or rectangular cross-section, at most squeezed in relation to their original shape, and the winding legs, which have flat contact surfaces, have an almost rectangular cross-section. This enables us to provide fabrics that meet all the requirements placed on them with regard to their assembly, their flexibility, their air permeability, their contact surfaces and their heat transfer from calender rolls to paper.

In particular, the flat structures according to the invention are characterized in one exemplary embodiment in that the width of the turn leg having a flat contact surface is up to twice as large as the wire diameter or the wire width of the head bends.

The coils of the new flat structure are wound on division in such a way that the coils have a tension spring-like pre-tension, but the fixed space between their head arches is larger than their wire diameter or wire width. As a result, the head arches of adjacent coils do not lie against one another, even though the coils as such have a pre-tensioned tension.

Further advantages and possible variations can be achieved in that the spirals are alternately right-handed or left-handed spirals.

Without changing anything at the core of the invention, all coils of the flat structures can also be right-hand or left-hand coils.

Although the distance between the head arches of the coils is larger than the width or the diameter of the head arch wires, the coils can be stored in collection containers before they are manufactured without them getting caught.

In a further exemplary embodiment of the invention, the turn legs form an angle different from 90 ° with the plug wires, whereas the head arches of the coils form an angle of approximately 90 ° with the plug wires.

Further different designs of the flat structures according to the present invention can be found in claims 13, 14 and 15.

Also advantageous are flat structures which, according to the invention, have eyelets or tabs for inserting thorns in their edge fastenings. In the case of such flat structures, the plug wires are preferably made of steel wire, so that the flat structures can be pulled apart to a greater or lesser extent via the spikes, for example in order to vary the passage of air. Without changing anything at the core of the invention, in this exemplary embodiment the plug wires can also be made of plastic. As a result of the elasticity of the individual coils, the fabrics can be reduced to their original length as required.

In order to achieve the same effect, the edge fastenings of some flat structures according to the invention also have reinforcements for attacking claws.

Embodiments of the invention are explained below with reference to the drawing.

• Fig. 1 eine Draufsicht in schematischer Darstellung auf ein Ausführungsbeispiel der Erfindung,
• Fig. 2 eine Draufsicht auf weitere Ausführungsbeispiele der Erfindung,
• Fig. 3 eine Draufsicht auf ein anderes Ausführungsbeispiel der Erfindung,
• Fig. 4 eine Draufsicht auf ein weiteres Beispiel der Erfindung,
• Fig. 5 die Draufsicht auf ein Ausführungsbeispiel der Erfindung, bei dem Windungsschenkel und Kopfbögen der Wendeln unterschiedliche Ausrichtungen zum Steckdraht aufweisen,
• Fig. 6 einen Querschnitt entlang der Linie VI, VI in Figur2,
• Fig. 7 einen Querschnitt entlang der Linie VII, VII in Figur 3,
• Fig. 8 einen Teilschnitt durch ein Flächengebilde,
• Fig. 9 einen Teilschnitt durch ein Flächengebilde entlang der Linie IX, IX in Figur 10 und
• Fig. 10 eine Konstruktionseinzelheit.

It shows:

• 1 is a plan view in a schematic representation of an embodiment of the invention,
• 2 shows a plan view of further exemplary embodiments of the invention,
• 3 is a top view of another embodiment of the invention;
• 4 is a top view of another example of the invention;
• 5 shows the top view of an exemplary embodiment of the invention, in which the winding legs and head bends of the coils have different orientations with respect to the plug wire,
• 6 shows a cross section along the line VI, VI in FIG. 2,
• 7 shows a cross section along the line VII, VII in FIG. 3,
• 8 shows a partial section through a flat structure,
• Fig. 9 is a partial section through a sheet along the line IX, IX in Figure 10 and
• Fig. 10 shows a construction detail.

FIG. 1 shows a schematic overview drawing, in which a partial section of a flat structure generally designated 1 is shown. The flat structure itself, which is only shown in the cutout, can have any length and width. The two vertical lines in the middle of the illustration are intended to indicate this schematically.

The flat structure consists of individual helices 2, which can be right-handed, for example, like the helix 3 or left-handed, like the helix 4. Adjacent coils themselves are made from resilient plastic or metal wire in a manner not of interest in connection with the present invention. As shown in FIG. 10, they consist of supporting winding legs 7 and winding legs 8 lying opposite them. The winding legs are connected to one another by means of head bends 17.

FIG. 1 shows that there are spaces 18 between the individual head arches, into each of which a head arch of the adjacent coils is inserted. As a result, there is an overlap area 24 between two adjacent coils, as can be seen in FIG. 8, in which the plug wire 25 is inserted. The head arches 17 of adjacent coils together with the plug wire 25 form an articulated hinge-like connection.

The plug wire 25, like the material of the coils, can be made of plastic or metal.

The supporting winding legs 7 lying on top in the plan view according to FIG. 1 have flat contact surfaces 12, the width 13 of which is greater than the wire diameter 23 or the wire width 23a of the head bends 17.

The space 18 between adjacent head arches 17 is larger than the wire diameter 23 or the wire width 23a of the head arches.

FIG. 2 shows that opposite winding legs 8 run below the supporting winding legs 7, which, in contrast to the contact surfaces 12, can have a round cross-section 9a or a triangular cross-section 9b.

In a further exemplary embodiment, the opposite winding legs 10 can also have rectangular cross sections 11.

FIG. 2 shows that the opposite winding legs 10 can also have a rectangular cross section 11.

In FIG. 2 it is further indicated that the wire from which the coils 3 or 4 are made is an elastic plastic or metal wire 5, the diameter 6 of which in some exemplary embodiments of the invention is approximately the same as the diameter of the head arches 17.

The opposite winding legs 10 can also have flat contact surfaces 12 in particular exemplary embodiments of the invention.

The flat contact surfaces 12 have a width 13 and edges 14, between which distances 16 are arranged.

According to FIG. 2, the flat structure consists of left-hand and right-hand helixes 4 and 3. It can be seen that the head arches of adjacent helixes are fundamentally not in contact with one another as a result of a spiral spring-like tension. This is due to the fact that the coils 2, 3, 4 are wound on division and that they have a tension spring-like pre-tension such that the fixed space 18 between their head bends 17 is larger than their wire diameter 23 or their wire width 23a. The wires 22 of the head arches 17 (FIG. 8) of the coils 2, 3, 4 have an essentially round cross section 20, an oval cross section 20a, a triangular cross section 20b or a rectangular cross section 20c, which is at best crimped against their original shape, as indicated by position 21 in Figure 7. Irrespective of the shape of the wires of the head bends, the turn legs 7 and 10 having flat contact surfaces 12 have an almost rectangular cross section 11.

In order to give the sheet-like structures according to the invention a wide range of variation with regard to the contact surface, air passage and heat transfer and with regard to their mechanical or manual production, the width 13 of the flat contact surfaces can be up to twice as large as the wire diameter 23 or the wire width 23a of the head bends 17. In one In another exemplary embodiment, the width 13 of the flat contact surfaces 12 and the winding legs 7, 10 having them is twice as large as or larger than the wire diameter 23 or the wire width 23a of the head bends 17. Which width ratio is selected in detail depends on the intended use of the fabric.

FIG. 3 shows an embodiment in which the coils 2 are all left-handed coils 4.

FIG. 4, on the other hand, shows an exemplary embodiment in which all the coils 2 are right-handed coils 3. The exemplary embodiment according to FIG. 4 shows that the edges 14 of adjacent flat contact surfaces 12 lie close together. According to the embodiment shown in Figure 3, a distance 16 is provided between the edges 14. The configuration of the width 13 of the flat bearing surfaces 12 and the resulting spacing 16 between the flat bearing surfaces 12 allow, for example, in paper production airflow passing through the fabrics varies.

Figure 5 shows an embodiment in which the winding legs 7 and the opposite winding legs 8 and 10, not shown, with the plug wires 25 form an angle a different from 90 °, while the head arches 17 of the spirals 2, 3, 4 form an angle β of approximately Take 90 °. This design of the flat structure allows the passage area for the air to be provided with an even smaller cross section than in the other exemplary embodiments.

FIGS. 6 and 7 show dimensions of the individual helices in detail. FIG. 6 shows that the load-bearing winding legs 7 have an almost rectangular cross-section 11, as a result of which flat contact surfaces 12 are created. The width 13 of these load-bearing winding legs 7 is dimensioned in accordance with FIG. 6 such that a distance is maintained between the edges 14. This distance is fixed.

The opposite winding legs 8 have a round cross section 20 according to FIG.

In the exemplary embodiment according to FIG. 7, the load-bearing turn legs 7 and the opposite turn legs 10 both have rectangular cross sections 11. The head arches 17, on the other hand, have a squeezed cross-section 21, which may also have resulted from an oval, triangular or rectangular base cross-section 20a, 20b, 20c.

The schematic representation according to FIG. 8 reveals details of the mass once again. The head arches 17 have outer edges 19. The total distance between these outer edges 19 is designated 32. It is given by the double wire diameter 23 or the double wire width 23a of the head bends 17, the diameter 26 of the plug wire 25 and by the play 27 between the head bends 17 and the plug wire 25. As a result of this play, the hinge effect between adjacent coils is possible.

8 in FIG. 8 denotes the so-called overlap area, which is given by the diameter 26 of the plug wire 25 and by the play 27 between the plug wire 25 and the head arches 17. With 33 the distance from the inner edge of a head bow to the outer edge 19 of the opposite one Called head bow.

FIGS. 9 and 10 show further details of the fabric with cross sections 11 of the head arches 17, which are rectangular, and cross sections 9a and 9b, which are oval or triangular. Which wire or head bow cross-section is used in detail depends on the desired use of the fabric.

According to FIG. 10, the head arches 17 are somewhat crushed during the manufacture of the coils. As a result of subsequent fixing of the coils, in most exemplary embodiments they have the oval shape according to FIG. 10.

Figure 1 reveals special features of an embodiment. The edge fastenings 28 are necessary in order to permanently fix the width of the flat structures. Eyelets 29 and spikes 30 are indicated on the right side of FIG. 1, whereas reinforcements 31 can be arranged in the edge fastenings 28 on the left side of FIG. With the aid of the mandrels 30, the flat structures can be pulled apart as required, especially if the plug wires 25 are made of metal, as a result of which the passage of air through the flat structure can be varied as desired. To ensure that eyelets 29 are held securely in the edge fastenings, barbs 34 are provided. The tabs 35, into which mandrels can also be inserted for pulling the flat structures apart during operation, have securing holes 36 which ensure their secure fit within the edge fastenings 28 made of plastic.

Claims (17)

1. A flat-shaped article, preferably an endless sieve band or composite band for paper machines or the like, comprising a plurality of helixes composed of an elastic plastic or metal wire each having opposite winding legs and head curves interconnecting said winding legs, in the intermediate spaces of which head curves is respectively inserted one head curve of the neighboring helix to such a degree that between the two helixes an overlapping region is formed in which is arranged an insertion wire of plastic or metal, characterized in that the supporting winding legs (7) of the helixes (2, 3, 4) have flat supporting surfaces (12) with a width (13) exceeding the wire diameter (23) or the wire width (23a) of the head curves (17).

2. A flat-shaped article according to claim 1, characterized in that the said winding legs (8) of helixes (2, 3, 4) disposed opposite supporting winding legs (7) having flat mounting surfaces (12), are of a round (9), oval (9a), or triangle-like (9a) cross-section.

3. A flat-shaped article according to claim 1, characterized in that both winding legs (7, 10) of helixes (2, 3, 4) respectively connected to one head curve (17) each comprise flat mounting surfaces (12).

4. A flat-shaped article according to claims 1 to 3, characterized in that the wires (22) of the head curves (17) of the helixes (2, 3, 4) have a substantially round (20), oval (20a), triangle-like (20b) or rectangle-like (20c) cross-section or a cross-section at best squeezed (21) relative to its initial design, and that the winding legs (7, 10) comprising flat mounting surfaces (12) are of an almost rectangle-like cross-section (11).

5. A flat-shaped article according to claims 1 to 4, characterized in that the width (13) of the winding legs (7, 10) comprising flat mounting surfaces (12) is double the wire diameter (23) or the wire width (23a) of the head curves (17).

6. A flat-shaped article according to claims 1 to 4, characterized in that the width (13) of the winding legs (7, 10) comprising flat mounting surfaces (12) is double or more than double the wire diameter (23) or the wire width (23a) of the head curves (17).

7. A flat-shaped article according to claims 1 to 6, characterized in that the helixes (2, 3, 4) are wound with a predetermined spacing.

8. A flat-shaped article according to claims 1 to 7, characterized in that the helixes (2, 3, 4) comprise a tension spring-type preload, whereas the fixed intermediate space (18) between the head curves (17) thereof is larger than the wire diameter (23) or the wire width (23a) thereof.

9. A flat-shaped article according to claims 1 to 8, characterized in that the helixes (2) are alternately arranged left-side or right-side helixes (3, 4).

10. A flat-shaped article according to claims 1 to 8, characterized in that all helixes (2) are right-side helixes (3).

11. A flat-shaped article according to claims 1 to 8, characterized in that all helixes (2) are left-side helixes (4).

12. A flat-shaped article according to any one or more of claims 1 to 11, characterized in that the winding legs (7) form with said insertion wires (25) an angle a differing from 90°, whereas the said head curves (17) of the helixes_'(2, 3, 4) form an angle β substantially corresponding to 90°.

13. A flat-shaped article according to any one or more of claims 1 to 12, characterized in that the edges (14) of the winding legs (7, 10) comprising flat mounting surfaces (12) are in abutting relationship.

14. A flat-shaped article according to any one or more of claims 1 to 12, characterized in that the edges (14) of the winding legs (7, 10) including flat mounting surfaces (12) are disposed in spaced (16) relationship with respect to one another.

15. A flat-shaped article according to claims 1 to 14, characterized in that the distance (32) between the outer edges (19) of head curves (17) disposed in side-by-side relationship is defined by the double wire diameter (23) or the double wire width (23a) of the head curves (17), the diameter (26) of the insertion wire (25) and the play (27) between the head curves (17) and the insertion wire (25) which permits a hinge action.

16. A flat-shaped article according to claims 1 to 15, characterized in that anchored in the marginal mountings (28) thereof are ears (29) or tongues (35) for the introduction of bolts (30).

17. A flat-shaped article according to claims 1 to 15, characterized in that marginal mountings (28) thereof include reinforcements (31) for the attack of tow jaws.

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