EP1110894B1 - Method and device for folding sheets of material - Google Patents

Abstract

The method for folding sheets of paper (2, 3) comprises conveying them along a folding table (12) parallel to a folding gap (14) in its center. An endless belt (30) mounted above the table moves sets of folding blades (20a -20c) down so that they contact the paper along its entire length and press it into the folding gap. Independent claims is included for: (a) a device for folding sheets of paper; and (b) a printing machine incorporating the device.

Description

The present invention relates to a method and a device for folding material sheets, in particular paper sheets or signatures produced from at least one paper web, according to the preamble of claims 1 and 7.

Such a method and apparatus are known from DE-A-197 25 610.

It is known that web-fed rotary printing machines have a continuous web, e.g. Print a paper web. The continuous web is then further processed in a folder of the printing press. Folding machines can produce desired folds in a finished printed product. As a rule, there is a cutting unit that cuts the web into individual signatures. Often not only the web but also the signatures cut by the web have to be folded.

From US-A-5,458,557 a Schwertfalzvorrichtung is known. A folding knife is suspended at two opposite ends on two pivots which are connected to rotatable connecting arms. The knife thus moves up and down to push a signature between two cylinders to form a longitudinal fold in this way. This device is complicated and requires a complex transmission.

Other folding devices and methods are known from US-A-4 594 876, US-A-2,072,790 and US-A-3,961,783.

US-A-5,030,193 shows a folder having a first folder which forms a first fold in a web along its path. This first fold is formed by drawing the web over a triangular stationary former and passing it between a pinch roller or press roll pair. Subsequently, the web is cut by a knife cylinder in signatures, which are then guided by a folding cylinder to a flap cylinder. A folding blade of the folding cylinder pushes the signature into a flap of the flapper cylinder to form a second fold which is transverse to the first fold. The signatures are then directed to a third folder which includes a belt assembly which grips the signatures and passes through the third folder. The band assembly maintains a straight direction within the third folder. Two fixed formers on the sides of the bands receive the pages of the signature when the signature is in the third folder entry. These formers converge at an angle to the bands so that the outer edge portions of the signatures are moved upwardly to form the fold of the third folder.

The first folding device of the above patent has the disadvantage that the folding device can not be used to fold a stream of individual signatures, since a continuous web has to be moved over the stationary former. The second folding device has the disadvantage that many moving parts are required; the device is complicated and does not have enough capacity for various types of printing machines operating at maximum printing speed. The third folding device has the disadvantage that its structure is complicated and requires a large number of belts of different lengths.

Moreover, prior art knife folding mechanisms require more than one blade folding mechanism for a single maximum speed printing press. Thus, the signature stream often needs to be split and slowed down, resulting in auxiliary devices, such as e.g. Redirecting, slowing down and merging devices required. These ancillary devices increase the risk of folding inaccuracies because the signatures must pass through each device while remaining properly aligned.

In DE-A-197 25 610 a pre-folding device is shown in which a plurality of folding blade segments are arranged side by side on a belt. The belt will fall down when the signature enters the prefold area. The knife segments fold the signature in stages due to the slope, so that the signature is gradually provided with a longitudinal fold from its leading edge to its trailing edge.

This gradual folding can lead to a reduction in quality, such as creasing of the signature during the fold is formed.

The invention is therefore based on the object to provide a method and apparatus for folding signatures in which the speed of the individual signatures to form a fold need not be substantially reduced, and in which the quality of the fold is improved. Furthermore, it is an object of the invention to provide a simplified method and apparatus for folding signatures.

This object is achieved by the features of claim 1 and claim 7. Further features of the invention are contained in the subclaims.

The method according to the invention for folding material sheets, in particular paper sheets or signatures produced from at least one paper web, wherein the material sheets are guided in a transport direction on a folding table having a gap, and wherein at least one folding blade arranged on an endless conveying means has a folded edge, has moved parallel to the transport direction and into the gap, among others the following features: the folded edge is oriented parallel to the sheet of material and the folded edge is contacted with the sheet of material over the entire length of the sheet of material. Contact in this sense means bringing into contact and thus refers to the period in which the Falzmesserkante enters into contact with the sheet of material. So it is the material sheet over the entire length of the sheet of material at the same time touched or hit by the fold edge.

The implementation of the method according to the invention allows the printer to simultaneously fold the material sheets with very high speed and accuracy, whereby only a few process steps are necessary to carry out the method. According to the invention, the material sheets can be folded at undiminished speed, so that advantageously the high speed of the upstream devices, eg printing units or cooling rollers, is maintained even for the folding process. The material sheets, which eg already have a first longitudinal and a first Have transverse fold can be moved forward on a folding table by means of transport devices, such as conveyor belts or blowing devices. They can enter into an area between the folding table having a folding table and the folding blade and get from the folding blade a longitudinal fold, in particular a second longitudinal fold granted. The arranged on the endless conveyor folding blade has a folded edge, which moves with the sheet of material in the transport direction and is oriented to him, that when approaching the fold edge of the material sheet this contacts the sheet of material over the entire length of the sheet of material, ie to the same Time over the entire length of the sheet sets up. By the further movement of the material sheet and the folding blade, which further moves parallel to the transport direction of the material sheet and at the same time in the gap in the folding table, the material sheet is given by the interaction of the folding blade and the folding gap in the folding table of the desired fold. For this purpose, below the folding table means, such as rollers or belts may be provided, which grasp the material sheet, further transport and thereby release the gap in the folding table for a new material sheet. The folding table may preferably have a flat surface, but it is also conceivable that the folding table in cross section has a substantially V-shaped surface, wherein the gap of the folding table is located at the lowest point of the V-shaped surface. The folding blade may have a folded edge with substantially the same length as the material sheets, but it is also preferably possible that the folding edge of the folding blade is longer than the material sheet, for example, to be able to fold larger sheets of material with changing print jobs.

It may further be provided to segment the folding blade, ie to build from individual folding blade segments, which are arranged successively in the transport direction. The segmenting of the folding blade is especially advantageous when large sheets of material to be folded, so that in unsegmented long folding blades Problems in guiding the folding blade on the substantially endless means of transport, in particular at the deflection of the means of transport, could arise.

The at least one folding blade can be moved in the transport direction at an angle of preferably less than 30 degrees to the surface plane of the folding table.

The guidance of the folding blade at an angle of preferably less than 30 degrees advantageously results in the folded edge approaching it during the parallel movement to the material sheet only slowly and contacting it precisely, so that high-quality folds can be produced. The folded edge may be oriented so that, as the folding blade moves in parallel with the sheet of material and as the folding blade moves toward the folding table, it sits perpendicular to the sheet of material.

The folding blades may be arranged in groups, preferably in such a way that at least two groups of folding blades simultaneously process respective signatures. In this procedure, an increased folding speed can be achieved in an advantageous manner.

However, it is also conceivable that only one folding blade, in particular a segmented folding blade, processes a signature, or that a multiplicity of folding blades process a corresponding multiplicity of signatures at the same time, the successive signatures simultaneously passing through different stages of the folding formation.

The folding blades may be disposed on a belt or belt, preferably a toothed belt, which is moved over the folding table at a speed similar to the signature speed. However, the belt may also extend at an angle A to the surface plane of the folding table. In this case, it may be advantageous to move the belt at a speed approximately equal to the signature speed divided by the cosine of the angle A, so that the Speed of the folding blades along the surface plane of the folding table is parallel to the signatures similar to those of the signatures.

The device according to the invention for folding material sheets guided in a transport direction, in particular paper sheets or signatures produced from at least one paper web, has the features of claim 7.

The device according to the invention makes a longitudinal fold in one step, whereby the risk of wrinkling of the material is advantageously reduced.

According to the invention, the material sheets run at a transport speed which advantageously equals that in upstream units, such as e.g. Printing units, prevailing transport speed of paper webs, in the device for folding, and can advantageously at substantially the same speed, the folding process, i. the device for folding, go through.

Each folding blade can preferably be segmented, ie it can consist of individual folding blade segments, which are arranged successively, for example, on the conveying means such that the segments together and aligned represent a folding blade. Preferably, each segmented folding blade comprises folding blade segments having a blade portion and a base portion. Each knife may preferably begin with a segment having a shorter blade portion, with the next blade portions becoming progressively longer. This sloping arrangement ensures that the blades contact the signatures at a favorable angle.

It can also be provided to make the blade and / or the base sections of the transport removable and attachable to the transport, so that different folding blades can be arranged with little effort on the transport.

The segmented folding blades are preferably arranged at intervals on the belt. The distance between the folding blades can correspond to the distance between the signatures entering the device.

The belt may be disposed over the folding table so that the folding blade can pass through a nip in the folding table. Preferably, a pair of folding rollers and conveyor belts are disposed on the other side opposite the folding table to facilitate folding. The folding table preferably comprises a plurality of driven belts for transporting the signature or the book. The folding table may also include tuyeres to assist in the transport of blast.

The belt is preferably so long and shaped that at least two of the e.g. segmented folding blade can fit on one side of the belt opposite the folding table. This arrangement allows folding over a longer distance, which preserves the signature during the folding process, even when the device is operating at maximum speed. The belt may preferably be a toothed belt and driven by a pair of gears. At least one of the gears may drive the belt and e.g. be connected to a drive mechanism for the bands of the folding table. The belt is preferably at an angle which advantageously is e.g. is less than 30 degrees, arranged to the surface plane of the folding table.

The present method and apparatus enable folding of individual signatures at high speed in a straightforward process. In addition, the signature force on folding is substantially reduced as compared to a direct vertical folding mechanism, as the signatures are processed by the folding blade for a longer time than in a direct vertical folding Folding mechanism, eg when a folding blade moves up and down. The folder can be used with different signature lengths, but a reduction in speed between 3% and 18% may be required as the section length varies. Another advantage is that the transport direction of the product is not changed during folding.

Furthermore, vibrations and vibrations of the folding device are advantageously avoided, as they are e.g. caused by moving up and down Falzschwertern, thereby positively affecting the folding quality.

An advantageous embodiment of the present invention is described below with reference to the following drawings:

Fig. 1

zeigt eine perspektivische Ansicht der erfindungsgemäßen Vorrichtung;

Fig. 2

zeigt eine Seitenansicht der erfindungsgemäßen Vorrichtung;

Fig. 3

zeigt eine Vorderansicht der erfindungsgemäßen Vorrichtung;

Fig. 4

zeigt eine mögliche Ausführungsform der vorliegenden Erfindung in einem Falzapparat.

In the drawings show:

Fig. 1

shows a perspective view of the device according to the invention;

Fig. 2

shows a side view of the device according to the invention;

Fig. 3

shows a front view of the device according to the invention;

Fig. 4

shows a possible embodiment of the present invention in a folder.

Fig. 1 shows a perspective view of a folding device 1 for folding the signatures 2 and 3. The signatures 2 and 3 are moved by driven belts 10 along the surface of the folding table 12 in the transport direction 13. Other upper bands move the upper part of the signatures 2 and 3, but are not shown for clarity. The folding table 12 has a gap 14 which extends in the transport direction 13. The folding device 1 comprises a multiplicity of segmented folding blades 20 which have individual folding blade segments 20a, 20b, 20c, etc. The segments 20a, 20b, 20c etc. are mounted on a belt 30 having internal teeth so as to serve as a toothed belt. The belt 30 is driven by at least one of the two gears 32 and 34 and is disposed at an angle A to the surface of the folding table 12, ie the portion of the belt 30 between the gears 32, 34 facing the folding table 12 extends in one Plane which forms an angle A with the plane of the folding table 12.

Each segment 20 a, 20 b, 20 c, etc. of the folding blade 20 comprises a base portion 40, which is preferably fastened to the belt 30 by means of fixing pins, so that the base portion 40 can not slip on the belt 30.

The base portion 40 carries a folding blade segment 20. Two removable bolts or screws may be used to hold the folding blade segment 20 so that the folding blade segment 20 is easily replaceable should it have been damaged. The base portion 40 and the folding blade segment 20 may be made of spring steel, however, these components may also be made of lightweight blended or plastic materials to reduce the weight of the individual folding blades.

Fig. 2 shows a side view of the device of Fig. 1, wherein the folding blade shown in Fig. 1 is moved by the belt 30. Since the folding blade 20 is segmented, the folding blade segments 20a, 20b, 20c etc. can be individually guided over the gear 32. Before the segmented folding blade 20 contacts the surface of the signature, the segments are again arranged in a row and strike the surface of the signature as a straight knife edge. The surface of the signature thus forms a plane, and the knife edge runs in a plane parallel to this plane.

The folding blade segments 20a, 20b, 20c etc. are preferably increasingly longer and have angled edges, so that the knife edge is inclined. The angle between the belt 30, while running straight, and the inclined blade edge preferably corresponds to the angle A between the belt 30 while running straight and the surface plane of the folding table 12. Before the folding blade Signature 4 contacted, it is in the position 4 ', as shown in Fig. 3. The folding blade 20 pushes the signature 4 through an opening, such as a gap 14, in the surface of the folding table 12, while the signature 4 moves further forward (perpendicular to the plane of the drawing). The signature 4 is then picked up by a nip 45 formed between two folding rollers 41 and 42 and transported by conveyor belts 43 and 44 which are passed around the folding rollers 41 and 42. Upon impact of the signature 4 by the folding blade 20 in the opening of the folding table 12 and when passing through the signature 4 of the gap 45 between the folding rollers 41 and 42 of the desired fold in the signature 4 is generated. Thereafter, the signature 4 of the conveyor belts 43 and 44 continued and, for example, a slowing down device and / or a storage device are supplied.

The belt 30 is preferably moved at a slightly higher speed than the signatures when they reach the folding table. This increased speed is intended to equalize the angle A so that the speed of the folding blades, which are moved parallel to the product flow, is similar in speed. Therefore, preferably, the belt may be moved at a speed approximately equal to the signature speed as it approaches the folding table, divided by the cosine of A.

Fig. 4 shows the use of the present invention in a folder. Signatures to be folded can be held on both sides by means of bands (not shown here) so as not to be influenced uncontrollably by gravity. As the signatures are moved through the nip 14 in the folding table 12, they are gripped by the conveyor belts 43 and 44. These transport the signatures to the deceleration device 50, which brakes the folded signatures and can forward them to a conveying device.

The present invention is shown here with segmented folding blades. However, it is also possible to fold the signatures by means of individual rotating folding blades with a continuous folding blade surface attached to a belt.

List of reference numbers

1

folding device

2

Web / Signature

3

Web / Signature

4

Web / Signature

4 '

position

10

powered band

12

folding table

13

transport direction

14

gap

20

segmented folding blades

20a, 20b, 20c etc.

Falzmessersegmente

30

Conveyor / belt

32

gear

34

gear

40

base section

41

folding roller

42

folding roller

43

conveyor belt

44

conveyor belt

45

gap

50

slowing device

60

conveyor

A

angle

Claims (16)

1. Method for folding sheets of material (2, 3, 4), particularly sheets of paper or signatures produced from at least one web of paper, wherein the sheets of material (2, 3, 4) are guided in a direction of travel (13) on a fold table (12) having a slot (14), and wherein at least one folding blade (20) having a folding edge and disposed on an endless conveyor (30) is moved parallel to the direction of travel (13) and into the slot (14),
   comprising the following steps:

   orienting the folding edge parallel to the sheet of material (2, 3, 4),

   bringing the folding edge which is parallel to the sheet of material into contact with the sheet of material (2, 3, 4) simultaneously over the entire length of the sheet of material (2, 3, 4),

   characterised in that the folding edge extends at a sloping angle with respect to the endless conveyor (30).
2. Method according to claim 1, characterised in that the folding blade (20) is segmented.
3. Method according to claim 1 or 2, characterised in that the folding blade (20) is moved at an angle (A) to the direction of travel (13), particularly at an angle (A) of less than 30° to the direction of travel (13).
4. Method according to claim 3, characterised in that the angle between the endless conveyor (30), while it is travelling straight ahead, and the sloping folding edge corresponds to the angle (A) between the endless conveyor (30) and a surface plane of the fold table (12).
5. Method according to one of the preceding claims, characterised in that the conveyor (3) is moved at a slightly higher speed than the speed of travel of the sheet of material (2, 3, 4).
6. Method according to one of the preceding claims, characterised in that the folding blade (20) is moved by means of an endless belt (30).
7. Device for folding sheets of material (2, 3, 4) guided in a direction of travel (13), particularly sheets of paper or signatures produced from at least one web of paper, which may be used to carry out a method according to one of the preceding claims, and which comprises a fold table (12) having a slot (14), an endless conveyor (30) and at least one folding blade (20) mounted on the conveyor (30) and having a folding edge, which is movable parallel to the direction of travel (13) and into the slot (14),
   the folding edge being oriented parallel to the sheet of material (2, 3, 4) and contacting the sheet of material (2, 3, 4) simultaneously over the entire length of the sheet of material (2, 3, 4),
   characterised in that the folding edge extends at a sloping angle to the endless conveyor (30).
8. Device according to claim 7, characterised in that the folding blade (20) is segmented, in particular comprises three blade segments (20a, 20b, 20c, etc).
9. Device according to claim 7 or 8, characterised in that the conveyor (30) has a straight section and in that the straight section forms an angle (A) with the surface of the fold table (12), in particular an angle (A) of less than 30°.
10. Device according to one of claims 7 to 9, characterised in that the folding blade (20) has an inclined blade edge.
11. Device according to one of claims 7 to 10, characterised in that the conveyor is a belt (30), particularly a cog belt.
12. Device according to one of claims 7 to 11, characterised in that at least two folding blades (20) fit on to the straight section of the conveyor (30).
13. Device according to one of claims 7 to 12, characterised by conveyor belts (43, 44) which are disposed underneath the fold table (12) opposite the conveyor (30), for picking up the sheets of material (2, 3, 4) after they have passed through the slot (14).
14. Device according to one of claims 7 to 13, characterised in that the conveyor (30) is disposed between drive wheels, particularly between two gear wheels (32, 34).
15. Folding apparatus, characterised by a device according to one of claims 7 to 14.
16. Printing press, characterised by a device according to one of claims 7 to 14 or a folding apparatus according to claim 15.

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