EP1213245B1 - Method and device for folding sheets - Google Patents

Abstract

The invention relates to a process and an apparatus for folding sheets (2), in particular printed sheets. A sheet (2) which is fed in a state in which it lies horizontally in a feed plane (7) is fed to at least two incipient-folding rollers (4) by a rectilinear knife (6), which can be moved perpendicularly to the feed plane (7), and is received between the incipient-folding rollers (4) in order to form a fold (8). The sheet is then conveyed away in the direction of the fold without being completely closed. The sheets are conveyed away by at least two removal rollers (5), by means of which the fold is also completed. The sheets are advantageously folded and conveyed away in one process step in the case of the invention, an additional opening step prior to the further processing of the sheet being dispensed with.

Description

The invention relates to a method for folding sheets according to the preamble of claim 1. The invention further relates to a device for folding sheets according to the preamble of claim 9.

For folding sheets, e.g. in the course of producing a nested and / or bound printed matter, it is known to have a bow half on the others to turn over and the bow along the crease line to smooth out. Sword crimps are also known, at to them a flat bow through a straight sword from below or bent up, between two or more in parallel to each other and to the sword oriented roles and by rotating the rollers between them is promoted. By placing the roles in pairs are pressed against each other when conveying a fold is formed in the arch. With such folding devices is the direction of conveyance of the folded sheet perpendicular to Original funding level. The folded sheet must therefore in a further step the original Funding level are fed. Furthermore, the Further processing of the sheet, e.g. to plug into each other. several sheets and, if necessary, the subsequent one Stapling, usually necessary after folding arch halves lying on top of each other are opened again, which requires an additional step. On Another problem with known swordfolds is that the activated sword spreads the folds presses, so that for the clean folding further parallel to arranged rollers are necessary. This is particularly problematic with thicker sheets that come from several single sheets one on top of the other strong paper.

EP-A 0 846 573 discloses a folding device and a Process for producing an Ω-shaped fold. After a incoming sheet or sheet stack with a sword in the middle the fold is raised by two relative to each other movable jaws manufactured. The folded product is after opening the jaws from the fold area towards the Folded edge ejected.

The invention is therefore based on the object Method and device for folding a sheet indicate with which or with which the named Problems are avoided. In particular, the process should or the device with the smallest possible number from working steps and components.

The object is achieved by a method for folding Sheets with the features of claim 1. The task is further solved by a device for folding Sheets with the features of claim 9 advantageous Further developments of the method and the device are in the dependent claims, the description and the drawing described.

According to the invention, a sheet fed in a feed plane is fed through at least two folding rollers by a straight sword movable perpendicular to the feeding plane and is picked up between the folding rollers to form a fold. The sheet is then conveyed away in the direction of the fold without being completely closed. At least two conveying rollers are used for conveying away, with which the fold can also be completed. In the case of the invention, the folding and the conveying away are advantageously carried out in one process step, an additional opening step before further processing of the sheet being omitted. In the context of the invention, a sheet is understood to mean a single sheet, a plurality of sheets placed one on top of the other or a sheet which has already been folded at least once.

For example, the sword is aligned horizontally, and lifts the sheet from the bottom up to the folding rollers or the other way around. The preferably parallel to each other arranged folding rollers can be rotated about an axis of rotation, that runs parallel to the sword. They form a fold which is aligned parallel to the sword. Of the The sheet is rolled further perpendicular to the Feed level, e.g. promoted upwards or downwards. However, its ends lie on one, for example Edition on, in particular one used for feeding Feeder so that the sheet is not complete is closed. Then the arch is between at least two removal rollers added and by these in the direction of the fold, i.e. parallel to the folding rolls or transported to the feed level. The axes of rotation of the Conveyor rollers are perpendicular to the feed plane directed. The conveyor rollers can be above or be arranged below the folding rollers. alternative or in addition, away conveyor rollers laterally, from. the Folding rolls are arranged so that this one of the Crimp rolls not picked up sheets above or below the folding rollers but behind in the folding direction pick up the crimp rolls. This is especially for suitable paper formats in which half Sheet width smaller than the distance of the feed plane from the side of the folding rollers facing away from the feed plane is so that the bow when shooting through on this Side arranged rollers would be closed.

By not completely closing the sheet when folding an opening step before further processing of the bow are eliminated. Preferably the folded, not completely closed sheets when conveyed away directly put a saddle on.

By removing the feed rollers functionally from the folding rollers separated, can be conveyed away in an advantageous manner also realized in the original feed direction become. This is particularly beneficial for continuously working processing facilities at which should avoid changing the current direction. Alternatively, the arch can also be perpendicular to Sword or fold direction are fed.

The conveyor rollers are advantageous especially with thicker layers or with several layers existing sheets are also used for end folding by the fold formed by the folding rollers between them record and during or by conveying away in one Complete the operation. According to the invention can therefore Folding station compact and space-saving in one Processing system for printed products integrated become. Another advantage is that the fold formation by rolling also for paper formats with fiber orientation is suitable across the fold. Finally, the folded one Sheet in the invention kept open in a simple manner by placing both bow ends facing away from the fold rest on a support surface. In this way the Sheet transported away in a V-shaped open state and can be done directly without an additional one Opening step can be processed further.

The invention is particularly suitable for folding printed sheets of paper made from a digital printing system come. Such paper webs usually have one Width of about 520 mm. By folding a booklet with the half web width generated. Even smaller booklet widths can be produced without loss of quality, because the Folding device according to the invention regardless of Fiber alignment within the sheet, i.e. also at Fiber alignment across the fold, good folds produced.

Fig. 1a,b

eine erfindungsgemässe Vorrichtung zu Beginn des Falzens eines Bogens im Querschnitt und in Seitenansicht;

Fig. 2a,b

eine erfindungsgemässe Vorrichtung beim Anfalzen eines Bogens im Querschnitt und in Seitenansicht;

Fig. 3a,b

eine erfindungsgemässe Vorrichtung beim Wegfördern eines Bogens im Querschnitt und in Seitenansicht;

Fig. 4a,b

eine erfindungsgemässe Vorrichtung in Ansicht von der Front und schräg von der Seite.

Embodiments of the method and the device are shown in the drawings and described below. Here show purely schematically:

1a, b

a device according to the invention at the beginning of the folding of a sheet in cross section and in side view;

2a, b

an inventive device when folding a sheet in cross section and in side view;

3a, b

a device according to the invention when conveying away a sheet in cross section and in side view;

4a, b

an inventive device in a view from the front and obliquely from the side.

In Figures 1a, 1b, 2a, 2b, 3a, 3b is one Device 1 according to the invention in various stages of the folding method according to the invention in each case Cross section (Fig. 1a, 2a, 3a) and in the view of the Side (Fig. 1b, 2b, 3b) shown. Same parts are provided with the same reference numerals.

A sheet 2 is for folding with a in the conveying direction F transporting feed device 3 in a feed plane 7 placed under two folding rollers 4. By means of a stop 14 shown only in FIG. 4a, b, which is arranged downstream of the folding rollers 4, the front edge 2a of the sheet 2 is perpendicular to Direction of delivery F aligned and below the downstream end 4a of the folding rollers 4 positioned. The length of the arch preferably exceeds 2 not the length of the crimp rolls 4. The feeder 3 comprises at least two in the feed plane 7 conveyor belts 3a, 3b arranged parallel to one another, in the parallel to the axes of rotation 9 of the folding rollers 4th Transport the running conveying direction F. In the middle is a flat between the conveyor belts 3a, 3b flat sword 6 arranged. Its upper edge 6a is in Direction of conveyance F aligned, the sword surface is located through the middle between the folding rolls 4 Central plane 11 running perpendicular to the feed plane 7, in which the sword 6 is moved to be folded. By Sword 6 and folding rolls 4 will be the direction of the fold 8 set. The upper edge 6a of the sword 6 is located first below the feed level 7 and thus below the arch 2, see Fig. 1a, 1b. Has the bow 2 the position shown in Fig. 1b below the folding rollers 4th reached, the feed device 3 is stopped. The Sheet 2 can also be moved vertically Be held in position without the stop Stop conveyor 3.

The sword 6 is now up in the middle plane 11 moves and presses the sheet 2 in the middle of the sheet up and between the crimp rolls 4. This situation is shown in Fig. 2a, 2b. The folding rolls 4 are now in a counter-rotating movement about its axes of rotation 9 offset and thus pull the sheet 2 to form a Fold 8 up. You can also run continuously. The folding rolls 4 are at least in this stage of the process pressed against each other, for example by means of a clamping device, e.g. a feather. After this the sheet has been gripped by the folding rollers 4, it will Sword 6 moved back to its starting position. The Folding rollers 4 convey the sheet 2 further upwards until the fold 8 arranged from above the folding rollers 4 Conveyor rollers 5 can be taken. The Conveyor rollers 5 are as close as possible the folding rollers 4 arranged and perpendicular to the Feed axis 7 rotating axes 10 rotatable. In the present case there are two conveyor rollers 5 as well the folding rollers 4 symmetrical to one through the sword surface extending center plane 11 is arranged. By opposite rotation of two away rollers 5 is the sheet is conveyed away in the original feed direction F. Two sheets 2 or 8 at a time between conveyor rollers 5 receiving each other are against each other pressed. When it is transported away, it is all in one Operation of the fold 8 improved, and there is a very clean, sharply folded fold. The situation with Removal is shown in Fig. 3a, 3b.

The folding rollers 4 are preferably used during folding and Conveying a sheet 2 pressed against each other while there is a gap between the conveyor rollers 5, which is used to accommodate the folded sheet 2 more easily. Before and during removal, the removal rollers 5 pressed against each other and the folding rollers 4 apart moved so that the sheet 2 transported away easily through the The gap between the folding rollers 4 are pulled through can.

As can be seen from FIGS. 2a, 2b, 3a, 3b, the Sheet 2 through the folding rollers 4 not completely by promoted. The parallel to the fold 8, in Conveying direction F lateral edges 2c, 2d remain below the folding rollers 4 and are also in the conveying away on the conveyor belts 3a, 3b. This will make the Sheet 2 kept open during and after folding in a simple manner. For example, it can be used when conveying away on a downstream of the folder 1 Saddle 16 (see. Fig. 4b) pushed on and in open or not completely closed condition to be processed further.

Downstream from the crimping rollers 4 are others Conveyor rollers 15 arranged (only shown in Fig. 3b), whose axes of rotation are also perpendicular to the feed plane 7 are. The distance of these further conveyor rollers 15 from the feed level 7 is less than the distance of the Above the folding rollers 4 4 arranged away rollers 5. The other conveyor rollers 15 are particularly for narrower sheet formats used. Extend here the other conveyor rollers over the entire height of the Folding rolls, their top end at the level of the Conveyor rollers 5 lies. This has the advantage that any paper formats with the other conveyor rollers 15 largely independent of the height of the fold can be finally folded. If only small sheet formats can be processed, the above the Folding rollers 4 arranged away rollers 5 also to be dispensed with.

In the manner described, several can be consecutively Collect folded sheets to be processed together to become.

4a, b show a further example of an inventive one Device in a view from the front and obliquely from the side. In the lower area between two Folding rollers 4 'there is a sword 6' for pushing up of on a feed device 3 'with at least two parallel conveyor belts 3a ', 3b' Arches (not shown). The feeder 3 'conveyed in the direction of conveyance F. Supplied arches through an aligned transversely to the conveying direction F. vertically movable stop 14 below the folding rollers 4 'positioned. Above the folding rollers 4 ' there are a plurality of opposed to each other in pairs Conveyor rollers 5 '. One conveyor roller each 5 'of a pair is driven by a drive rod 12 driven. The other is via gears 13 Conveyor roller 5 'with the opposite direction of rotation driven. Other drive variants are conceivable. The Feed device 3 'extends into the Area downstream of the crimping and Conveyor rollers 4 ', 5' and also serves to convey the folded sheet in the open state. Of the The sheets are transported away onto a saddle 16 pushed on so that they stay open. to Processing narrower sheet formats can also process more Conveyor rollers, as shown in Fig. 3b, may be present.

Claims (18)

1. A process for folding sheets (2), in particular printed paper sheets, it being the case that a sheet (2) which is fed in a feed direction (F) in a state in which it lies horizontally in a feed plane (7) is fed to at least two incipient-folding elements (4, 4') by a rectilinear knife (6, 6'), which can be moved perpendicularly to the feed plane (7), is received between said rollers in order to form a fold (8) and is conveyed away in the direction of the fold without being completely closed, characterized in that the incipient-folding elements are incipient-folding rollers (4, 4'), and, once it has been incipiently folded, the sheet (2) is received between at least two removal rollers (5, 5') and is conveyed away by said removal rollers (5, 5') in the direction of the fold.
2. The method as claimed in claim 1, wherein, once it has been received by the incipient-folding rollers (4, 4'), the sheet (2) is conveyed further by said rollers perpendicularly to the feed plane (7) and then is received between the at least two removal rollers (5, 5') and is conveyed away by the latter in the direction of the fold.
3. The method as claimed in claim 1 or 2, wherein, as it is conveyed away, the sheet (2) is positioned on a saddle (16) aligned in the direction of the fold.
4. The process as claimed in claim 3, wherein the removal rollers (5, 5') receive the sheet (2) in the region of the fold (8) and convey it away while the lateral borders (2c, 2d) of the sheet (2) are preferably at least partially located between the feed plane (7) and the incipient-folding rollers (4, 4').
5. The process as claimed in one of the preceding claims, wherein the incipient-folding rollers (4, 4') are pressed against one another as the sheet (2) moves through them and are preferably spaced apart from one another as the sheet (2) is conveyed away.
6. The process as claimed in one of the claims 3 to 5, wherein the removal rollers (5, 5') are pressed. against one another as the sheet (2) is conveyed away and are preferably spaced apart from one another as the sheet (2) is conveyed through the incipient-folding rollers (4, 4').
7. The process as claimed in one of the preceding claims, wherein the feed direction (F) and the direction of the fold correspond to one another.
8. The process as claimed in one of the preceding claims, wherein use is made of a feed arrangement (3, 3') for feeding the sheet (2), and it also serves for conveying away the folded sheet in the feed direction (F).
9. An apparatus for folding sheets (2), in particular printed paper sheets, having a knife (6, 6') which has a rectilinear top edge (6a), located in the feed plane (7), and can be moved perpendicularly to the feed plane (7), and having two incipient-folding elements in order to form a fold, characterized in that the incipient-folding elements are at least two incipient-folding rollers (4, 4') which are arranged parallel to the feed plane (7) and of which the axes of rotation (9) run parallel to the edge (6a) in each case, and that at least two removal rollers (5, 5') are present, of which the axes of rotation (10) run perpendicularly to the feed plane (7) and which are arranged on that side of the incipient-folding rollers (4, 4') which is directed away from the feed plane (7) and/or to the side of the incipient-folding rollers (4, 4').
10. The apparatus as claimed in claim 9, which comprises a saddle which is intended for receiving folded sheets (2) and is arranged downstream of the knife (6, 6').
11. The apparatus as claimed in claims 9 or 10, wherein the incipient-folding rollers (4, 4') can be moved in relation to one another so as to form between them a gap in which the sheet (2) can be displaced as it is conveyed away.
12. The apparatus as claimed in one of claims 9 to 11, which comprises a feed arrangement (3, 3') for feeding a horizontally lying sheet (2), in a feed direction (F), into the region between the knife (6, 6') and the incipient-folding rollers (4, 4').
13. The apparatus as claimed in claim 12, wherein the top edge (6a) of the knife (6, 6') is aligned in the feed direction (F).
14. The apparatus as claimed in claim 12 or 13, wherein the feed arrangement (3, 3') comprises at least two transporting belts (3a, 3b, 3a', 3b') which are arranged to the sides of the knife (6), parallel to the same.
15. The apparatus as claimed in one of claims 9 to 14, which comprises a stop for fed sheets (2), said stop being arranged in the feed plane (7) downstream of the knife (6, 6') and perpendicularly to the feed direction (F).
16. The apparatus as claimed in one of the claims 12 to 15, wherein the distance of the removal rollers (5, 5') from the feed plane (7) is less than half the sheet width.
17. Use of the apparatus as claimed in one of claims 9 to 16 for carrying out the process as claimed in one of claims 1 to 8.
18. Use of the apparatus as claimed in one of claims 9 to 16 for folding paper sheets with a grain direction transverse to the fold.

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