EP0795507B1 - Device for folding sheets - Google Patents

Description

The invention relates to an arrangement for folding sheets by means of Folding rollers and an adjustable stop.

Folding devices are required to prepare letterhead for inserting or to fold sheets for bookbinding. Depending on the application, the sheets are simply folded in the middle, for example if A4 format sheets are to be filled in C5 format envelopes, or folded twice if, for example, A4 format sheets are to be filled in C6 format envelopes. In the latter case, the fold can be Z-shaped or a so-called folded fold.
If such folding devices are an integral part of sorting and inserting devices, it is also sometimes necessary, for example in the case of account statements or booking receipts, that the sheets pass the folding device without being folded.
Two fold principles have prevailed, the sword fold principle - compare DE 40 18 709 A1 and DE 43 24 199 C1. - and the pocket fold principle, also known as the compression fold principle, compare DE 40 12 859 C2, EP 0 583 587 A1, EP 0 595 105 A1 and EP 0 641 733 A1.

With the sword fold principle, the sheets to be folded are pressed through a gap between two folding rollers by means of a pointed, sharp-edged sword.
In the folding device according to DE 43 24 199 C1, each folding roller is mounted in bearing levers which are adjustable about pivot axes.
The folding roller gap is set by means of a swivel drive which engages a bearing lever. The setting of the folding nip must be precisely matched to the thickness of the folded material - one or more sheets - and the folding sword. Incorrect settings can damage the folded goods or lead to folding errors. Each time the thickness of the folded material changes, the folding nip must be readjusted. In order to achieve a symmetrical pivoting of the opposite bearing levers, these have extensions which are adjustable relative to one another by means of a forcing screw and a locking screw.
The effort for this folding device, in particular for the required linear drive for the first bearing lever and the adjustment, is correspondingly large.

The pocket folding principle includes at least one pair of folding rollers and one Folding pocket available. The folded material is placed between transport rollers first passed into the folding pocket up to a stop. The opening the folding pocket, the folding pocket mouth, is in the immediate vicinity Near the folding area of the folding rollers. If the rear end of the If folded goods are moved through the transport rollers, a jam occurs and the folded material bulges in front of the fold pocket mouth The folding area of the folding rollers is grasped and folded by them.

So that there is no curvature of the folded material inside the folding pocket, this must be narrow according to the thickness of the folded material, that is, the scope is narrow. Usually with the Folding pocket process between one to five sheets can be folded simultaneously, if it is assumed that a sheet between 30 to 80 g can weigh. But there is definitely a need for a larger one Fold number of sheets at the same time.

A compression folding machine is known, see EP 0 583 587 A1, which in the folding pocket has an adjustable stop rail. The The stop rail is used to determine the fold length - corresponds to the Immersion depth of the folded material in the fold pocket - and the fold shape individually with the help of an electric drive by a programmable control device or manually adjustable. The The stop rail points towards the fold pocket mouth Side several stop fingers, the front end faces in one common level, the paper stop in the folding pocket form. The stop rail can still be a front one Take the redirection position in which the front end faces together serve as paper deflectors and the fold pocket mouth close. The folded material arriving at the fold pocket mouth becomes then either past the folding pocket through the folding rollers a subsequent folding pocket or in an inserting machine directed. In any case, this part of the edging machine both the "folding" function and the "smooth through" function, as mentioned at the beginning, realizable. The problems with the slot width the folding pocket still exist.

A compression folding machine is also known, see EP 0 595 105 A1, the at least one folding pocket and on different gap widths adjustable and against each other has resiliently pivotable folding rollers. The folding rollers are rotatably supported in two-arm pairs of swivel levers and form with each a further folding roller a feed or Fold point. The inlet gap of the folding pocket has a minimum width and can be resiliently changed according to the thickness of the folded goods. floor and Cover of the folding pocket are formed by grids, which around axes Fold pocket base are pivotable. The inlet end sections the grids are on angular rails running transversely to the filling direction attached, on the other hand with the pairs of swivel levers Folding rollers are coupled. As a result, at the same time Change of the folding gap of the folding rollers of the inlet gap Folded pocket adjusted. The folding pocket is usually in this way wedge-shaped in profile with variable wedge width, the wedge tip but is essentially the same thickness. This is the fold pocket mouth and the first two thirds of the folding pocket the thickness of the folded material adaptable, but jams on the bottom of the folding pocket are not locked out. An inlet lock and an adjustable stop are missing from this upset folding machine. As a result, they are only arches processable length.

Finally there is a device for folding sheets or Layers of sheet-like materials known by folding rollers, see DD-101 875, at the axially symmetrically adjustable to the folding roller pair Pressure roller pair is arranged. The center distance of the pressure rollers is smaller than that of the folding rollers. That way, one can Folding sword can be dispensed with.

All of the above solutions also have the disadvantage that Sheets with a length less than the set fold length are not can be processed. Such arches are common Mail items included as an attachment.

The purpose of the invention is to increase the functional reliability and the area of application.

The invention has for its object an arrangement for folding of sheets of different lengths and larger numbers by means of Folding rollers and an adjustable stop to create the Folding gap is automatically adjusted to the thickness of the folded goods, a waiver a folding sword or folding pocket is possible and the functions: Single folds, multiple folds - wrap - or Z fold, leporello fold - and smooth run are executable.

According to the invention, this object is achieved according to the claims solved.

The combination of active driven folding rollers and passive pressure rollers with a diameter smaller than half The diameter of the folding rollers becomes a gentle and safe fold enables. The resilient mounting of the folding rollers enables one automatic adjustment of the folding gap to the thickness of the folded goods and simultaneous folding of a large number of sheets. The appropriate choice of spring force is routine. Because the pinch rollers are driven by the folding rollers directly or via the folding material, are always synchronism between all rollers and symmetrical Guaranteed paper feed into the nip. The pressure rollers both serve to ensure that the curvature of the folded goods according to the desired Direction takes place, as well as that the folding process takes place. Because only Round elements act on the folded material, are damage to the Folded goods, like the sword fold principle, are completely excluded. With the by means of a lifting table with adjustable pressure rollers and up to Folding area adjustable stop is also the realization of the 'Smooth run' function possible. In the first case, the Move the lifting table with the pressure rollers to the folding rollers and the stop pushed between the folding rollers before the sheets in the area between the stop and the folding rollers.

It is even possible to implement the "smooth pass with turning" function. In In this case, the lifting table with the pressure rollers on the Folded rollers moved up after the sheets between the area Leave the deflection element and folding rollers in the direction of the stop have, but still between the rear pressure and folding rollers are located.

Are correspondingly many arrangements according to the invention offset arranged one after the other, so a fan fold or accordion fold respectively. This is easily done by adjusting the Stops possible.

The design is for particularly short or not to be folded sheets with more than two pressure rollers and assigned to them, driven additional guide rollers suitable.

The invention is explained in more detail below using the exemplary embodiment explains:

Fig. 1

Eine perspektivische Darstellung einer Falzeinrichtung,

Fig. 2

den Ablauf eines Falzvorganges mit einer Anordnung gemäß Fig. 1,

Fig. 3

den Ablauf für die Funktion "glatter Durchlauf" mit Anschlaghilfe,

Fig. 4

Verstellmöglichkeiten für den Anschlag,

Fig. 5

den Ablauf für die Funktion "glatter Durchlauf" ohne Anschlaghilfe,

Fig. 6

den Ablauf für die Funktion "Wenden und glatter Durchlauf",

Fig. 7

eine Anordnung für Mehrfachfalzung,

Fig. 8

eine Anordnung zum Falzen kurzer Bögen,

Fig. 9

Details einer Lagerung der Falzwalzen in schwenkbaren Lagern.

Show it:

Fig. 1

A perspective view of a folding device,

Fig. 2

the sequence of a folding process with an arrangement according to FIG. 1,

Fig. 3

the sequence for the "smooth flow" function with stop aid,

Fig. 4

Adjustment options for the stop,

Fig. 5

the sequence for the "smooth flow" function without a lifting aid,

Fig. 6

the sequence for the "turning and smooth run" function,

Fig. 7

an arrangement for multiple folding,

Fig. 8

an arrangement for folding short sheets,

Fig. 9

Details of a storage of the folding rollers in swiveling bearings.

The drawings are for convenience and understanding partially carried out schematically.

1, the arrangement according to the invention for folding sheets consists of a sliding table 2, on which a pair of folding rollers 3 in bearings 32 and a stop 21 are arranged so as to be adjustable in slots (not specified). The bearings 32 are provided with elongated holes 321, in which the folding rollers 3 are held with their axes 31 so as to be rotatable and displaceable. Tension springs 33 tensioned between the axes 31 cause the folding rollers 3 to bear against one another in a force-fitting manner or, adapted to folding material of different thicknesses, clamp the same between them. The sliding table 2 preferably occupies a sloping position at an angle of 35 °; not taken into account in the drawing for reasons of simplified representation. Below the sliding table 2, a pair of pressure rollers 4 are mounted on a lifting table 6 that can be adjusted parallel to the same. The lifting table 6 is positioned in relation to the sliding table 2 in such a way that the pressure rollers 4 lie axially symmetrical to the folding rollers 3.
The pressure rollers 4 are subdivided in the axial direction, and a stop 21, also not shown, which is also subdivided, can be displaced into the gaps 42 between the axes 41.
The diameter Db of the pressure rollers 4 is smaller than half the diameter Da of the folding rollers 3.

In Fig. 2 the sequence of a folding process is shown schematically with the arrangement according to the invention.
According to FIGS. 2a and 2b, a sheet 1 is moved on the sliding table 2 in the direction of the stop 21. The stop 21 is set accordingly to the arc length and the desired fold length. The stop 21 is flat in its part 211 adjacent to the sliding table 2. The more distant part 212 is concave, adapted to the curvature of the folding roller 3. The lifting table 6 is initially lowered. In this case, sheet 1 should be folded in the middle. After the sheet 1 has reached the stop 21, the lifting table 6 is moved upwards until the pressure rollers 4 press the sheet 1 against the folding rollers 3, see FIGS. 2b and 2c. Due to the smaller diameter of the pressure rollers 4, the sheet 1 is pre-oriented in the direction of the folding rollers 3 before the clamping action occurs between the pressure rollers 4 and the folding rollers 3. The sheet 1 is pressed into the area between the folding rollers 3, gripped by them, folded and pushed on. The folding rollers 3 are automatically pushed apart by the double sheet thickness against the spring force of the tension spring 33.

In Fig. 3 the process is shown when the sheet 1 the folding rollers 3rd happened unfolded. First, the sheet 1 on the slide table 2 up to the vicinity of the area between the first folding roller 3 and the first Pressure roller 4 moves and at the same time the lifting table 6 upwards hazards. Before the stop 21 is in the range between the folding rollers 3 adjusted. The sheet 1 can the position before or take between the pair of rollers 3, 4; it depends on the Control of the movement sequence. After passing through the first Clamping point, the arc 1 meets the concave flank 212 of the Stop 21 and is guided by this between the folding rollers 3. The folding rollers 3 capture the sheet 1 and move it smoothly further.

In Fig. 4, the adjustment options of the stop 21 are by means of a unspecified scenery guide shown.

In Fig. 5 the movement sequence "smooth passage" is without Stop adjustment made clear. Sheet 1 runs on the sliding table 2 to the first pair of rollers 3, 4, is further moved by this, hits with its front edge on the second folding roller 3 and is in through this deflected the folding area and passes this, see Fig. 5b and 5 c.

In Fig. 6, the movement sequence of the function "turn and smoother Pass ". First, the sheet 1 passes the area between pressure and folding rollers 4, 3 until the stop is reached 21, see Figs. 6a and 6b. The lifting table 6 takes the lower one distant location. The stop 21 is set so that the adjacent sheet 1 with its rear part between the second Pressure roller 4 and second folding roller 3 is located. If the lifting table 6 moved upwards, the rear part of the sheet 1 is between the rollers mentioned and clamped in the direction of the first folding roller 3 guided, deflected by this between the folding rollers 3, the so turned sheet 2 passes smoothly, see Fig. 6c and 6d.

7 there are several folding arrangements according to the invention one after the other and staggered. So the advantage the sequence of movements with the sliding table falling below 35 ° 2 is used, the pressure rollers are above and Folding rollers arranged below the assigned sliding table. The black fully marked line means the Course of the arch. The accompanying symbolism is the respective one Folded condition shown. The bottom line at three Folding arrangements is a fourfold fan fold.

8 are parallel on both sides and parallel to the Folding rollers 3 still driving guide rollers 9 are provided. Assigned to the guide rollers 9 are on a corresponding widened lifting table 6 additional pressure rollers stored. This Arrangement is for safe guidance for particularly short folded goods or short, not to be folded sheets intended.

In Fig. 9 is an alternative to a resilient mounting of the folding rollers 3 shown. The folding rollers 3 are in this case with their axes 31 in pivoted bearings 32, between which a tension spring 33 is tensioned. The bearings 32 are in turn with its axis 322 rotatable in bearing blocks 34 attached.

Reference symbols used

1

Sheets, folded goods

2nd

Sliding table

21

adjustable stop on the sliding table

211

flat part of the stop 21

212

concave part of the stop 21

22

Recesses in the sliding table

23

Guide for stop 21

3rd

Folding rollers

31

Axes of the folding rollers

32

Bearings for axles 31

321

Elongated holes in bearings 32

322

Axes of the swivel bearings 32

33

Tension springs

34

Pillow blocks for swivel bearings 32

4th

Pressure rollers

41

Axes of the pressure rollers 4

42

Gaps in the pressure rollers 4

6

Lift table

There

Diameter of the folding rollers 3

Db

Diameter of the pressure rollers 4

Claims (13)

1. An arrangement for folding of sheets (1) by means of folding rollers (3),

   in which a pair of pressure rollers (4) with parallel axes are arranged in sheet feed direction in front of a pair of folding rollers (3) with parallel axes, said

   pressure rollers being axis-symmetrical and adjustable in relation to said folding rollers,

   characterized in

   that the folding rollers (3) are in elastic contact with each other;

   that the diameter (Db) of the pressure rollers (4) is smaller than half the diameter (Da) of the folding rollers (3);

   that a stopper (21) is provided that is adjustable up into the area between the pressure rollers (4) and at the same time is designed as a deviation element;

   that the pressure rollers (4) are divided in direction of the axes and that the adjustment range of the equally divided stopper (21) runs into the gaps (42) of said pressure rollers; and

   that, in case of need, there are provided transport means (4, 9) for sheets with lengths smaller than the fold length.
2. An arrangement according to Claim 1, characterised in that the pressure rollers (4) are mounted on a common lifting table (6).
3. An arrangement according to Claims 1 to 2, characterised in that, for the sheets (1), there is provided a sliding table (2) that, in the lifting area of the pressure rollers (4), has got cutouts (22) adapted to said pressure rollers and, in the adjustment range of the stopper (21), is provided with a guide (23) under the folding rollers (3) for lowering and lifting the stopper (21).
4. An arrangement according to Claims 1 to 2, characterised in that, for the sheets (1), there is provided a sliding table (2) that, in the lifting area of the pressure rollers (4), has got cutouts (22) adapted to said pressure rollers.
5. An arrangement according to Claims 3 to 4, characterised in that the sliding table (2) is sloping in sheet feed direction, preferably inclined at an angle of 35°.
6. An arrangement according to Claims 1 and 3, characterised in that the part (211) of the stopper (21) that faces the sliding table (2) is plane and that its part (212) that is opposite to the sliding table (2) has a concave form adapted to the curvature of the folding roller (3).
7. An arrangement according to Claims 1 and 3 or 4, characterised in that the folding rollers (3) are arranged above and the pressure rollers (4) are arranged below the sliding table (2).
8. An arrangement according to Claims 1 and 3 or 4, characterised in that the folding rollers (3) are arranged below and the pressure rollers (4) are arranged above the sliding table (2).
9. An arrangement according to Claims 1 and 8, characterised in that, in sheet feed direction, there are provided several folding arrangements in an alternating orthogonally staggered relation with one another.
10. An arrangement according to Claim 1, characterised in that the folding rollers (3) run on fixed bearings (32) with oblong holes (321) and that the axles (31) of the folding rollers (3) are connected by tension springs (33).
11. An arrangement according to Claim 1, characterised in that the folding rollers (3) run on pivoted bearings (32) that are connected by tension springs (33).
12. An arrangement according to Claims 1 and 10 to 11, characterised in that the maximum range of spring (fm) of the tension springs (33) corresponds to the maximum thickness of the folded material to be processed.
13. An arrangement according to Claims 1 and 2, characterised in that, parallel to the folding rollers (3), there are provided guide rollers (9) driven at the same circumferential speed as well as further pressure rollers (4) assigned to said guide rollers.

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