EP0999163B1 - Device for creating a gap in a stream of sheets in shingled formation - Google Patents

Description

In cross cutters, especially large format cross cutters for Paper, will be relatively large, mostly as printed sheets used sheets cut from paper webs, quality checked and filed. There are usually several lanes that coming from different rolls of paper, lying on top of each other fed to the cross cutter, so that individual sheet packages or Arch groups exist, commonly referred to as clips become. After the cross cutting, these are in an overlap station into a shingled arc stream, i.e. each other partially overlapping clips, which eventually converts have it deposited in a shelf or stacking station.

Although such a paper giant or stack is sometimes a very take up a large number of single sheets (approx. 10,000 to 15,000), becomes with the high running speed of such sheeters a pallet with such a stack after just a few Minutes full. Since it is impossible to use the machine Completely stopping batch changes has been up to now Cross cutter type over one arranged after the cross cutter Connection switch controlled a number of clips, according to the degree of scaling at least the length corresponded to an arc and then a turnout inside to be able to switch this gap and the subsequent arc stream section to steer to a second shelf on which another batch was collected until the first was transported away and thus the shelf is ready for use again could be.

In another known cross cutter type Gap in the arc stream by stopping the subsequent ones Arches in front of the offshoot, but what by the mechanical action on the sheets with mark sensitive Little sheet material due to possible damage suitable is. In another known cross cutter type the arc current section is separated in the Sheet depositing station with the help of mechanical sheet clamping devices and / or intermediate collecting devices (e.g. format width, retractable table tops or collecting grates), but what because of possible damage to delicate arches and the partially complicated sequence of separating movements causes relatively high technical effort and often only runs smoothly under ideal conditions.

Sheeter designs in which the gap between the Arch flow sections by ejecting arches or Generated clips are usually characterized by a relatively simple, clear advantageous and uncomplicated Stacking process, which is also in a straight line, expresses clean stack edge as a quality feature. The However, the serious disadvantage of this type of construction is the removal good sheets of paper for the purpose of gap formation.

Since the discarded paper is waste, it is economical and ecologically a big disadvantage. A cross cutter could only through this measure 50 to 100 tons of paper waste per year to produce paper that is in itself of perfect quality.

All attempts to remedy this are so far failed, which is partly due to the very high train speeds lies, but on the other hand is due to the fact that the cut papers, especially if it is acts particularly high quality, very sensitive are. They tend to be at the slightest mechanical Influencing markings to get into further processing and not be tolerated in the end product.

For insensitive flat materials or made from them Products are already known devices for gap-pulling become. DE 39 26 966 C2 describes a device for Gaping in a shingled stream of corrugated cardboard became known in which a slow-running feed conveyor the scaled arc current over a gap-pulling position away on a faster-running gap pull conveyor pushes. By moving the gap-pulling position in the conveying direction while raising the feed conveyor creates a gap between two sheets of corrugated cardboard. This device is not included for large and sensitive sheets of paper the necessary operational safety. There would be collisions in the area of the gap-pulling position.

In the same document a device is described in of the two nested tape systems with higher ones and lower speed are present, whereby by different position of two pulleys that can be moved are one or the other band engaged with the Paper can be brought. This device has the same disadvantages as the previously described, with the additional there is also the disadvantage that two different ones Belt systems must be managed so that the one in the The other's gap is running.

It has also become known from EP 0 497 002 A1, in a shingled stream of printed matter, for example folded sheet layers to draw a gap by one System of belts running parallel to each other with slower and higher speed is used. On middle conveyor belt with higher speed, that something below the level of the neighboring, at a slower speed running tapes is arranged to Gaping brought into engagement with the layers by suction air and drag it over the slower belts until a gap has been closed. This is for sensitive papers Surfaces unacceptable because it is at least the lowest Arch leads to markings.

TASK AND SOLUTION

The object of the invention is to create a possibility in an arc flow also for sensitive materials and at high processing speeds reliably To draw a gap in a shingled stream of arcs without on the simple and optimal execution of the stack quality No need to dispose of the archives.

This object is solved by claim 1. As a result of that the last arc of the front arc stream section after which the gap is to be drawn on the gap pulling conveyor is held, on the other hand this end but in the gap pulling speed together with the gap pulling conveyor, i.e. at a higher speed, is movable, and thereby that this end on the gap pull conveyor at a lower Level lies as the feed conveyor, becomes a clean one Separation reached. The first arc of the next arc stream section is by a vertical gap from the last one Bow of the front section separated. Especially if advantageously a blowing device at the gap-pulling position is arranged, which moves with this position, then the first arc of the trailing section floats an air cushion over the back of the front arc stream section, so that this is under the following Section may prefer.

Since the holding means are preferably controlled Actuated suction device is by a air-permeable, for example perforated conveyor belt of the Gap pull conveyor sucks through, and also no tapes at different speeds parallel to each other run, but only one after the other, there are no relative speeds between the bow and the ribbons, so that no marks on sensitive papers too are to be feared. The feed conveyor, which is preferably opposite the conveying speed in the cross cutter area can run slower, can be the one on which the shingled arc stream forms. Right after that can start the gap-pulling station. The feed conveyor can by an appropriate length compensation device lengthen so that it follows the gap-pulling position when the gap-pulling process is initiated. Shortened accordingly the gap puller. Feed conveyors normally run and gap pullers at the same speed until the gap-pulling process is initiated.

One can immediately follow the gap-pulling station Switch for lossless division of the arc current over two Funding routes should be provided in the gap that has arisen switches. This will make the modulation necessary so far some of the products in the waste are avoided if this Distribution for the purpose of changing stacks or from others Reasons. In another advantageous one This gap pulling station can also be executed without division in different delivery quantities of a stacking device, e.g. a so-called single sheet deposit, upstream be, in which case a sheet deposit with automatic Pallet changing device in simple, but for that Stacking optimal execution, and thus without loss of quality on the product. Then it will e.g. generates only one sink stack, the one without auxiliary stack formation or sheet separators.

These and other features go beyond the claims also from the description and the drawings, wherein the individual features individually or separately several in the form of sub-combinations in one embodiment of the invention and in other fields be and advantageous as well as protective designs can represent, for which protection is claimed here. The division of the application into individual sections as well Subheadings limit those made under them Statements not in their general validity.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine schematische Ansicht eines Teils eines Querschneiders mit einer Überlappungs- und Lückenziehstation,

Fig. 2

eine vergrößerte schematische Ansicht eines Lückenziehwagens in der in Fig. 1 dargestellten Arbeitsposition und

Fig. 3 und 4, 5 und 6 sowie 7 und 8

jeweils Darstellungen entsprechend Fig. 1 bzw. Fig. 2 in weiteren Arbeitspositionen, wobei gegenüber Fig. 1 einige Neben- und Anschlußaggregate weggelassen sind.

An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:

Fig. 1

1 shows a schematic view of part of a cross cutter with an overlap and gap-pulling station,

Fig. 2

an enlarged schematic view of a gap car in the working position shown in Fig. 1 and

3 and 4, 5 and 6 and 7 and 8

representations corresponding to FIG. 1 or FIG. 2 in further working positions, with some auxiliary and connection units being omitted compared to FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings, a section of a cross cutter 11 shown, which is a large format or folio sheeter is. Left of that shown in Fig. 1 Section of the cross cutter there are paper rolls, from which numerous, for example six individual layers of paper be pulled off, lying one above the other to form a web are merged with a rotating cross cutter is cut into individual sheets. Under arch or Clip will be associated with this registration accordingly both a single sheet and a group of several, jointly cut single paper layers in the corresponding Understood the format. In front of the cross cutter the individual papers e.g. optical sensor devices go through, identify and register the paper errors, so that the arches contained therein are specially treated, e.g. can be controlled.

In preparation for stack formation, the individual clips 12 in an overlap station 13 Overlap or stagger in a scaled stream 14 transferred.

The arriving in the direction of clips 15 are in the Overlap station between upper bands 16 and lower bands 17, together a feed conveyor 18 for the subsequent Form gap-drawing station 19, guided, each of which top clip is braked by a braking station 20. This Brake station is described in detail in DE 38 12 685 A, on the here because of the constructive and functional Details are referenced. To adapt to the different The brake station 20 with its format lengths Brake bands 21 displaceable in the conveying direction, what a corresponding tape guide of the upper and lower tapes 16, 17 is made possible.

A gap-pulling car 22 belongs to the gap-pulling station 19 along a horizontal guideway 23 e.g. a ball guide is movable in or against the conveying direction, and by a drive not shown in FIG. 1, for example an electrical, hydraulic or pneumatic Linear drive or derived from the overall drive the cross cutter, via a mechanical gear or Lever gears, clutches or the like. In Fig. 1 is schematic an independent controlled drive 24 with an electric motor and an endless drive belt running over two rollers 25 shown for it.

The gap pulling wagon 22 shown in FIGS. 2, 4, 6 and 8 each enlarged compared to the previous figures is shown, contains deflection rollers 26 for the lower belt 17th of the feed conveyor 18 and pulleys 27, 28 for an under the conveyor level 29 of the gap-pulling station 19 running belt 30, which belongs to a gap pulling conveyor 31. It is e.g. through perforations, permeable to air.

Both sub-bands 17, 30 are over length compensation devices 32, 33 out and are driven by drives 34 with controllable Speed driven. The length compensation devices 32, 33 have guided horizontally movable Deflecting rollers 35 which, e.g. thanks to pneumatic spring cylinders 36, keep the ligaments taut, but a movement of the Gap puller 22 along the guide 23 also during the Allow the belts 17, 30 to run. The end of effectiveness of the feed conveyor 18 in the form of the deflecting rollers 26 and in particular the beginning of the gap pulling conveyor 31 define the belt 30 at the position of the deflection rollers 27, 28 between them a gap-pulling position 37, which together with the gap pulling carriage 22 in the conveying direction 15 along the Guide 23 is essentially horizontally displaceable.

The gap pulling car 22, which can also be called a sled or Movable frame could contain a controllable Suction device 41, which is horizontally transverse to the conveying direction 15 running suction channel 38 with upper, slide-controlled Suction openings 39 exists. The one with the gap-pulling car 22 horizontally and together with one the suction openings 39 having suction table 40 limited vertically (see Fig. 4) movable suction device 41, e.g. about one not shown flexible suction hose, with a vacuum source, for example a suction fan or one for the entire machine associated suction air or vacuum network connected.

In Figures 2, 4, 6 and 8 there is also a blowing device 42, which is shown via a blowing or compressed air duct 43 and also a flexible hose to a compressed air source connected in the form of a blower or compressed air network is. This connection is made schematically in Fig. 2 indicated air control device 44 in the form of a electrically operated valve or slide. The control the suction and blowing device 41, 42 can also be used on others Done wisely, but should because of the quick response as close as possible to the suction openings 39 or the blowing air nozzles 45 take place as a flat jet or slot nozzles on the Width of the gap-pulling station as even and as possible preferably distributed without large distances between them are arranged. The slide control of the suction openings 39 can, for example, by a relative to the suction table 40 slidable and embedded in this slide 49th respectively. This can correspond to that in DE 195 10 364 A1 described be formed, referred to here becomes.

Subsequent to the gap-pulling station 19 and the gap-pulling conveyor 31 a switch 46 is arranged, the arc stream between two different funding routes 47 (in the example horizontal) and 48 (run diagonally upwards). Both run to different, not shown Collection stations, in which the arc stream each in one relatively high stack is collected on a pallet. there can separate strips depending on a counting device can be controlled, each in the stack with giant cut off a certain number of sheets. The two funding channels 47, 48 are used alternatively, so that the operation of Machine is loaded into one collection station each the other can be cleared by removing the stack.

FUNCTION

The clips 12 lying one behind the other in the conveying direction 15 arrive at the production speed V _P at the entrance of the overlap station 13 and are taken over by the slower, namely the lower speed V _{S of} the feed conveyor, in the overlap or shingling station. Brake bands 21 in the braking station 20 act on the front edges of the respective upper sheet and brake it after it had previously been pushed over the slower running lower sheet. The brake station 20 is horizontally displaceable in order to adapt to the format length in the conveying direction and counter to this for adjustment.

Thereafter, the shingled sheet stream 14 runs into the gap drawing station 19. During normal operation, i.e. while the cut and shingled sheets are deposited in a stack, for example those connected to the conveying path 47, the shingled sheet stream runs at the speed V _S over the gap pulling carriage 22 on the one driven at the corresponding speed V _S Gap-pulling conveyor 31. The gap-pulling carriage 22 is in the position shown in FIG. 1, that is to say in relation to the conveying direction 15, in the most upstream position. Fig. 2 shows that the suction device 41 with the suction table 40 and the associated deflection roller 28 is in a raised position, that is, with its conveying plane 29 in the extension of the feed conveyor 18. The gap-pulling conveyor 31 thus only forms an extension of the feed conveyor 18 in this working state. Suction and blowing device 41, 42 are not in operation, ie the corresponding valves or slides 44, 49 are closed. The cross cutter can run at web speeds of 300 to 400 m / min. run, so that despite the relatively large sheet length 300 to 500 cuts are made per minute and with six unwinds, ie six single sheets per clip, run through about 1,800 sheets per minute. Accordingly, a stack of approx. 10,000 individual paper sheets is full after about 6 minutes and has to be removed.

For this purpose, the cross cutter cannot be stopped because this would require a very large set-up effort, including considerable paper losses to restart, but with very fast running cross cutters, the production speed V _P , depending on the sheet materials to be processed, can possibly be something for the stack change be humiliated.

Then the gap-pulling process begins:

The gap pulling carriage 22 is still standing, as in FIGS. 3 and 4 shown in the upstream position (left). It then the unit suction device 41 / suction table 40 / Deflection roller 28, the vertical opposite the suction truck 22 form movable holding means 50, lowered, namely by an amount of e.g. 10 to 30, preferably about 20 mm, the a clear vertical gap 51 between the suction table 40 and the feed conveyor 18 and thus between those on it running arches.

At the same time by opening the slide 49 and Valve 44 both the suction device and the blowing device put into operation. The suction device sucks air through the perforated conveyor belt 30 of the gap pulling conveyor 31 and thus holds the rear end 52 in the conveying direction 15 of the last sheet or clips 12 that before lowering the Holding means 50 had run onto the gap pulling conveyor 31, firmly. Although only the bottom sheet of paper absorbs of the clip is held, however, the clips are through the previous processing so close together that their natural cohesion is enough to cover the entire clip hold.

Due to the switched on blowing air coming out of the slot nozzles 45 emerges, an air cushion is generated in the gap 51. The Gap 51 is somewhat wedge-shaped because of the lowering of the Holding means 50 and thus the guide roller 28 of the gap conveyor is directed slightly upwards. On this wedge-shaped Air cushions can be the first sheets 12 in the conveying direction of the arc flow section 53 following in the conveying direction from the last arcs of the leading arc stream section be separated and hover over it, so to speak.

At the same time, the gap-pulling conveyor 31 is now brought to a higher speed, the gap-pulling speed V _L , and set in motion by actuating the drive 24 shown in FIG. 1 of the gap-pulling carriage 22 along the guide 23 at the gap-pulling speed V _L.

Figures 5 and 6 show a working position during the gap-pulling process. The gap-pulling carriage 22 has already traveled a distance in the conveying direction 15 in FIG. 5 at the gap-pulling speed V _L. The suction device 41 is still in operation and holds the rear end 52 of the leading sheet flow section 54 firmly on the gap pulling carriage 22, blowing air still flows out of the blowing device 42 with the nozzles 45 and the holding means 50 are still in the lowered position.

It can be seen that the rear end 52 of the leading Arc flow section 54 under the first arc 12th of the subsequent arc stream section 53 largely pulled out and the overlap is very small Amount has decreased. From this position the blowing air is hardly necessary anymore and can either be throttled or completely be switched off, also in order to avoid that the bend itself wave or flutter under the influence of blowing air. Definitely the blowing air should be switched off when the suction device is switched off.

Fig. 5 shows that the conveyor belts 17, 30 of the feed conveyor 18 and of the gap-pulling conveyor 31 have been lengthened or shortened in the conveying direction by the movement of the gap-pulling carriage 22. This is made possible by the length compensation devices 32, 33, which release the required strip length or take up the strip length that is released. Since the movement of the gap pulling carriage 22 runs at the same speed V _L as the belt 30, the deflecting rollers 27, 28 can stand still on the gap pulling carriage 22, while the deflecting rollers 26 of the feed conveyor running at the slower speed V _S run backwards. Due to the fact that both conveyors have their ends on the gap pulling carriage 22, however, the gap pulling position 37 runs at the gap pulling speed V _L , and, relative to the gap pulling carriage 22, the subsequent arc flow section 53 is seen on the feed conveyor which runs backwards from the point of view of the gap pulling carriage 22 18 withdrawn. In the leading sheet flow section 54, the degree of overlap need not be changed, although this conveyor is running faster. The difference in speed causes a gap to be drawn between the two sections. When the gap-pulling carriage 22 continues to run in the conveying direction 15, the slight overlap which can still be seen in FIG. 6 is completely eliminated and a clear gap 56 (FIG. 8) is drawn between the rear end 52 of the preceding section 54 and the beginning 55 of the following section. By choosing the appropriate length and speed differences depending on the sheet format and the degree of overlap, this gap can be chosen as large as is necessary.

7 and 8, the gap-pulling process has ended. The gap 56 can be seen in FIG. 8, blowing and suction air are switched off and the holding means 50 are pulled back into their upper position, where the feed and gap pulling conveyors 18, 31 are aligned with one another. If the production speed V _P had been reduced, it can now be started up again.

When the rear end 52 has passed the switch 46 shown in FIG. 1, the switch arm is switched from the solid position there to the dashed position, ie obliquely upwards, within the gap 56. The beginning 55 of the subsequent arc stream section 53 then runs on the conveyor path 48 into a newly forming stack, while the previous one connected to the conveyor path 47 is cleared away. At the end of the gap-pulling process, at which the gap-pulling carriage 22 stands on the side of its travel path lying in the conveying direction, the speed of the gap-pulling conveyor 31 is also reduced again from the higher gap-pulling speed V _L to the speed of the feed conveyor V _S when the gap-pulling carriage 22 stops. The gap pulling carriage 22 can now be moved back into its position according to FIG. 1 at any point in time before the next gap pulling process, which will only take place in a few minutes. Due to the conveyor belts running over it at the same speed, just as with the entire gap-pulling process, there are no differential speeds between the belts and the sheets. The carriage rolls back into its starting position smoothly under the following sheet stream 53, so to speak.

It can be seen that after the gap pulling device the invention enables a process in which any Friction between the arches and device parts and also be avoided between the arches themselves. In particular are no parallel belt sections of different lengths Speed necessary. At the increase the speed of the leading section 54 necessary Acceleration of the gap pulling conveyor 31 becomes the last clip in front of him covering the last clip through the The suction effect is drawn on them and thus not only reinforces them for yourself, but also for the clips in front of it the idle friction on the conveyor belt 30 so that the acceleration forces can be transmitted without any tendency to slip.

Claims (10)

1. Apparatus for forming a gap between two portions (53, 54) of a tegulated sheet flow (14) comprising mutually partly overlapping sheets or sheet groups (clips 12), particularly in the case of large-format crosscutters (11) for paper, in which the sheet flow (14) is supplied on a feed conveyor (18) with a feed speed (V_s) to a gap formation position (37), which is formed on the effective rear end of a gap formation conveyor (31) in the conveying direction and which for gap formation purposes is movable in the conveying direction (15) at a gap formation speed (V_L) higher than the feed speed (V_S) and in which the effective, rear end of the gap formation conveyor (31) is movable relative to the front end of the feed conveyor (18) in the conveying direction (15) to a lower level, wherein in an area of the gap formation conveyor (31) adjacent to the gap formation position (37) in the conveying direction (15) are provided holding means (50) for the last sheet (12) of the front sheet flow portion (54) and which are jointly movable with the effective, rear end of the gap formation conveyor (31) at the gap formation speed (V_L) in the conveying direction (15).
2. Apparatus according to claim 1, wherein the holding means (50) incorporate a controlled operable suction device (41) which can be switched on in its remote position counter to the conveying direction (15) and is directly adjacent to the end, located in the conveying direction (15), on one of the overlapping stations (13) forming the tegulated sheet flow (14) and the feed conveyor (18) is the conveyor on which the tegulated sheet flow (14) is formed.
3. Apparatus according to claim 1 or 2, wherein the front end of the feed conveyor (18) in the conveying direction (15) is jointly movable adjacent to the gap formation position (37).
4. Apparatus according to one of the preceding claims, wherein the gap formation position (37) is formed on a gap formation carriage (22) moveable in the conveying direction (15) and which has the suction device (41) and in the conveying direction (15) rear conveyor belt guides (27, 28) for the gap formation conveyor (18) and in the conveying direction (15) front conveyor belt guides (26) for the feed conveyor (18), the conveyors (18, 31) preferably having length compensating devices (32, 33) for example in form of compensating rolls (33) tensioned by pneumatic cylinders, and having in particular interconnected overlap-free conveyor belts (17, 30) along the conveying area.
5. Apparatus according to one of the preceding claims, wherein in the vicinity of the gap formation position (37) is provided a blowing device (42), which is also moveable with the gap formation position (27) in the conveying direction (15) and is directed onto a clearance (51) between the feed and gap formation conveyors (18, 31) with a blowing direction located substantially in the conveying direction (15), and is preferably periodically operable, at least in a first time period the gap formation process, and preferably the blowing device (42) substantially has flat jet nozzles (45) extending over the entire sheet width.
6. Apparatus according to one of the preceding claims, wherein the feed speed (V_s) of the feed conveyor (18) can be reduced compared with normal operation for gap formation purposes.
7. Apparaus according to one of the claims 4 to 6, wherein the suction device (41) has a suction duct adjacent to the gap formation position on the gap formation carriage (22) transversely to the conveying direction and which has suction openings (39) under an air-permeable conveyor belt (30) of the gap formation conveyor (31) and which can be opened and closed by means of a controlled operable slide preferably located directly at said openings.
8. Apparatus according to one of the preceding claims, wherein the holding means (50) incorporating a suction device and a blowing device, as well as a guide pulley (28) of the gap formation conveyor can be lowered within a gap formation carriage carrying them, nozzles (45) or the blowing device being released for blowing into a substantially horizontal clearance (51) formed by them.
9. Apparatus according to one of the preceding claims, wherein in the conveying direction (15) and following onto the gap formation station (19) is provided a switch or points (46) for the lossfree subdivision of the sheet flow (14) over two conveying paths (47, 48) at the gap (56).
10. Apparatus according to one of the preceding claims, wherein in the conveying direction (15) following onto the gap formation station (19) is provided a stack forming device, which carries out or initiates the stack change in the gap (56).

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