DE102008008397B4 - Device for conveying a shingled stream of sheets - Google Patents

Abstract

Device for conveying an imbricated stream of sheets from a stack of sheets (3) via a transfer table (9) to a belt table (21) which transports the sheets (2) to a sheet processing machine, the sheets (2) being transported at a constant scale distance from one another and with Separated from the stack of sheets (3) with the aid of separating suction devices and the separated sheets (7) are conveyed to the transfer table (9) by transport suction devices (6), characterized in that in the transfer table (9) one of the separated sheets (7) grips and this one the staggered distance (20) corresponding path in a sheet conveying direction (8), single-turn revolving transport roller (14; 14.1) is arranged and that the circumference of the transport roller (14; 14.1) corresponds to the staggered distance (20).

Description

The invention relates to a device for conveying a shingled stream of sheets from a pile of sheets via a transfer table to a belt table transporting the sheets to a sheet processing machine, the sheets being transported at a constant scale distance from one another and separated from the sheet pile with the aid of suction cups and the separated sheets through Transport suction cups are conveyed to the transfer table.

In such devices, the top sheet of a stack of sheets is grasped and lifted in the region of the sheet trailing edge in order to separate them by separating suction devices that execute a lifting movement. By blowing under, the top sheet is separated from the next sheet over the entire surface. To implement the air cushion separating the top sheet from the subsequent sheet, a sheet flap is provided on the front edge of the sheet, which flap is arranged on a flap shaft extending transversely to the sheet conveying direction. After the top sheet has been separated, it is transferred to suction cups that execute movement in and against the sheet conveying direction, which transport the separated sheet in the sheet conveying direction and thus with the area of the sheet leading edge onto the transfer table. For this purpose, before the start of the movement of the suction cups in the sheet conveying direction, the flap shaft with the sheet flap is pivoted in the sheet conveying direction and the leading edge of the separated sheet is thus guided onto the transfer table. A continuously rotating transport roller is assigned to the transfer table, which corresponds to timing rollers which are controlled against the transport roller in the working cycle. If the front edge of the sheet reaches the area of the active pairing of timing rollers / transport roller, the timing rollers are controlled against the transport roller, the sheet is released by the transport suction devices and thus transported to the conveyor table, while the transport suction devices take over the subsequent sheet that has been separated from the separating suction devices in the meantime their original position can be returned. Correspondingly, the following sheet is transported onto the transfer table, overlapping the top sheet. In the same way, the other sheets are fed in so that a shingled sheet flow is achieved, with the distances between the sheets matching. ( DE 10258416A1 )

The disadvantage of these devices is the high level of complexity due to the flap shaft / curved flap and the active pairing of transport roller / timing rollers and the mechanisms required for actuation. In addition, the implementation requires a large installation space, which is contrary to a compact design. In addition, it is disadvantageous that when the sheet flap is swiveled to transport the sheets held by the suction cups, the flow conditions are suddenly changed, which leads to disruptions in sheet conveyance or productivity losses when processing problematic materials.

In the DE 4442629C2 a belt table designed as a suction belt table for conveying a shingled stream of sheets from a sheet pile to a sheet processing machine is described. A suction roller is provided between the first suction chamber of the suction belt table and the stack of sheets, which is also designed as a deflection roller for the conveyor belt. A transfer table is not provided and a flap shaft provided with a sheet flap is assigned to the stack of sheets.

It has also been proposed to arrange a suction roller between the transfer table with the transport roller and the timing rollers and the flap shaft with the sheet flap, which is continuously driven and captures the sheets conveyed to the transfer table by the transport suction devices. The transport speed impressed on the sheet by the suction roller is greater than the speed imparted by the transport suction device, so that the sheets are tightened.

As a result of this measure, the effort and the need for installation space are increased, with the swiveling away of the curved flap likewise the risk that the sudden changes in the flow conditions lead to disadvantageous consequences when conveying problematic materials.

the DE 10 2007 042 376 A1 shows a device for conveying an imbricated sheet stream from a sheet stack over a transfer table to a belt table transporting the sheets to a sheet processing machine, the sheets being transported at a constant scale distance from one another and separated from the sheet stack with the help of separating suction devices and the separated sheets being opened by transport suction devices conveyed to the transfer table, with a rotating transport roller arranged in the transfer table. "

The object of the invention is to design a device of the generic type in such a way that the effort is reduced and a compact design and trouble-free processing of problematic materials are possible.

According to the invention, the object is achieved by a device according to the features of claim 1.

The solution according to the invention reduces the number of mechanisms to be controlled in the working cycle and thus reduces the effort. In addition, a compact design is possible and work productivity is increased by optimizing the flow conditions when separating and transporting the sheets.

• 1 die prinzipielle Ausführungsform der Vorrichtung zum Fördern eines geschuppten Bogenstroms in der Seitenansicht,
• 2 eine weitere Ausführungsform der Vorrichtung nach 1.

The invention is explained in more detail using an exemplary embodiment. In the accompanying drawings show:

• 1 the basic embodiment of the device for conveying a shingled stream of sheets in the side view,
• 2 another embodiment of the device according to 1 .

In 1 is from a sheet feeder 1 excerpts from a sheet 2 existing stack of sheets 3 shown. The arch 2 of the sheet stack 3 lie with the leading edge of the sheet 4th at stacking stops 5 , which are usually designed as vertically arranged strips and are arranged distributed over the format width, while the stack of sheets 3 rests on a stacking plate, not shown, which is lifted by a stacking elevator, also not shown, so that the top of the stack of sheets 3 is constantly at a given level. From the sheet feeder 1 is still a transport sucker 6th shown, the one of suction separators, not shown, from the stack of sheets 3 scattered arch 7th has taken over and in a sheet conveying direction 8th transported. The transport suction cups 6th are provided in the usual way distributed over the format width.

In the sheet conveying direction 8th is the sheet feeder 1 a transfer table 9 subordinate. The transfer table 9 consists of a table sheet 10 , which extends over the maximum format width and in the sheet stack 3 facing area a continuation of the vertically arranged stacking stops 5 forms. A tabletop surface 11 and the stacking stop surfaces 12th form a common vertical plane on which the arches 2 of the sheet stack 3 with the leading edge of the sheet 4th issue. In the pile of sheets 3 facing area forms the table sheet surface 11 a closed surface extending over the width of the format. The bowlayer 1 is a well-known overhead guide 34 assigned to the sheet feeder 1 as well as the sheet feeder 1 facing part of the transfer table 9 extends and the path of the arch 2 limited upwards.

Above that for separating the top sheet in each case 2 characteristic levels of the stack of sheets 3 goes the table sheet 10 of the transfer table 9 from the vertical plane into a plane that rises to a horizontal plane and is transverse to the sheet conveying direction 8th running recess 13th Mistake. In the recess 13th grips a transport roller 14th a, which is driven single-speed by means not shown. The coat 15th the transport roller 14th consists of a circular jacket segment 16 and one is a flat surface 17th forming flattening. The circular jacket segment 16 is with suction holes 18th provided, during the flat lateral surface 17th no suction holes 18th assigned. The circular jacket segment 16 associated suction holes 18th are in the area of the recess 13th can be acted upon with negative pressure. This is in the transport roller 14th a vacuum supply extending over its length 19th intended. That on the suction holes 18th acting vacuum level is adjustable.

The circumference of the transport roller 14th is dimensioned in such a way that it can be achieved with a staggering distance 20th matches. As a relay interval 20th becomes the distance between the sheet leading edges 4th two adjacent arches 2 understood a shingled stream of arches. The relay interval 20th is in 1 between two adjacent arches 2 shown on one of the transfer table 9 downstream conveyor table 21 be transported. The belt table 21 consists of at least one in the sheet conveying direction 8th circulating conveyor belt 22nd over an upper deflection roller 23 and a lower deflection roller, not shown, and guided by means of tension rollers 24 is tensioned. The at least one conveyor belt 22nd is between the upper deflection roller 23 and the lower deflection roller on a belt table plate 25th led, with the table sheet 10 and the band table sheet 25th merge into each other comparatively. The belt table 21 can also be designed as a suction belt table. This is at least one conveyor belt 21 designed as a perforated suction belt and in the track of the suction belt are in the belt table plate 25th Recesses provided, which are in communication with a vacuum source. The at least one conveyor belt 22nd The impressed speed profile matches that of the transport roller 14th match.

The transport roller 14th are one or more pressure rollers 26th assigned. Any pressure roller 26th is in a roller lever 27 added, the pivotable of a bearing shaft 28 assigned. The roller levers 27 is one setting unit each 29 assigned with which the distance between the pressure roller 26th and the transport roller 14th can be adjusted. In addition, it acts on every roller lever 27 an energy store 30th at. Through the action of the energy store 30th becomes the roller lever 27 against the actuator 29 led and removed from it contrary to the effect.

The pressure rollers 26th are with an elastic lift 31 provided, which has a Shore hardness of about 45 °. On the bearing shaft 28 are still pivotable and lockable bearing levers 32 intended to accommodate guide rollers 33 , which are in operative connection with the conveyor table 21 or conveyor belt 22nd can be brought.

In 2 a further embodiment of the device is shown in principle. This embodiment differs from that according to 1 only by the fact that the coat 15th a single-speed revolving second transport roller 14.1 from a circular jacket segment that completely encloses it 16 consists. The jacket segment 16 is with suction holes 18th provided that when passing through the recess 13th of the transfer table 9 via the vacuum supply 19th can be subjected to an adjustable negative pressure. The circumference of the second transport roller 14.1 with the circular jacket segment that completely envelops it 16 is chosen in such a way that it matches the staggering distance to be achieved 20th matches.

• In bekannter Weise wird der jeweils oberste Bogen 2, der mit der Bogenvorderkante 4 an der eine Fortsetzung der Stapelanschlagflächen 12 bildenden Tischblechoberfläche 11 anliegt, an der Hinterkante von Trennsaugern erfasst und in diesem Bereich vom Bogenstapel 3 abgehoben. Durch Blasdüsen wird zwischen dem von den Trennsaugern an der Hinterkante gehaltenen Bogen 2 sowie dem Folgebogen ein Luftpolster aufgebaut, damit vom Folgebogen getrennt und so zum vereinzelten Bogen 7, der von den Transportsaugern 6 übernommen wird, während eine Freigabe durch die Trennsauger erfolgt. Die Ausbildung des Tischblechs 10 vom Überführtisch 9 als sich über die maximale Formatbreite erstreckende geschlossene Fläche und als senkrechte Fortsetzung der Stapelanschläge 5 sichert die Ausbildung eines optimalen Luftpolsters, welches ein störungsfreies Vereinzeln der Bogen 2 ermöglicht und gleichzeitig die freie Bogenvorderkante 4 des vereinzelten Bogens 7 so positioniert, dass bei der Bewegung der Transportsauger 6 in Bogenförderrichtung 8 die Bogenvorderkante 4 problemlos über den ansteigenden Teil des Überführtischs 9 in Bogenförderrichtung 8 geführt werden kann. Die Förderbewegung der Transportsauger 6 ist so mit der eintourig umlaufenden Transportwalze 14 abgestimmt, dass die Bogenvorderkante 4 des vereinzelten Bogens 7 synchron mit der ebenen Mantelfläche 17 in den Bereich der Aussparung 13 einläuft und damit diesen überdeckt. Der mittels der Stelleinheit 29 zwischen der ebenen Mantelfläche 17 und den Andrückrollen 26 einstellbare Spalt entspricht etwa der zur Verarbeitung gelangenden Materialstärke, sodass der vereinzelte Bogen 7 auch als Einzelbogen durch Fiktion und nachfolgend zusätzlich durch die Wirkung der mit Unterdruck beaufschlagten Saugbohrungen 18 in Bogenförderrichtung 8 transportiert werden kann, wobei der vereinzelte Bogen 7 nach dem Positionieren mit der Bogenvorderkante 4 im Wirkbereich Andrückrollen 26 / ebene Mantelfläche 17 von den Transportsaugern 6 freigegeben wird.
• Der von der Transportwalze 14 erfasste Bogen 7 wird innerhalb einer Umdrehung der Transportwalze 14 in Bogenförderrichtung 8 und damit auf den Bändertisch 21 transportiert, wobei durch eine Umdrehung der Staffelabstand 20 realisiert wird. Nach einer Umdrehung der Transportwalze 14 wird durch die Transportsauger 6 ein Folgebogen unterlappt zugeführt. Die durch die Unterlappung bedingten Höhendifferenzen werden durch die den Andrückrollen 26 zugeordneten Kraftspeicher 30 kompensiert.

The device works as follows:

• In a known manner, the top sheet in each case 2 , the one with the leading edge of the sheet 4th on the one continuation of the stacking stop surfaces 12th forming table sheet surface 11 is in contact with the rear edge of suction cups and in this area from the stack of sheets 3 picked up. Blowing nozzles are used between the sheet held by the suction cups at the rear edge 2 as well as the following curve, an air cushion is built up, thus separated from the following curve and thus becoming an isolated curve 7th that of the transport suckers 6th is taken over while the release takes place through the separating suction unit. The formation of the table sheet 10 from the transfer table 9 as a closed surface extending over the maximum format width and as a vertical continuation of the stacking stops 5 ensures the formation of an optimal air cushion, which allows for trouble-free separation of the sheets 2 and at the same time the free leading edge of the sheet 4th of the isolated bow 7th positioned so that when the transport suction cup is moved 6th in sheet conveying direction 8th the leading edge of the sheet 4th easily over the rising part of the transfer table 9 in sheet conveying direction 8th can be performed. The conveying movement of the transport suction cups 6th is the same with the single-speed rotating transport roller 14th matched that the sheet leading edge 4th of the isolated bow 7th synchronous with the flat outer surface 17th in the area of the recess 13th runs in and thus covers it. The by means of the actuator 29 between the flat surface 17th and the pressure rollers 26th The adjustable gap corresponds roughly to the material thickness to be processed, so that the individual sheet 7th also as a single sheet through fiction and subsequently additionally through the effect of the suction holes subjected to negative pressure 18th in sheet conveying direction 8th can be transported, with the separated sheet 7th after positioning with the leading edge of the sheet 4th pressure rollers in the effective area 26th / flat outer surface 17th from the suction cups 6th is released.
• The one from the transport roller 14th captured arch 7th is within one revolution of the transport roller 14th in sheet conveying direction 8th and with it on the conveyor table 21 transported, with one revolution of the staggered distance 20th is realized. After one revolution of the transport roller 14th is made by the transport suction device 6th a subsequent sheet is fed underlapped. The height differences caused by the underlap are caused by the pressure rollers 26th assigned lift mechanism 30th compensated.

The one in the transport roller 14th The effective negative pressure can be set and the effective holding force can be adapted to the material being processed. It is possible to completely dispense with a supply of negative pressure and to place the sheets on the belt table in a scale-like manner simply by means of friction 21 to promote. In order to ensure trouble-free conveyance even when processing stiff materials, the guide rollers 33 be employed accordingly.

In the further execution according to 2 become the arch 2 correspondingly isolated and the isolated sheets 7th with the leading edge of the sheet 4th to the recess 13th guided. In the area of the recess 13th becomes the isolated arch 7th from the single-speed revolving second transport roller 14.1 a the relay interval 20th corresponding way to the belt table 21 transported. Depending on the material to be processed, the separated sheet can 7th by friction or by means of the suction holes 18th initiated holding force are promoted.

The transport rollers 14th , 14.1 can be designed so that they extend over the maximum format width. But it is also possible to use the transport rollers 14th , 14.1 only in the track of the conveyor table 21 provided conveyor belts 22nd the transfer table 9 assign. For better peeling off the sheets 2 from the transport rollers 14th , 14.1 it is also conceivable to provide these with indentations and at the transfer table 9 Form guides that engage in the grooves.

List of reference symbols

1

Sheet feeder

2

arc

3

Stack of sheets

4th

Sheet leading edge

5

Stacking stop

6th

Transport suction cups

7th

Isolated sheet

8th

Sheet conveying direction

9

Transfer table

10

Table sheet

11

Table sheet surface

12th

Stacking stop surface

13th

Recess

14th

Transport roller

14.1

Transport roller

15th

a coat

16

Circular jacket segment

17th

Flat lateral surface

18th

Suction holes

19th

Vacuum feed

20th

Relay spacing

21

Belt table

22nd

Conveyor belt

23

Upper deflection roller

24

Tension roller

25th

Belt table sheet

26th

Pressure roller

27

Roller lever

28

Bearing shaft

29

Control unit

30th

Energy storage

31

Elastic elevator

32

Bearing lever

33

Leadership role

34

Overhead

Claims (13)

Device for conveying an imbricated stream of sheets from a stack of sheets (3) via a transfer table (9) to a belt table (21) which transports the sheets (2) to a sheet processing machine, the sheets (2) being transported at a constant scale distance from one another and with Separated from the stack of sheets (3) with the aid of separating suction devices and the separated sheets (7) are conveyed to the transfer table (9) by transport suction devices (6), characterized in that in the transfer table (9) one of the separated sheets (7) grips and this one the staggered distance (20) corresponding path in a sheet conveying direction (8), single-turn revolving transport roller (14; 14.1) is arranged and that the circumference of the transport roller (14; 14.1) corresponds to the staggered distance (20). Device according to Claim 1 , characterized in that a jacket (15) of the transport roller (14) consists of a circular jacket segment (16) and a flat jacket surface (17). Device according to Claim 2 , characterized in that the jacket segment (16) is provided with suction bores (18). Device according to Claim 1 , characterized in that the transfer table (9) is provided with a table plate (10) which, in its area facing the stack of sheets (3), acts as a vertical continuation of the stacking stops (5) provided for contacting the sheets (2) of the stack of sheets (3). is trained. Device according to Claim 4 , characterized in that the table plate (10) in the area facing the stack of sheets (3) is designed as a continuous surface extending over a maximum format width. Device according to Claim 4 , characterized in that the table plate (10) merges in the upper area from the vertical plane into a plane rising to a horizontal plane and is provided with a recess (13) extending transversely to the sheet conveying direction (8). Device according to Claim 1 and 6th , characterized in that the transport roller (14; 14.1) engages in the recess (13). Device according to Claim 2 and 7th , characterized in that the flat lateral surface (17) forms a common plane with the table plate (10). Device according to Claim 3 and 7th , characterized in that the suction bores (18) can be subjected to negative pressure in the region of the recesses (13). Device according to Claim 9 , characterized in that the negative pressure is designed to be adjustable. Device according to Claim 1 , characterized in that the transport roller (14; 14.1) is assigned at least one pressure roller (26) which is adjustable at a distance from the transport roller (14; 14.1). Device according to Claim 11 , characterized in that the pressure roller (26) is assigned an adjusting unit (29) which realizes the distance between the transport roller (14; 14.1) and the pressure roller (26). Device according to Claim 11 , characterized in that the pressure roller (26) is assigned an energy storage device (30) which enables the distance to be increased.

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