DE102009016067A1 - Device for conveying a bow - Google Patents

Abstract

In an apparatus for conveying a sheet with grippers (1, 1A-1D) and a first belt-shaped conveying means (3A-7A, 3B-7B, 15) for moving at least a first one of the grippers (1, 1A-1D) a second conveyor means (3A-7A, 3B-7B, 15) for moving a second one of the grippers.

Description

The The present invention relates to a sheet conveyor for Sheet processing machines according to the preamble of Claim 1.

STATE OF THE ART

The following principles are known for the sheet transport in sheet-processing machines:
Principle 1. The majority of today's sheet-fed offset printing presses today have arc leading cylinder having at least one mechanical or pneumatic gripper system for holding the sheet at the leading edge of the sheet. The gripper system usually consists of a plurality of individual grippers, which are arranged along a gripper closure line parallel to the axis of rotation of the cylinder. The grippers of the gripper system interact with the grippers of adjacent cylinders by intermeshing the arc from cylinder to cylinder. The sheet transport through the machine takes place undulating, ie the arc is constantly experiencing an alternating curvature. Typical representatives of such sheet transport systems can be found in many patents of Heidelberger Druckmaschinen, König & Bauer AG or manroland AG.

Of the Disadvantage of this sheet guiding system lies in the high Requirements for the precision of sheet transport, the high cost of the bow leading cylinders and in the fact that the bow from the investment table from the rest position Coming up on a short distance at machine speed Preload and possibly accelerated by the plant drum must become. Within the sheetfed machine, the bow becomes during the sheet transport during production with a constant speed.

This explains why such sheet transport systems high accuracy but are very expensive. The wavy Transport also has the disadvantage that in rigid substrates the bow by mechanical and / or pneumatic holding means during of the sheet pass on the cylinder must be kept to one strong lift due to the curvature and consequent possibly striking and damaging the substrate surface to avoid. Pneumatic holding means, for example pressure cylinder blowing devices, need a steady air supply. In addition to the investment costs For such systems are constantly operating costs at. Very rigid substrates, such as glass, metal from a certain Strength, strong corrugated board are because of the wavy Sheet transport completely excluded from processing. Except high precision and decades of experience therefore nothing else speaks with such sheet transport systems for their use, but rather closes the sheet transport system due to the high cost applications in cost-critical equipment out.

Principle 2: Another known principle is the vacuum transport system, in which the sheet is attached by vacuum to a transport system. The sheet transport takes place with suction belts or with suction boxes, which are equipped with rollers. Such sheet guiding systems are in the DE 69 60 048 "Processing system for cardboard with vacuum transport system" and in the DE 698 07 547 "Device for transporting plate-shaped objects in rotary printing machines" disclosed. Against such transport systems speaks in the first line that after a transport route in printing processes with high pressure in the use of thin papers and thin cardboard they can not be passed through the printing nip of a printing unit, as the suction would impress themselves in the thin material. Therefore, this transport principle is used only for very rigid substrates or in transport areas of printing machines, for example on the feeder table, where the sheet is not exposed to high pressure loads. Like the patent CH 638 116 or CH 648 772 shows, a Saugbändertransport can be combined with a cylinder printing unit. However, this structure has the disadvantage that in the transition region between the conveyor belt and cylinder, the sheet is not defined. Therefore, such systems are only used for production areas with low requirements for register accuracy, for example in full-surface painting.

Principle 3: The sheet guiding principle based on the fact that the sheet transport device have movable and flexible conveyors extending on both sides of the printing press and that on the conveyors gripper carriages or gripper bars are fixed, which grab the sheet with their grippers at least at the front edge and through Pull the whole press or parts of it. A generic representative of such a printing press is in the DE 1 930 317 , of the US 2,138,405 . DE 39 36 345 and the US 3,853,315 disclosed.

The conveyors, which extend along the printing press, may be straps, ropes or link chains. A disadvantage of the transport with such continuous conveyors that transport the sheet from the system of the printing press to its storage by the printing units, are once the inaccuracies of the sheet transport by the elasticities, manufacturing tolerances and elongations of the system, the ne gatively affect the accuracy of fit and print quality. Accurate printing can only be achieved by determining the position of the sheet during transport and correcting the commissioned work. Such a complicated control loop is inter alia in the DE 10 2004 050 725 disclosed.

One Another disadvantage of these sheet transport systems is that Shaking, for example, by starting up the gripper carriage result in a gripper opening curve over the conveyance propagate into the printing unit. Pressure disturbances and register deviations in critical pressure subjects are the consequence.

chain as conveyors also have the disadvantage that Polygon error and length tolerances of the chain links no allow constant sheet travel. That is why such transport systems have enforced in the printing industry only in niche areas. at modern printing machines are therefore such conveyor systems used only in the less critical display area of a printing press.

Typical gripper trucks for the use of cantilevers in sheetfed presses are in the DE 20 2005 015 009 U1 disclosed. However, these systems also have the disadvantage in this application that they circulate equally spaced, ie they can not assume different speeds during their circulation. In the field of storage of a sheet-fed rotary printing press in which the transported sheet is released by the grippers of the gripper carriage and stored on a discard pile, the sheet is therefore not braked by the transport system during the transport phase. If the systems could be controlled individually, the system would decelerate the sheet and place it gently on the stack. Because of the constant rotational speed must therefore be braked with sheet brakes, which detect the arc pneumatically and decelerate. This touching speed delay can lead to pressure disturbances, eg smearing of a fresh printed image or damage of the printing material.

Principle 4: The desire to be able to control the sheet transport systems individually, in order to adapt them to the respective transport and processing situation, led relatively early to the idea of connecting grippers or gripper carriages to individually controllable linear motors. The DE 25 01 963 shows a gripper carriage, which is guided by a linear motor through the printing press into the delivery of the printing press. Other embodiments of such sheet transport systems with linear motors and associated control systems are in the DE 20 2007 012 355 U1 , in the DE 10 2008 021 317 , in the DE 101 55 033 and in the DE 10 2004 050 725 disclosed. The advantages of such individually driven sheet conveyors are obvious.

Despite the current patent literature on the subject of sheet transport with linear transport systems, no current installations and research results are known. The main reason for this lies in the high costs of the linear drives, which are due to the costs of the linear drives themselves and the high expenses for control technology required for this. With today's competitive situation in the printing industry, such additional costs can not be justified in most cases. Furthermore, the sheet transport systems driven by linear motors always have the risk of losing synchronization with other moving parts, for example rotating cylinders of the printing press, in the event of a loss of function. The potentially resulting risk of collision must be meticulously intercepted by appropriate precautions to avoid destruction of the machine or machine parts. Such a complex synchronization device between sheet conveyor and cylinder for linearly driven sheet conveyors is in the DE 101 55 033 disclosed. The safety-related expenditures for synchronization devices make the sheet conveyors with linear motors more expensive.

Principle 5: The DE 10 2006 043 053 A1 has another sheet guiding principle individually driven gripper carriage. Each gripper carriage is assigned a motor which drives the gripper carriage individually and independently of other gripper carriages. The disadvantage of the solution found is to be found, inter alia, that the gripper carriage must be built very stable because they have to carry the engine and possibly a part of the control electronics. Furthermore, the power supply for the motor must be ensured over the entire circulation path. This can be done by trouble-prone sliding contacts, non-contact power transmission or accumulators. The energy transfer devices required for this purpose make the overall system more expensive and, in some cases, more susceptible to errors.

It is also known to relieve the chains by the gripper carriage laterally roll on guide rails or supported in another suitable form. Applications of such support mechanisms to relieve the means of transport are inter alia from the CH 391 739 and the DE 195 25 635 known.

Connections of toothed belt with gripper devices in connection with printing processing machines reveal the DE 28 49 273 , the DE 27 24 979 , the DE 36 05 534 , the DD 292 428 and the DE 100 05 323 ,

OBJECT OF THE INVENTION

Of the Invention is based on the object, a sheet conveying device with an individual control of gripper carriages to create which is cost effective to implement and yet an individual Speed profile of each gripper carriage or gripper carriage group during the passage through a printing machine processing machine allowed.

SOLUTION OF THE TASK

According to the invention The object is achieved by a device having the features of claim 1 solved. Meaningful further education results from the Dependent claims.

The Invention has the advantage that each gripper or gripper carriage or gripper device individually to a cost-effective and effective type can be controlled.

The Invention is for use in a printing technology Processing machine with sheet transport suitable. The sheet transport can thereby completely or only on sections of the printing technology Processing machine with the inventive sheet transport system respectively. Printing technology processing machines are within the meaning of Invention Printing machines (offset, flexo, gravure, screen, high pressure machines or combination printing machines), varnishing machines, embossing machines, Hot foil stamping machines, cold foil stamping machines, Punching machines or folding machines. The processing machine can but also be a machine that has any combination of represents the above method.

Of the Sheet conveyor is formed by each gripper carriage / gripper device or at least two groups of gripper carriages of the sheet conveying system with an individual and exclusively the gripper carriage / gripper device or the gripper carriage group / gripper device group associated funding which is above the individual subsidy associated terminal deflection wheels running, wherein at least one of the deflection wheels an individually having controllable drive.

The individually the gripper or gripper carriage / gripper carriage group or associated with the gripper, the gripper device / gripper device group Conveyor may be a link chain, a rope or a Band, but is in a preferred form a timing belt. today Timing belts can be made by incorporation of technical fibers, through metal inserts and through the selection of suitable engineering materials be designed very stretch-resistant. They are suitable for their smoothness, the elimination of the polygon effect of the chain and the good positive connection with the pulleys and optionally further training wheels very good for this application. The connection of a gripper device or a gripper carriage with a toothed belt is according to of the prior art perfectly solvable.

Thereby, that each drive wheel is assigned its own drive can the conveyor and the associated gripper or Gripper group imprinted an individual speed profile become.

By This type of sheet conveying can be compared, for example Solutions with linear drive or self-propelled gripper via Engines massive engineering and control engineering savings Achieve, with the procedural advantages arising out of the individual control of individual grippers or gripper groups, remain.

inventive Devices are used as sheet conveyors in different Used machines. So exemplary, but not exhaustive as part of a printing press, a punching machine, a Embossing machine, a painting machine or a machine, which represents a combination of the other machines.

The Position, position or the state of charge of the gripper is partially monitored during the entire orbital period and the obtained data will be corrected, adapted or adjusted by software changed. This is done in particular to the correction Added value. This process can also be done manually by the user a panel can be controlled. The correction happens, for example by correcting an inclination by adaptation and / or Increasing the speed of a conveyor.

The Location of the claw or the gripped bow will be determined by at least detected a sensor. The results of the sensor become control signals won to correct the position. These are sent to the control device passed on and on the fixed, the funding assigned drive is the position by change the conveying speed corrected.

In particular, the position detection and the state of charge is detected immediately before the entry into a processing station and corrected accordingly, for example, to obtain an optimum printing result. For example, the Erfindungsge thank, gripper without a bow in the processing station does not work. It should also be encompassed by the idea of the invention to transfer sheets by slowing down one gripper and accelerating a following gripper.

Besides For example, the device may be designed to have one Sheet from the feed table in rest position and at machine speed accelerated.

DESCRIPTION OF THE FIGURES

These and other features of the invention will be apparent from the description the embodiments, the listed Embodiments not limiting examples represent. Embodiments of the invention will be referred to in the following drawings:

1 : A plan view of a section of the inventive sheet transport device:

2 : A sketchy cross-section of an exemplary sheet transport system of a sheet-fed printing machine;

3 : An extension of a sheetfed press.

The top view in 1 shows a section of a novel sheet guiding system. The individual grippers shown schematically ( 1 ), shown here without individual grippers, are connected via the connecting elements ( 8th ) with the respective individual gripper ( 1 ) associated funding ( 3A - 7A . 3B - 7B ) connected. The funding ( 3A - 7A . 3B - 7B ) may be ropes, belts and / or in a preferred form, timing belt. Each grant ( 3A - 7A . 3B - 7B ) has its own stationary drive, which is ideally associated with one of the respective conveyor associated peripheral wheel (not shown here). This allows every funding ( 3A - 7A . 3B - 7B ) an individual speed profile (V3A-V7A, V3B-V7B) can be impressed by the different control of the fixed drives. The grippers ( 1 ) are preferred, but not mandatory, on both sides outside via the connecting elements ( 8th ) with the respectively assigned funding ( 3A - 7A . 3B - 7B ) connected. Due to the two-sided arrangement, as in the example of the conveyor ( 3A . 3B ) a different speed (V3A <> V3B) are impressed on these.

This has the advantage that the gripper ( 1 ) can be inclined to, for example, a skew of a sheet in the holders of the gripper ( 1 ) before entering the processing station (eg printing unit, coating unit, punching unit) of the printing technology processing machine. This compensation can be part of a control loop in which, for example, with one or more sensors, the position of the sheet in the holders of the gripper ( 1 ) is detected and in a misplacement in the transport direction by an acceleration or deceleration of the respective funding ( 3A - 7A . 3B - 7B ) and a skew by a different speed of the respective pairings of the conveying means (eg. 3A / 3B ) is compensated.

Thereby can individual misplacements in the circumferential direction and / or Slopes can be compensated without great mechanical engineering effort. Error register and register error of the individual processing stations and thus waste (scrap) are thus reduced and the Quality of processing is increased.

In a preferred embodiment, the grippers ( 1 ) mounted laterally, for example on the side walls of the machine, ( 2A . 2 B ). The rails ( 2A . 2 B ) ensure that the funding ( 3A - 7A . 3B - 7B ) only have to apply the forces for the forward movement and thus be spared from further stress. The grippers ( 1 ) can have laterally arranged rollers, which are below and above the track ( 2A . 2 B ) are arranged. This has the advantage that the load on the funds ( 3A - 7A . 3B - 7B ) is effectively reduced and thus the wear of the funds ( 3A - 7A . 3B - 7B ) is reduced.

In a further particular embodiment, one of the rollers, which is below or above the track ( 2A . 2 B ) unrolls a gear that on a toothed side of the track ( 2A . 2 B ) rolls off. As a result, the precision of the sheet transport and thus the positioning accuracy can be further increased. Of course, the gripper ( 1 ) have laterally only one roller, which rolls in a cage formed by a below and above the roller guide rail arranged.

The sketchy 2 shows schematically and only by way of example the advantages that result from the inventively found solution for the sheet transport within a printing sheet processing machine. The individual sheets are placed in a feeder ( 8th ) with a suction head ( 9 ) from a feeder pile ( 4 ) and accelerated. The sheets are fed via a feeder table ( 10 ) transported to the system (not shown here) and there usually aligned laterally with a side pull mark.

In sheetfed offset presses, a leading edge alignment is additionally carried out leads by the arc is guided against stops which are arranged across the entire machine width. The alignments take place in the rest position of the bow. After the alignment process, the sheet is then accelerated from the rest position over a complex pre-gripper and usually an investment drum to machine speed.

In the exemplary embodiment in 2 , the bow in the gripper ( 1 ) at a speed V0 (see below assigned speed diagram) directly, waiving a pre-gripper and drum conditioning, and with the gripper ( 1 ) are accelerated to machine speed VD. With this speed VD then the arc through the processing station or processing stations, here represented by a pressure ( 12 ) and impression cylinder ( 13 ) at approximately constant speed VD. The fact that the sheet is during transport from the plant to the processing station in a gripper closure of a gripper carriage, quality-reducing and mechanical complex handovers of a gripper system (such as in a sheetfed offset press from the pre-gripper, the plant drum leading to the bow cylinders ) avoided. In addition to the quality improvements due to smaller deviations, this leads to a considerable reduction in the engineering expenditure.

Another advantage is the connection of the individual grippers ( 1 ) or gripper carriage groups with an individually assigned thereto funding ( 3A - 7A . 3B - 7B ). From the prior art (see prior art, principle 3 ) It is known all gripper carriage on laterally circulating transport systems, eg. B. circulating chain systems to fasten. In addition to the fact that then all gripper cars have the same speed in the circulation, this transport system is only limited for transport through a printing or coating unit. In a printing unit, for example, layer thicknesses of a few micrometers thickness are applied, which are very sensitive to changes in the sheet transport.

In gripper carriages, which are attached to the prior art on a circulating transport system, vibrations, for example, by a gripper opening when recording the sheet in the investment area can occur, propagate into the printing area along the sheet conveying system and there printing interference, such as stripes in the print or lacquer image. In contrast, in the solution according to the invention, grippers ( 1 ) or gripper group with an individually assigned funding ( 3A - 7A . 3B - 7B ) connected. This results in a decoupling of the individual systems. A vibration at the gripper opening, for example, in a gripper ( 1 ) with the subsidy ( 3A . 3B ) is also generated along the conveyor ( 3A . 3B ), but show no printing-technical effects, since the gripper carriage system ( 1 ), which, for example, with the subsidies ( 4A . 4B ), and thus from the grant ( 3A . 3B ) is decoupled. The major drawback / disadvantage of the sheet transport with rotating gripper carriage is the propagation of the disturbances along the conveyor.

This Disadvantage is achieved by the inventive solution, the decoupling of the individual gripper or gripper group, solved. Printing errors are thus effectively avoided.

In 3 is the application of the inventive solution in a boom ( 14 ) of a sheet-fed printing machine. From the last sheet leading cylinder of the sheet-fed press, the sheet to a circulating sheet transport system with gripper carriage ( 1A - 1D ) and from this to the display area ( 18 ) and there on the delivery pile ( 19 ) filed.

This example is intended to show that it can also be useful. Gripper carriage groups ( 1A - 1D ) to be connected to a respectively associated with the group funding. Each of the groups ( 1A - 1D ) an individual speed profile can be impressed.

The revolving gripper system of a boom ( 14 ) usually runs around two deflection drums ( 16 . 17 ), to which according to the invention individual gripper groups ( 1A - 1D ) associated deflection drums ( 16 . 17 ) are assigned, which have a drive. Since the requirements for bowing in a boom ( 14 ) are not very high, the drive of the deflection wheels ( 16 . 17 ) for a gripper carriage group ( 1A - 1D ) on both sides with a drive. The drive to the opposite side can be done via a shaft or an overdrive.

The individual control of a gripper carriage or a gripper carriage group ( 1A - 1D ) has the procedural advantage that the sheet is arranged by a usually arranged in a boom of a sheet-fed press drying device, eg. As a thermal or UV dryer, compared to the machine speed of the sheet-fed press slowed speed can be transported. As a result, the efficiency of the drying can be increased by the longer exposure time.

Also it makes sense the sheet transport with the gripper ( 1 ) in the display area ( 18 ) of the jib ( 14 ) at a reduced speed.

Normally, in today's known sheet-fed presses in a boom ( 14 ) all gripper systems at an identical speed. The bows must therefore be in the display area ( 18 ) of the grippers ( 1 ) by opening the gripper ( 1 ) to be loaded onto the stack ( 19 ) can be stored. The sheets have initially the speed of the sheet transport after release and must be braked for example by pneumatically acting braking devices. These braking devices are complex and can, since they act directly on the sheet, lead in both sides printed sheets to a greasing and thus waste (scrap). With the solution found according to the invention, the gripper system or the gripper group ( 1A - 1D ) in the display area ( 18 ) and thus also that of the gripper ( 1 ) transported bow, so that this at a reduced speed gently and without damage to the delivery pile ( 19 ) can be stored. Braking devices can be made easier or even eliminated altogether.

The example of the application of the inventive solution in a boom of a sheet-processing machine makes it possible to show that it may be useful to form groups of gripper systems, which are each connected to a, the group associated funding. The first group of grippers ( 1D ) must, for example, assume the speed of the upstream machine since the sheet transfer must be synchronized by the machine's last sheet leading cylinder.

The second group of grippers ( 1A ) runs on the other hand with reduced speed to a smooth and damage-free storage of the bow on the discard pile ( 19 ). The systems ( 1B . 1C ) are assigned to the returning upper part of the circulating sheet conveying system, an area in which no sheet transport takes place. Their speed can be chosen freely in a meaningful way. By combining gripper carriages into groups, which assume phase-wise different speeds, the mechanical engineering effort and the effort for the drive technology can be reduced, without losing the procedural advantages of different speed profiles during the run.

This Principle of the inventive bowing leaves to all variants of cantilevers of sheet-processing machines and does not apply to sheetfed presses limited.

By the solution found according to the invention, the mechanical engineering can be simplified, costs are reduced and the procedural quality can be increased. The sheet transport through a sheet-processing machine can thus be done completely or only on sections through the sheet-processing machine with the inventive method. LIST OF REFERENCE NUMBERS 1 grab 2 Rails ( 2A . 2 B ) 3 Funding ( 3A . 3B ) 4 Funding ( 4A . 4B ) 5 Funding ( 5A . 5B ) 6 Funding ( 6A . 6B ) 7 Funding ( 7A . 7B ) 8th holder 9 suction head 10 feed table 11 circulating sheet conveying system 12 pressure cylinder 13 Impression cylinder 14 boom 15 funding 16 Delivery drum (deflection wheels) 17 Extension drum (deflection wheels) 18 display area 19 delivery pile

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 6960048 [0005]
• - DE 69807547 [0005]
• - CH 638116 [0005]
• - CH 648772 [0005]
• - DE 1930317 [0006]
• US 2138405 [0006]
• - DE 3936345 [0006]
• US 3853315 [0006]
• - DE 102004050725 [0007, 0011]
• - DE 202005015009 U1 [0010]
• - DE 2501963 [0011]
• - DE 202007012355 U1 [0011]
• - DE 102008021317 [0011]
• - DE 10155033 [0011, 0012]
• - DE 102006043053 A1 [0013]
• - CH 391739 [0014]
• - DE 19525635 [0014]
• - DE 2849273 [0015]
• DE 2724979 [0015]
• - DE 3605534 [0015]
• - DD 292428 [0015]
• - DE 10005323 [0015]

Claims (15)

Device for conveying a sheet with grippers ( 1 . 1A - 1D ) and a first belt-shaped conveying means ( 3A - 7A . 3B - 7B . 15 ), for moving at least a first one of the grippers ( 1 . 1A - 1D ), characterized in that a second conveying means ( 3A - 7A . 3B - 7B . 15 ) for moving a second one of the grippers. Device according to claim 1, characterized in that each conveying means ( 3A to 7A . 3B to 7B . 15 ) at least one gripper ( 1 . 1A to 1D ) assigned. Device according to claim 1 or 2, characterized in that each conveying means ( 3A to 7A . 3B to 7B . 15 ) is driven independently of each other. Device according to one of claims 1 to 3, characterized in that the gripper ( 1 . 1A to 1D ) partially or circumferentially, along or in a running track ( 2A . 2 B ) is guided. Apparatus according to claim 4, characterized in that the gripper ( 1 . 1A to 1D ) via a roller or a wheel or a toothed wheel in a corresponding track ( 2A . 2 B ) is guided. Device according to at least one of claims 1 to 5, characterized in that each gripper ( 1 . 1A to 1D ) at least one holder ( 8th ) assigned. Device according to at least one of claims 1 to 6, characterized in that the conveying means ( 3A to 7A . 3B to 7B . 15 ) comprise a toothed belt, a belt, a rope and / or a link chain. Device according to at least one of claims 1 to 7, characterized in that the position or the state of charge of the gripper ( 1 . 1A to 1D ) can be determined by sensors in any position. Apparatus according to claim 8, characterized in that the sensor information about the position or the state of charge of the gripper ( 1 . 1A to 1D ) and automatically or manually adjusts the further course to target values via software. Device according to at least one of claims 1 to 9, characterized in that the gripper ( 1 . 1A to 1D ) is circumferentially movable. Device according to at least one of claims 1 to 10, characterized in that the conveying means ( 3A to 7A . 3B to 7B . 15 ) by deflecting wheels ( 16 . 17 ) is driven. Device according to at least one of claims 1 to 11, characterized in that a bow the gripper ( 1 . 1A to 1D ) od. By an investment table. Like. Supplied. Device according to at least one of the claims 1 to 12, characterized in that they are part of a Jib of a sheet-fed rotary printing machine is used. Device according to at least one of the claims 1 to 13, characterized in that a bow to, through and away is feasible by at least one processing station. Device according to claim 14, characterized in that that the processing station, for example, a printing or a Stamping is.