US20040026851A1

US20040026851A1 - Device for conveying sheet-like material

Info

Publication number: US20040026851A1
Application number: US10/275,442
Authority: US
Inventors: Johannes Schaede; Gerald Reinhard; Steve Brown
Original assignee: KBA Giori SA
Current assignee: KBA Notasys SA
Priority date: 2000-05-08
Filing date: 2001-04-30
Publication date: 2004-02-12
Also published as: AU2001250232B2; RU2248317C2; EP1280724A1; DE50103633D1; CN1427793A; ATE276188T1; CA2407844A1; EP1280724B1; JP2004517787A; KR20030007585A; AU5023201A; UA74581C2; WO2001085586A1

Abstract

The device enables the inspection (10, 11, 12), marking (9) or other processing or monitoring of a printed sheet (1), conveyed in register on a radial path by means of a rigid, rotating sheet conveying device (2, 3, 4, 5), from the inside, that is to say the concave side of the movement path.

Description

The invention relates to enabling the inspection, marking or other processing or monitoring of a printed sheet, conveyed in register on a radial path by means of a rigid, rotating sheet conveying device, from the inside, that is to say the concave side of the movement path.

The sheet conveyance in sheet-fed printing machines (for example in securities sheet-fed machines), both in the area of the feeder and of the sheet delivery, is conventionally carried out by means of suction, belt and chain conveying systems which do not maintain register, and also, in the area of the printing unit, by forcible guidance in register in gripper systems on transfer or impression cylinders.

For all the processes which are relevant to the printing process, such as the printing operation itself and marking, processing, reading or monitoring operations, the individual printed sheet is therefore only partially accessible, resting on a convex cylinder surface (line contact during the printing operation, line monitoring with a linear camera).

If, by contrast, the entire surface is simultaneously to be accessible, for example for sheet inspection by a two-dimensional camera, without any impermissible influence of the curvature of a cylinder surface, then this can be carried out in a known manner only in a sheet-guiding system by means of a chain or other linear sheet conveying system over a guide device such as, for example, a suction plate.

In this case, the mechanical tolerance of the existing conveying system (for example conveying chain) itself has a detrimental effect, as does the expenditure (e.g. mechanical or electronic register system) required to eliminate the register inaccuracy.

In addition to the components for the conveying system itself (chain, chain rails, sprocket shafts), in particular additional devices for aligning the printed sheet or the gripper system are required when the printed sheet is to be fed immediately in register to a subsequent printing process in a printing unit after the conveying or inspection operation has been carried out.

It is therefore an object of the present invention to enable the maintenance of register of a cylinder conveying means of a printed sheet at the same time as the accessibility of the entire surface of a flat conveying means of a printed sheet.

The expenditure on construction and costs for the subsequent alignment of a conveying system that does not maintain register is to be avoided. The sheet is to be accessible over its entire area at the same time, that is to say capable of being monitored or processed, without the interfering influence of the curvature of a convex cylinder outer surface.

The sheet conveying device is to permit compact, cost-effective and flexible integration into existing printing machines.

According to the invention, this object is achieved by a rotating sheet conveying device which is equipped with a plurality of sheet gripper systems and describes a circular sheet conveying path and has a rigid, register-maintaining mounting. The sheet guidance is in this case carried out from the outside of the circular path described, so that the sheet conveyed is freely accessible from the concave inside of the transport path.

A first advantageous property of the invention is that the outer sheet transport and guide path encloses the inner inspection, marking, reading or processing devices.

This permits both a space-saving design and also the accessibility of the concave inner surface of the circular path, which is optically substantially more beneficial for inspection or image acquisition processes as compared with a cylinder outer surface, with a radius of curvature which is large in relation to the sheet format (R>sheet length).

A second advantage of the conveying system is the design as a rigidly mounted unit, that is to say one rotating about a stationary axis, and provided with sheet gripper systems, for example on radial gripper arms, with the resultant maintenance of register of a cylinder conveying means, without additional mechanical expenditure on register being required for this purpose, as compared with a conventional cylinder.

A further advantageous refinement is distinguished by the fact that the sheet conveying device can also be driven in a cost-effective manner by a drive having a low torsional rigidity, such as a toothed belt drive, when in-register synchronous running in the circumferential direction is not required during the entire conveying path, but only the in-register transfer of the printed sheets from one conveying device to a second or to a transfer drum.

In this design, a gear segment fitted to the gripper system of the transferring conveying system engages in an opposing gear segment fitted to the gripper system of the accepting conveying system in such a way that, at the transfer point of the printed sheet, the two conveying systems are aligned exactly radially opposite each other and, therefore, an in-register sheet transfer is carried out.

The gear segments are in this case produced in such a way that the pitch circle diameter of the selected toothing is smaller than the nominal diameter of the sheet conveying path of the device.

This ensures that when the sheet gripper system approaches the transfer point, first of all, the two opposite, associated gear segments initially make coarse engagement with relatively high tooth play.

Since the point of contact of the pitch circle diameter of the toothed segment having the nominal diameter of the sheet conveying path coincides with the transfer point of the printed sheet, the tooth play decreases with increasing approach to the transfer point down to zero play or a minimum value, and in this way permits the exact in-register alignment of the conveying device during the sheet transfer.

After the sheet transfer, the toothing engagement described runs in the opposite direction, so that outside the sheet transfer, the conveying devices are coupled to one another and to following transfer drums only via the toothed belt drive.

A production advantage of the toothed segments used consists in enabling the required variable tooth play during operation with simultaneous cost-effective use of conventional toothing with constant dimensions.

A design of the toothed belt drive which is particularly beneficial in terms of installation and maintenance is to guide the part of the side machine frame which is used to hold the stationary axis of the conveying device to the outside, through the region between toothed belt sprockets and toothed belts, in such a way that when the device is ready to operate, replacement or installation of the toothed belt is possible at any time from the outside without disassembling parts of the frame.

In an advantageous expansion of the functional principle, two sheet conveying devices are coupled in opposite directions, so that the printed sheet to be processed, marked, monitored or to be inspected is accessible both from the front side in the first conveying device and also, immediately thereafter, from the rear in the second device in order to carry out these processes. In addition, by means of a vertical arrangement of the second conveying device above the first conveying device, the necessary overall length of the printing machine or of the unit in which the conveying device described is incorporated can be shortened substantially as compared with conventional sheet conveying systems.

A design of the conveying device, which is beneficial in production and cost terms, results from configuring the machine frame for holding the device as a load-bearing component only in the region of the axis of rotation and mounting, while in the region of the outer circular sheet movement path, only sheet guide elements and housing components which can be produced cost-effectively are required in accordance with the given intended purpose.

In addition to the familiar sheet guide rods or sheet guide plates, the aforementioned sheet guide elements can preferably be constructed as suction elements, such as suction boxes with perforated suction plates, in order firstly to guide the printed sheet on the circular movement path counter to the force of gravity in the upper part of the device and, secondly, as said sheet passes through the processing, marking, monitoring or inspection operation, to keep the sheet surface resting exactly smoothly on the guide surface.

Furthermore, the suction elements can be interrupted at right angles to the conveying direction in order to implement transmitted light inspection, that is to say to transilluminate the printed sheet, in such a way that the result is a light passage gap for a light source arranged outside the sheet path.

An advantageous configuration of the suction elements consists in designing individual sections of the sheet guiding means such that they can be folded up or removed easily, in order to enable free access from the outside to the systems installed in the internal region of the sheet conveying device, for installation, maintenance and adjustment purposes.

An alternative configuration variant results from designing the conveying device to be freely accessible from an operating side, as it is called, if this is required for specific intended uses.

In this case, all the drive, mounting and control elements are located on a drive side of the conveying device, which is closed in accordance with the design, while on an operating side, which is open in accordance with the design, a supporting bearing is provided by means of a running ring arranged approximately at the nominal diameter of the conveying path and guided by cam rollers fitted in the side frame.

Thus, all of the systems to be installed in the conveying device and to be operated can advantageously both be operated, supplied or mounted freely accessibly in the operating position within the conveying device, and removed sideways in a simple manner for maintenance, installation or adjustment purposes, or moved sideways out of the conveying device by means of a suitable apparatus.

The present invention can be used both as a self-contained sheet conveying machine to be operated for processing, monitoring, sorting or inspection purposes in conjunction with a sheet feeder, a sheet delivery and self-contained drive, and also advantageously integrated in already existing sheet-printing or numbering machines.

A particularly advantageous arrangement results from the sheet conveying device being connected constructionally upstream of the actual printing or numbering unit of a printing machine in such a way that, on the basis of a classification of the printed sheet taking place as it passes through the conveying device, for example by means of an inspection or reading operation, the sequence of the subsequent printing process can be controlled with respect to whether this printing operation is to take place for a relative sheet or blank, is not to take place or is to be changed.

For example, the further printing or numbering of a printed sheet can be interrupted if, on the basis of an inspection operation within the conveying device connected upstream, the sheet has been assessed as a reject sheet.

Further details and advantages of the present invention are given by using the following descriptions in conjunction with the figures, in which:

FIG. 1 shows a schematic drawing of a conveying device having four sheet gripper systems, inside processing or monitoring systems that are arranged and outside suction or sheet guide elements that are arranged. [0034]
FIG. 2 shows an exemplary cross section of the conveying device from FIG. 1 with a schematic representation of the stationary central axis for holding the installed systems in the device, and also a drive gear located outside the frame. [0035]
FIG. 3 shows a schematic drawing of a conveying device of double design for acting both on the front side and the rear side of the printed sheet, with processing and monitoring systems arranged by way of example, and also transfer drums for sheet transport. [0036]
FIG. 4 shows a schematic drawing of a conveying device of double design having a toothed belt drive and centrally arranged bearing frames for the free assembly and disassembly of the drive belts. [0037]
FIG. 5 shows an exemplary cross section of the drive variant with toothed belt drive from FIG. 4, with a schematic representation of the bearing frames led sideways to the outside through the drive plane. [0038]
FIG. 6 shows a schematic drawing of a conveying device of double design having toothed segments arranged radially at the sheet transfer points with d[0039] _{0 toothed segment}<d_{0 sheet path}for the accurate-register transfer of the conveyed sheet from one device to the following or to a transfer drum.
FIG. 7 shows a schematic drawing of the design as a closed hollow cylinder without separate gripper arms but with radial cutouts in the cylinder outer surface for the free accessibility to the entire sheet surface to be processed or to be monitored. [0040]
FIG. 8 shows a schematic drawing of the design as a conveying device closed on the drive side and open on the operating side for free sideways accessibility to the systems installed in the interior of the device. [0041]
FIG. 9 shows an exemplary cross section of the design as a sheet conveying device according to FIG. 8, closed on the drive side and open on the operating side. [0042]
FIG. 10 shows an exemplary arrangement of the sheet conveying device of double design for the processing or inspection of the front side and rear side of the sheet within a sheet-fed printing machine. [0043]
FIG. 11 shows an exemplary arrangement of the sheet conveying device of double design for the processing or inspection of the front side and rear side of the sheet as a self-contained sheet conveying machine to be operated without integration into a printing machine.[0044]
In the illustration according to FIG. 1, the [0045] sheet 1 to be conveyed is moved on a circular path by gripper systems 2. The gripper systems are connected to the hollow shaft 4 of the central mounting 5 by rigid gripper arms 3.
The actual guidance of the sheet is provided by [0046] suction elements 6 or sheet guide rods 7 located on the outside. As described, the printed sheet is thus freely accessible from the interior 8 of the device during the entire conveying path.
Illustrated by way of example in the interior are a [0047] sheet marking system 9, a sheet inspection or monitoring system 10 with illumination 11 located on the inside, and also a sheet transillumination or transparent inspection system 12 with light source 13 located on the outside.
As a result of the rigid design and play-free mounting of the rotating conveying device and also the register system shown in FIG. 6, the sheet being transported is transferred in register from one gripper system to the other gripper system at the [0048] transfer point 14 between the devices and also at the transfer point 15 to the transfer drum 16, without additional mechanical guide or locking elements being required for this purpose.
In the illustration according to FIG. 2, the stationary [0049] central axis 20 is shown in cross section through the conveying device according to FIG. 1, said central axis 20 being used for the installation of the systems designated 9, 10, 11 and 12 in FIG. 1.
As illustrated here, a special design of the [0050] marking system 9, having a plurality of marking stations, is used for the separate marking of individual blanks on the printed sheet.
The gripper arms or [0051] side flanges 3 of the device enclose the systems located on the inside, as illustrated, and are led together in the hollow drive shaft 22 mounted in the side frames 21.
The drive of the conveying device is provided via the [0052] drive shaft 22 inside or outside the side frame by means of gears 23, toothed belts, sprockets or other drive means, and can alternatively also be designed as an electronically controlled direct drive (not illustrated here).
The hollow [0053] central shaft 20 is used at the same time also to guide cables of control and supply lines to the installed systems.
In the illustration according to FIG. 3, the double arrangement of two conveying devices for the successive processing, monitoring, marking or inspection both of the [0054] sheet front side 30 and of the sheet rear side 31 is shown.
In this case, the printed sheet is first picked up from a [0055] transfer drum 33 by the first conveying device 32 and fed to a system, illustrated here by way of example as a camera/illumination system 34, to act on the front side of the sheet.
As shown, the sheet guidance can be provided by [0056] guide plates 35 or guide rods if, by means of the influence of gravity and centrifugal force, a sufficient flat attitude of the printed sheet on the guide elements is ensured.
In the [0057] second conveying device 36, the sheet is then fed to a second system, likewise illustrated here as a camera/illumination system 37, to act on the rear side of the sheet.
The sheet guidance is carried out as shown by means of suction plates or [0058] suction boxes 38 in the region of the sheet path in which the sheet additionally has to be held on the guide plane counter to the action of gravity. In addition, as illustrated by way of example here in the second conveying system, further monitoring or inspection systems 39 can be installed, for example for the transillumination of the sheet, or marking systems 40 can be arranged for marking the sheet classifications determined, for example, in the installed inspection systems.
After passing through the [0059] second conveying device 36, the printed sheet is transferred to further transfer drums 41, 42, for example for onward transport within a printing machine or to a sheet delivery.
All the sheet transfers from transfer drums to the conveying device and also from the first to the second conveying device are additionally synchronized in register by the gear segments at the transfer point, described in FIG. 6, if the conveying device is not driven by gears. [0060]
In the illustration according to FIG. 4, the drive of the sheet conveying device is advantageously provided by [0061] toothed belts 50, 51 from the drive side of the machine or from the drive motor.
This makes it possible both to save material and expenditure on production as a result of the omission of drive gears, and to easily adapt the drive medium to the installation position of the conveying devices and transfer drums in the machine. [0062]
The [0063] gears 52 represent the conventional gear train of the machine drive.
The drive pulleys [0064] 53 of the toothed belt drive are coupled to the two last oppositely rotating gears.
The drive pulleys [0065] 54 of the actual conveying devices can also be designed, as shown, to be smaller than the nominal diameter of the conveying device, taking note of the step-up ratio, for space-saving reasons.
The [0066] toothed belts 50, 51 can be guided over tensioning rollers 55 in such a way that a plurality of axes with identical direction of rotation, as shown here, for example, the drive of the second conveying device and also of the transfer drive 56, are connected to the first conveying device by only one belt train.
In a particularly advantageous design, the [0067] side frame parts 57 which are used to hold the stationary central axes of the conveying devices are led through the drive plane in the region 58 within the toothed belt train that is enclosed by the respective toothed belt drive, in such a way that assembly and disassembly of the toothed belt is made possible without disassembly of frame parts or loosening of the central axis of the conveying systems, which may be permanently adjusted on account of the installed systems.
In the illustration according to FIG. 5, a cross section is shown through the double arrangement of the conveying device according to FIG. 4, driven by toothed belts. [0068]
The systems which are installed in the interior of the device but not shown here are fitted, as described, to the rigid [0069] central axis 60 which serves at the same time to guide the cables of the systems and, on the drive side, is mounted in the frame parts 57 led through the toothed belt drive plane according to the description of FIG. 4.
The toothed belt drive plane is formed by the toothed pulleys and [0070] tensioning rollers 53, 54 and 55 already described and illustrated in section here.
The output gear of the [0071] gear train 52 is at the same time coupled to the drive pulley 53 of the belt train.
Together with the gripper arms or [0072] side flanges 63 and the inner hollow shafts 64, the gripper systems 62 form the actual rigidly connected, rotating sheet conveying device.
Mounting is carried out in rolling-[0073] contact bearings 61 in the side machine frames 65.
In the illustration according to FIG. 6, as already described, the accurate-register synchronization of the gripper systems of the conveying device in relation to one another and to the transfer drums is carried out by means of [0074] gear segments 70.
The latter are arranged laterally on the circumference of the conveying device in such a way that each sheet gripper system is assigned an associated toothed segment, oriented to the central axis (center line) of the sheet transfer. [0075]
The [0076] pitch circle diameter 71 of the toothed segments 70 is a certain amount smaller than the nominal diameter 72 of the conveying device, so that as two toothed segments approach each other, initially there is tooth engagement with relatively large tooth play.
During further movement toward the sheet transfer point, the tooth play decreases in accordance with the approach of the two [0077] diameters 71 and 72, down to the adjusted minimum play at the sheet transfer point, which simultaneously represents the tangential point of contact of the diameters 71 and 72.
In this way, a complete alignment or register cycle takes place for each sheet transfer and ensures that, even in the case of possible drive-side fluctuations of the circumferential register, for example as a result of the elasticity of the drive used, an accurate-register sheet transfer takes place. [0078]
One particular production advantage of the [0079] toothed segments 70 used resides in the fact that these segments merely represent extracts from a toothing geometry which can be produced conventionally and cost-effectively, and nevertheless a tooth play which narrows continuously and widens again in relation to the sequence of the register operation is made possible, without these tooth play differences having to be taken into account, for example during the production of the toothing.
Furthermore, the toothed segments are arranged on the conveying device such that they can be displaced radially, so that, in a simple way, the best possible register maintenance of the sheet transfer can be produced by adjusting intermeshing toothed segment to a minimum tooth play at the transfer point. [0080]
The illustration according to FIG. 7 shows an alternative design of the sheet conveying device as a cylinder body. [0081]
In this case, the sheet conveying cylinder comprises a hollow shaft or [0082] flange 80 to hold the mounting, one or two side walls 81 instead of separate gripper arms, and also the cylindrical outer body 82 instead of separate gripper cross members.
The [0083] sheet gripper systems 83 are incorporated in the cylinder cover in a manner corresponding to a conventional impression or conveying cylinder.
However, for each sheet conveyed, the cylinder outer surface has a [0084] cutout 84 in each case, which ensures the accessibility of the sheet surface from the inside of the conveying device, at least in the region of the monitoring, processing, marking, reading or inspection processes to be carried out.
If the dimensions of the conveying cylinder are selected such that the circumferential division exceeds the maximum sheet or sheet extract length by a certain amount, then, because of the remaining outer surfaces—[0085] webs 85, there results a torsionally stiff construction which at the same time is advantageous to produce and which has the functional properties of the invention described.
In the description according to FIG. 8, a design variant which is particularly beneficial in terms of installation, maintenance and operation is shown, which is freely accessible from an operating side (here: viewing side) to the interior of the conveying device. [0086]
All the bearing, control and drive elements are combined on one [0087] drive side 90 in the manner already described.
From the operating side shown here, the mounting of the rotating conveying device is carried out via a running [0088] ring 91 which is arranged approximately at the nominal diameter of the sheet path and which is guided by supporting rollers or bearing elements 92 fitted in the side frames of the operating side.
The [0089] area 93 is inside the running ring 91 is therefore free of bearing or other structural elements and can be used for the free accessibility to the systems installed in the interior of the device. The side frames 94 of the operating side are cut out appropriately in this area. Since this accessibility also exists in the operating state of the system, holding device or supply devices relating to the operating systems can also be guided from the operating side, or devices can be fitted which permit the systems to be moved out laterally from the operating position into a maintenance position.
The illustration according to FIG. 9 shows an exemplary cross section through the design described in FIG. 8 with the operating side open on one side. [0090]
In this view, the systems to be installed in the interior are not illustrated. [0091]
The [0092] side frame 100 of the drive side is used to hold a bearing element 101 for the main mounting 102 of the sheet conveying device. The drive sprocket 104, illustrated as a toothed sprocket here, is mounted on the drive flange 103.
By means of the transmission elements, here, by way of example, the [0093] toothed belt 105, toothed belt pulleys 106 and gears 107, the drive to the conveying device is provided, as already described.
Likewise, all the control elements, such as cam disks (not shown here) for the control of the [0094] sheet gripper systems 109 of the conveying device via cam rollers 108 are arranged on the drive side. Furthermore, the mechanically closed or load-bearing part 110 of the conveying device itself is located on the drive side.
On the operating side, a supporting mounting is provided via a running [0095] ring 111, which is arranged approximately at the nominal diameter of the sheet path and which can be constructed as an outer or inner running ring, and by cam rollers 112 fitted in the side frame.
The [0096] side frame 113 of the operating side is open to the greatest possible extent within the area described by the running ring 111 in order to ensure the free access through the operating opening 114 to the systems installed in the interior 115.
In order to enable load-bearing mechanical fixing of the operating systems on both sides, the [0097] opposite drive flange 103 is also constructed as a hollow shaft. Through the flange opening 116, for example, holding cross members or installation elements can advantageously be led to the outside for the purpose of rigid anchoring to the side frame on the drive side.
In the illustration according to FIG. 10, the sheet conveying device is integrated as functional component into an existing sheet-fed machine. [0098]
From a [0099] sheet feeder 120, the sheet is fed to the sheet conveying device via a feed drum 121, maintaining circumferential and lateral register.
The conveying device illustrated here by way of example permits the sheet front side to be acted on in its [0100] front side unit 122, and permits the sheet rear side to be acted on in the manner according to the invention in its rear side unit 123.
The sheet data or markings obtained or applied by means of the [0101] systems 124, 125, 126, 127 installed in the sheet conveying device, in the arrangement illustrated here, can advantageously be used for the purpose of controlling, interrupting or changing further production or sorting operations in the printing or sheet delivery units arranged downstream. On account of the in-register sheet transport according to the invention in the sheet conveying device, the printed sheet can be transferred directly, that is to say without further mechanical sheet alignment, by transfer cylinders, for example to a following sheet printing machine 128.
Furthermore, in a [0102] marking device 129, the sheet data produced by the systems installed in the sheet conveying device and transmitted can be applied to the printed sheet as legible or encoded information, for example by means of an inkjet printer or an ink spraying system.
In a suitable design, the marking [0103] device 129 can also be used for the purpose of canceling individual printed sheets or individual blanks by applying a detectable or machine-readable symbol, such as color bars, or to identify them specially.
Sorting of the produced printed sheets can be carried out in a [0104] sheet delivery 130 having a plurality of sheet stacks, depending on the production classification attained by the systems 124, 125, 126, 127 installed in the conveying device 122, 123, or the identification made in the marking station 129.
In the illustration according to FIG. 11, the sheet conveying device is shown as the main unit of a sheet-fed machine operated on its own. [0105]
The [0106] sheet feed components 120, 121 and the conveying device 122, 123 and their operating systems 124, 125, 126, 127 in this case correspond to the arrangement shown in FIG. 10.
However, there follows no further production or printing operation in a printing unit, but the direct transfer of the conveyed sheet to the [0107] sheet delivery 130, with the functions already described in FIG. 10 and, for example, an integrated marking station 129.
In order to drive the conveying device and the sheet feed and delivery, a self-contained [0108] drive part 131 is integrated into the sheet-fed machine. The main function of the design illustrated therefore consists in the performance, separated from other types of production processes, of the sheet conveying, processing, monitoring, marking and inspection operations proceeding in accordance with the invention.

Claims

1. A device for conveying sheet-like material on a conveying path produced by means of an intrinsically rigid system moving about a stationary axis of rotation in order to act on the side of the conveyed material that faces the axis of rotation by means of devices installed in the interior of the space enclosed by the conveying path.

2. The device as claimed in claim 1, characterized in that the conveying system is formed by a number of gripper systems connected by means of an intrinsically rigid mechanical frame to hold, convey and forward sheet-like material, and which enables accessibility to the entire or partial surface of the material from the interior of the conveying path.

3. The device as claimed in claim 1, characterized in that the guidance of the sheet-like material conveyed by the device on the conveying path produced by the device is carried out by means of sheet guide elements arranged outside the space enclosed by the conveying path.

4. The device as claimed in claim 1, characterized in that the devices installed in the interior of the space enclosed by the conveying path can be material processing, monitoring, marking, registering, illuminating, inspecting or other systems.

5. The device as claimed in claim 1, characterized in that the devices described in claim 4 act on a sub-area or the entire area of the conveyed sheet-like material from the interior of the space enclosed by the conveying path.

6. The device as claimed in claim 1, characterized in that two sheet conveying devices as claimed in claim 1 are coupled in such a way that the conveyed material is fed first to a sheet conveying device to act on one sheet side and then to a second sheet conveying device to act on the opposite sheet side.

7. The device as claimed in claim 1, or coupled devices as claimed in claim 6, characterized in that the drive to the sheet conveying devices is provided by mechanical means such as a gear drive, chain drive or toothed belt drive from the drive source of the printing or conveying machine in which the devices are installed.

8. The device as claimed in claim 1 or coupled devices as claimed in claim 6, characterized in that the drives to the individual sheet conveying devices are designed as separate individual drives synchronized with the printing or conveying machine in which the devices are installed.

9. The device as claimed in claim 7, characterized in that the transmission elements used, such as chains or belts, are arranged in such a way that when the conveying device is ready to operate, with all the working systems installed in the interior of the device and mechanically rigidly connected on both sides to the machine frame, the transmission elements can be assembled or disassembled mechanically and freely accessibly without disassembly or loosening of these connections.

10. The devices as claimed in claim 7 or 8, characterized in that the synchronism between coupled sheet conveying devices and between the conveying devices and transfer cylinders connected upstream or downstream is additionally synchronized by toothed segments which are arranged at the nominal diameter of the conveying path in the area of the gripper systems, are radially adjustable and interengaged during the sheet transfer.

11. A method for synchronization of the drive as claimed in claim 10, characterized in that the pitch circle diameter of the toothed segments used is smaller than the nominal diameter of the sheet conveying path, and in that the two diameters touch at the transfer point of the conveyed sheet from one gripper system to the corresponding gripper system in such a way that, before the sheet transfer is reached, the result is a tooth play which decreases continuously, is the lowest possible during the sheet transfer and widens continuously after the sheet transfer.

12. The device as claimed in claim 1, characterized in that the conveying system is alternatively formed by a hollow body of cylindrical design and provided on the circumference with sheet gripper systems, and the accessibility from the interior of the device to all or part of the sheet area facing the interior of the device is enabled by suitable cutouts in the cylinder cover.

13. The device as claimed in claim 1 or coupled device as claimed in claim 6, characterized in that all the drive, bearing and control elements are combined on a drive side, as it is known, of the conveying device in such a way that the interior of the device is freely accessible from the opposite operating side of the conveying device through a cross section which is open at the side.

14. The device as claimed in claim 13, characterized in that the installation, adjustment, operation, maintenance, supply and removal of all the devices located in the interior of the conveying device are preferably carried out from the open operating side.

15. The device as claimed in claim 13, characterized in that the mounting of the conveying device in the machine frame is carried out on only one side on the drive side, or on the operating side, comprises a running ring with an operating opening of suitable diameter, which is guided by cam rollers or bearings arranged in the machine frame, and the machine frames have operating openings of appropriate size.

16. The device as claimed in claim 1, or coupled device as claimed in claim 6, characterized in that the sheet transport device is a functional component, with the systems installed therein, of a sheet printing, numbering, conveying, application, embossing, packaging, sorting or processing machine.

17. Integration of the sheet conveying device into a machine as claimed in claim 16, characterized in that, on the basis of the information produced by the systems installed in the device, classifications, processes carried out, inspections, or applied identifications or marking, the progress of subsequent operating processes in the machine is controlled with the effect that these are carried out, not carried out or changed for a corresponding sheet.

18. The device as claimed in claim 1 or coupled device as claimed in claim 6, characterized in that the sheet conveying device is operated as a self-contained machine with material feed and delivery and a self-contained drive source for processing, monitoring, marking, registering, classifying, inspecting or sorting sheet-like material with the aid of the devices arranged in the interior of the device.