EP3694718B1 - Sheet-processing machine comprising a sheet transport device, and method for transporting sheets from a sheet-guiding cylinder to a sheet conveyor system - Google Patents

Description

The invention relates to a sheet processing machine with a sheet transport device with a sheet conveying system taking over a sheet from a sheet guiding cylinder and a method for conveying sheets from a sheet guiding cylinder to a sheet conveying system in a sheet processing machine.

the end DT 2 025 849 , DE 73 03 778 U and DE 28 13 136 A1 it is known to assign additional sheet support elements to sheet guide cylinders that only contact the sheet in some areas. It is disadvantageous that the drums are of massive design and are therefore dynamically unfavorable. Furthermore, the adjustment effort is great.

the end U.S. 2,965,026 , DT 1 761 714 , DT 2 002 877 , DT 25 18 334 B1 and GB 2 256 426 A it is known to form support disks of sheet guide drums with adjustable contact elements. It is disadvantageous that the setting effort is great and cannot be carried out rationally in the case of fast job changes on sheet processing machines.

the end DE 35 35 621 A1 and DE 196 44 011 A1 it is known to move flat sheet support segments on chains below the periphery of sheet guide drums. It is disadvantageous that these sheet guide drums are not suitable for transporting freshly coated sheets in the delivery of a sheet processing machine.

the end DE 10 2004 031 171 A1 and already DE 517 004 it is known to remove sheets from a cylinder jacket surface by means of suction disks which can be adjusted on pressure-free side edges to decrease. The vacuum required to hold the sheet edges is generated by a pump and transferred to the main sprocket shaft via a rotary valve. The rotary valve takes over the timing of the suction air. The disadvantage is that this rotary valve usually works without contact and very large amounts of leakage air are drawn in. Furthermore, high demands are placed on the rigidity of the assembly, since even the slightest deformation leads to a change in the gap between rotor and stator, which makes leakage losses unacceptable or which leads to unwanted contact and thus heavy wear. Due to the desired minimal gap widths in connection with the need to exclude contact, high demands are placed on the adjustment during assembly. Although it is possible to make the rotary valve non-contacting, this is associated with high wear of the components rubbing against each other, especially in the powder-loaded display. Another disadvantage is the fact that the rotary slide valve and the point of action (suction device) are not directly next to each other, which leads to very long suction lines that first have to be evacuated with each cycle. These systems run the risk of becoming too sluggish, especially in the case of high-speed machines with cycle times of 180 ms and below. It is also disadvantageous that the construction of the suction disks must have an axial extent that requires relatively large pressure-free side edges. This reduces the usable arch area.

the end DE 10 2005 002 509 A1 , DE 10 2013 224 489 A1 and DE 10 2015 204 113 A1 it is known to press the sheets mechanically or pneumatically against support disks of the delivery drum after a transfer center. The disadvantage is that mechanical or pneumatic support has to be adjusted in a complex manner. A certain axial extension of the support disks is necessary for a secure hold of the arches.

the end DE 100 14 417 A1 , DE 10 2004 051 323 A1 , DE 10 2004 052 656 A1 , DE 10 2011 012 808 A1 and DE 10 2004 009 703 A1 it is known to take over sheets from a printing cylinder through a delivery drum having supporting disks.

The trailing edge of the sheet is held by a cross member that extends over the maximum format width and has suction cups. The disadvantage is that the traverse to take over the sheet trailing edge is large and therefore dynamically unfavorable. The available arched area is reduced by the crossbeam and high leakage losses occur.

From the DE 10 2012 206 928 A1 a sheet brake with axially adjustable braking stations is known.

The invention is based on the object of providing an alternative sheet processing machine with a sheet transport device and an alternative method for sheet transport. In particular, a sheet transfer from a sheet guide cylinder to a downstream sheet conveying system is to be further improved.

According to the invention, the object is achieved by a device with the features of an independent device claim or a method with the features of an independent method claim. Advantageous refinements result from the subclaims, the description and the drawings.

The invention has the advantage that an alternative sheet processing machine with a sheet transport device and an alternative method for sheet transport are provided. In particular, sheet transfer from a sheet guide cylinder to a downstream sheet conveying system is further improved.

A sheet transport device can be used within a sheet processing machine, for example a sheet printing machine, or in a display of a sheet processing machine, for example a sheet printing machine. A sheet conveyor system can for example be designed as a sheet guide drum and in particular be arranged between two printing cylinders of a sheet-fed printing machine. There will be a accordingly sheet processing machine, in particular a sheet-fed printing machine, provided with a corresponding sheet transport device. The sheet conveyor system preferably contains a delivery drum, which is in particular in the delivery of a sheet processing machine is used. The delivery drum particularly preferably contains a sprocket shaft around which the gripping devices, in particular the gripper carriage of a chain conveyor system, are moved to take over the leading edges of the sheet.

For example, when printing on sheet-fed printing machines, small amounts of ink are transferred from the plate via the blanket cylinder to the printing cylinder, even in areas that are actually print-free. In places where there is no sheet on the impression cylinder, these small amounts of ink remain on the impression cylinder, where they can build up over a long period of time. In the case of washing processes, these can also be larger quantities. Sheet support segments that are constantly in contact with the impression cylinder become soiled over time. This also applies to the rear part of the sheet support segments, if the maximum format is not being printed. It is therefore advantageous to format the support elements or contact elements that come into contact with a sheet in the area of a sheet guide drum or delivery drum.

Because suction takes place exclusively at the rear edge of the sheet or at the rear corners, the lateral sheet support segments or support elements can be made very narrow, which in turn leads to advantageous, very narrow, pressure-free side margins. For example, the arch support segments in the space between the gripper carriages can be designed as brackets or carry brackets around which a traction means, in particular a chain, is guided, which is at least partially covered with preferably elastic support elements, preferably in such a way that these elements are only in The area of the lateral sheet edges between the gripper carriage and fixing devices, in particular suction cups, are located. When adjusting a fixing device, in particular a suction device, to the correct arc length, the traction means, in particular the chain, is preferably also adjusted. In this way, when moving to a smaller format length, the excess support elements can advantageously be "stored" in an area in which they have no contact with the sheet.

The support elements are advantageously only used at the points where there is still a printing material, in particular paper, between these support elements and the cylinder jacket surface. The support elements are thus protected from contamination.

The support elements preferably only contact printing material and never the soiled printing cylinder surface of a printing cylinder of a sheet-fed printing press. The entire device is therefore much less susceptible to dirt and therefore requires little maintenance. With exclusively supporting arch support segments, it is particularly preferable to use particularly narrow support elements, whereby it has been shown that a preferably pneumatic fixing of the arches on the lateral trailing sheet edges or at the rear corners is sufficient. In particular, the sheet fixed or held on the cylinder jacket surface from the front edge to the rear edge can easily be taken over by fixing devices arranged adjacent to the sheet support segments.

In particular, the sheet support segments, in particular support elements, can have the function of pressing the sheet against the sheet guide cylinder, in particular a pressure cylinder, and thereby preventing a “sheet fall”. On the other hand, the sheet can be supported on its way around the sheet guide drum or delivery drum, in particular a sprocket shaft, on these sheet support segments, in particular support elements, and held on the desired path, for example near sheet guide plates, so that the sheet cannot describe a secant.

Particularly preferably, each sheet is captured at its rear edge in a transfer center by fixing devices, in particular pneumatic suction devices, which are preferably arranged exclusively in the area of the lateral sheet support segments. The vacuum required for suction is preferably generated "on site" by means of fixing devices working according to the ejector principle. In particular compressed air is preferably not clocked via a rotary inlet of a rotatably mounted shaft of the sheet guide drum or delivery drum, in particular a rotary inlet of a sprocket shaft. For example, a solenoid valve, preferably a quick-acting valve, which is connected to a vacuum ejector via a line that is as short as possible is located near the active points of the fixing devices, in particular at the corners of the sheet. This sits as close as possible to the suction device or is integrated into the suction device assembly in order to keep the dead volume to be evacuated as low as possible. Advantageously, leakage losses are thereby reduced or avoided, which leads to a lower energy consumption (although the generation of a vacuum by compressed air is actually more energy-intensive than generation by a pump). The elimination of the complex assembly of the rotary valve and the availability of a practically wear-free solution are also advantageous. A highly dynamic behavior can be achieved through small dead volumes after the solenoid valve both in the pressure and in the suction line. The switch-on and / or switch-off times can also advantageously be set or changed as a function of sheet speed and / or printing material, for example via the machine software.

For example, the sheets can be transferred from a rotating sheet guide cylinder to rotating gripping devices, in particular gripper trolleys, and a sheet conveying system having a delivery drum. The delivery drum of the sheet conveying system preferably has circumferential, in particular rotating, driven sheet support segments which are arranged adjacent to the sheet guide cylinder and which in particular have recesses for the gripper carriages. The sheet support segments together with the cylinder jacket surface of the upstream sheet guide cylinder form a transfer center in which the gripper carriages take over the sheet leading edges in the gripper connection from the gripper systems of the sheet guide cylinder. The arch support segments in particular have a small axial extent compared to the cylinder width. Pneumatic means can also be used be provided which press the sheet onto the cylinder jacket surface and / or which hold the sheet after the transfer center on the sheet support segments or press against the sheet support segments.

For example, the sheets can be pressed against the outer surface of the upstream sheet guide cylinder at the same time in the transfer center by exactly two sheet support segments. Below the sheet support segments, a sheet guide element can be arranged, which preferably with a comb element extends far into the area of the transfer centers, with support blow holes preferably being arranged in the sheet guide element. The support blow holes can preferably be arranged in the middle area of the sheet guiding element across the machine width in a high density and in the adjacent areas, in particular in the areas upstream and / or downstream in the sheet conveying direction, in a lower density compared to the middle area. The blown air of the sheet guiding element could also be varied or clocked or controlled or regulated according to sensor values in accordance with the progress of the sheet transfer. Particularly preferably, a sheet transport from a sheet guide cylinder of a last work to a sheet conveyor system in the delivery of a sheet processing machine can be provided, with a sheet guide element being provided below the delivery drum.

Fig. 1:

Auslage einer bogenverarbeitenden Maschine mit einer Kettenradwelle;

Fig. 2:

Perspektivische Darstellung der Kettenradwelle mit verstellbaren Bogenstützsegmenten;

Fig. 3:

Perspektivische Darstellung der Kettenradwelle mit Stützelemente tragenden Bogenstützsegmenten und Fixiereinrichtungen für die Bogenhinterkante;

Fig. 4:

Seitliche Ansicht der doppeltgroßen Kettenradwelle mit an Ketten angeordneten Andrückelementen;

Fig. 5:

Vergrößerte Ansicht eines Bogenstützsegmentes mit Andrückelementen und einem Sauger für die Bogenhinterkante;

Fig. 6:

Ausführung eines Andrückelementes für eine auf einem Bügel geführte Kette;

Fig. 7:

Ausführung eines Kontaktelementes als Sauger für eine Fixiereinrichtung.

The invention is to be explained below by way of example. The accompanying drawings show schematically:

Fig. 1:

Delivery of a sheet processing machine with a sprocket shaft;

Fig. 2:

Perspective view of the sprocket shaft with adjustable arch support segments;

Fig. 3:

Perspective view of the sprocket shaft with sheet support segments carrying support elements and fixing devices for the sheet trailing edge;

Fig. 4:

Side view of the double-sized sprocket shaft with pressure elements arranged on chains;

Fig. 5:

Enlarged view of a sheet support segment with pressure elements and a sucker for the sheet trailing edge;

Fig. 6:

Execution of a pressure element for a chain guided on a bracket;

Fig. 7:

Execution of a contact element as a suction cup for a fixing device.

the Fig. 1 shows, for example, a delivery 1 of a sheet-processing machine, here in particular a sheet-fed printing machine, specifically a sheet-fed offset rotary printing machine, preferably in aggregate and in-line construction. The machine is accordingly preferably operated in the offset process, with other printing processes, such as, for. B. screen printing, can be integrated in the machine. In the factories of the machine, not shown, the sheets are gripped by gripper systems from rotating cylinders at the front edge and transferred between the cylinders in the gripper connection. In printing units, the sheets are colored in a printing nip formed by a cylinder and a rubber cylinder with one printing ink each according to the motif. Furthermore, one or more coating units can be provided in which the sheets can be coated by a coating forme cylinder. The cylinders arranged in the machine can be single-sized or multiple-sized, a single-sized cylinder being able to accommodate at least one sheet and a double-sized cylinder being able to accommodate at least two sheets of maximum format on the circumferential side. The machine is preferably assigned a turning device for turning the sheets in a perfecting mode while the machine is running. Further can also processing facilities or processing plants, such. B. cold foil works, be integrated in the machine.

In particular, the machine has a drive wheel train which, particularly preferably as a continuous drive wheel train, drives at least the sheet guide cylinders of the machine. Sheet guide cylinders designed as transfer drums or transfer cylinders are also preferably driven by the drive wheel train. For this purpose, the sheet guide cylinders on the drive side of the machine each have interlocking gears that form the drive gear train. The drive train is driven by at least one main drive motor, which drives the drive train at at least one input point. Preferably, the blanket cylinders of the printing units are also driven from the drive train. Further rotating bodies or rollers of the machine or of the printing units can also be driven at least temporarily by the drive wheel train, and these can also be designed to be coupled to the drive wheel train.

Plate cylinders of printing units can also be assigned to individual drives, in particular direct drives. Direct drives are in particular individual drives, the rotors of which are aligned and concentrically preferably attached directly to the associated cylinders. During printing, the plate cylinder in question is then tracked electronically and in an electronically synchronized manner to the blanket cylinder, which is preferably driven by the main drive motor via the drive wheel train. For this purpose, the plate cylinder and / or blanket cylinder can be assigned a rotary encoder, which can be connected to a control unit of the printing unit and / or the machine control. Alternatively, the plate cylinder (s) can also be driven from the main drive motor via the drive gear train.

The current machine angle is preferably known to a control device of the machine, for example the machine control. The machine angle can be defined as the position of a cylinder in space. For example, the machine angle can be derived or recorded from the main drive motor. Alternatively or additionally, a rotary encoder, in particular a rotary encoder, can be assigned to a preferably rotating element of the machine, which feeds or provides rotary encoder signals to the control device, in particular the machine control. For example, a sheet guide cylinder of the machine, in particular a sheet guide cylinder after a turning device (not shown) and / or a sheet guide cylinder from a last work, can be assigned a rotary encoder, preferably designed as a rotary encoder. The rotary encoder can in particular be assigned to the last sheet guide cylinder of the machine arranged immediately in front of the delivery 1 and / or be connected to the control device and / or to a quality control device, for example to an inspection system.

From a sheet-processing machine, for example sheet-fed printing press, a last double-sized sheet guide cylinder and a sheet conveying system of the delivery 1 that takes over the sheet are shown. The sheet guide cylinder has an at least approximately closed cylinder jacket surface and is here in particular a printing cylinder 2 of a last printing unit. Alternatively, the sheet guide cylinder can also be a last cylinder in a coating or other processing unit. The pressure cylinder 2 is made twice as large here and contains two diametrically arranged gripper systems located in gripper channels. The leading edges of the sheet are clamped and thus fixed by these gripper systems for sheet transport. Alternatively, the sheet guide cylinder can also be designed to be single, triple or multiple sizes.

The sheet conveying system is also arranged in the delivery 1, which in particular has endless, preferably continuously revolving driven and guided gripping devices for taking over and transporting the sheets. The gripping devices are preferred arranged on traction means and driven endlessly revolving via wheels and / or on deflection guides. The gripping devices are in particular arranged parallel to one another and evenly spaced between the traction means and are preferably designed as clamping grippers. The sheet conveying system here has, in particular, a chain conveying system 3 with circumferentially guided gripper carriages and a chain wheel shaft 4 assigned adjacent to the sheet guiding cylinder, in particular the printing cylinder 2. The chain conveyor system 3 contains here in particular on both sides of the frame of the display 1 on chain guide rails guided guide chains, on which and between which the gripper carriages are attached. Each gripper carriage contains a clamping gripper system which, for example, has grippers that are fixedly arranged on a movable gripper shaft and fixed gripper supports. A gripping movement for fixing a respective sheet leading edge can be controlled by rotating the gripper shaft. The gripper shaft of a gripper carriage can preferably be actuated by means of roller levers and cam rollers, particularly in the area of sheet transfer and in the area of sheet deposit by control cams.

The sheets are taken over by the sheet guide cylinder, in particular the printing cylinder 2, from the gripper carriage of the chain conveyor system 3 and guided along a sheet conveying path in the sheet conveying direction BFR to a delivery stack 5. The gripping movements of the gripper carriages can be controlled preferably via the roller levers and cam rollers, especially in the area of sheet transfer in the transfer center from the sheet guide cylinder, in particular pressure cylinder 2, and in the area of the sheet deposit, especially above the delivery stack 5, by control cams. Particularly preferably, the sheets are transported in the delivery 1 exclusively at the leading edge of the sheet by the gripping devices, in particular the gripper carriages. On the sheet conveying path from the sheet guide cylinder, in particular the impression cylinder 2, to the delivery stack 5, the sheets are preferably guided on guide elements (not shown), for example sheet guide plates, it being possible for an air cushion to be formed between the sheet and the sheet guide plates. In particular in the Contact-free sheet transport can take place in the front and back printing mode. For example, one or more dryers and / or dusting devices can be provided on the sheet conveying path.

In the delivery 1, the delivery stack 5 is preferably preceded by a sheet brake in the sheet conveying direction BFR, which takes over the sheets to be deposited from the gripper carriage and, after their release, decelerates them from machine speed to deposit speed. After the delay by the sheet brake, the sheets are aligned with leading edge stops, trailing edge stops and / or side edge stops (not shown) and deposited neatly on the delivery stack 5. The delivery stack 5 is preferably lowered by a stack lift drive (not shown) during the sheet depositing process in such a way that the delivery stack surface forms an at least approximately constant deposit level for the coming sheets. The sheet brake can, for example, contain at least two braking stations which are preferably arranged axially, that is to say transversely to the sheet conveying direction BFR, displaceably, in particular displaceably. The braking stations are placed in particular on a respective lateral, usually unprinted, sheet edge. In the case of other planned braking stations, these can be placed on pressure-free corridors and / or on adequately dried areas of paint. Braking stations that are not required can be deactivated and / or moved out of the area of the sheet format. Alternatively, follower grippers can also be used.

the Fig. 2 shows a perspective view of the sprocket shaft 4, which is assigned directly adjacent to the last sheet guide cylinder of the machine. The chain wheel shaft 4 has a shaft which is arranged parallel to the axis of rotation of the adjacent sheet guide cylinder and to which chain wheels for the circulating chains of the chain conveyor system 3 are assigned on both sides. The chain wheels work with the respective chain guide rails to guide the gripper carriages in the Area of the sprocket shaft 4 together. The chain wheels are thus coaxially and spaced apart from one another, in particular permanently assigned to the chain wheel shaft 4. A drive is assigned to the sprocket shaft 4, which drives the sprocket shaft 4 in rotation about its axis of rotation in synchronism with the drive gear train. The sprocket shaft 4 here preferably carries a helical gearwheel which interacts with the drive of the machine or is driven by it. The helical gearwheel, which is in particular permanently assigned to the sprocket shaft 4, is preferably part of the continuous drive gear train or gear train of the machine in meshing engagement with a gear of the sheet guiding cylinder immediately upstream, in particular of the printing cylinder 2. A gripper carriage of the chain conveyor system 3, which is guided in the area of the chain wheel shaft 4, takes over a sheet in a common transfer center by gripper closure from a gripper system of the upstream sheet guide cylinder, in particular of the printing cylinder 2.

The chain wheel shaft 4 has between the two chain wheels at least two and preferably exactly two sheet support segments 6 for simultaneously supporting a sheet against the cylinder jacket surface of the sheet guide cylinder, in particular the printing cylinder 2. At least one and preferably both arch support segments 6 are axially displaceable with respect to the sprocket shaft 4, for example on a hub. In the double-sized embodiment of the sprocket shaft 4, for example, each hub has exactly two arched support segments 6, which are arranged diametrically to one another and are firmly assigned to the hub. As a result of the joint mounting of the arch support segments 6 on a hub which is axially displaceable with respect to the shaft of the sprocket shaft 4, a joint adjustment of the arch support segments 6 on the respective side takes place. The hub can, for example, have rollers rolling on the surface of the shaft. It can be provided, for example, to assign six rollers to each hub, which run on preferably ground tracks of the sprocket shaft 4. In particular, an adjusting means is provided for the axial adjustment of the arch support segments 6. A drive, for example an electrically operating drive motor, is preferred for one or for each hub, for example on the operating side, which acts on the respective hub preferably via a spindle drive and effects an axial adjustment of the hub or of the arched support segments 6 assigned to the hub. For example, the axial adjustment of the sheet support segments 6 can be carried out together with the axial adjustment of the braking stations of the sheet brake to the sheet format. The axial adjustment can also be carried out and / or monitored in an automated manner on the basis of the same data by a control device, in particular the machine control.

The sheet support segments 6 can preferably be moved so far apart that sheets of the maximum format to be processed can be supported on the respective lateral side edges of the sheet. It can further be provided that one or both sheet support segments 6 are displaced outside of the maximum sheet format in order, for example, to enable sheet transport without sheet support segments 6 or maintenance. The arch support segments 6 or the hubs can also be axially adjustable or displaceable or adjusted or displaced independently of one another. For this purpose, the drive motors for the axial adjustment of the hubs carrying the sheet support segments 6 can be controlled independently, for example, by the control device, in particular the machine control. For the rotating gripper carriages of the chain conveyor system 3, the arch support segments 6 have recesses or their circumferential extent is dimensioned accordingly.

For example, a respective arch support segment 6 has a bracket 6, which is preferably held in a separate plane. A traction means carrying support elements, in particular a chain 8 carrying pressure elements 7, is assigned to the bracket 6 on the circumferential side. The bracket 6 contains a guide, oriented in the circumferential direction, for the traction means, in particular the chain 8, which can thus be displaced or displaced relative to the bracket 6 in the circumferential direction or in and / or against the sheet conveying direction BFR. The support elements assigned to the traction means, in particular the pressure elements 7 assigned to the chain 8 are accordingly mounted such that they can be displaced together in the circumferential direction along the bracket 6 or the guide of the bracket 6 when the traction means or chain 8 is displaced. A common displacement of the support elements, in particular pressure elements 7, in and / or against the sheet conveying direction BFR for adjustment, in particular for format adjustment, can thus take place.

The support elements, in particular pressure elements 7, assigned to the traction means, in particular the chain 8, have a curved contact surface with a minimal axial extension. The axial extent of an arc contact surface can be, for example, 0.5 mm to 3 mm, preferably at least approximately 1 mm. The support elements, in particular pressure elements 7, preferably contain elastic material or are made of elastic material. The pressing elements 7 can in particular contain rubber or be made of rubber. For example, the support elements, in particular pressure elements 7, viewed in the sheet conveying direction BFR, can also have a wedge-shaped cross section or an increased sheet contact surface. In the circumferential direction or along the sheet conveying direction BFR, the extension of the pressing elements 7 can be, for example, up to 50 mm. By means of a contact line of the support elements, in particular the sheet contact surfaces of the pressure elements 7, a sheet can be pressed against the cylinder jacket surface of the sheet guide cylinder, in particular pressure cylinder 2, and can thus be fixed or retained thereon. A sheet fall is thus avoided as long as the sheet is between the support elements, in particular pressure elements 7, and the sheet guide cylinder, in particular pressure cylinder 2. A sheet is preferably pressed against the cylinder jacket surface exclusively by the support elements, in particular pressure elements 7, and is not sucked in by the sheet support segments 6.

A hub of the sprocket shaft 4, here, for example, carrying two respective arched support segments 6, in particular furthermore has a hub sleeve which is movable in the circumferential direction and which is preferably supported in a rotationally movable manner on the hub. Of the The hub sleeve is preferably assigned a separate drive which can move the hub sleeve relative to the hub in the circumferential direction or in and / or against the sheet conveying direction BFR. The drive can, for example, be arranged directly on the hub or hub sleeve and displace the hub sleeve with respect to the hub. The hub can, for example, have an internally toothed tooth segment in which a pinion driven by the drive engages. The hub sleeve or the drive is correspondingly displaced axially along the shaft of the sprocket shaft 4 with the hub. The energy and / or signal transmission to the drive seated on the hub is preferably carried out by means of a rotary infeed 11 of the rotatably mounted sprocket shaft 4 is. The two drives, each assigned to a hub, are supplied from the cable chain.

Preferably, a sprocket shaft 4 and in particular a respective hub sleeve is assigned at least one fixing device for preferably pneumatically fixing a sheet trailing edge in areas. In the double-sized embodiment of the sprocket shaft 4, each hub sleeve carries exactly two fixing devices arranged diametrically to one another, which are preferably each firmly connected to the hub sleeve. By means of a drive displacing a respective hub sleeve with respect to the hub, the fixing devices can be placed on the respective sheet trailing edge in and / or against the sheet conveying direction BFR. The drive, particularly preferably at the same time, moves the traction means associated with the arch support segment 6, in particular the bracket 6, in particular the chain 8. The traction means, in particular the chain 8, is in particular also displaced in and / or against the sheet conveying direction BFR along the guide of the bracket 6. A respective fixing device is preferably connected to the traction means, in particular a chain link of the chain 8, in such a way that an adjustment movement of the fixing device simultaneously adjusts the traction means associated support elements, in particular the pressure elements 7 associated with the chain 8.

the Fig. 3 shows a perspective view of the sprocket shaft 4 with support elements, in particular pressure elements 7, bearing arch support segments 6, in particular brackets 6, and fixing devices for the rear edge of the arch. The fixing devices are in particular arranged exclusively in the area of the arch support segments 6, in particular brackets 6, between the arch support segments 6, in particular brackets 6, with one fixing device in each case being assigned directly to an arch support segment 6, in particular bracket 6. Further fixing devices for the rear edge of the sheet between the two outer fixing devices fixing the rear corners of the sheet are not provided. In particular, precisely one fixing device is assigned to a respective arch support segment 6, in particular bracket 6. One fixing device is preferably in each case mounted directly adjacent to an arch support segment 6, in particular bracket 6, and / or movably mounted relative to an arch support segment 6, in particular bracket 6, in particular for adjustment. The fixing devices are designed to be format-adjustable in particular in the sheet longitudinal direction, ie in the sheet conveying direction BFR, and / or in the sheet width direction, ie transversely to the sheet conveying direction BFR. The fixing devices are preferably designed to be format-adjustable together with support elements, in particular pressure elements 7, of the arch support segments 6, in particular brackets 6. The fixing devices with the support elements, in particular pressure elements 7, can preferably be adjusted simultaneously or jointly by the drive seated on the hub.

In particular, a respective fixing device for the sheet trailing edge contains a contact element which, preferably as a pneumatically acting suction device 10, fixes a limited area of the sheet trailing edge by suction. In particular, each fixing device, in particular each suction device 10, has a separate pneumatic device Connection, the pneumatic connections of the fixing devices, in particular suction devices 10, preferably being in pneumatic connection or flow connection with a common compressed air generator. The compressed air generator provides, in particular, a pneumatic pressure that is permanently above ambient pressure and / or is not clocked, which is accordingly available at the pneumatic connections of the fixing devices, in particular suction devices 10. A compressor, for example, can be used as the compressed air generator. Particularly preferably, the pneumatic connection of the fixing devices, in particular suction devices 10, also takes place via a rotary inlet 11 of the rotatably mounted sprocket shaft 4, in particular with the implementation of a cable chain, for example in the center of the machine. The compressed air generator is here in particular connected to both laterally arranged fixing devices, in particular suction cups 10, which fix the sheet at the same time. In the case of the double-sized delivery drum, in particular the sprocket shaft 4, the compressed air generator is in pneumatic or flow connection with all or exactly four fixing devices, in particular suction cups 10.

A contact element of the fixing device has an at least approximately flat contact surface for an arched area. In particular, a suction device 10 has a suction surface which transmits a suction effect of the fixing device to the sheet. The pneumatically operating suction cups 10 of the fixing devices preferably each have at least one opening for generated suction air in the suction surface, through which a sheet is held in contact with the suction cup 10. For example, each teat 10 can have a number of openings or suction openings, for example four to six suction openings. The fixing devices can also have, for example, exchangeable contact elements, in particular suction cups 10, which, for example, have differently arranged or designed openings or openings. The contact surface of a contact element or the suction surface of a suction cup 10 can extend, for example, up to 20 mm in Have sheet conveying direction BFR and / or by up to 50 mm transversely to the sheet conveying direction BFR. Each fixing device is preferably assigned an air control element, in particular immediately adjacent to the suction surface, which is preferably designed as a solenoid valve 13, particularly preferably as a quick-acting valve.

The fixing devices could also have a separate holder, but are preferably assigned directly to the arch support segments 6, in particular brackets 6. The contact surfaces of the contact elements, in particular the suction surfaces of the suction devices 10, of the fixing devices are preferably always held at the level of the support elements, in particular the contact surfaces of the pressure elements 7, of the arch support segments 6. For example, the contact elements, in particular suction cups 10, can be received by a fixing device via a lockable plug connection. In particular, a contact element, in particular suction device 10, can be assigned to a receptacle of the fixing device in the axial direction, wherein the contact element, in particular suction device 10, can be held fixable in its position by the fixing device, for example via a ball catch. In this way, differently designed contact elements, in particular suction cups 10, can each be assigned interchangeably to a fixing device. In particular, contact elements, in particular suction cups 10, of different material compositions and / or shapes of a fixing device can each be assigned interchangeably with one another. For adjustment, assembly, cleaning and / or maintenance work, the contact elements, in particular suction cups 10, are assigned to the fixing devices so that they can be removed or replaced quickly or without tools.

the Fig. 4 shows a side view of the, for example, double-sized sprocket shaft 4 with supporting elements 7 arranged on traction means, in particular pressing elements 7 arranged on chains 8 Bracket 6 out in the circumferential direction. The chain is on the inside 8 held in the desired or adjustable tension by a tensioning means, here in particular a tensioning roller 9. An adjusting means, in particular a drive, preferably an electrically operating drive motor, is provided for displacing the chain 8 carrying the pressure elements 7 relative to the bracket 6 in and / or against the sheet conveying direction BFR, in particular for setting or setting the format.

The chain 8 has chain links connected to one another in an articulated manner, to which the pressure elements 7 can be assigned. Exactly one pressure element 7 can be assigned to each chain link of the chain 8. The pressing elements 7 are preferably interchangeably assigned to the chain 8, wherein a respective pressing element 7 can be received by a chain link of the chain 8 in a form-fitting and / or force-fitting manner. In particular, a pressure element 7 is received by a chain link of the chain 8 via a lockable plug connection. A pressure element 7 is preferably received by a respective chain link of the chain 8 via a screw connection. In this way, differently designed pressure elements 7 can be assigned interchangeably to a respective chain link of a chain 8. In particular, pressing elements 7 of different material compositions and / or shapes can be assigned to a respective chain link of a chain 8 in such a way that they can be exchanged with one another. For adjustment, assembly, cleaning and / or maintenance work, the pressure elements 7 are assigned to the chain 8 or to the arched support segments 6, in particular brackets 6, which can be quickly removed or exchanged.

the Fig. 5 shows an enlarged view of a sheet support segment 6, in particular bracket 6, with pressure elements 7 assigned to a chain 8 and a fixing device for the sheet trailing edge. The fixing device has a compressed air connection connected to the compressed air generator and works according to the ejector principle. The fixing device contains in particular an ejector 12 which opens into an outlet channel. Via the outlet channel directed, for example, in the direction of the shaft leak stale air. In addition, deflection or diffusion means can be provided for the air emerging from the outlet duct. The fixing device preferably has an air control element, which is designed in particular as a solenoid valve 13. The air control element, in particular solenoid valve 13, controls the suction effect of the respective fixing device, for example as a function of the machine speed and / or of the properties of the printing material. In this case, all fixing devices are preferably designed as ejector suckers. Each fixing device, in particular each suction device 10, is preferably assigned an air control element, in particular a remotely controllable solenoid valve 13, for the individual and / or remotely controllable control of the suction effect, the air control element, in particular the solenoid valve 13, in particular controlling the compressed air feeding the ejector 12.

The activation of an air control element, in particular a solenoid valve 13, of one or preferably each fixing device can be carried out by a control device, in particular the machine control. The electrical control connection is preferably also made via a rotary lead-in 11 of the rotatably mounted sprocket shaft 4 and, if necessary, a cable chain. In this case, an air control element, in particular solenoid valve 13, can be activated by the control device, in particular machine control, for the order-related setting of the pneumatic action of the fixing device, in particular of suction device 10. It is particularly preferred that the air control element, in particular the solenoid valve 13, be used to set or change the start, the intensity and / or the end of the pneumatic suction effect of the fixing device, in particular of the suction device 10. The setting or change can also be made while the machine is running or during the printing process. The air control element, in particular the solenoid valve 13, is particularly preferably used to influence or influence the suction effect of the fixing device, in particular of the suction device 10, depending on the machine speed and / or on the properties of the printing material. set. The air control element, in particular solenoid valve 13, can interact with the control device in such a way that the beginning, the intensity and / or the end of the pneumatic action can be set manually or automatically.

By means of the respective solenoid valve 13 assigned to a fixing device, in particular a suction device 10, in particular the compressed air feeding the ejector 12 is controlled in such a way that the beginning, the intensity and / or the end of a suction effect is set. The setting of the suction air of the fixing device, in particular on the suction device 10, by the air control element, in particular solenoid valve 13, can also be carried out as a function of the sheet travel when the sheet is accepted and / or when the sheet is released. The sheet travel can therefore also be influenced or controlled or regulated individually and / or remotely during the printing process. An automated setting of the suction effect on the individual fixing devices, in particular suction cups 10, of the sprocket shaft 4 can be carried out, for example, according to sensor values. In particular, when influencing the pneumatic suction effect, a dead time in building up the suction effect can be taken into account. This dead time can also be compensated for as a function of the speed, for example.

the Fig. 6 shows an embodiment of a pressure element 7 for a chain 8 guided on a bracket 6. The pressure element 7 can be interchangeably assigned to a chain link of the chain 8 via a screw connection. The pressure element 7 is designed in particular to be elastic and has a contact surface for an arc that extends in the circumferential direction and has a minimal axial extent. The pressing element 7 can be made of rubber, for example. An elasticity of the pressure element 7 can be achieved in particular through the choice of material and / or a suitable shape.

the Fig. 7 shows an embodiment of a contact element as a suction device 10 for a fixing device. The suction device 10 can be assigned to the fixing device, in particular the ejector 12, via a receptacle. For example, the suction device 10 can have guide surfaces which are received or guided by guide surfaces of the fixing device. For example, the suction cup 10 can be assigned to the fixing device in the axial direction, a lockable plug connection for fixing the position preferably being provided. At least one hemispherical recess, for example, can be provided on the underside of the teat 10, which interacts positively with a spring-loaded locking ball of the fixing device to fix the position and thus enables the teat 10 to be changed or exchanged without tools.

The suction cup 10 has at least one and here in particular four openings and forms the suction surface for the sheet trailing edge with centrally arranged supporting elevations. The suction cup 10 is preferably dimensioned such that its suction surface is always or permanently at the level of the contact line of the immediately adjacent support element, in particular the pressure element 7, of the arch support segment 6. An elastic cover, such as a rubber cover, can also be assigned to the teat 10. The opening or openings of the suction cup 10 enable the effect of suction air generated by the ejector 12 in areas on the sheet trailing edge, so that a suction force keeps the sheet trailing edge in contact with the suction surface of the suction cup 10.

How it works: Before a new job, for example a new print job, the sheet support segments 6, in particular the bracket 6, can be placed axially on the side edges of the new sheet format. Before, at the same time or afterwards, the fixing devices, in particular suction devices 10, can be placed on the rear edge of the sheet of the new sheet format, with the support elements, in particular pressing elements 7, preferably being displaced at the same time in such a way that only the respective Sheet side edge of the new sheet format is contacted by support elements, in particular pressure elements 7. If necessary, suitable support elements, in particular pressure elements 7, can be assigned to the arch support segments 6, in particular brackets 6, and / or suitable contact elements, in particular suction cups 10, to the fixing devices.

During the subsequent sheet travel, the sheet support segments 6, in particular brackets 6, or the support elements, in particular the pressure elements 7, simultaneously support or press a respective sheet against the cylinder jacket surface of the upstream sheet guide cylinder, in particular pressure cylinder 2, with a respective sheet trailing edge next to the sheet support segments 6, in particular brackets 6, or the support elements, in particular the pressure elements 7, in the area of the arch support segments 6, in particular brackets 6, or the support elements, in particular the pressure elements 7, is held and guided exclusively by the immediately adjacent fixing devices, in particular suction cups 10 .

The suction air of the fixation devices, in particular suction devices 10, is preferably obtained from compressed air from a compressed air generator according to the ejector principle, with air control elements, in particular solenoid valves 13, assigned to the fixation devices, in particular suction devices 10, controlling the suction air with precise timing. If necessary, the suction air control can also be changed individually and / or remotely. For example, the air control elements, in particular solenoid valves 13, can be activated according to characteristic curves. In this way, maximum suction power can be ensured during sheet transfer in the transfer center. Subsequently, the suction effect can be reduced as a function of the angle, for example, since a lower suction force is sufficient for holding the sheet trailing edge resting on the suction surface of the suction device 10.

List of the reference symbols used

1

Display

2

Printing cylinder

3

Chain conveyor system

4th

Sprocket shaft

5

Display pile

6th

Arch support segment, bracket

7th

Pressure element

8th

chain

9

Tension pulley

10

Mammal

11

Swivel lead-in

12th

Ejector

13th

magnetic valve

BFR

Sheet conveying direction

Claims (15)

1. A sheet-processing machine comprising: a sheet transport device having a sheet-conveying system (3, 4) receiving sheets from a sheet-guiding cylinder (2); a gripping device (3) for the clamped fixing and transporting of a front edge of a sheet; and at least two peripheral sheet support segments (6) simultaneously holding the sheet on the lateral cylinder surface of the sheet-guiding cylinder (2) and/or pneumatic fixing devices (10) for the rear edge of the sheet,
   characterized in that the pneumatic sheet support segments and/or the fixing devices (10) are pneumatically connected to a compressed air generator, wherein the compressed air generator provides a pneumatic pressure that is permanently above the ambient pressure.
2. The sheet-processing machine according to claim 1, wherein the pneumatic sheet support segments and/or the fixing devices (10) operate according to the ejector principle and/or the fixing devices (10) are embodied as vacuum ejectors and a remote-controllable solenoid valve (13) is assigned to each fixing device (10), which controls the compressed air feeding the ejector (12).
3. A sheet-processing machine comprising: a sheet transport device having a sheet-conveying system (3, 4) receiving sheets from a sheet-guiding cylinder (2); a gripping device (3) for the clamped fixing and transporting of a front edge of a sheet; and at least two peripheral sheet support segments (6) simultaneously holding the sheet on the lateral cylinder surface of the sheet-guiding cylinder (2) and/or pneumatic fixing devices (10) for the rear edge of the sheet,
   characterized in that an air control element (13) for remote-controllable or custom remote-controllable influence of the pneumatic effect of pneumatic sheet support segments and/or fixing devices (10) is provided.
4. The sheet-processing machine according to claim 3, wherein the air control element (13) is provided as an alternative to the remote-controllable or custom remote-controllable influence of the pneumatic effect of pneumatic sheet support segments and/or of the fixing devices (10) for custom influence of the pneumatic effect of pneumatic sheet support segments and/or the fixing devices (10), wherein by means of the air control element (13) the beginning, the intensity and/or the end of the pneumatic effect is modifiable.
5. The sheet-processing machine according to claim 1, 2, 3 and/or 4, wherein a separate air control element (13) is assigned to each pneumatic sheet support segment and/or to each fixing device (10).
6. The sheet-processing machine according to claim 1, 2, 3, 4 and/or 5, wherein the air control element (13) influences a suction effect as a function of the machine speed and/or the printing material properties.
7. The sheet-processing machine according to claim 1, 2, 3, 4, 5 and/or 6, wherein the air control element (13) interacts with a control device such that the beginning, the intensity and/or the end of the pneumatic effect is manually or automatically adjustable.
8. The sheet-processing machine according to claim 1, 2, 3, 4, 5, 6 and 7, wherein an air control element (13) interacts with a control device for order-specific adjustment of the pneumatic sheet support segments and/or of the fixing devices (10) .
9. The sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7 and/or 8, wherein the sheet-conveying system is embodied as a sheet guiding drum or has a delivery drum (4) and a provision of compressed air occurs via a rotary inlet (11) of a rotatably mounted shaft from the sheet guiding drum or delivery drum (4).
10. The sheet-processing machine according to claim 1, 2, 3, 4, 5, 6, 7, 8 and/or 9, wherein the fixing devices (10) are format adjustable in and/or against the sheet conveying direction (BFR) and/or transversely to the sheet conveying direction (BFR) and/or are format adjustable together with support elements (7) of the sheet support segments (6).
11. A method for transporting sheets from a sheet-guiding cylinder (2) to a sheet-conveying system (3, 4) in a sheet-processing machine, wherein a gripping device (3) clamped fixes a respective front edge of the sheet for transport, wherein the sheet is held by at least two revolving sheet support segments (6) simultaneously on the lateral cylinder surface of the sheet-guiding cylinder (2) and/or the rear edge of the sheet is held by pneumatic fixing devices (10), characterized in that pneumatic sheet support segments and/or the fixing devices (10) are pneumatically connected to a compressed air generator for generating forces holding the sheet, wherein the compressed air generator provides a pneumatic pressure that is permanently above the ambient pressure.
12. The method according to claim 11, wherein the suction effect of the pneumatic sheet support segments and/or of the fixing devices (10) is modified and/or adjusted by means of air control elements (13) acting on the pneumatic sheet support segments and/or the fixing elements (10) feeding the compressed air.
13. A method for transporting sheets from a sheet-guiding cylinder (2) to a sheet conveying system (3, 4) in a sheet-processing machine, wherein a gripping device (3) clamped fixes a respective front edge of the sheet for transport, wherein the sheet is held by at least two revolving sheet support segments (6) simultaneously on the lateral cylinder surface of the sheet-guiding cylinder (2) and/or the rear edge of the sheet is held by pneumatic fixing devices (10), characterized in that the pneumatic effect of pneumatic sheet support segments and/or of the fixing devices (10) is influenced individually and/or remotely by means of an air control element (13).
14. The method according to claim 12 and/or 13, wherein the adjustment is performed by the air control element (13) as a function of the sheet travel during transfer and/or release of the sheet.
15. The method according to claim 12, 13, and/or 14, wherein by means of a respective solenoid valve (13) assigned to a pneumatic sheet support segment and/or a fixing device (10) a compressed air feeding an ejector (12) is controlled, in order to adjust the beginning, the intensity and/or the end of a suction effect.

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