DE102015226322A1 - Display for a sheet-processing machine and method for depositing sheets - Google Patents

Abstract

The invention relates to a display for a sheet-processing machine, wherein the display gripper systems for taking over the sheet on one edge and for transporting the sheet up to a stacking area and wherein a means for opening the gripper systems is provided in a gripper opening point for filing the sheet in the stacking area and a method for depositing sheets. The invention is therefore based on the object to improve the sheet transport and / or the sheet storage in a sheet-processing machine on. According to the invention the object is achieved in that the means is designed such that with this the gripper opening point in direct dependence on the thickness of the sheet to be deposited is adjustable.

Description

The invention relates to a display for a sheet-processing machine and a method for depositing sheets.

The increasing idea of efficiency in printing presses leads to the demand for reduction of setting actions by operators and to the increase of automated solutions. Any action that needs to be taken by the operator and required by the experience of operators to perform basic press functions such as sheet travel, sheet braking, and stacking is therefore considered to be a hindrance to the actual task of printing on sheets to become.

In the area of stacking, mechanized or automated solutions are currently used, for example, for presetting, but in principle the substrate thickness is neglected. Previous controls and regulations of the gripper opening for stack formation are based on the substrate grammage and determine from this the kinetic energy of the printing sheet for sheet braking.

In a gripper carriage, the holding forces for the bow are usually provided by springs. The holding force is therefore inherently dependent on the substrate thickness and realized either by specifying a twist angle or by specifying a spring force or a moment.

The term "gripper opening point" is understood here in particular the geometric location at which the gripper carriage, in particular its gripper, is located when, for example, by pressing a roller lever, the grippers have reduced their holding force to zero on the substrate or with this only in contact.

With constant input values of the gripper opening point by the operator or the control or regulation moves the real gripper opening point depending on the substrate thickness depending on the design of the curve and the portion of the curve section in which the opening takes place, more or less. The substrate thickness is a size that is independent of the grammage, and for a grammage different substrate thicknesses are available.

The shift between the suggested and the actual gripper opening point leads to errors in the operator's assessment and understanding of real conditions, which in turn leads to consequential errors in information exchange and misjudgments. This is currently being compensated for by building experience. In the case of controls or arrangements for sheet braking, neglecting the printing substrate thickness leads to a printing material-dependent correction value which must be known for automatic default settings.

From the DE-PS 628 450 is an adjustable stop for opening the chain grippers of sheet-fed presses known in which the opening of the chain gripper takes place sooner or later. It is intended to open the chain gripper with rapid machine running at a greater distance from the sheet stops than at slower machine speed. A disadvantage of this solution is that no opening of the gripper takes place as a function of the sheet thickness.

From the DE-AS 1 141 296 is a gripper control of chain arms of printing presses known in which an adjustment of the curve takes place as a function of the engine speed, wherein the adjustment of the curve is effected by an electric motor. A disadvantage of this solution is that no opening of the gripper takes place as a function of the sheet thickness.

From the DE 42 20 582 A1 a device for controlling and / or controlling individual control elements in the boom area of a printing press is known. It is proposed to let the setting of the gripper opening curve initially constant and only to calculate the suction force of the suction roll. To calculate the suction force of the suction roll in addition to the speed of the sheet, the mass of the sheet is necessary. The mass can also be calculated from the known sizes of the length, width, thickness and density of the arc. When the force of the suction roll is reached, the necessary correction of the setting of the gripper opening curve is then calculated, taking also into account the mass of the sheet. A disadvantage of this solution is that sheets of the same mass but unequal thickness are still stored with the same gripper opening points.

From the DE 42 23 232 A1 a device for controlling the opening time of grippers of a sheet delivery of a sheet-processing machine is known in which, depending on various parameters, such as sheet weight, printing speed / sheet speed, sheet size, etc., the opening time or the position of the gripper, where the opening is to take place, is to pretend. A disadvantage of this solution is that no opening of the gripper takes place as a function of the sheet thickness.

From the DE 195 39 598 A1 is a method and a device for Sheet delivery control known, wherein for a gripper opening point, based on the machine speed, a transfer function is stored for each type of printing material or for Druckstoffartbereiche. For a new print job, the gripper opening point is set according to the stored transfer function, with the grammage of the print material or the print job being selected in addition to the machine speed as the parameter of the transfer function. A disadvantage of this solution is that no opening of the gripper takes place as a function of the sheet thickness.

From the DE 196 42 804 A1 is an adjusting device for a gripper opening curve in a chain boom of a sheet-fed press known by a suitable program control of an additional motor adjustment the position of the gripper opening curve when starting the speed of the sheet-fed press and also when returning the speed itself due to influences of inertia under the influence of the respective Printing material and the current work process changing operating conditions is adjusted. A disadvantage of this solution is that no opening of the gripper takes place as a function of the sheet thickness.

From the DE 10 2012 222 525 A1 a delivery and a method for transporting sheets in a delivery is known, wherein a sheet is transported streamlined in the Doppelgreiferauslage. How such a streamlined sheet is properly filed or handed over to a post-gripper system is not disclosed.

The invention is therefore based on the object to improve the sheet transport and / or the sheet storage in a sheet-processing machine on.

According to the invention the object is achieved by a device having the features of the independent device claim and a method having the features of the independent method claim. Advantageous embodiments will become apparent from the dependent claims, the description and the drawings.

The invention has the advantage that the sheet transport and / or the sheet storage in the display, in particular the Doppelgreiferauslage, a sheet-processing machine is further improved.

In particular, a solution is provided which allows both the operator and a controller to more geometrically determine the gripper opening point, thus preventing errors and reducing waste. Particularly preferably, a mathematical determination of the required curve position for the realization of a gripper opening is created taking into account the printing substrate thickness at a predetermined by an operator or a control or regulation place or value.

According to one embodiment, a simplification of the operability of a printing machine is achieved. At the same time, the stress potential, for example at the facility for the print job, can be reduced. Furthermore, a meaningful automation solution is made possible by the consideration of the printing material thickness, since this is already present by other processes.

According to a preferred embodiment, the setting or displacement of the gripper opening point is calculated by means of a machine or control center computer, in particular by means of SPS, so that control values or setting steps are present, for example for a drive of a transmission for the gripper opening curve. In this case, the entire transmission calculation can take place or even only the processing of a previously calculated transmission law between the drive and gripper opening point. The printing material thickness is available in particular via an operator input, for example at a control station, or via a mechanical adjustment, for example in conjunction with a double-sheet control. Using this known printing material thickness, the printing plate thickness-dependent necessary angle of rotation of the roller lever, up to the state of the powerless resting of the gripper tips of gripper fingers, is calculated. This can, for example, be done directly online or in advance of the calculation of the transfer law.

Particularly preferably, a printed-material thickness-corrected real gripper opening point is created, in particular while maintaining a speed compensation. This can advantageously lead to a reduction in the necessary operator actions for a basic function of sheet travel and to reduce operating errors and waste. Further, a direct relationship between the gripper opening point and a display or controlled variable can be produced. Furthermore, the quality of the setting values for operators and subsequent controls can be improved. In particular, this also leads to direct comparability and more obvious values.

In one embodiment, a display may be provided which has only front edge gripper carriage, with which the sheets are transported to the stack area, in particular to a sheet stack. For example, the acquisition of the bow at the leading edge in one area a sprocket main shaft and the transport along an ascending branch or horizontally, in particular exclusively horizontal, take place. The sheet leading edge can be released by leading edge gripper carriage over the stack area or fed to a leading edge Nachgreifersystem. It may be provided for bow deceleration a sheet brake or Nachgreifersystem.

Preferably, a Doppelgreiferauslage is used with front edge gripper carriage for fixing the sheet leading edges and trailing edge gripper carriage for fixing the sheet trailing edges. The sheets can be guided in the Doppelgreiferauslage along an ascending branch, but are preferably horizontally and particularly preferably transported only horizontally from a sheet guiding cylinder, in particular a storage drum to the stacking area and preferably to a delivery stack. In this case, the leading edge gripper carriage and / or the trailing edge gripper carriage can release the bow according to the proposed solution. The trailing edge gripper carriages can release the sheet trailing edges in the area of a sheet brake or transfer the sheet trailing edges to a trailing edge Nachgreifersystem.

In particular, on double gripper displays, in which a sheet to be transported is fixed both at the front edge and at the trailing edge, a correctly set gripper opening point is important. The slightest deviation of the gripper opening point can lead to cracks in the sheet. Advantageously, an optimized gripper opening point for the leading edge gripper carriages reduces the risk of bow damage since the sheet is fixed to the trailing edge by a trailing edge gripper carriage. Alternatively or additionally, an optimized gripper opening point for the trailing edge gripper carriages reduces the risk of sheet damage, since the sheet is fixed at the leading edges by a leading edge gripper carriage and / or is already fixed by a gripper system for depositing on the sheet stack.

In the following, the invention will be explained by way of example. The accompanying drawings show schematically:

1 : Section of a sheet-processing machine with a double gripper delivery;

2 : Gripper opening curve determines the gripper opening point of a gripper carriage for an arch thickness A;

3 : Gripper opening curve determines the gripper opening point for a sheet thickness B according to the prior art;

4 : Gripper opening curve determines the gripper opening point for the sheet thickness A;

5 : Gripper opening curve determines the improved gripper opening point for the sheet thickness B.

The 1 shows a section of a sheet-processing machine, such as a sheet-fed press, here in particular a Bogenoffsetrotationsdruckmaschine, with a Doppelgreiferauslage 1 , The printing press may be, for example, a sheet-fed press in aggregate and series construction and not shown elements such as feeder, plant, several printing and possibly coating plants, finishing and / or drying plants included. Additionally, the machine may include turning means for turning the sheets for backside printing. The turning device can be designed in particular as a single-drum turn or as a three-drum turn for a trailing edge turn. The machine can continue to have dryers, for example, in the factories.

In the machine to be printed sheets of cylinders are promoted and passed in a gripper closure between the cylinders. The sheets are thus clamped on the front edge on the lateral surfaces of the rotating cylinder up to the double gripper delivery 1 transported. In the double gripper display 1 The sheets are taken from conveyor systems with endless rotating gripper systems and fixed to the leading edge and trailing edge up to a stacking area, for example, up to a pile support plate promoted. Above the pile support plate are the sheets to form a delivery stack 6 Approved. The pile support plate is lowered vertically by a lifting drive depending on the incoming sheet.

The printing press is preferably of modular construction, wherein a sub-module of the last machining unit of the machine is a printing cylinder 2 and can accommodate a subordinate sheet transfer system. The printing cylinder 2 has, for example, an at least approximately closed lateral surface. After the printing cylinder 2 the last work, such as a last printing or coating unit, the sheets from the sheet transfer system to a downstream sheet guiding cylinder 3 to hand over. The sheet transfer system may be interchangeably associated with the machine or adapted to the equipment of the machine.

That between the impression cylinder 2 the last processing plant and the sheet guiding cylinder 3 arranged sheet transfer system can, for example, in an equipment of the machine as a perfecting press as a transfer drum 7 be educated. The transfer drum 7 contains at least shroud segments for carrying the sheet to be transported. The transfer drum 7 preferably contains pivotable arch support surfaces for guiding the sheet flat. Further education is on the transfer drum 7 a coating can be arranged. As a cover, for example, a removable jacket or drum caps can be used. Through the transfer drum 7 The sheets are at the leading edge of the upstream printing cylinder 2 taken over and the downstream sheet guiding cylinder 3 to hand over. The sheet transport can in particular, as shown here further education, by a pneumatically actuated sheet guide 8th get supported.

Alternatively, in an equipment of the machine as a straight printing machine, the sheet transfer system between the impression cylinder 2 the last processing plant and the sheet guiding cylinder 3 be designed as Transferter without lateral surface elements, through which the sheet at the front edge of the upstream printing cylinder 2 taken over and the downstream sheet guiding cylinder 3 be handed over. In an equipment of the machine as a perfecting press with a coating unit, in particular dispersion varnish, formed last processing unit, the sheet transfer system for sheet transport as a Bogentragsegmente, for example, formed as a support or suction discs, sheet guiding device comprising. The Bogentragsegmente can be axially adjustable and, for example, touch only pressure-free sheet edges.

The sheet transfer cylinder downstream of the sheet transfer system 3 may be stored in a last modified sub-module of the machine. Alternatively, the sheet guiding cylinder 3 be assigned to the last sub-module or it can be an enlarged sub-module of the last processing plant are used or the sheet guiding cylinder 3 be included in the delivery rack. The axis of rotation of the sheet guiding cylinder 3 can in a plane with axes of rotation of cylinders, in particular pressure cylinders 2 , lie in the works of the machine or arranged above such a plane. Further, the sheet transfer system and / or the sheet guiding cylinder 3 cooperate with additional equipment.

Preferably, the sheet guiding cylinder 3 a smoothing device 10 assigned to the sheet conveying path of the sheet guiding cylinder 3 acts. In this case, the smoothing device 10 pneumatic openings and / or vanes, such as baffles have. The smoothing device is preferred 10 the contour of the sheet guiding cylinder 3 adjusted, with the smoothing device 10 particularly preferably extends to the upstream sheet transfer system. Next, the smoothing device 10 in the direction of rotation of the sheet guiding cylinder 3 have an increasing nozzle density. As an alternative, inspection systems, powdering devices, inkjet and other marking systems, cutting, embossing and ionizing devices, counting devices, numbering devices, cold foil devices, as well as dryers or sheet discharge devices may be provided as an alternative to or in addition to the sheet guiding cylinder 3 can also be assigned in standardized interfaces.

The rotating sheet conveying systems or cylinders, in particular the impression cylinder 2 and the transfer drum 7 the last processing plant and this downstream sheet guiding cylinder 3 , are preferably formed as double-sized systems, which each contain two diametrically arranged gripper systems for fixing the sheet leading edges for the sheet transport. The lateral surfaces having sheet conveying systems can have open or coverable gripper channels, which extend in particular axially over the cylinder width. Alternatively, however, the sheet conveying systems can also be single or multiple-sized, with a single-sized system capable of accommodating at least one sheet of maximum format on the periphery.

Preferably, that of the Doppelgreiferauslage 1 immediately preceding sheet guiding cylinder 3 as a double-sized storage drum 3 be formed, which has format adjustable, comb-like intermeshing shell segments. From the storage drum 3 The sheets are held at the leading edge and trailing edge by sheet fuser systems. By relative movement of Bogenfixiersysteme each other, a respective sheet on the storage drum 3 or aligned during sheet transfer and / or streamlined longitudinally or transversely.

The double gripper delivery 1 Contains one with the sheet guiding cylinder 3 For example, the storage drum 3 , cooperating and this immediately downstream leading edge transport system with circumferentially feasible gripper systems for sheet leading edges and a trailing edge transport system with circumferentially feasible gripper systems for sheet trailing edges for taking over and conveying the sheet from the sheet guiding cylinder 3 to the stack area, in particular to the delivery stack 6 , The leading edge transport system is here as a chain conveyor system with circumferentially guided leading edge gripper carriage 4 and the trailing edge transport system as a chain conveyor system with circulating guided Trailing edge gripper carriages 5 educated. Each chain conveyor system includes laterally arranged guided in guide rails chains. The leading edge grab cars 4 and / or the Hinterkantengreiferwagen 5 are arranged in particular parallel to each other and evenly spaced from each other between the respective chains. The leading edge grab cars 4 and / or trailing edge gripper carriage 5 can each be assigned to the chains on both sides via gripper carriage plates.

Preferably, the leading edge transport system and the trailing edge transport system each include the sheet guiding cylinder 3 adjacent front pair of sprockets 9 and one above the delivery stack 6 arranged rear pair of sprockets 9 , The sprockets 9 from the leading edge transport system and the trailing edge transport system can be arranged coaxially and axially offset from each other. Between the sprockets 9 The chains preferably move exclusively in horizontal guide rails. In an alternative embodiment, only front or rear sprockets can 9 and further Kettenumlenkführungen be used. Next alternatively but also sprockets 9 be arranged eccentrically offset from each other. In a further alternative embodiment, the two front pairs of sprockets 9 or deflecting guides are arranged such that the leading edge gripper carriage 4 and / or trailing edge gripper carriage 5 the deflection in the sheet transfer from the sheet guiding cylinder 3 have left and are already on the straight, preferably horizontally extending chain section. Possibly occurring vibrations of the leading edge gripper carriage 4 and / or trailing edge gripper carriage 5 when leaving the deflection are largely subsided. The sprockets 9 or deflection guides can inner and / or outer supports for guiding the leading edge gripper carriage 4 and / or trailing edge gripper carriage 5 be assigned in the deflection.

Both the front edge transport system and the rear edge transport system are preferred for transporting the sheets from the sheet guiding cylinder 3 to the delivery pile 6 arranged above a horizontal plane, which is the upper generatrix of the sheet guiding cylinder 3 affected. The sheet transport through the leading edge gripper carriage 4 and / or trailing edge gripper carriage 5 in particular takes place exclusively on a horizontal sheet conveying path from the sheet guiding cylinder 3 in sheet travel direction BLR to above the delivery pile 6 What makes bowing much easier. The horizontal sheet transport path allows the leading edge gripper carriages 4 and / or the Hinterkantengreiferwagen 5 to be supported in the deflection region in particular from the outside. As a result, the stresses and deformations occurring by centrifugal forces can be reduced, which allows the use of relatively small deflection radii and / or the use of low gripper carriage heights. Lower gripper carriage heights enable a smaller and therefore much more effective dryer distance.

For the sheet transport contain the leading edge gripper carriage 4 Gripper systems for fixing the sheet leading edges, which are preferably designed as a clamping gripper. The rear edge gripper carriage 5 contain gripper systems for fixing the sheet trailing edges. These gripper systems can be designed as vacuum systems and / or clamping gripper systems. The rear edge gripper carriage 5 are in a known manner phase adjustable to the leading edge gripper carriage 4 designed so that different sheet formats can be used at the front and rear edge. Through the leading edge gripper carriage 4 The sheets are approximately at the upper generatrix of the sheet guiding cylinder 3 taken over in the gripper conclusion. Through the rear edge gripper carriage 5 The sheets are also from the sheet guiding cylinder 3 accepted. Alternatively, the trailing edges but also spaced from the lateral surface of the sheet guiding cylinder 3 or on the way the bow to the delivery pile 6 through the rear edge gripper carriage 5 be taken. The sheets can also be stabilized and / or fixed by transfer systems, not shown in between. On the Bogenförderweg to the delivery pile 6 Additional equipment, such as dryers and / or powder devices can be arranged, which act on one or both sides of the sheet during sheet transport. It may also be arranged below the Bogenförderweges more powder devices, Entroller, etc.

The one of the leading edge gripper cars 4 at the leading edge and from the trailing edge gripper carriages 5 Arches fixed at the trailing edge are over the delivery pile 6 released for storage and attach to leading edge stops. Further, side and / or rear edge stops can be provided which can form a storage slot together with the leading edge stops. To delay the sheet, a not shown filing system can be arranged, which can be designed as Nachgreifer for gripping a sheet edge or as a pneumatic sheet brake. Preferably, however, the storage system is designed as a forceps gripper, which is the trailing edge of the sheet from the respective trailing edge gripper carriage 5 in gripper conclusion takes over, decelerates and on the delivery pile 6 stores. Pressure-free corridors are not necessary.

In the delivery is a means for influencing the gripper opening point of the circulating Leading edge gripper carriages 4 and / or trailing edge gripper carriage 5 arranged gripper systems provided. The means comprises in particular a gripper opening curve 13 in the stacking area, especially above the delivery stack 6 , is arranged. With the means, in particular the gripper opening curve 13 , the gripper systems of the leading edge gripper carriage 4 and / or trailing edge gripper carriage 5 opened in a geometric place. In this case, preferably a recurring same opening of the gripper systems for similar sheets to be deposited, for example, for all sheets of a print job.

The 2 shows a gripper opening curve 13 a sheet-processing machine, the gripper opening point of the gripper system of a leading edge gripper carriage 4 for an arch thickness A determined. The revolving driven front edge gripper carriage 4 here is about two chain pins 12 associated with the chain. The leading edge gripper carriage 4 is correspondingly by a chain conveyor 11 following chains circulating driven. The leading edge gripper carriage 4 follows accordingly the chain track 11 in sheet travel direction BLR up to the stack area. At the downstream end of the stacking area with respect to the sheet running direction BLR, above the sheet stack, is the gripper opening curve 13 arranged, which has a curved path. The gripper opening curve 13 is for setting the gripper opening point, for example, about a pivot point 14 movably mounted. In particular, the gripper opening curve 13 around the fulcrum 14 be panned. Preferably, the movement of the gripper opening curve 13 automated, for example via an actuator done. The actuator can be connected to a control device, for example the machine control.

The leading edge gripper carriage 4 has clamp gripper for clamping the sheets at the leading edge. The clamping grippers are preferably made firmly on the leading edge gripper carriage 4 arranged gripper serves 19 or a continuous gripper bar and against these movable gripper fingers 18 educated. The gripper fingers 18 For example, you can use the gripper carriage width of a gripper shaft 17 be assigned firmly with a roller lever 16 communicates. The roller lever 16 preferably carries a cam roller 15 connected to the curved path of the gripper opening curve 13 is in active connection. When running the cam roller 15 on the curved path of the gripper opening curve 13 gets over the roller lever 16 the gripper shaft 17 twisted, in turn, the preferably spring-loaded gripper fingers 18 from the gripper serves 19 lifts or between the gripper serves 19 and the gripper fingers 18 clamped bow releases. The gripper shaft 17 can the roller lever 16 for example, be assigned to one side or center with respect to the gripper carriage width. Alternatively, the gripper shaft 17 also on both sides a roller lever 16 be assigned.

The 3 shows the gripper opening curve 13 which determines the gripper opening point for a sheet thickness B according to the prior art. The sheet thickness B is for example a comparison with the sheet thickness A smaller thickness of the sheet or the printing material. Due to the arch thickness B, the gripper fingers touch 18 of the leading edge gripper carriage 4 the bow in a relation to the sheet thickness A different position. In the thinner arc of the arch thickness B, the gripper fingers touch 18 the bow, for example, the gripper serves 19 further approximated. So take the gripper shaft 17 and the cam roller 15 another situation. Another position of the cam roller 15 But this causes a contact between the cam roller 15 and the curved path of the gripper opening curve 13 in another geometric point of the curved path of the gripper opening curve 13 established. This shift of the contact point of the cam roller 15 on the curved path of the gripper opening curve 13 adjusts itself with otherwise identical external parameters, such as machine speed, sheet format, suction roll adjustment, etc. Due to the changed contact point of the cam roller 15 on the curved path of the gripper opening curve 13 also becomes the gripper opening point of the leading edge gripper carriage 4 postponed.

It is according to the 3 a displacement of the gripper opening point due to the different printing material thickness B, for example, by 10 mm against the sheet running direction BLR shown. According to the prior art, neglecting the printing substrate thickness for the gripper opening in connection with the stack formation results, for example, in the following for the operating personnel as well as for the automation of the process:
A first problem concerns reproducibility in repeat jobs. According to the prior art, the characteristic values of the sheet braking stored for repeat jobs are based on the assumption that exactly the same printing material is processed in a repeat job, but this is ad absurdum due to the possibly provided calibration of a double-sheet control in a feeder or a system. At the latest when a different print substrate has to be used for a repeat job, the sheet brake settings, which depend on the substrate thickness, can not be taken over without correction. A second problem concerns the damage to the sheet edge. If the gripper opening is set incorrectly with sensitive substrates, this will damage the leading edge of the sheet and thus increase waste. A third problem concerns resulting crumbs. In the worst case, the incorrectly set gripper opening leads either to a too-timed sheet braking, whereby the sheet brake is severely hampered in their function, or too late sheet braking, whereby the sheet from the pit stacking, in particular over leading edge stops in sheet travel direction BLR away, out becomes. In both cases, it usually comes to crush and the consequent machine stop, especially to an emergency stop the machine.

The 4 shows a gripper opening curve 13 for the leading edge gripper carriage 4 a sheet-processing machine, such as a Doppelgreiferauslage as described above, which determines the gripper opening point for the sheet thickness A. The position of the gripper opening curve 13 determines via the curved path the gripper opening point for the leading edge gripper carriage 4 the double gripper delivery. If the printing material thickness increases, the real gripper opening point would shift in the curve inlet in sheet travel direction BLR and thus no longer coincide with the suggested or desired gripper opening point. In order to prevent this, according to a preferred embodiment, the position of the gripper opening curve 13 in direct dependence of the printing material thickness, in particular sheet thickness changed.

The 5 shows the gripper opening curve 13 , which determines an improved gripper opening point for the sheet thickness B. In particular, the gripper opening curve becomes 13 twisted, for example, around the fulcrum 14 in order to realize a comparable gripper opening point at different substrate thicknesses. The gripper opening curve 13 Here, for example, by 0.31 ° counterclockwise around the fulcrum 14 has been rotated to realize a gripper opening point at the printing material thickness B, which corresponds to the gripper opening point at the sheet thickness A. Alternatively, other displacements of the gripper opening curve 13 possible to compensate for the substrate thickness difference. A relocation can be done manually or automatically.

Preferably, it is provided that the control device, in particular the machine control, or a control generates a control instruction based on transmission link dimensions and the necessary pivot angle of the roller lever 16 for the realization of the desired (optimized) gripper opening point is based. Subsequently, the control or regulation realized by shifting the gripper opening curve 13 the calculation result. Neglecting speed compensation, a thicker sheet located in the gripper closure (for example an arc of the sheet thickness A) is now released at the geometrically same location, as previously a thinner sheet (for example an arc of the sheet thickness B). Further development is a link with a measurement, in particular an online measurement, the substrate thickness and / or the realization of an online control or an online control of the direct printing material thickness-dependent gripper opening point provided.

LIST OF REFERENCE NUMBERS

1

 Double Gripper position

2

 pressure cylinder

3

 Sheet guiding cylinder, storage drum

4

 Leading edge gripper carriages

5

 Trailing edge gripper carriages

6

 delivery pile

7

 Transfer drum

8th

 sheet guide plate

9

 sprockets

10

 smoothing

11

 chain conveyor

12

 chain pins

13

 Gripper opening cam

14

 pivot point

15

 follower

16

 roller lever

17

 gripper shaft

18

 gripper fingers

19

 gripper pads

BLR

 Sheet running direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 628450 [0008]
• DE 1141296 [0009]
• DE 4220582 A1 [0010]
• DE 4223232 A1 [0011]
• DE 19539598 A1 [0012]
• DE 19642804 A1 [0013]
• DE 102012222525 A1 [0014]

Claims (10)

Display for a sheet-processing machine, wherein the display has gripper systems for taking over the sheets on one edge and for transporting the sheets to a stacking area and wherein a means for opening the gripper systems is provided in a gripper opening point for depositing the sheets in the stacking area, characterized that the means is designed such that with this the gripper opening point in direct dependence on the thickness of the sheet to be deposited is adjustable. Apparatus according to claim 1, characterized in that a gripper opening curve ( 13 ) provided with a roller lever ( 16 ) of a gripper system is in operative connection and that the gripper opening curve ( 13 ) is arranged displaceable in direct dependence of the arch thickness. Apparatus according to claim 1 or 2, characterized in that a gripper opening curve ( 13 ) in direct dependence of the arch thickness around a pivot point ( 14 ) is displaceable. Device according to claim 1, 2 or 3, characterized in that an actuator for displacement of a gripper opening cam ( 13 ) is provided in direct dependence on the arch thickness of the sheet to be deposited. Apparatus according to claim 1, 2, 3 or 4, characterized in that a control device or control device is provided which determines a gripper opening point in direct dependence of the current sheet thickness and with a display device and / or an actuator for changing the position of a gripper opening curve ( 13 ) connected is. Apparatus according to claim 1, 2, 3, 4 or 5, characterized in that the display a Doppelgreiferauslage ( 1 ), in which the gripper opening point for leading edge gripper carriage ( 4 ) and / or trailing edge gripper carriage ( 5 ) is changeable in direct dependence of the arch thickness. Method for depositing sheets on a delivery stack ( 6 ) in a sheet-processing machine, wherein gripper systems are provided for taking over the sheets on one edge and for transporting the sheets to a stacking area and wherein the gripper systems are opened in a gripper opening point for depositing the sheets in the stacking area, characterized in that the gripper opening point in the immediate Dependence of the thickness of the sheet to be deposited is set. A method according to claim 7, characterized in that the value of the sheet thickness of a control device or a control device is supplied and the control device or the control device outputs correction values for the gripper opening point influencing means. A method according to claim 7 or 8, characterized in that a control device or a control device is connected to a measuring device for measuring sheet thickness. A method according to claim 7, 8 or 9, characterized in that the gripper opening point via a gripper opening curve ( 13 ) and the gripper opening curve ( 13 ) is shifted in direct dependence of the sheet thickness.

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