Delivery device of a sheet processing machine with a sheet conveying system for transporting sheets to a sheet stack and method for transporting sheets

Abstract

Delivery device of a sheet processing machine with a sheet conveying system for transporting sheets (4) to a sheet stack, wherein a first conveying system with circumferentially guided front edge gripper systems (2) and a second conveying system with circumferentially guided rear edge gripper systems (3) is provided, with which the sheets (4) can be conveyed to the sheet stack fixed at the front edge and rear edge, characterized by that each trailing edge gripper system (3) is designed to be guided on a traction element track and to be displaceable, pivotable and / or slidable relative to the traction element (5) in certain areas, that a cam roller (13) is assigned to the trailing edge gripper system (3) and that this cam roller (13) is rotatably arranged on the trailing edge gripper system (3) via a coupling and that the curve roller (13) is connected to the traction element (5) via a further coupling.

Description

[0001] The invention relates to a delivery device of a sheet processing machine with a sheet conveyor system for transporting sheets to a sheet stack according to the preamble of the first claim and to a method for transporting sheets in a delivery of a sheet processing machine to a sheet stack.

[0002] DE 41 19 188 C1 discloses a controllable gripper unit for sheet delivery in printing presses. This gripper unit grips the leading edges of sheets and is arranged so that it can be moved against the direction of travel relative to the transport chains. The disadvantage of this solution is that the sheets are only gripped by the leading edges, causing them to flutter along the sheet conveyor. This can cause smearing in the printed image, especially at higher press speeds. Furthermore, additional stacking systems are required to slow down and tightly deposit the sheets on the stack.

[0003] DE 10 2007 061 394 A1 discloses a delivery system for a sheet-processing machine, in particular a printing press, in which the trailing edge gripper systems are arranged on chains by means of couplings to relocate them relative to the leading edge gripper systems. Because the trailing edge gripper systems' orbital paths differ from the chain path, they are moved relative to the leading edge gripper systems. The disadvantage of this solution is that a trailing edge gripper system's orbital path differing from the chain path is structurally complex and not sufficiently suitable for sheet delivery at reduced speeds.

[0004] DE 100 61 703 A1 shows a gripper system with adjustable speed.

[0005] The invention is therefore based on the object of further improving the sheet transport in a sheet processing machine.

[0006] According to the invention, this 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 emerge from the subclaims, the description, and the drawings.

[0007] The invention has the advantage that the sheet transport in a sheet processing machine is improved.

[0008] In one embodiment of the invention, it is provided to attach a trailing edge gripper system to a traction means in such a way that it is guided along the traction means path and executes a relative movement with respect to the trailing edge of the sheet.

[0009] In a preferred embodiment of the invention, the trailing edge gripper system is designed as a gripper carriage guided by chains on a chain track, which is arranged via two elongated holes on chain pins of the chains. This connection of the trailing edge gripper carriage to the chains makes it possible to pivot the trailing edge gripper carriage out and / or in and / or move it in a sheet take-over and / or sheet transfer area in order to move it past an outer casing of a cylinder in the closed state with or without a sheet and / or to take over a sheet beforehand by pivoting it out and then pivoting it in and / or to follow the sheet for gripping during sheet take-overs, or to retract it during depositing / delivering it and / or to tighten and / or deposit the sheet by delaying it with subsequent gripper opening.

[0010] In a further development, the trailing edge gripper system is rotatably, pivotably and / or displaceably articulated on a traction device and is preferably controlled by a movement initiated from the outside.

[0011] The invention further advantageously enables sheet capture before it leaves a cylinder, for example, a printing cylinder or a transfer drum, particularly outside the traction center track, with the trailing edge gripper system subsequently pivoting in. Alternatively, sheet capture of a sheet already captured by another system can be achieved by lagging.

[0012] The sheet transfer area of ​​the leading edge gripper system preferably corresponds to the sheet transfer area of ​​the trailing edge gripper system, but may also differ. In one embodiment of the invention, an ascending branch of the leading edge gripper system and the trailing edge gripper system is provided in a delivery, on which the sheets to be transported are brought to the deposit level of a delivery stack. In a preferred embodiment of the invention, however, the sheets are conveyed on an at least approximately horizontal sheet conveying path from a cylinder to above the sheet stack.

[0013] Advantageously, a relative movement of the trailing edge gripper system is generated, particularly in the transport direction for gripping the sheet, and particularly counter to the transport direction for decelerating and ultimately depositing the sheet. Sheet deposit can advantageously be achieved by decelerating the trailing edge gripper system while the sheet is still gripped, followed by the gripper opening for sheet deposit. This eliminates the need for an additional deposit system such as suction rollers, suction rings, suction belts, or re-grippers. Alternatively, a sheet can also be deposited by decelerating it using a deposit system.

[0014] The invention will be explained below by way of example. The accompanying drawings illustrate this schematically: Fig. 1a: Section of a delivery of a sheet-fed printing press in one embodiment; Fig. 1b: Section of a delivery of a sheet-fed printing press in a further embodiment; Fig. 2: Connection of a trailing edge gripper carriage to a chain of the chain conveyor system; Fig. 3a: Trailing of the trailing edge gripper carriage to grasp or take over the trailing edge of the sheet; Fig. 3b: Trailing edge gripper carriage gripping the trailing edge of the sheet; Fig. 4a: Deceleration of the sheet by the trailing edge gripper carriage after the release of the leading edge of the sheet; Fig. 4b: Release of the trailing edge of the sheet by the trailing edge gripper carriage; Fig. 4c: Further deceleration and pivoting away of the trailing edge gripper carriage during sheet delivery.

[0015] The Fig. 1a shows, in one embodiment of the invention, a section of a delivery of a sheet-processing machine, in this case a sheet-fed printing press. The printing press can, for example, be a sheet-fed offset rotary printing press in a unit or in-line design and contain elements not shown in detail, such as a feeder, infeed, multiple printing units, and optionally coating units. The printing press can be a straight-printing press or, as a perfecting press, equipped with a turning device. Between the printing cylinders and transfer drums or transferters of the machine (not shown in detail), sheets 4 to be printed are transferred at the leading edge in the gripper closure and thus transported to the delivery.

[0016] The printing press is preferably modular in design, whereby a final sheet-guiding cylinder 1 of the press can be accommodated in the delivery frame or the sheet-guiding cylinder 1 can be assigned to a final substructure module of the press. Preferably, however, the sheet-guiding cylinder 1 forms a standalone module. The rotational axis of the sheet-guiding cylinder 1 can be in the same plane as the rotational axes of cylinders in the press units or can be arranged above such a plane.

[0017] The sheet guiding cylinder 1 is designed here as a double-sized printing cylinder with an at least approximately closed outer surface and is arranged downstream of a sheet transport system of a final printing, coating, finishing, or drying unit of the printing press. For sheet transport, the double-sized sheet guiding cylinder 1 contains two diametrically arranged gripper systems located in gripper channels for securing the leading edges of the sheets. Additional devices (not shown) can be assigned to the sheet guiding cylinder 1, which, for example, varnish, inspect, mark, perforate, etc., the sheets 4. Alternatively, the sheet guiding cylinder 1 can be designed as a cylinder, drum, transfer unit, or similar, and can be designed as a single- or multiple-sized cylinder, whereby a single-sized cylinder can accommodate at least one sheet 4 of the maximum format circumferentially.

[0018] In addition to the sheet guiding cylinder 1, the delivery also contains a sheet conveying system, comprising a first conveying system with circulating leading edge gripper systems and a second conveying system with circulating trailing edge gripper systems for receiving and conveying the sheets 4 from the sheet guiding cylinder 1 to a sheet stack (not shown in detail). The first conveying system with the circulating leading edge gripper systems is preferably designed as a chain conveying system with circulating leading edge gripper carriages 2. The second conveying system with the circulating trailing edge gripper systems is preferably designed as a chain conveying system with circulating trailing edge gripper carriages 3.

[0019] Both the first chain conveyor system with the rotating leading edge gripper carriages 2 and the second chain conveyor system with the rotating trailing edge gripper carriages 3 are arranged above a horizontal plane for transporting the sheets 4 from the sheet guide cylinder 1 to the sheet stack, which intersects the upper surface line of the sheet guide cylinder 1. The sheet transport from the sheet conveyor system takes place exclusively on a horizontal sheet conveyor path from the sheet guide cylinder 1 to above the sheet stack. Additional devices (not shown) can be arranged on the sheet conveyor path to the sheet stack, such as dryers, powder devices, unrollers, etc., which act on the sheets 4 during sheet transport.

[0020] The first chain conveyor system for the leading edges of the sheets contains laterally arranged chains 5 wrapped around sprockets, which drive the leading edge gripper carriages 2 continuously on a circular path. The second chain conveyor system for the trailing edges of the sheets also contains laterally arranged chains 5 wrapped around sprockets, which drive the trailing edge gripper carriages 3 continuously, essentially on the circular path of the leading edge gripper carriages 2. Preferably, the leading edge gripper carriages 2 and the trailing edge gripper carriages 3 are guided around sprockets assigned adjacent to the sheet guiding cylinder 1. Additional sprockets (not shown) are arranged above the sheet stack. The sprocket pairs assigned to the sheet guiding cylinder 1 and the sprocket pairs of the chain conveyor systems located above the sheet stack are arranged coaxially but axially offset from one another.One of the sprocket pairs is permanently assigned to a hollow shaft, within which an inner shaft supporting the other sprocket pair is mounted. The inner shafts are designed to be rotatable relative to the hollow shafts.

[0021] The Fig. 1b shows, in a further embodiment of the invention, a section of a delivery of a sheet-processing machine, in this case a sheet-fed printing press, with a first and a second chain conveyor system. The two chain conveyor systems here also have leading edge gripper carriages 2 and trailing edge gripper carriages 3 that rotate parallel to one another. The chain conveyor systems are driven in such a way that one chain conveyor system is driven by a pair of sprockets assigned to the sheet-guiding cylinder 1, while the other chain conveyor system is driven by the other pair of sprockets. For example, the chains 5 of a chain conveyor system, driven by the upper pair of sprockets, rotate around a deflection guide arranged parallel to the lower pair of sprockets and a further deflection guide arranged above a sheet stack (also not shown).The chains 5 of the other chain conveyor system, driven by the lower pair of sprockets, revolve around a deflection guide above the sheet stack and around a deflection guide arranged parallel to the upper pair of sprockets. Alternatively to a curve / groove above the sheet stack, sprockets or deflection wheels could also be provided.

[0022] The respective leading edge gripper carriages 2 contain gripper systems for securing the leading edges of the sheets, which are preferably designed as clamp grippers. The respective trailing edge gripper carriages 3 contain gripper systems for securing the trailing edges of the sheets. These gripper systems can be designed as suction systems and / or clamp gripper systems. The trailing edge gripper carriages 3 are designed to be format-adjustable relative to the leading edge gripper carriages 2.

[0023] The leading edge gripper carriages 2 pick up the sheets 4 from the sheet guide cylinder 1 at the gripper closure. The trailing edge gripper carriages 3 pick up the sheets 4 in a sheet transfer area located in the area of ​​the upper surface line of the sheet guide cylinder 1. Alternatively, the trailing edges can also be gripped by the trailing edge gripper carriages 3 at a distance from the surface of the sheet guide cylinder 1 or on the way of the sheets 4 to the sheet stack. The sheets 4 can also be stabilized or secured in between by transfer systems (not shown).

[0024] The sheets 4, which are held at the leading edge by the leading edge gripper carriages 2 and at the trailing edge by the trailing edge gripper carriages 3, are released above the sheet stack for storage and are positioned against the leading edge stops. A storage system (not shown) can be arranged to decelerate the sheets 4. This system can be configured as a re-gripper for gripping the trailing edges of the sheets or as a pneumatic sheet brake. Preferably, however, the sheets 4 can also be decelerated by trailing edge gripper carriages 3 that are decelerated for storage, whereby no additional storage systems are required.

[0025] The Fig. Figure 2 shows a trailing edge gripper carriage 3 with its connection to the chain 5. The trailing edge gripper carriage 3 has gripper stops 6 that interact with movable gripper fingers 7. During a gripping movement of the gripper fingers 7, the trailing edge of the sheet 4 is fixed against the gripper stops 6. A drive controlling the gripping movement of the gripper fingers 7, for example, a cam roller gear, is not shown here.

[0026] The trailing edge gripper carriage 3 is assigned to the chains 5 on both sides via a first elongated hole 10 interacting with a first chain pin 8 and a second elongated hole 11 interacting with a second chain pin 9, which are arranged one behind the other in the sheet conveying direction BFR. Both elongated holes 10, 11 extend at least approximately in the sheet conveying direction BFR. The second elongated hole 11 is curved. The curvature of the second elongated hole 11 runs in the sheet conveying direction BFR with a small radius of curvature toward the side of the trailing edge gripper carriage 3 carrying the gripper cuffs 6.

[0027] The trailing edge gripper carriage 3 is thus guided by the chain pins 8, 9 according to the slot geometry and can be moved in and against the sheet conveying direction BFR with respect to the chains 5. The chain pins 8, 9 also reliably guide the trailing edge gripper carriage 3 in deflection areas, since shortenings in deflections (secants) are compensated for by the suspension via sliding blocks.

[0028] The trailing edge gripper carriage 3 is also assigned a cam roller 13, which is mounted on the gripper carriage body by means of a first coupler via a pivot point 12. The cam roller 13 is also connected to the first chain pin 8 of the chain 5 via a second coupler. On the orbit of the trailing edge gripper carriage 3, the cam roller 13 is at least partially assigned to a curve 14 with which the cam roller 13 comes into contact. The curve 14 could simply be designed as a grooved curve. A curve 14 is preferably provided in a sheet receiving area and / or in a sheet transfer or sheet depositing area. As a further development, a closed curve 14 along the orbit can also be used. When displaced in the direction of the chains 5, the cam roller 13 causes the trailing edge gripper carriage 3 to move via the first coupler and the second coupler counter to the sheet conveying direction BFR.When the cam roller 13 is displaced away from the chain 5, the trailing edge gripper carriage 3 is displaced relative to the chain 5 in the sheet conveying direction BFR.

[0029] The following figures show the movement of the gripper carriage in the sheet transfer area ( Fig. 3a and Fig. 3b) and in the sheet transfer area ( Fig. 4a, Fig. 4b and Fig. 4c), whereby the reference numerals have been omitted for clarity. The gripper carriage can be adapted to requirements using suitable slotted hole geometries and can be moved accordingly in one or both areas relative to the trailing edge of the sheet.

[0030] The Fig. 3a shows the trailing edge gripper carriage 3 lagging behind the trailing edge of the sheet in order to grasp it. Here, the trailing edge gripper carriage 3, with its gripper fingers 7 open, moves through the curve 14 directed away from the trailing edge gripper carriage 3 faster than the sheet 4 transported along the leading edge. The trailing edge gripper carriage 3 continues to move faster until the gripper system reaches the trailing edge of the sheet.

[0031] The Fig. Figure 3b shows the trailing edge gripper carriage 3 in a fixed position relative to the chain 5. As soon as the trailing edge of the sheet is within the gripper system's range, it is secured by the gripper system. The trailing edge gripper carriage 3 has securely grasped the trailing edge of the sheet. Slight sheet tightening is also possible.

[0032] The Fig. Figure 4a shows the deceleration of sheet 4 by the trailing edge gripper carriage 3 after the leading edge of the sheet has been released in the sheet delivery area. The curve 14 directed toward the chain 5 causes the trailing edge gripper carriage 3 to rotate more slowly than the chain 5. The trailing edge gripper carriage 3 is thus decelerated. The trailing edge gripper carriage 3 continues to hold the trailing edge of the sheet in place, so that the sheet 4 is also decelerated relative to the chain speed.

[0033] The Fig. Figure 4b shows the release of the trailing edge of the sheet for sheet deposit by the trailing edge gripper carriage 3 at its maximum deceleration. Release occurs when the grippers of the trailing edge gripper carriage 3 open at the ideal deposit point above the sheet stack. Curve 14 is directed further toward chain 5, so that the second chain pin 9 transitions into the curved area of ​​the second elongated hole 11 of the trailing edge gripper carriage 3 upon further slight deceleration of the trailing edge gripper carriage 3.

[0034] The Fig. 4c shows the trailing edge gripper carriage 3 pivoted away from the sheet transport path for unobstructed sheet deposit. The second chain pin 9, guided into the radius of curvature of the second elongated hole 11, also lifts the gripper fingers 7 out of the sheet transport plane, allowing the slower-falling sheet 4 to be deposited without contact with the gripper fingers 7.

[0035] How it works: By means of an actuator, for example by means of the cam control, the trailing edge gripper carriage 3 is moved relative to the trailing edge of the sheet in such a way that a takeover and / or transfer can take place without disruption. List of reference symbols used 1 sheet guiding cylinder 2 front edge gripper carriages 3 trailing edge gripper carriages 4 sheets 5 chains 6 Gripper impact 7 gripper fingers 8 first chain pin 9 second chain pin 10 first slot 11 second slot 12 articulation point 13 Cam roller 14 Curve BFR sheet feed direction

Claims

[1] Delivery device of a sheet processing machine with a sheet conveyor system for transporting sheets (4) to a sheet stack, wherein a first conveyor system with circulating leading edge gripper systems (2) and a second conveyor system with circulating trailing edge gripper systems (3) are provided, with which the sheets (4) can be conveyed to the sheet stack with the leading edge and trailing edge fixed, characterized by , that a respective trailing edge gripper system (3) is designed to be guided on a traction means track and to be displaceable, pivotable and / or displaceable in regions relative to the traction means (5), that a cam roller (13) is assigned to the trailing edge gripper system (3) and this cam roller (13) is arranged rotatably on the trailing edge gripper system (3) via a coupling and that the cam roller (13) is connected to the traction means (5) via a further coupling. [2] Device according to claim 1, characterized by that the rear edge gripper system (3) is connected to the traction means (5) via elongated holes (10, 11). [3] Device according to claim 1 or 2, characterized by that an elongated hole (11) has a curvature. [4] Device according to claim 2 or 3, characterized by that the elongated holes (10, 11) of the rear edge gripper system (3) are arranged such that the rear edge gripper system (3) is rotatable, pivotable and / or displaceable relative to the traction means (5). [5] Device according to at least one of the preceding claims, characterized by that the rear edge gripper system (3) can be displaced, pivoted and / or moved relative to a traction means (5) by mechanical adjusting means. [6] Device according to claim 1, characterized bythat in a region of a sheet take-over and / or in a region of a sheet transfer a cam element (14) cooperating with the cam roller (13) is provided. [7] Device according to at least one of the preceding claims, characterized by that the conveyor system with the revolvingly guideable rear edge gripper systems (3) is designed as a chain conveyor system with revolvingly driven chains (5). [8] Method for transporting sheets (4) in a delivery of a sheet processing machine to a sheet stack, wherein a first conveyor system with circulating leading edge gripper systems (2) and a second conveyor system with circulating trailing edge gripper systems (3) are provided, with which the sheets (4) are conveyed to the sheet stack fixed at the leading edge and trailing edge, characterized by , that the trailing edge gripper systems (3) are guided in such a way that they follow a traction means path and are displaced, pivoted and / or shifted relative to the traction means (5) in an area of ​​sheet takeover and / or in an area of ​​sheet transfer, wherein the trailing edge gripper systems (3) are connected to the traction means (5) via elongated holes (10, 11) and wherein the elongated holes (10, 11) of the trailing edge gripper systems (3) are arranged in such a way that the trailing edge gripper systems (3) are rotatable, pivotable and / or shiftable relative to the traction means (5).

Images