Delivery system of a sheet-processing machine with a first conveying system with leading-edge gripper carriages guided by traction elements and a second conveying system with trailing-edge gripper carriages guided by traction elements, trailing-edge gripper carriages and method for transporting sheets

Abstract

Delivery system of a sheet processing machine with a first conveying system with leading edge gripper carriages (2) guided circumferentially by traction means and a second conveying system with trailing edge gripper carriages (3) guided circumferentially by traction means, wherein the leading edge gripper carriages (2) have gripper fingers cooperating with gripper impacts for fixing the sheet leading edges, wherein the trailing edge gripper carriages (3) have gripper fingers cooperating with gripper impacts for fixing the trailing edges of the bow and wherein sheets (4) are fixed at the front and rear edges and can be transported up to a stack of sheets (5), wherein the trailing edge grab carriages (3) are guided on the traction center track (6) and wherein the grab fingers and the grab strikes of a trailing edge grab carriage (3) are displaceable relative to the traction center track (6) in certain areas, characterized by that a gripper system body of the trailing edge gripper carriage (3) is designed to be rotatable about a virtual axis of rotation (9).

Description

[0001] The invention relates to a delivery of a sheet processing machine with a first conveyor system with leading edge gripper carriages that can be guided in a rotating manner by traction means and a second conveyor system with trailing edge gripper carriages that can be guided in a rotating manner by traction means.

[0002] 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 path differs from the chain path, they are moved in the area of ​​the sheet stack 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.

[0003] DE 10 2008 000 792 A1 shows a manipulation device and delivery device for a sheet-processing printing machine, wherein the manipulation device is used as a re-gripper system.

[0004] The invention is therefore based on the object of further improving the sheet transport in a sheet processing machine.

[0005] According to the invention, this object is achieved by a device having the features of the independent device claim. Advantageous embodiments emerge from the subclaims, the description, and the drawings.

[0006] The invention has the advantage that the sheets are gripped at the front and rear edges and transported to the sheet stack where they are better stored.

[0007] In preferred embodiments, fluttering movements and the resulting smearing of sheets gripped at the leading and trailing edges are advantageously avoided, while simultaneously improving sheet placement due to the gripper systems of the trailing edge gripper carriages, which slow down relative to the chain speed. Proper sheet placement can thus be achieved even at higher machine speeds.

[0008] Advantageously, the trailing edge gripper carriage follows the chains driving it at the chain speed, and only the gripper stops and gripper fingers that secure the trailing edge of the sheet are decelerated relative to the chain speed. This allows the sheet to be transferred to a stacking system at a lower speed. The sheet, already slowed by the trailing edge gripper carriage, can be decelerated more effectively by pneumatic stacking systems. Alternatively, if follow-up gripper systems are used, these can grip the trailing edge of the sheet more easily and reliably, thus also ensuring better stacking.

[0009] By connecting the trailing edge gripper carriages to the traction means, it is possible to swivel the gripper systems out and / or in the sheet takeover area and / or in the sheet transfer area in order to move the gripper systems past an outer casing of a sheet guiding cylinder in the closed state with or without a sheet and / or to take over a sheet beforehand by swiveling it out and then swiveling it in.

[0010] In a preferred embodiment of the invention, the trailing edge gripper carriage is rotatably and / or pivotably connected to the traction means such that the gripper system body rotates at the same speed as the chain, while the gripper cuffs and gripper fingers that further secure the trailing edge of the sheet are slowed down relative to the chain speed. This allows the sheet to be decelerated with the smallest possible moving mass. In a further development, the gripper fingers and gripper cuffs are shifted toward the sheet stack during deceleration, which further supports the depositing process.

[0011] Advantageously, a trailing edge gripper carriage according to the invention can be used to tighten the sheet at any point along the sheet conveying path. Sufficient clearance is also created between the cylinder surface during sheet transfer and a stacking system during sheet stacking, if a stacking system is used. Preferably, however, the trailing edge gripper carriage also takes over the deceleration during stacking.

[0012] The trailing edge gripper carriage is preferably designed such that the gripper fingers can be moved by a first drive, and the gripper cuffs interacting with the gripper fingers can be moved by a separate, additional drive. In this case, one drive can also at least partially move or at least influence the other system. In principle, any drive can be used to move and / or pivot the gripper cuffs and / or gripper fingers. However, mechanical drives are provided as the actuating means. Roller levers interacting with cam segments are preferably used.

[0013] The invention will be explained below by way of example. The accompanying drawings illustrate this schematically: Fig. 1: Delivery of a sheet-fed printing press; Fig. 2: Detailed view of the suspension of the gripper system body in an embodiment using four-bar gears on gripper carriage shields; Fig. 3a: Perspective view of a trailing edge gripper carriage in front of the sheet stack; Fig. 3b: Side view of the trailing edge gripper carriage with fixed sheet trailing edge in front of the sheet stack; Fig. 4a: Perspective view of the trailing edge gripper carriage above the sheet stack; Fig. 4b: Side view of the trailing edge gripper carriage with fixed slowed sheet trailing edge above the sheet stack.

[0014] The Fig. Figure 1 shows, in one embodiment of the invention, a delivery of a sheet-processing machine, in this case a sheet-fed printing press, after a final cylinder of the press. The printing press can, for example, be a sheet-fed offset rotary printing press in a unit or in-line configuration and contain elements not shown in detail, such as a feeder, infeed, multiple printing units, and, if applicable, coating units. In the press, sheets 4 to be printed are clamped at the leading edge by sheet-guiding cylinders and transported to the delivery.

[0015] The sheets 4 are transferred from the last cylinder of the machine to conveyor systems of the delivery. From the conveyor systems, the sheets 4 are transported to a sheet stack 5 and released there for storage. The last cylinder of the machine is preferably designed as a cylinder with an at least approximately closed outer surface. In the illustrated embodiment, the last cylinder of the machine is designed as a double-sized impression cylinder 1 and has two diametrically arranged gripper shafts (not shown) located in gripper channels with leading edge grippers. The outer surface of the impression cylinder 1 is closed here. Alternatively, a transfer drum or storage drum could also be used as the last cylinder. The sheets 4 could also be transported to the sheet stack 5 on an at least approximately horizontal sheet conveyor path.

[0016] The delivery includes a first conveyor system with leading edge gripper carriages 2 guided in a rotating manner by traction means, and a second conveyor system with trailing edge gripper carriages 3 guided in a rotating manner by traction means. The conveyor systems are designed as chain conveyor systems, each with two chains guided laterally along the frame, which drive the gripper carriages in a continuously rotating manner.

[0017] The first chain conveyor system contains the leading edge gripper carriages 2, which are evenly spaced between the chains and have fixed gripper cuffs that interact with gripper fingers arranged on gripper shafts to secure the sheet leading edges. The gripper fingers are cam-controlled and movable against the gripper cuffs.

[0018] The second chain conveyor system contains the trailing edge gripper carriages 3, which are evenly spaced between the chains and designed to be format-adjustable relative to the leading edge gripper carriages 2. The trailing edge gripper carriages 3 rotate endlessly on a chain track 6, corresponding to the chains. Clamping gripper systems or suction and clamping gripper systems for securing the trailing sheet edges are assigned to the trailing edge gripper carriages 3. Preferably, the trailing edge gripper carriages 3 also have gripper fingers arranged on a gripper shaft, which are cam-controlled and movable relative to gripper impacts for securing the trailing sheet edges.

[0019] From the last printing cylinder 1 of the press, the sheets 4 are picked up by the leading edge gripper carriages 2 at the gripper closure and transported in the sheet conveying direction BFR toward the sheet stack 5. The trailing sheet edges are also picked up by the trailing edge gripper carriages 3 from the cylinder, transferred via an intermediate system, or gripped along the sheet conveying path. A sheet 4, fixed at the leading and trailing edges, is transported in the delivery by the leading edge gripper carriage 2 and the trailing edge gripper carriage 3 along an ascending branch or exclusively horizontally in the sheet conveying direction BFR to the sheet stack 5.

[0020] The Fig. 2 shows, in a preferred embodiment of the invention, a trailing edge gripper carriage 3 with a gripper system body carrying gripper cuffs and gripper fingers suspended via a four-bar linkage on gripper carriage shields 8 that are constantly driven by the chains. The trailing edge gripper carriage 3 has a gripper carriage shield 8 on each side, each with two chain pins 7, which are driven by the chains (not shown) on the chain track 6 (also not shown). The gripper system body with the gripper cuffs and gripper fingers is arranged between the two gripper carriage shields 8. The gripper system body of the trailing edge gripper carriage 3 thus always rotates along the chain track 6 at chain speed. To relocate the gripper cuffs and gripper fingers, the gripper system body of the trailing edge gripper carriage 3 is mounted so that it can be moved around a real or virtual axis of rotation 9.In the embodiment shown here, the gripper system body is suspended on both sides by means of four-bar gears on the gripper carriage shields 8 and can be rotated about the virtual axis of rotation 9.

[0021] In addition to the two four-bar linkages that pivotally hold the gripper system body, the trailing edge gripper carriage 3 includes other parts not shown or labeled, such as the air baffles shown here, which can also be pivoted but do not have to be. Preferably, the gripper cuffs and the gripper fingers are pivoted together with the air baffles. A four-bar linkage shown here includes a first pivot point 10 arranged on the gripper system body, located downstream in the sheet conveying direction BFR, and a second pivot point 11 arranged on the gripper system body, located upstream in the sheet conveying direction BFR.The first articulation point 10 on the gripper system body is connected via a coupling to a first articulation point 12 on the gripper carriage shield 8, which is located downstream in the sheet conveying direction BFR, and the second articulation point 11 on the gripper system body is connected via a coupling to a second articulation point 13 on the gripper carriage shield 8, which is located upstream in the sheet conveying direction BFR. A spring 14, in particular a tension spring, is arranged between the first articulation point 10 on the gripper system body and the second articulation point 13 on the gripper carriage shield 8.

[0022] The trailing edge gripper carriage 3 is assigned a first drive 15 for moving the gripper fingers relative to the gripper cuffs, as is necessary for securing the trailing edge of the sheet. This first drive 15 is designed here as a mechanical drive, in particular as a cam roller drive. The trailing edge gripper carriage 3 is also assigned a second drive 16, with which the gripper cuffs can be displaced relative to the traction means, here the chains with the gripper carriage shields 8 fixedly arranged thereon. This second drive 16 is preferably also designed as a mechanical drive. In the illustrated embodiment, the second drive 16 is designed as a cam roller drive arranged on both sides of the gripper system body.The rear edge gripper carriage 3 shown carries cam rollers on both sides of the gripper system body, which come into contact with cam segments (not shown) in order to pivot the gripper system body via the four-bar linkage about the virtual axis of rotation 9.

[0023] The first drive 15 assigned to the trailing edge gripper carriage 3 grips or releases the trailing edge of the sheet by controlling the movement of the gripper fingers relative to the gripper strikes. The further second drive 16 causes a displacement of the gripper system body and thus of the gripper strikes and the gripper fingers, here with the additional air baffles, relative to the chains. In the illustrated embodiment, the gripper system body is pivoted by the further second drive 16 about the virtual axis of rotation 9 specified by the four-bar linkages.

[0024] The Fig. Figure 3a shows the trailing edge gripper carriage 3 in a perspective view before reaching the sheet stack 5, in its normal position, not pivoted for sheet transport, with chain pins 7 as the connecting means to the chains (not shown). In this area, the cam rollers of the second drive 16 are guided on a high notch of the upper cam elements (not shown), so that the spring 14 is tensioned and the gripper system body of the trailing edge gripper carriage 3 rotates in its normal position.

[0025] The Fig. Figure 3b shows the trailing edge gripper carriage 3 according to the previous figure, in a side view and in its normal, unpivoted position, before reaching the sheet stack 5. The trailing edge gripper carriage 3 continues to grip the sheet 4 being transported toward the sheet stack 5 by means of the gripper stops and gripper fingers. The upper cam elements (not shown) interact with the cam rollers of the gripper system body in such a way that the gripper system body continues to maintain its unpivoted, i.e., normal, position.

[0026] The Fig. Figure 4a shows the trailing edge gripper carriage 3 in a perspective view upon reaching the sheet stack 5 in a position pivoted for sheet deposit. The second drive 16, i.e., the upper cam elements (not shown here) and the cam rollers of the gripper system body, enable a pivoting movement of the gripper system body around the virtual rotation axis 9 in this area through a low detent of the cam segments, supported by the spring force of the spring 14. At the same time, the pivoting of the gripper system body displaces the gripper stops and gripper fingers against the sheet conveying direction BFR and slightly downward toward the sheet stack 5.

[0027] The Fig.Figure 4b shows the trailing edge gripper carriage 3 according to the previous figure, viewed from the side and pivoted in a tilted position, upon reaching the sheet stack 5. The trailing edge gripper carriage 3 continues to grip the sheet 4 to be deposited by means of the gripper cuffs and gripper fingers. By pivoting the gripper cuffs and gripper fingers against the sheet conveying direction BFR, the still-fixed sheet 4 is decelerated relative to the chain speed. The sheet 4, thus largely decelerated, is then released for deposit by the first drive 15 opening the gripper fingers and is deposited with precision at the leading edge stops.

[0028] In the delivery, the gripper fingers and gripper cuffs can also be relocated in other areas of the orbit. By pivoting the gripper system body in the opposite direction using the second drive 16, both the gripper cuffs and the gripper fingers can be raised and thus relocated within the chain track 6. These raised gripper fingers and gripper cuffs make it possible to move past the outer surfaces of cylinders in the sheet transfer areas without the risk of collision. This allows for simplified transfer of the sheet trailing edge from cylinders with a closed outer surface, with the gripping of the trailing edges being supported by a transfer system or by catching the trailing edges on the sheet conveyor path.

[0029] How it works: During sheet transport in the delivery of a sheet-processing machine, the trailing edges of the sheets are lifted from the outer surface by a cylinder transfer system, according to one embodiment. The trailing edge is picked up by the trailing edge gripper carriage 3 before the cylinder leaves the center of gravity by pivoting the gripper system body using the second drive 16 and opening the gripper fingers using the first drive 15, whereby only a slight opening of the gripper is required. Subsequently, the gripper system body, with the gripped trailing edge of the sheet, is pivoted onto the center of gravity by the second drive 16. This allows the trailing edge of the sheet to be picked up outside the center of gravity and transported within the center of gravity by the trailing edge gripper carriage 3.

[0030] The sheet deposit by the trailing edge gripper carriage 3 is achieved by pivoting the gripper system body, including the gripper stops and the gripper fingers, with the trailing sheet edge further gripped by means of the second drive 16, whereby the transport speed of the sheet 4 is reduced compared to the chains rotating at a constant speed. In the case of sheet deposit without an additional deposit system, a sheet braking can be achieved by quickly pivoting the gripper system body by means of the second drive 16 and a delayed opening of the gripper fingers by means of the first drive 15. If a deposit system is used, after the trailing sheet edge has been transferred to the deposit system, the sheet 4 is braked by the deposit system, such as a pneumatic sheet brake or re-gripper system, without moving the gripper fingers far (e.g.90°) as the trailing edge of the sheet is released by the trailing edge gripper carriage 3 itself. List of reference symbols used 1 printing cylinder 2 front edge gripper carriages 3 trailing edge gripper carriages 4 sheets 5 stacks of sheets 6 chain conveyor 7 chain pins 8 Gripper carriage shield 9 virtual rotation axis 10 first joint point on the gripper system body 11 second joint point on the gripper system body 12 first pivot point on the gripper carriage shield 13 second pivot point on the gripper carriage shield 14 spring 15 first drive 16 second drive BFR sheet feed direction

Claims

[1] Delivery of a sheet-processing machine with a first conveyor system with leading edge gripper carriages (2) which can be guided in a rotating manner by traction means and a second conveyor system with trailing edge gripper carriages (3) which can be guided in a rotating manner by traction means, wherein the leading edge gripper carriages (2) have gripper fingers which interact with gripper stops for fixing the leading edges of the sheets, wherein the trailing edge gripper carriages (3) have gripper fingers cooperating with gripper stops for fixing the sheet trailing edges and whereby sheets (4) are fixed at the front edge and rear edge and can be transported up to a sheet stack (5), wherein the trailing edge gripper carriages (3) are guided on the traction center track (6) and wherein the gripper fingers and the gripper impacts of a trailing edge gripper carriage (3) are displaceable in regions relative to the traction center track (6), characterized by , that a gripper system body of the rear edge gripper carriage (3) is designed to be rotatable about a virtual axis of rotation (9). [2] Display according to claim 1, characterized by that the rear edge gripper carriage (3) has a gripper carriage plate (8) on each side and that each gripper carriage plate (8) is directly assigned to a traction means. [3] Display according to claim 1 or 2, characterized by that the gripper system body of the rear edge gripper carriage (3) is mounted so as to be rotatable and / or pivotable relative to the traction means. [4] Display according to claim 1, 2 or 3, characterized by that the gripper system body of the rear edge gripper carriage (3) is assigned to the traction means by means of articulated gears. [5] Display according to at least one of the preceding claims, characterized by that the gripper system body of the rear edge gripper carriage (3) is assigned to the traction means by means of four-bar gears. [6] Display according to at least one of the preceding claims, characterized by that the rear edge gripper carriage (3) has a first drive (15) for displacing the gripper fingers and a second drive (16) for displacing the gripper cuffs or the gripper cuffs and the gripper fingers.

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