Device for ejecting bows

Abstract

Device for diverting sheets from a transport path of a sheet processing machine to a receiving container by means of a discharge drum with grippers, characterized by that the delivery drum (27) has a drive (61) arranged separately and mechanically decoupled from the drive (60) of the sheet processing machine, that a rotary encoder (72) is provided for synchronizing the drive (61) with the speed of the sheet processing machine to detect the speed of a gripper bridge chain of a gripper chain system (23) of the sheet processing machine, that the rotary encoder (72) is driven by a belt drive (73) which is driven by a pinion gear (74) which is engaged with the gripper chain system (23).

Description

[0001] The invention relates to a device for diverting sheets from a transport path of a sheet-processing machine, e.g., a die-cutting machine or a printing press. In the delivery head of a die-cutting or printing press, sheets are fed one after the other to a stack of sheets and placed onto it.

[0002] There are already known designs in which sheets are diverted from the transport path and placed on an auxiliary stack before being deposited on the sheet stack.

[0003] DE 10 2008 006 528 A1 discloses a device for combing out a sheet from a transport path between the printing units of a printing press and a stack of sheets, wherein the combed-out sheet is fed to an auxiliary stack by means of a transport belt that slows down the sheet.

[0004] German patent DE 198 19 491 C2 discloses a delivery drum that picks up a sheet from the transport path using gripper systems and feeds it into a stacking or delivery system. The delivery drum, designed for sheet delivery, is mechanically coupled to the printing press's drive train. The operation of the delivery drum introduces increased vibrations into the printing press system, which negatively impact print quality.

[0005] DE 10 2006 052 367 B3 and DE 10 2006 020 907 A1 represent further state of the art.

[0006] The invention is therefore based on the objective of creating a further device for diverting sheets from a transport path of a sheet processing machine.

[0007] The problem is solved according to the invention by the features of claim 1.

[0008] A particular advantage of the invention is that by having a separate drive for the delivery drum that is decoupled from the drive of the printing press, the smooth running of the printing press is increased and the print quality is improved.

[0009] Furthermore, it is very advantageous to drive the sheet transport rollers, which are located downstream of the delivery drum in order to feed the sheet to a wastepaper container or stack, from the delivery drum's own drive.

[0010] The sheet transport rollers have profiles to improve frictional forces, and it is specifically provided that the profiles interlock between two communicating transport rollers, so that a sheet is deformed in a meandering shape.

[0011] To synchronize the cooperation of grippers of a boom chain and the grippers of the delivery drum, a rotary encoder is provided which detects the speed (working cycle of the printing press) of the boom chain and supplies this signal to a control for the self-drive, e.g., the electric motor of the delivery drum.

[0012] Advantageously, the receiving container has a device for pressing down the incoming sheets. This device preferably has the form of a rake and is guided on a track B by means of a lever mechanism. This measure allows a larger number of sheets to be accommodated in the receiving container than would be possible with a simple feeder.

[0013] Further advantages of the invention are described in the dependent claims. An embodiment of the invention is illustrated in the drawings and is described below.

[0014] They show: Fig. 1. A cross-section of a sheet-fed rotary printing press in a schematic representation, Fig. 2 A cross-sectional schematic representation of a delivery drum of the sheet-fed rotary printing press, Fig. 3 a receiving container in top view, Fig. 4. The collection container in a rear view, Fig. 5 a pair of transport rollers.

[0015] A sheet-processing machine 7, e.g., a printing press, has a feeder 2, at least one printing unit 3 or 4, and a delivery unit 6. The sheets 7 are taken from a stack of sheets 8 and fed singly or in batches via a feed table 9 to the printing units 3 and 4. These units each contain a plate cylinder 11, 12, as is known. The plate cylinders 11 and 12 each have a device for attaching flexible printing plates. In addition, each plate cylinder 11, 12 is assigned a device for semi- or fully automatic plate changing.

[0016] The stack of sheets 8 rests on a controllably liftable main stacking plate 10. The sheets are removed from the top of the stack 8 by means of a suction head 18, which includes, among other things, a number of lifting and trailing suction cups 19, 21 for singulating the sheets 7. In addition, blowing devices are provided to loosen the upper layers of sheets, and sensing elements are provided for stack tracking. A number of lateral and rear stops are provided for aligning the stack 8, in particular the upper sheets 7 of the stack 8.

[0017] The boom 6 has a conveying section 22, which consists of a gripper chain system 23 with gripper bridges 24 for transporting sheets to a main stack 26 of the boom 6.

[0018] In the direction of sheet transport, in front of the main stack 26, a device for diverting sheets from the conveyor section 22, defined by the gripper chain system 23, is provided below the conveyor section 22. This device essentially comprises a sheet transport drum 27, which is designed as a delivery drum with at least one gripper device 28 for taking the sheets from the gripper bridges 24 of the gripper chain system 23. The gripper devices 28 grasp the sheet at its leading edge and convey it into a receiving container 31 arranged adjacent to the delivery drum 27.

[0019] To transport the sheets from the delivery drum 27 to the receiving container 31, a roller assembly is arranged downstream of the delivery drum 27. A first roller 34 interacts with support discs of the delivery drum 27. Here, the roller 34 is pressed against the sheet before the grippers 28 of the delivery drum 27 open. The distance between the roller 34 and the delivery drum 27 can be adjusted manually or by motor to accommodate the paper thicknesses being processed. If no sheet is being delivered, a minimum distance must be maintained between the roller 34 and the delivery drum 27 to prevent ink transfer from sheets that have already been delivered and are still wet with ink. The roller assembly also includes a driven, interacting pair of rollers, consisting of an upper roller 32 and a cooperating lower roller 33, which feed the sheet into the receiving container 31 via a transport gap.

[0020] All transport rollers 32, 33, 34 have a profile 36 to increase their grip. The profiles of rollers 32, 33 and the profile of roller 34 with the support discs of the discharge drum 27 interlock in such a way that, according to Fig. 5 results in a meandering curve of the arc in the transverse direction.

[0021] The transport rollers 32, 33, 34 each consist of individual rollers arranged transversely to the direction of the sheet transport.

[0022] A transport track between the discharge drum 27 and the receiving container 31 has upper and lower guide surfaces 37, 38. Openings 39, 41 in the guide surfaces allow the transport rollers 32, 33 to pass through. The upper guide plate 37 is designed to be long enough to extend well beyond the upwardly open receiving container 31.

[0023] The receiving container 31 has a device, e.g. in the form of a rake 42, for pressing down the supplied sheets.

[0024] The rake 42 has a traverse 43 and a number of rake bars 44 arranged at intervals on this traverse, which are movably mounted through vertical, parallel slots 46 in a side wall 47 of the receiving container 31 into the receiving container 31.

[0025] The movement of the rack 42 is controlled by a linkage 48 or a cam mechanism (not shown). The linkage 48 has a lever 51 pivotally mounted on the crossbeam 43, the opposite end of which is stationary, e.g., on the side frame of the printing press. Parallel to the lever 51 is a linkage 52, the lower end of which is pivotally mounted at a distance from the crossbeam 43 on a rack bar 44, and the opposite end of which is connected to the first end of an angled double lever 53. The double lever 53 is pivotally mounted in a stationary position, e.g., on the side frame, and has a receiving point at its second end for a first stationary actuator 54, e.g., a pneumatic cylinder. A second stationary actuator 56, e.g., a pneumatic cylinder, engages the lever 51 approximately in the middle.By controlling the actuators 54, 56, an oscillating motion path B of the rake 42 is achieved according to . Fig. 2. To prevent a frontal collision between the screen 42 and the incoming sheet, the screen 42's entry into the receiving container 31 is synchronized with the clearance between two successive sheets. The device for pressing down the sheets can be arranged on one or both sides.

[0026] As in Fig. Figure 2 shows a pressing device arranged both in front of and behind the receiving container 31, viewed in the direction of arc transport. This allows the rakes 42 to have shorter rake bars 44. The pressing devices have the same design and are therefore described using only one pressing device as an example.

[0027] A drive 61, e.g., an electric motor (synchronous motor), is provided to drive the delivery drum 27. This stationary drive unit drives the delivery drum 42 by means of a belt drive, preferably a high-stiffness synchronous belt. The transport roller 32 is driven by the delivery drum 27 by means of a belt drive 63 and in turn drives the transport roller 33 by means of provided gears (not shown). The transport roller 34 is driven by the lower transport roller 33 by means of a belt drive 64.

[0028] A control unit 71 is provided for synchronizing the drive 61 of the delivery drum 27 with the grippers of the gripper bridge 24 of the gripper chain system 22. This control unit receives actual values ​​from a rotary encoder 72, which is driven, in particular, by a belt drive 73. The belt drive 72 is driven by a pinion gear 74, which is engaged with the gripper chain system 23. The pinion gear 74 is preferably arranged at the point of sheet transfer between the gripper bridge 24 and the delivery drum 27.

[0029] A sheet to be discharged is picked up by the grippers 28 from the grippers of the gripper bridge 24 and fed into a transport gap between the delivery drum and the transport roller 34. From there, the sheet enters a guide area between the guide surfaces 37, 38, from where it enters a transport gap of the transport roller pair 32, 33. The sheet, now released by the grippers 28, is safely transported further by the transport rollers 32, 33, 34 until it reaches the receiving hopper 31. Once in the hopper, the sheet is pressed downwards by the rake of the press-down system. The press-down system is driven in sync with the delivery drum 27 and, particularly when the receiving hopper 31 is partially filled, ensures that a large number of sheets can be accommodated in the receiving hopper 31. Reference symbol list 1 printing press 2 investors 3 Printed matter 4 Printing work 5 . / . 6 outriggers 7 sheets 8 stacks of sheets 9 Feed table 10 stacking plates 11 plate cylinders 12 plate cylinders 13 Pressure plate mounting 14 Pressure plate mounting 15 . / . 16 printing plate changers 17 printing plate changers 18 suction heads 19 vacuum cleaners 20 . / . 21 trailing suction machines 22 Conveyor route 23 Gripper chain system 24 Grab bridge (23) 25 . / . 26 main stacks 27 Dispensing drum 28 Gripper device (27) 29 auxiliary stacks 30 . / . 31 collection containers 32 Transport roller 33 Transport roller 34 Transport roller 35 . / . 36 Profile (32, 33, 34) 37 Guide surface (upper) 38 Guide surface (lower) 39 - 41 . / . 42 rakes 43 Traverse 44 Slide rule 45 . / . 46 slots (31) 47 Side wall (31) 48 coupling gears 49 . / . 50 . / . 51 levers 52 couplings 53 Double levers 54 Actuator 55 . / . 56 Actuator 57 - 60 . / . 61 Drive motor 62 Belt drive 63 Belt drive 64 Belt drive 65 - 70 . / . 71 Control 72 rotary encoders 73 Belt drive 74 Pinion gear B Path of motion (42)

Claims

[1] Device for diverting sheets from a transport path of a sheet processing machine to a receiving container by means of a delivery drum having a gripper, characterized by , that the delivery drum (27) has a drive (61) arranged separately and mechanically decoupled from the drive (60) of the sheet processing machine, that a rotary encoder (72) is provided for synchronizing the drive (61) with the speed of the sheet processing machine to detect the speed of a gripper bridge chain of a gripper chain system (23) of the sheet processing machine, that the rotary encoder (72) is driven by a belt drive (73) which is driven by a pinion gear (74) which is engaged with the gripper chain system (23). [2] Device according to claim 1, characterized by, that a transport device with transport rollers (32, 33, 34) is provided and that the transport rollers (32, 33, 34) are arranged to be driven directly or indirectly by the discharge drum (27). [3] Device according to claim 2, characterized by , that the transport rollers (32, 33, 34) have profiles (36) and that the profiles (36) of the transport rollers (32, 33) are arranged interlocking. [4] Sheet-fed die-cutting or sheet-fed printing machine with a device according to one of the preceding claims.

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