Stack lifting device

Abstract

Device for lifting a stack (8) in the feeder (2) of a sheet processing machine (7), comprising a main stacking plate (10) and an auxiliary stacking carrier (21) for uninterrupted sheet feeding, wherein lifting means (23 to 26) are provided for lifting the sheet stack (8a) from the main stacking plate (10), characterized in that the lifting means (23 to 26) are supported below the main stacking plate (10) and are arranged adjustably transversely to a sheet travel direction.

Description

[0001] The invention relates to a device for lifting a stack in the feeder of a sheet processing machine.

[0002] Sheet-processing machines, such as die-cutting or printing presses, have non-stop feeders for the uninterrupted feeding of sheets. These feeders allow a new stack of sheets to be placed in the feeder while the old one is still being processed. For processing, stacks of sheets are placed on system pallets, which have a grooved surface to accommodate an auxiliary stacking carrier.

[0003] German patent DE 101 21 038 A1 discloses a non-stop feeder with an auxiliary stack support for underpinning and carrying the auxiliary stack. A main stack intended for stack merging is provided on a system pallet.

[0004] German patent DE 10 2006 021 214 A1 describes a device for combining an auxiliary stack and a main stack in a feeder of a sheet-fed printing press. This device comprises a main stack lifting device for lifting a main stack stacked on a pallet and an auxiliary stack support device for carrying an auxiliary stack. It further comprises an auxiliary stack lifting device for lifting the auxiliary stack support device and thus an auxiliary stack positioned on the auxiliary stack support device.

[0005] DE 40 26 277 A1 describes a sheet feeder with a non-stop device. The non-stop device has a vertically guided, driven support device arranged under the sheet stack, which has support bars extending in a horizontal plane across the width of the stacking table in the sheet conveying direction and projecting freely into the area of ​​the sheet stack.

[0006] German patent DE 26 47 96 A describes a support element designed for stacks of paper, which can be moved beneath the stack. The support element consists of a stacking plate and a flexible covering that winds up at the edge of the stacking plate.

[0007] The invention is based on the objective of creating a system that allows the processing of stacks of sheets arranged on a disposable pallet.

[0008] The problem is solved according to the invention by the features of the independent claims.

[0009] A particular advantage of the invention is that disposable pallets can be processed in non-stop feeders. This allows stacks of sheets with different sheet sizes to be placed directly onto the feeder's main stacking plate. The restacking process, which is otherwise common when using system pallets and requires a stack turner, is therefore eliminated.

[0010] Non-stop feeders typically feature auxiliary stack carriers with a rigid rack, which has rack bars arranged according to the slot spacing of the system pallets. Since the slot spacing of disposable pallets varies with the sheet size, a rigid rack cannot process different disposable pallet formats.

[0011] It is therefore advantageously proposed to provide an arch stack lifting system which allows the arch stack to be gripped from below, independent of the groove. This system is arranged on the main stacking plate and has a number of vertically displaceable lifting elements that create a gap under the arch stack into which the auxiliary stacking support can be inserted.

[0012] The lifting system according to the invention can be used on non-stop feeders with auxiliary stack carriers that can be moved in or against the direction of the arc travel, or also transversely to it.

[0013] Further advantageous configurations are described in the dependent claims.

[0014] An embodiment of the invention is illustrated in the drawings and is described below. The drawings show... Fig. 1. A cross-section of a sheet-fed rotary printing press in a schematic representation Fig. 2 a main stacking plate with lifting elements seen in the direction of the arc Fig. 3 the main stacking plate with lifting elements and a raised arched stack Fig. 4 a lifting element from the side with an auxiliary stacking carrier that can be inserted transversely to the direction of arc travel Fig. 5 a lifting element from the side with a support for an arc stack edge Fig. 6 a lifting element with roller seen from above Fig. 7 the lifting element with swiveling supports

[0015] A sheet-processing machine 7, e.g., a die-cutting or printing press 1, has a feeder 2. In the exemplary embodiment according to Fig. Figure 1 shows a printing press 1 with at least one printing unit 3 or 4 and a delivery unit 6. The sheets 7 are taken from a sheet stack 8 and fed individually or in batches to the printing units 3 and 4 via a feed table 9. These units each contain a plate cylinder 11, 12, as is known. The plate cylinders 11 and 12 each have a device 13, 14 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 7 are removed from the top of the stack of sheets 8 by means of a suction head 18, which includes, among other things, a number of lifting and trailing suction cups 19 for singulating the sheets 7. In addition, blowing devices are provided to loosen the upper layers of sheets for stack tracking. A number of lateral and rear stops are provided for aligning the stack of sheets 8, in particular the upper sheets 7 of the stack.

[0017] An auxiliary stacking support 21, which can be inserted into the stacking area against the direction of sheet travel, enables non-stop operation; that is, a sheet stack 8a that has been processed down to a residual stack can be combined with the new main stack 8 without interrupting the feeding operation. For this purpose, the auxiliary stacking support 21, preferably designed as a rake, is inserted into a gap L between the sheet stack 8a and the main stacking plate 10 in the stacking area.

[0018] To create this gap L, a lifting system 22 is provided, which lifts the stack of arched sheets 8a from the main stacking plate 10. The lifting system 22 is arranged on the main stacking plate 10 and has a number of lifting elements 23, 24, 25, 26 evenly distributed across the main stacking plate support.

[0019] The lifting elements 23 to 26 are arranged on a common support 28, which is vertically displaceable relative to the main stacking plate 10 by means of a lifting motor 29. The lifting elements 23 to 26, which are vertically displaceable together with the support 28, correspond to through-openings 30, 31, 32, 33 in the main stacking plate 10, so that they can support and lift the underside of the sheet stack 8a through the through-openings 30 to 33. The auxiliary stacking support 21 can then be inserted into the resulting gap L to support the sheet stack 8a.

[0020] In order for a stack of sheets 8; 8a arranged on a pallet 34 to be lifted by the lifting elements 23 to 26, these elements must also extend through the slots 36 arranged between the slats 35 of the pallet 34. For this purpose, the slots 36 and the lifting elements 23 to 26 must be aligned. Sensors 37 are provided which detect the lateral deviation of the slots 36 from the common alignment and control actuators 37, 38, 39, 40 for the lifting elements 23 to 26, which, according to the positional deviation, move the lifting elements 23 to 26 laterally by means of actuators.

[0021] The adjusting devices 37 to 40 are arranged below the main stacking plate 10 on the support 28.

[0022] The auxiliary stack carrier 21, designed as a rake, has a number of parallel, adjacent rake bars 42, which in the exemplary embodiment according to the Fig. 1 to 3 can be inserted into the stacking area against the direction of arc travel. The rake bars 42 each engage in a gap S formed between the spaced-apart lifting elements 23 to 26 transversely to the direction of arc travel.

[0023] The lifting elements 23 to 26, arranged one behind the other in the direction of arc travel, are identical in construction and can be arranged according to Fig. 4 have the form of a punch 23; 24; 25; 26, which has support prongs 23.1, 23.2, 23.3, 23.4 arranged one behind the other in the direction of the arc.

[0024] The rack bars 42 can be accommodated in the spaces formed between two adjacent support tines 23.1 to 23.4.

[0025] In the Fig. 4 and Fig. 5 The auxiliary stacking support 21 is arranged transversely to the direction of travel of the arc and can be inserted into the stacking area. In this arrangement, the gaps between the support tines serve to receive the rake bars 42. As in Fig. As shown in Figure 5, the support tine 23.1 can have a support 46, e.g., in the form of a nose. It is provided that, after being raised to below the sheet stack 8a, the punches 23 to 26 are moved against the sheet travel direction by means of an actuator 47 before the sheet stack 8a is lifted, until a sheet stack edge is supported by the nose 46.

[0026] In the case where the auxiliary stack carrier 21 is used according to the Fig. 4 and Fig. 5 is arranged to be displaceable in the direction of arc travel, a centering element 43, 44 is provided to avoid a collision between the auxiliary stacking carrier 21 and the lifting elements 23 to 26, which, for example, has a rotatably mounted roller 43 that is arranged on the lifting elements 23 to 26 and, upon contact with a ramp 44 of a rake bar 42, deflects the laterally displaceable auxiliary stacking carrier 21 to such an extent that the auxiliary stacking carrier 21 can be fully inserted into the stacking area.

[0027] To support the stack of arches 8a in its lateral area, where it is no longer supported by the pallet 34 in the raised state, it is necessary according to Fig. 7 provided that the support tines 23.1 to 23.4 are preferably arranged to pivot horizontally in order to support the stack of arches in the lateral area.

[0028] A stack of sheets 8a, together with the disposable pallet 34 supporting it, is placed on a main stacking plate 10 and processed until the main stacking plate 10 only supports a small remaining stack of sheets 8a. During this process, the main stacking plate 10 is continuously raised to a point where the auxiliary stacking support 21 is horizontally slidable within the stacking area.

[0029] In order for the rakes 42 of the auxiliary stacking support 21 to be inserted into the stacking area for supporting the sheet stack 8a, a gap L is formed by lifting the sheet stack 8a from a pallet 34 and thus from the main stacking plate 10 into which the auxiliary stacking support 21 can be inserted horizontally either in the direction of sheet travel or perpendicular to it.

[0030] The auxiliary stack carrier 21 is then driven faster in the vertical direction than the main stack plate 10, so that the arc stack 8a is lifted off the lifting elements 23 to 26 by means of the calculating rods 42.

[0031] These are then lowered below the level of the main stacking plate 10, so that the pallet 24 can be removed horizontally and a new stack of sheets 8 can be provided on the lowered main stacking plate 10 for joining with the remaining stack 8a. 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 Pressure plate mounting 17 printing plate changers 18 suction heads 19 vacuum cleaners 20 . / . 21 auxiliary stackers 22 . / . 23 Lifting element 24 lifting elements 25 lifting element 26 lifting element 27 . / . 28 carriers 29 Hub motor 30 Passage opening (10) 31 Passage opening (10) 32 Passage opening (10) 33 Passage opening (10) 34 pallets 35 battens (34) 36 slots (34-34) 37 Actuator 38 Actuator 39 Actuator 40 Actuator 41 . / . 42 Slide rule 43 rolls 44 Lead-in slope (42) 45 . / . 46 Support (nose) 47 Actuator S gap L gap

Claims

[1] Device for lifting a stack (8) in the feeder (2) of a sheet processing machine (7), comprising a main stacking plate (10) and an auxiliary stacking carrier (21) for uninterrupted sheet feeding, wherein lifting means (23 to 26) are provided for lifting the sheet stack (8a) from the main stacking plate (10), characterized by , that the lifting means (23 to 26) are supported below the main stacking plate (10) and are arranged adjustable transversely to a direction of arc travel. [2] Device according to claim 1, characterized by , that the lifting means (23 to 26) are lifting elements (23 to 26) which are adjustable in relation to slots (36) detected by sensors in pallets (34). [3] Device according to one of claims 1 to 2, characterized by , that the lifting means (23 to 26) are designed as rams (23 to 26) with support tines spaced apart from each other (23.1 to 23.4). [4] Device according to claim 3, characterized by, that the support prong (23.1) arranged at the edge of the respective punch (23 to 26) has a support nose (46) for a sheet stack edge. [5] Device according to claim 4, characterized by that the stamps (23 to 26) are arranged individually or together to be displaceable within a slot (36) by means of an actuator (47). [6] Device according to claim 4, characterized by , that the support tines (23.1 to 23.4) are arranged to pivot horizontally. [7] Device according to any one of the preceding claims 1 to 6, characterized by , that the lifting means (23 to 26) are lifting elements (23 to 26) and the auxiliary stack carrier (21) and the lifting elements (23 to 26) have common centering elements (43, 44). [8] Sheet-fed rotary printing press with a device according to any one of claims 1 to 7. [9] Punching machine with a device according to any one of claims 1 to 7.

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