DE9010117U1 - Device for straightening stacks - Google Patents

Description

SYSTEM GmbH Ul. July 1990

ii -4000 Dusseldorf

ST 39. Gl

Device for straightening stacks

Description

The invention relates to a device of the type specified in the preamble of claim 1.

Such a device for straightening a stack of several sheets of paper or the like

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is known from DE 37 12 104 A1. This is connected to a horizontal conveyor system consisting of several longitudinal conveyors arranged at a distance from one another. A stacking grid with longitudinal beams parallel to the individual longitudinal conveyors is arranged below the transport level of the horizontal conveyor system. A front stack stop is also provided which can be moved vertically to and above the transport level. The stacking support grid is mounted with its front end pivotable about a horizontal transverse axis in the horizontal conveyor system and can be lifted above the transport level with the aid of a lifting unit acting on its rear end with its stacking support surface formed by the longitudinal beams. A lower and two vibrator plates and an upper press plate for straightening the stack are assigned to the stacking support grid.

The known device has the disadvantage that it is very complicated and expensive to design. The stacks can only be straightened when they are tilted. Each stack to be straightened must therefore be swung back and forth by the straightening device. Due to these design-related processes, the device is susceptible to failure, especially under continuous load.

Furthermore, the high time required for the alignment process and the resulting costs have an adverse effect on the profitability of the known device. The device can therefore only be loaded and unloaded via the horizontal conveyor, which makes it very inflexible and unsuitable for other, differently designed conveyor devices. Furthermore,

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During further transport on the horizontal conveyor after straightening, the straightened stack retains both its pressed state and its straightened shape.

The invention is based on the object of specifying a simple construction for a device of the type mentioned at the beginning while eliminating the disadvantages mentioned, with which the device can be linked to other conveying means and/or processing machines while retaining its aligned shape. In particular, the time required for the alignment process in connection with the transport processes should be reduced.

This object is achieved with the characterizing features of claim 1.

The invention is based on the knowledge that the desired alignment quality of a stack can be achieved with the device by aligning in the plane, the process speed can be significantly increased and process-favorable measures in connection with a pressure means and with access areas for a gripper can be made possible.

The decisive factors for the resulting short processing and transport time are, on the one hand, the arrangement of the straightening area in the stack conveyor area, on the other hand, the straightening of the stacks essentially in this area, and finally a free access area for the gripper to ensure fast and suitable further transport. To maintain the straightening quality of the stack,

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pels, the linking of the movements of the pressure means that hold the stack after straightening and the support surface with the movements of the gripper are crucial. After the straightening process, the stack is held by the pressure means that can be lowered onto the stack from above during the straightening process and the support surface that counteracts it from below under a load that presses the individual layers of the stack together. The moment the gripper takes hold of the stack, the pressure means is released from the stack. The stack is now pressed together by the gripper and can be moved freely with the gripper. The essentially uninterrupted pressing together since straightening prevents the individual films of the stack from slipping. The straightened shape of the stack can therefore also be advantageously maintained during transport.

It is particularly advantageous that a support surface for the stack and a pressure means that can be lowered vertically from above onto the stack are provided. The pressure means and the support surface are assigned to one another. It is also advantageous that an access area that is free from at least one side is provided above and below the aligned stack arranged between the pressure means and the support surface for a gripper. The stack can thus be grasped by the gripper without hindrance.

As a result, the stack remains in place after straightening, first by the pressure device and the support surface and then by the tines of the gripper that press the stack together.

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almost continuously under a load that compresses the stack. The pressure on the stack is also maintained during the transport process, so that no air can get between the individual films, which would destabilize the stack. From this point of view, the gripper is therefore significantly more suitable for transport processes than the horizontal conveyor. This is why it is particularly advantageous to remove the straightened stack from the straightening area using a gripper.
10

In particular, the following advantageous further training courses are favorable:

Recesses in the supporting plane of the stack form the
gripping area for the gripper underneath the stack, so that the gripper can be guided underneath the stack. The stack can thus be gripped by the gripper in a time- and transport-efficient manner after it has been guided into the recess against the conveying direction towards the stack. The lower prongs of the gripper are arranged completely underneath the stack during the gripping process. This ensures optimized access and a load that optimally holds the stack in the aligned state. Furthermore, the recesses extend essentially horizontally in the supporting plane of the stack against the conveying direction.

Furthermore, it is particularly advantageous that the pressure means is designed as a press plate that can be guided from above onto the stack located in the straightening area. The press plate advantageously presses

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When the stack is straightened, the air between the sheets or foils is removed, so that after straightening the stack is in a stable, compact and pressed together state. This largely prevents the foils forming the stack from slipping against each other.

In another variant when straightening the stack, the straightening area, the exit area and thus the position in which the stack is gripped by the gripper correspond to one another. This means that the stack is gripped directly and without any loss of time.

According to another advantageous development, the support surface is formed by a lifting plate with a lifting drive for the stack in the straightening area. The lifting plate is arranged below the support level of the horizontal conveyor in the straightening area. The lifting device, consisting of the lifting plate and the lifting drive, is characterized by a stroke that exceeds the straightening area. Accordingly, the press plate is designed to be movable upwards by the lifting height of the lifting plate through a coordinated movement with it.

This advantageously makes it possible to compensate for the height without having to remove the forces acting on the stack and stabilizing it. The stack can thus be aligned, compressed and taken over by the gripper at a height that is favorable for further processing. A compensation for the height proves particularly useful in the overall design of an alignment station, transport

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and further processing systems or palletizing machines are considered to be process-efficient and to shorten process times, particularly with regard to possible parallel operations.
5

In order to be able to straighten the stack faster and better, an additional stop plate is arranged on the side of the stack that is furthest from the stack stop for the straightening process. The additional stop plate is designed to be pivotable into the conveying area about a rotation axis that extends parallel to the conveying direction. The additional stop plate also has a vibrator drive and thus also acts as a vibrator plate for the straightening process. This enables the stacks to be transported unhindered into the straightening area by the horizontal conveyor and to be limited from all sides and stimulated from three sides when straightening the stack.

Preferably, the side stop plates are mounted so that they can pivot around a vertical axis. This gives the stack enough space for further movements and transport processes. Furthermore, the stop plates can be adapted to different stack widths.
25

In the straightening area of the conveyor support level, air nozzles are preferably arranged to lift the stack during alignment. The stack can thus be lifted just above the support surface during the straightening process, which prevents damage to the underside due to the vibration movements of the stack or the bottom film.

ft ft · ♦ ft * ft · · · * ft ft

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It has also proven particularly advantageous that a separating device for the continuously moving stack is provided in front of the entry area, so that the stacks from running into each other in the straightening area are prevented from the outset.

Useful developments of the invention are characterized in the subclaims or are described in more detail below together with the description of the preferred embodiment of the invention using the figures. They show:

Figure 1 is a plan view of an embodiment of the invention, and

Figure 2 shows a cross section A-A through the embodiment of the invention shown in Figure 1.

Figure 1 shows a top view of an embodiment of the device for straightening a stack, in particular one consisting of several films, and Figure 2 shows a cross section of the same embodiment of the invention formed along a straight line A-A shown in Figure 1. The description below refers to both figures.

The device 10 according to the invention for straightening the stack (not shown here) has the following elements and features:

A horizontal conveyor 12 for transporting the stacks from one end to the other is integrated into a worktop 11 of the device 10.

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entry area 13, a straightening area 14 and an exit area 15. The horizontal conveyor 12 extends essentially parallel to the upwardly facing work surface 111 of the work plate Ii and consists of two individual conveyors 121 and 122 arranged parallel to one another. The support surface 123 of the ho
ri^ontal conveyor 12 is arranged just above the working surface 111, so that the horizontal
The lifting platform 12 is not ground onto the work plan 11 during transport over the entry area 13 into the field of view 14 of the device 10.

In the exit area 15 of the horizontal conveyor 12 of the device 10, a stack stop 16 is arranged that extends transversely to the conveying direction of the stack S and can be moved into the stack conveying area. The stack stop 16 is pivotally mounted on a rotation axis that is parallel to the conveying direction of the horizontal conveyor 12 and is connected to a drive means 17 via a pivot arm 18. The stack stop 16 can thus be easily pivoted into the stack conveying area by the drive means 17.

Two stop plates 19 and 20 are provided on the side of the straightening area 14 of the stack, both of which are designed as vibrator plates. Each stop plate 19 and 20 for the stack has a vibrator drive 21 and 22. The stop plates 19 and 20 are each designed to be pivotable about a vertical axis and are connected to a pivot drive 23 or 24 via a rotary arm 25 or 26 and a parallel guide 27 or 28, in

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In relation to the center line of the two individual longitudinal conveyors 121 and 122, the pivotable stop plates 19 and 20 on the work plate ¹¹ are arranged symmetrically.

"■ The stop plates VJ and 20 are pivoted parallel to the side surfaces of the stack S and at the same time together for alignment by this arrangement. After the alignment process, the stop plates 19 and 20 are released from the side surfaces of the stack. In this way, the stack is released for removal from the alignment area 14. Furthermore, the stop plates 19 and 20 can be easily adapted to different stack widths due to their design and arrangement. The stop plates 19 and 20 are simply moved according to the stack size.

A further stop plate 29 is provided in the entry area 13 of the stack. This is also designed as a vibrator plate with a vibrator drive 30, a rotary arm 31 and a further drive means 32 corresponding to the stack stop 16. The stop plate 29 is mounted so that it can rotate about an axis that is essentially parallel to the conveying direction and can thus be pivoted into the stack conveying area, corresponding to the stack stop 16. A rail 33 that is parallel to the conveying direction and assigned to the further drive means 32 enables a locking displacement of the arrangement consisting of the further drive means 32, the rotary arm 31, the vibrator drive 30 and the stop plate 29. In order not to restrict the range of rotation of the pivotable, adjacently arranged lateral stop plate 20, the

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Rail 33 is inserted into the worktop 11 so that it is flush with the work surface 111.

On the one hand, the ability to move the stop plate 29 in the conveying direction means that it can be optimally positioned for the stack straightening process according to the dimensions of the stack to be straightened. Furthermore, this additional stop plate 29, designed as a vibrator plate, improves the straightening quality of the stack. This is particularly true because the vibrating stop plates 19, 20 and 29 on the stack from three sides and the stack stop 16, by countering the forces occurring during alignment, generate strong vibration movements of the films forming the stack and thus ensure that the stack is straightened effectively.

In the straightening area 14, below the support surface 123 of the horizontal conveyor 12, between the individual longitudinal conveyors 121 and 122, a lifting device acting vertically upwards is provided, consisting of a pneumatic lifting drive 34 and a lifting plate 35. The lifting plate 35 is not quite as wide as the two individual conveyors 121 and 122, so that the lifting plate 35 can be moved unhindered between the individual longitudinal conveyors 121 and 122 in the vertical direction.

In front of the side of the lifting plate 35 closest to the stack stop 16, a recess forming an access area 36 is provided in the conveying direction, which is laterally delimited by the individual conveyors 121 and 122 of the horizontal conveyor 12, for the gripper having tines 37.

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The access area 36 corresponds in its extent

The distance in the conveying direction between the stack stop 16 and the lifting plate 35 is at least the length of the tines 37 of the gripper. The tines are shown here in dashed ^lines and the recess forming the access area 36 extends from the lifting plate 35 in the conveying direction to the edge area of the work plate 11. This allows the gripper to be guided into the access area 36 after the stack stop 16 has been swung away and to grasp the stack.

A guide rail 3Θ extending vertically upwards from the worktop 11 is arranged to the side of the entry area 13 on the worktop 11 f. On this is:

A press plate 40 is mounted so as to be movable in the vertical direction via a lever arm 41 via a further drive means 39. The press plate 40 is assigned to the vertical movement axis of the lifting plate 35, whereby the further drive means 39 and the lifting drive 34 are designed to be movable upwards in coordinated movements, holding the stack.

The device 10 is characterized by the different possibilities for transporting the aligned stack from the alignment area 14. Therefore, with regard to the subsequent machines, palletizing machines or corresponding devices, the device 10 has an adaptability of the process heights or access areas required by these different devices and thus a high degree of flexibility.

/13

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When aligning the stack, it is first moved by the horizontal conveyor 12 over the entry area 13 into the alignment area 14 until the stack touches the stack stop 16. The horizontal conveyor 12 is switched off by a sensor provided there, not shown here. The side stop plates 19 and 20 and the further stop plate 29 are swung towards the stack. By vibrating the stop plates 19, 20 and 29, the counterholding of the stack stop 16 and the pressure from the press plate 40, which has meanwhile been lowered onto the stack from above, the stack is aligned and pressed together into a stable state. By subsequently swung away the side stop plates 19 and 20, the stack is prepared for further movement.

tions free at the sides.

The stack is now transported further in different processes that are optimized according to its further use.

Firstly, the stack stop 16 and the further stop plate 29 fold back. The pressing plate 40 is moved upwards so that the stack is transported further in the conveying direction by the horizontal conveyor 12 and/or is grasped at its end by the gripper for further transport. The conveying height of the stack 14 moving on the horizontal conveyor 12 is sufficient for the further process. Height compensation is not necessary in this case.

In another method, the stack is removed directly from the

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The gripper removes the stack from the straightening area 14 by releasing the pressing plate 40. The additional stop plate 29 is provided in this case as a stack stop for the forces acting against the conveying direction of the horizontal conveyor during the gripping process. During the gripping process, the gripper is guided into the recess in front of the lifting plate 35 forming the access area 36, so that the gripper can grasp the stack and move it forward.

The stack can also be gripped by the gripper above the straightening area 14 if height compensation is beneficial for further handling. The stack is moved vertically beyond the straightening area 14 in a coordinated movement of the lifting plate 35 and the pressing plate 40. The gripper now moves against the conveying direction towards the stack until the stack hits a stop device on the gripper. The tines 37 are arranged completely under or above the stack during the gripping process and grip it when the pressing plate 40 is released. The stack stop 16 does not need to be moved in this process variant, but the additional stop plate 29 is pivoted out of the conveying area to pick up the next stack. Advantageously, the height compensation required for moving the stack to the following machine or to the following palletizing machine can be achieved in a simple and speed-optimized manner by the lifting movement of the lifting plate 35 and the pressing plate 40.

In a further embodiment of the invention not shown here, in the straightening area 14 in the work

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Air nozzles are provided on the support plate 11 for lifting the stack just above the support surface 123 of the horizontal conveyor 12. In the embodiment shown in the figures, the lifting of the stack is carried out by the lifting plate 35 in order to avoid damaging the bottom film of the stack due to the profiled support surface 123 of the horizontal conveyor 12.

In front of the entry area 13, a separating device (not shown here) is provided for the continuously following stacks, so that the stacks are prevented from running into each other in the straightening area 14 from the outset. The control of the separating device is coupled with the processes of the device 10 and the horizontal conveyor. This advantageously enables the device to be continuously fed with stacks.

The invention is not limited in its implementation to the preferred embodiment given above. Instead, a number of variants are conceivable which make use of the solution presented even in fundamentally different designs.

Claims (14)

ST39.G1 Sheet 16 Claims 1. Device for viewing a stack consisting of several films, the device having the following features: a horizontal conveyor to transport the stacks ^- '
a Sn.tH.tis~, "over a direction into an exit area, a stack stop extending transversely to the conveying direction of the stack, arranged in the discharge area and movable into the stack conveying area,
15 two stop plates arranged to the side of the stack, of which at least one is designed as a vibrator plate, and each with a vibrator drive for a vibrator plate, characterized by a support surface for the stack, a pressure means that can be lowered vertically from above onto the stack, wherein the pressure means and the support surface are guided in a common, preferably vertical, axial direction relative to one another and the pressure or support surface is smaller than the respective stack cover surface, and r ■ · ■« ST39.G1 Sheet 17 having an access area (36) free from at least one side above and below the aligned stack arranged between the pressure means and the support surface for a prong gripper, so that the aligned stack can be grasped unhindered from a direction perpendicular to the axis direction. 2. Device according to claim 1, characterized in that recesses in the support plane of the stack form the access area (36) for the gripper below the stack. 3. Device according to claim 2, characterized in that the recesses in the support plane of the stack extend essentially horizontally against the conveying direction, so that in particular the gripper can grasp the stack in the straightening area (14) against the conveying direction. 4. Device according to one of the preceding claims, characterized in that the pressure means is designed as a press plate (40) that can be guided from above onto the stack located in the straightening area (14). 5. Device according to one of the preceding claims, characterized in that the ST39.G1 Sheet 18 The support surface is designed as part of a lifting plate (35) adapted to the access area below the stack and movable vertically upwards. 6. Device according to claim 5, characterized in that the lifting plate (35) with its lifting drive (34) has a stroke that exceeds the pitch range (14). 7. Device according to one of claims 5 and 6, characterized in that the pressing plate (40) is designed to be movable upwards by the lifting height of the lifting plate (35) by a coordinated movement with the latter. 8. Device according to one of claims 1 to 5, characterized in that the straightening area (14), the exit area (15) and thus the position in which the stack is gripped by the gripper correspond to one another. 9. Device according to one of the preceding claims, characterized in that a further stop plate (29) is arranged on the side of the stack opposite to the stack stop (16) for the straightening process, the further stop plate (29) being designed to be movable into the conveying area. ST39.G1 Sheet 19 10. Device according to claim 9, characterized in that the further stop plate (29) is designed to be pivotable about an axis of rotation extending parallel to the conveying direction. 11. Device according to one of claims 9 and 10, characterized in that the further stop plate (29) is designed as a vibrator plate with a vibrator drive (30), whereby this vibrator drive (30) can move together with the further stop plate (29). 12. Device according to one of the preceding claims, characterized in that the lateral stop plates (19, 20) are pivotally mounted about a vertically directed axis. 13. Device according to one of the preceding claims, characterized in that air nozzles for lifting the stack during straightening are arranged in the straightening area (14) of the support plane of the conveyor. 14. Device according to one of the preceding claims, characterized in that a separating device for the continuously following stacks is provided in front of the exit area (13), so that the stacks are prevented from running into each other in the straightening area (14) /20 ST39.G1 Sheet becomes.