EP3521229B1 - Conveyor system and buffering device for a conveyor system and method of operation - Google Patents

Description

The invention relates to a buffer device for stacking flat objects that are supplied via a conveyor system, a conveyor system with at least one such buffer device, and an operating method for such a buffer device.

In the printing industry, several work stations are used in process lines, for example in printing lines, by means of which flat objects can be processed. For example, sheets of paper are printed, coated, cut to size, scored, perforated and/or folded. A printing line with several work stations is, for example, from JP4327996 famous. Printing lines of this type are usually tailored to precisely defined processes that cannot subsequently be changed without changing the structure of the printing lines. All paper sheets often run through the printing line in the same way.

From the US2007120934A1 a system is known which comprises a first and a second printer, from which sheets of paper are fed to a mixing module which has a sheet rotor, by means of which the sheets can be rotated by 90°. In addition, input buffers and output buffers are provided, from which the sheets are removed or into which the sheets are deposited. With this system it is possible to transfer the sheets from a first printing line to a second printing line running perpendicular thereto. The mixing module comprises a plurality of controllable switches and at least one mixing path along which the sheets are brought together and at least one bypass path along which the sheets can be guided from a first work station directly to a second work station.

From the US8998193B2 a conveying device is known which allows sheets fed to a receiving device to be pneumatically coupled to a conveyor belt and fed to any delivery device.

The devices mentioned above allow the work processes in a conveyor system to be made more flexible. Process goods, eg sheets of paper, can be shifted more easily in complex conveyor systems which, for example, have several process lines coupled to one another. While this makes the conveying processes more flexible, it also requires relatively complex conveying devices, such as input buffers, ie delivery devices that remove the sheets from a stack and place them in the Feed in the process line and output buffer, ie stacker devices that take over the sheets from the process line and place them on a stack.

Known output buffers also have the disadvantage that the objects fed to the stack are often subjected to undesired stresses. In particular, objects with low strength can suffer undesirable deformations. An imprint that may have been completely dried can be altered in a disadvantageous manner.

the EP2711318A1 discloses a device which serves to convey sheet material, comprising control means for controlling the conveying process, at least one conveyor belt with air ducts provided therein and at least one pneumatic device which can be connected to the air ducts of the conveyor belt, so that sheets fed in from a receiving device are pneumatically connected the conveyor belt can be coupled and fed to a dispensing device.

the EP2385007A2 discloses a suction and conveying system for sucking and conveying an object, comprising means for generating a negative pressure caused by an air vortex for sucking the object and means for conveying the sucked object. The aspiration and conveyance system can be arranged to face an edge of a stack of items to aspirate and convey items from the stack.

the US2008111297A1 discloses a sheet feeding apparatus used in an image forming apparatus such as a printer, a facsimile machine, a copying machine, and a multifunctional peripheral having corresponding functions.

The present invention is therefore based on the object of creating an improved buffer device which is suitable for stacking flat objects arriving along a conveyor axis, an improved conveyor system with such a buffer device and an improved operating method for this buffer device.

The buffer device provided for stacking flat objects is intended to avoid undesired effects on the flat objects being conveyed, so that, for example, flat objects with low strength can be conveyed without suffering any deformation. The surface of the flat objects should not be changed either.

In addition, conveyor systems according to the invention, which are equipped with at least one such buffer device, should be able to be constructed flexibly and cost-effectively, so that the customer's investments result in maximum benefit.

This object is achieved with a buffer device according to claim 1, a conveyor device according to claim 9 and an operating method according to claim 13. Advantageous configurations of the invention are specified in further claims.

1. a) eine Steuervorrichtung zur Steuerung der Förderprozesse, insbesondere des Stapelprozesses;
2. b) einen Bandförderer mit wenigstens einem von Bandrollen angetriebenen Endlosband, mittels dessen eintreffende flächige Objekte sequenziell in Richtung zur Ablageposition transportierbar sind;
3. c) eine mit dem Bandförderer verbundene Saugvorrichtung, mittels der eintreffende flächige Objekte gegen das wenigstens eine Endlosband saugbar und an dieses ankoppelbar sind;
4. d) eine Blasvorrichtung, mittels der ein gegen die Ablage gerichteter Luftstrom entlang der Seite des wenigstens einen Endlosbandes führbar ist, die den eintreffenden flächigen Objekten zugewandt ist; und
5. e) wenigstens ein Führungselement, entlang dem ein an den Bandförderer angekoppeltes flächiges Objekt entlang einer Führungssachse vorzugsweise bis zu einem Anschlag in die Ablageposition führbar ist.

The buffer device according to the invention is used for taking over and stacking flat objects arriving along a conveying axis, in particular made of paper, cardboard or plastic, in a depositing position on a tray. The buffering device includes

1. a) a control device for controlling the conveying processes, in particular the stacking process;
2. b) a belt conveyor with at least one endless belt driven by belt rollers, by means of which incoming flat objects can be transported sequentially in the direction of the storage position;
3. c) a suction device connected to the belt conveyor, by means of which incoming flat objects can be sucked against the at least one endless belt and can be coupled to it;
4. d) a blowing device, by means of which an air stream directed against the tray can be guided along the side of the at least one endless belt that faces the incoming flat objects; and
5. e) at least one guide element, along which a flat object coupled to the belt conveyor can be guided along a guide axis, preferably up to a stop, into the storage position.

It is provided that the running axis of the at least one endless belt is inclined by an angle of inclination in relation to the conveying axis, so that a transverse force pointing to the guide element acts on the transported flat objects.

By means of the buffer device according to the invention, incoming flat objects can be recorded in a material-friendly manner, precisely guided and placed on a stack. The flat objects are sequentially coupled to the belt conveyor by means of the suction device and supported by the air flow emitted by the blowing device, practically on an air cushion, to the storage position. The decoupling from the belt conveyor can take place before reaching or after reaching the storage position.

The flat objects remain aligned in one plane due to the air flow emitted by the blowing device, so that curvatures and folds are avoided. Since the storage position is further away from the blowing device than the pick-up position at which the flat objects are coupled to the belt conveyor, the flat object in the storage position can gently sink onto the already present stack with flat objects.

Due to the absence of mechanical conveying elements, such as pairs of rollers, the flat objects are treated as gently as possible. Deformation and contamination of the flat objects are avoided. In particular, changes to a coating that may not yet have fully solidified or contamination are avoided.

The flat objects can be conveyed quickly and precisely. The coupling to the at least one endless belt allows the flat Transport objects powerfully and at high speed. In preferred configurations, a plurality of endless belts are provided, between which openings, for example longitudinal slots, preferably running in the conveying device, are provided through which air is sucked. In preferred configurations, the flat objects are therefore coupled to a number of endless belts that ensure reliable transport.

The suction device comprises at least one suction unit and the blowing device comprises at least one blowing unit. The suction unit and the blowing unit are preferably in the form of a fan having an electric motor and a rotor or propeller.

The air flow of the suction device and/or the air flow of the blowing device can preferably be controlled manually or electronically in terms of intensity and/or cross-section and/or can be selectively switched on or off. The air flow of the suction device can preferably be switched on or off by means of a flap which is driven by a flap motor. The coupling of the flat objects to the belt conveyor and/or the decoupling from the belt conveyor can preferably be selectively controlled or influenced by actuating the flap motor. Sliders can also be used to advantage, by means of which the air flow can be changed, d. H. whose cross-section and/or intensity can be controlled and/or switched on or off.

The blowing device preferably has at least one slide, which can be actuated to adapt the width and/or height of the cross section of the air flow to the dimensions and/or the weight of the flat objects.

The pressing force with which the flat objects are pressed against the belt conveyor is preferably set by controlling the suction unit or by controlling an electric motor provided in the suction unit. The intensity of the air flow of the blower device is adjusted by controlling the at least one blower unit or the electric motor. It is also possible to use several suction units or blower units that can be switched on or off individually. A higher intensity of the air streams of the suction device and/or the blowing device is set for flat objects with a higher grammage.

Due to the inclination of the belt conveyor at the end against the guide element, the flat objects are subjected to a required force or transverse force moved against the guide element, such as a side wall or a ruler. The inclination preferably takes place in a plane parallel to the guided flat objects. The angle of inclination, which is preferably set taking into account the dimensions and the weight of the flat objects, is preferably <10° and is, for example, in the range of 3°-6°.

The various parts of the buffer device, in particular the belt conveyor, the suction device, the blowing device and the at least one guide element can be connected to a mounting structure in a fixed, displaceable and/or rotatable manner.

Preferably, the belt conveyor can be rotated by a rotating device connected to the mounting structure in one plane continuously or stepwise in one or more steps in a rotating range relative to the conveying axis, preferably in one and/or the other direction by the selectable angle of inclination -a and/or +a , which is preset or selectable. A servomotor, preferably a stepping motor, is preferably provided, by means of which the desired rotation can be set. By changing the angle of inclination, it is possible to convey flat objects to the stack or back from the stack, with the flat objects always being pushed against the guide element and guided along it if the angle of inclination is selected accordingly.

This measure makes it possible to use the buffer device either as an output buffer or stacker or stacker and as an input buffer or feeder or dispenser. The control device includes a control program, by means of which the buffer device can preferably be operated selectively in one or more operating modes. When operating as an output buffer, planar objects arriving along a conveying axis are deposited on the deposit and when operating as an inbound buffer, planar objects are removed from the deposit or from the stack and delivered along the transport axis.

When operating as an input buffer, the flat objects lying at the top of the stack are fanned out by the air flow emitted by the blowing device and separated from one another at least at the front. The uppermost flat object is coupled to the belt conveyor and carried away by the latter by means of the suction device. The air flow emitted by the blowing device supports the further Coupling to the belt conveyor and complete separation of the coupled flat object from the other objects in the stack.

To ensure the separation of the flat objects, a separating device with a blocking element is preferably provided, which can be displaced in the region of a transfer height in which a flat object to be released is separated from subsequent flat objects. The blocking element can be adjusted manually, e.g. by means of a slider or cable, or electrically by means of a servomotor. For example, the space below the belt conveyor is monitored optically and the blocking element is moved up if necessary.

In preferred configurations, a control circuit is provided, with a sensor coupled to the control device, preferably an optical or mechanical sensor, and a lifting drive coupled to the control device and provided for driving the shelf, which can be controlled by means of the control circuit in such a way that the respective uppermost flat Object of the stack on the shelf, which can be displaced by means of the drive along a displacement axis perpendicular to the belt conveyor, can be regulated to the transfer height monitored by the sensor. The position of the shelf is therefore regulated in such a way that the top edge of the stack is always at the transfer height at which flat objects can be added or removed. If flat objects are added, the stack is preferably lowered step by step. If flat objects are removed, the stack is moved upwards. In this way, it is possible to remove or precisely position flat objects exactly at the placement position and at the transfer height. If necessary, adjustments are made according to the selected operating mode. When operating as an output buffer, the transfer height can be lower.

If a buffer device according to the invention is used as an output buffer or stacker in a conveyor system, an input buffer can be implemented with minimal effort using the technology according to the invention. The conveyor system can therefore be inexpensive with practically uniform technology, i. H. an output buffer and an equivalent input buffer.

This is achieved in a particularly simple manner in that the buffer device according to the invention can be switched over to different operating modes, which can be selected and implemented using the control device. By means of the control device, the buffer device according to the invention can be converted from an input buffer to an output buffer and back by changing the operating mode.

The buffer device according to the invention can also be constructed either only as an input buffer and/or only as an output buffer with only minimal changes. In both configurations, the buffer device has device features or device elements that are configured identically, with the same function or as mirror images. Due to the use of largely identical device parts, these can be procured, stored and assembled with greatly reduced effort. If buffer devices according to the invention are integrated into a conveyor system as a mirror image as an input buffer and as an output buffer, e.g. to ensure accessibility of the operating means on only one side of a process line, then again almost all parts of the device can be used identically. In this case, it is preferably provided that mechanical parts are designed symmetrically and are inserted in the input buffer or output buffer in the appropriate orientation.

The buffer device according to the invention therefore has the advantage that input buffers and output buffers for conveyor systems can be made available with little or no material expenditure. Conveyor systems with one or more process lines can therefore be implemented with significantly reduced effort. This has the additional advantage that the buffer device handles the flat objects optimally in its function as an input buffer or as an output buffer.

In addition to the reduction in the production costs of the buffer devices in the bimodal configuration with optional operation as an input buffer or output buffer, the result is increased flexibility of the conveyor system. Buffer devices according to the invention can not only be used optionally, but extended processes can also be carried out. Flat objects can be moved back and forth via process lines and, for example, processed several times. Due to the flexibility of the buffer devices according to the invention, the number of devices can normally also be reduced. For example, with six bimodal buffer devices, a process line can be implemented in a conveyor system, which has, for example, one input buffer and five output buffers or five input buffers and one output buffer. On the other hand, if only unimodal buffer devices were used, five input buffers and five output buffers and thus a total of ten unimodal buffers would have to be used Buffer devices are available to realize the same configurations of the conveyor system.

Fig. 1

eine erfindungsgemässe Puffervorrichtung 10 in einer bevorzugten bimodalen Ausgestaltung mit einer Steuervorrichtung 8 zur Umschaltung zwischen einer ersten Betriebsart als Ausgangspuffer, in der entlang einer Förderachse ×10 eintreffende flächige Objekte 71, 72 auf einer Ablage 51 einer Hubvorrichtung 5 abgelegt werden und einer zweiten Betriebsart als Eingangspuffer, in der flächige Objekte 71, 72 vom Stapel 7 entnommen und nach aussen abgegeben werden;

Fig. 2

aus der Puffervorrichtung 10 von Fig. 1 extrahiertes Teilsystem mit einem Bandförderer 1, einem damit gekoppelte Saugvorrichtung 2, einer Blasvorrichtung 3 sowie zwei separat gezeigten Schiebern 33, 42;

Fig. 3a

von der Seite, das aus der Puffervorrichtung 10 von Fig. 1 extrahierte Teilsystem von Fig. 2 mit der aktivierten Blasvorrichtung 3, mittels der ein Luftstrom gegen die Oberkante eines auf der Ablage 51 vorgesehenen Stapels 7 von flächigen Objekten 71, 72 geführt wird, um beim Betrieb als Ausgangspuffer ein Luftkissen für die eintreffenden flächigen Objekte 71 zu bilden und um beim Betrieb als Eingangspuffer die obersten flächigen Objekte 71, 72, 73 voneinander zu trennen;

Fig. 3b

von der Seite, das aus der Puffervorrichtung 10 von Fig. 1 extrahierte Teilsystem von Fig. 3a mit der zusätzlich aktivierten Saugvorrichtung 2, mittels der ein zugeführtes flächiges Objekt 71 vom Bandförderer 1 erfasst und über den Stapel 7 geführt oder ein vereinzeltes flächiges Objekt 71 vom Bandförderer 1 auf der Ablage 51 erfasst und nach aussen abgegeben wird;

Fig. 4

das aus der Puffervorrichtung 10 von Fig. 1 extrahierte Teilsystem von Fig. 2 zusätzlich mit der Ablage 51, auf der, schematisch gezeigt, ein Stapel 7 mit flächigen Objekten 71, 72 angeordnet ist;

Fig. 5a

ein erfindungsgemässes Fördersystem 100 mit zwei weitgehend identischen unimodalen oder bimodalen Puffervorrichtungen 10, 10', von denen eine als Eingangspuffer und die andere als Ausgangspuffer betrieben wird;

Fig. 5b

das eine Prozessstrasse 1000 einschliessende Fördersystem 100 von Fig. 5a in räumlicher Darstellung; und

Fig. 6

ein Fördersystem 100 mit zwei spiegelbildlich zueinander ausgebildeten unimodalen oder bimodalen Puffervorrichtungen 10, 10', von denen eine als Eingangspuffer und die andere als Ausgangspuffer betrieben wird.

The invention is explained in more detail below with reference to drawings. It shows:

1

a buffer device 10 according to the invention in a preferred bimodal configuration with a control device 8 for switching between a first operating mode as an output buffer, in which planar objects 71, 72 arriving along a conveying axis ×10 are deposited on a tray 51 of a lifting device 5, and a second operating mode as an input buffer , in which flat objects 71, 72 are removed from the stack 7 and released to the outside;

2

from the buffer device 10 of 1 Extracted subsystem with a belt conveyor 1, a suction device 2 coupled thereto, a blowing device 3 and two slides 33, 42 shown separately;

Figure 3a

from the side, which consists of the buffer device 10 of 1 extracted subsystem from 2 with the activated blowing device 3, by means of which an air flow is guided against the upper edge of a stack 7 of flat objects 71, 72 provided on the shelf 51, in order to form an air cushion for the incoming flat objects 71 during operation as an exit buffer and in order to input buffer to separate the top planar objects 71, 72, 73 from each other;

Figure 3b

from the side, which consists of the buffer device 10 of 1 extracted subsystem from Figure 3a with the additionally activated suction device 2, by means of which a supplied flat object 71 is picked up by the belt conveyor 1 and guided over the stack 7 or an isolated flat object 71 is picked up by the belt conveyor 1 on the shelf 51 and released to the outside;

4

that from the buffer device 10 of 1 extracted subsystem from 2 additionally with the shelf 51, on which, shown schematically, a stack 7 with flat objects 71, 72 is arranged;

Figure 5a

a conveyor system 100 according to the invention with two largely identical unimodal or bimodal buffer devices 10, 10', one of which is operated as an input buffer and the other as an output buffer;

Figure 5b

the conveyor system 100 of FIG Figure 5a in spatial representation; and

6

a conveyor system 100 with two mutually mirror-inverted unimodal or bimodal buffer devices 10, 10', one of which is operated as an input buffer and the other as an output buffer.

1 shows a buffer device 10 according to the invention, which serves as an output buffer for the stacking of planar objects 71, 72, . . . A unimodal buffer device 10 is present if the buffer device serves only as an output buffer or stacker.

In the particularly preferred embodiment of 1 However, the buffer device 10 is bimodal, ie can be switched between two operating modes in which it can be used as an output buffer or as an input buffer or dispenser or feeder for delivering stacked flat objects 71, 72, . That is, the buffer device 10 shown can optionally receive flat objects 71, 72 and add them to the stack 7 or remove them from the stack 7 and deliver them.

The working processes of the processing device can be controlled by means of a control device 8 . If available, the different operating modes can also be selected and implemented by the control device 8 . In other words, the control device 8 can switch the buffer device 10 from the “output buffer” operating mode to the “input buffer” operating mode. The control device 8 can be controlled by the user or by a central computer, for example via a touch screen. The control device 8 can be integrated into a wired or wireless network and connected to other devices of the Communicate conveyor system. For this purpose, the control device 8 has an operating program 81, by means of which the buffer device 10 is controlled. It is shown symbolically that the program flow has program sequences for a first and a second operating mode MODE1, MODE2.

Each buffer device 10 comprises a mounting structure 6 which supports the individual device parts. The assembly structure 6 typically has columns, traverses and/or plates, which optionally also serve as the cladding or as a housing for the buffer device 10 . In addition to the control device 8 for controlling the work processes, the buffer device 10 includes a belt conveyor 1 for transporting flat objects 71, 72; a suction device 2 for sucking or coupling the flat objects 71, 72 to the belt conveyor 1 and a blowing device 3 for forming an air flow below the belt conveyor 1, which acts as an air cushion for incoming flat objects 71, 72 or for fanning out or separating the objects on the stack 7 overhead flat objects 71, 72 is used.

If the buffer device 10, as in the embodiment of 1 , is used as an input buffer or feeder, a separating device 4 is preferably provided, by means of which the uppermost flat object 71 can be separated from a subsequent flat object 72 using a blocking element 43 when flat objects 71, 72 are removed from the stack 7.

The belt conveyor 1, the suction device 2, the blowing device 3 and the separation suggestion 4 can preferably be controlled individually. Each of the devices mentioned can be controlled manually or automatically, e.g. by the control device 8 .

In this preferred embodiment, the belt conveyor 1 has four endless belts 12, each held by a pair of rollers or belt rollers 11, by means of which incoming flat objects 71, 72, . . . can be transported sequentially in one direction or the other. The belt rollers 11 are each coupled via a coupling 150 to a belt motor 15, which can preferably be selectively controlled by the control device 8 in order to rotate the endless belts 12 forwards or backwards at a desired speed (see, e.g 6 ).

The conveying axis of the buffer device 10, which normally corresponds to the conveying axis of the conveying system, is indicated with a first arrow ×10. This conveying axis ×10 runs parallel to a guide element 9 which is connected to the mounting structure 6 in the form of a guide plate. The flat objects 71, 72 should always be guided along this guide element 9 so that they can be stacked precisely and also removed again and guided to the outside. For this purpose, the running direction ×1 of the belt conveyor 1 is inclined in a plane parallel to the upper side of the stack 7 and thus parallel to the support 51 by the angle of inclination α with respect to the conveying axis ×10. i.e. the belt conveyor 1 is rotated against the guide element 9 by the angle α. The flat objects 71, 72 are therefore guided precisely along the guide element 9, preferably up to a stop 94.

The angle of inclination α can be fixed or, if the belt conveyor 1 is rotatably mounted by means of a rotary device 19, it can be adjusted manually or by means of a servomotor 190 (see Fig 2 ). Provision is preferably made for the belt conveyor 1 to be rotatable by the angle +/-α in one direction or the other, so that the flat objects 71, 72 are always pushed against the guide element 9 when moving in and out and are guided precisely by it. Preferably, the running speed of the endless belts 12 is optionally adjustable.

The suction device 2 connected to the belt conveyor 1, by means of which incoming flat objects 71, 72 are sucked against the endless belts 12 and coupled to them, is preferably likewise controllable. For example, the air flow can be switched on and off completely and/or its intensity can be controlled in order to couple flat objects 71, 72 to or decouple them from the endless belts 12 with a desired pressing force.

Preferably, the blowing device 3 can also be controlled, so that the width and/or height of the cross-section of the air flow can be adjusted. The adjustment of the width of the air flow makes it possible to support incoming flat objects 71, 72 of a corresponding width or to separate flat objects 71, 72 of a corresponding width lying on the stack 7 from one another. If provided, the adjustment of the height and, if necessary, the radiation angle of the air flow allows an adaptation to the respective conveying process. In preferred configurations, the air flow for supporting incoming flat objects can be upwards are shifted and for the separation of flat objects 71, 72 are shifted downwards on the stack 7. It is normally sufficient if the planar objects 71, 72 can be separated reliably. Adjusting the airflow for the stacking process is less critical. That is, with bimodal buffer devices 10, it is usually sufficient to optimize the airflow for the input buffer mode. The air flow is preferably changed by moving a perforated slider 33 (see 2 ), which can be moved back and forth in a blowing channel 30 by means of a control button 35 in order to open or close wall openings 320 of a channel wall 32 facing the stack 7 .

The blocking element 43 of the separating device 4 can preferably also be adjusted manually or automatically. In the embodiment shown, the blocking element 43 can be moved by means of a separating slide 42, which can be moved by means of a control button 41 (see FIG 2 ), down and up to ensure that only a flat object 71 leaves the buffer device 10.

When loading or unloading flat objects, the height of the stack 7 lying on the shelf 51 changes. So that the conveying processes described, in particular the coupling to the belt conveyor 1, succeed reliably, the upper edge of the stack 7 or the uppermost flat object 71 is controlled by a control loop maintained at a desired transfer height. This position of the uppermost flat object 71 is measured by an optical sensor 56 and reported to the control device 8, which subsequently controls the lifting drive 52 and moves the tray 51 up or down until the specified transfer height is reached. This ensures that the air streams of the suction device 2 and the blowing device 3 always act in the same way on the flat object 71 to be transported and that the depositing process or removal process runs identically in each case. In preferred configurations, this transfer height can be specified as desired.

As described, the guidance of the flat objects 71, 72 is determined by the guide element 9. The end stop 94 ensures that the stacked flat objects 71, 72 are flush at the end. To ensure the safe guidance of the flat objects 71, 72, a guide blade 93 is additionally provided, which is held by a carriage 92, which can be displaced along a traverse 91 and can be selectively fixed by means of a locking element 921.

2 shows a from the buffer device 10 of FIG 1 extracted subsystem, namely the belt conveyor 1, the suction device 2 coupled to it, parts of the blowing device 3 and separately the air slide 33 and the separating slide 42. The air slide 33 and the separating slide 42 have teeth on the left-hand side, into which the associated control button 35 or 41 connected gears 34 or 44 can engage. With the rotation of the control knob 35 or 41, the slides can therefore be moved axially.

The air slide 33 has 3 slide openings 331, 332, 333 of different sizes, which can be displaced relative to the wall openings 320 in the duct wall 32 of the blowing device 3. The first slide opening 331 ensures that the associated wall opening near the belt conveyor 1 is always open. If the air slide 33 is moved further, the adjacent wall opening 320 is opened, and if the air slide 33 is moved further, the last wall opening 320 is opened, so that flat objects 71, 72 of maximum width can be served.

The separating slide 42 has an inclined slot opening 421 in which a cam 431 held by the blocking element 43 is guided. When the separating slide 42 is displaced, the cam 431 moves downwards or upwards with the blocking element 43 which is held in a vertically displaceable manner. By turning the control knob 41, the blocking element 43 can thus be adjusted to the desired height.

The belt conveyor 1 is in 2 shown from below. The front half of cover 16 is cut away. On the right side there is a suction unit 21 which, depending on the position of an air flap actuated by a flap motor 22, draws in air through a suction channel 20 which has longitudinal slots 201 running parallel to it on the underside between the endless belts 12. Air is therefore sucked in below the belt conveyor 1 through the longitudinal slots 201 and carried away via the suction channel 20 . During operation of the suction device 2, flat objects 71, 72 can therefore be sucked in and pulled against the endless belts 12 and conveyed away by them.

Figure 3a shows the subsystem of 2 with the activated blower device 3, by means of which an air flow emitted by a blower unit 31 through the blower channel 30 and further through the slide openings 331, 332, 333 and the wall openings 320, if they are superimposed, outwards against the Upper edge of a stack 7 provided on the tray 51 of flat objects 71, 72 is guided. The blow channel 30 is separated by a vertical section along the conveying axis, so that the view into the interior is clear. The cover 16 of the belt conveyor 1 has also been removed.

When the buffer device 10 is operated as an exit buffer, the air flow from the blower device 3 forms an air cushion for the incoming flat objects 71 . When the buffer device 10 is operated as an input buffer, the flat objects 71, 72, 73 lying on top of the stack 7 are fanned out and at least partially separated from one another. To ensure that there is no collision between an incoming flat object and the flat objects 71, 72, 73 of the stack when buffer device 10 is operated as an output buffer, stack 7 or its upper edge is preferably regulated to a lower transfer height h _T at which the flat objects 71, 72, 73 is avoided.

Figure 3b shows the subsystem of Figure 3a with the additionally activated suction device 2, by means of which a supplied flat object 71 is picked up by the belt conveyor 1 and guided over the stack 7 or an isolated flat object 71 is picked up by the belt conveyor 1 on the shelf 51 and released to the outside. If the buffer device 10 serves as an exit buffer and the coupled flat object 71 is moved over the stack, it is ensured that an air cushion results below the flat object 71 and a flat object 72 of the stack 7 does not get in between. As mentioned, the stack 7 is preferably regulated to a lower transfer height h _T by means of the lifting device 5 in this mode of operation.

If, on the other hand, the buffer device 10 is operated in the input buffer operating mode, a transfer height h _T is selected at which the fanning out of the flat objects 71, 72, 73 on the upper side of the stack 7 is guaranteed.

4 shows the subsystem of 2 additionally with the tray 51 on which a stack 7 with flat objects 71, 72 is shown schematically arranged. The left side of the partial system is along the section line A--A of 1 cut away. It is shown schematically that the air flap 221 driven by the flap motor 22 is provided inside the intake duct 20 . Depending on the position of the air flap 221, the air is either drawn in from the left side through the endless belts 12 of the belt conveyor 1 or from the right side or from the outside through the suction channel 20 to the suction unit 21. In the position of the air flap 221 shown, the air is sucked in from the belt conveyor 1 through the endless belts 12 of the belt conveyor 1 . The air flow or the vacuum is suddenly switched on or off by means of the air flap 221, so that flat objects 71 can be coupled to or decoupled from the endless belts 12 practically without delay. The intensity of the air flow is adjusted by controlling the suction unit 21 or the electric motor provided therein.

4 shows that a flat object 71 is coupled to the belt conveyor 1, while the flat object 72 lying underneath is held back by the blocking element 43. The transported flat objects 71 are monitored by an ultrasonic detector with an ultrasonic transmitter 88 and an ultrasonic receiver 89 . If two flat objects 71, 72 have passed the blocking element 43, this is reported to the control device 8 by the ultrasonic detector.

4 also shows the suction unit 21 and the blower unit 31. Several blower units 31 are preferably provided, by means of which it is ensured that a uniform air flow is emitted over the entire required cross section.

Also shown are parts of the air slide 33 and the separating slide 42, which are guided in a guide plate 36 and can be displaced horizontally, as shown by the hatched arrows.

the Figure 5a , Figure 5b and 6 show schematically conveyor systems 100 with a first buffer device 10' serving as an input buffer and a second buffer device 10 serving as an output buffer. Parts of the buffer device in 10, 10' that are not necessary for the following description or have already been discussed have been removed or cut away.

Figure 5a shows a conveyor system 100 according to the invention with two largely identical unimodal or bimodal buffer devices 10, 10', which are rotated by 180° relative to one another and are separated from one another by interfaces 101, between which any process line can be inserted.

The buffer devices 10, 10' can preferably be operated selectively in the input buffer or output buffer mode. At least one of the buffering devices 10 is configured as a fixed or selectable output buffer. If there are two bimodal buffer devices 10, 10', the flat objects 71, 72 can be transported back and forth in both directions as desired.

The guide element 9, along which the flat objects 71, 72 are guided, is shown schematically with a line for each of the two buffer devices 10, 10'. Due to the inclination of the belt conveyor 1 at the end against the associated guide element 9, the flat objects are pushed against the guide element 9, e.g. a side wall or a ruler, with a force Fa. The inclination preferably takes place in a plane parallel to the guided flat objects 71, 72. It can be seen that the belt conveyors 1 of the two buffer devices 10, 10' are inclined by the angle of inclination α in one direction and the other relative to the conveying axis ×10 or × 10' are rotated so that the flat objects 71, 72 are pressed against the respective guide element 9 with a transverse force Fa or -Fa. Due to the low angle of inclination of preferably less than 10°, the main component of the force which the belt conveyor 1 exerts on the flat objects 71, 72, which is several times larger, acts in the direction of the conveying axis ×10 or ×10′ and ensures powerful conveying . The transverse force Fa or -Fa therefore ensures the precise guidance of the flat objects 71, 72 and can be adjusted accordingly by adjusting the angle of inclination α.

The two buffer devices 10, 10' therefore differ essentially by the inverse operation as an output buffer or input buffer and by the described setting of the angle of inclination α, which can be done in different ways.

Regarding 2 it has been described that the belt conveyor 1 is rotatable by a rotating device 19 connected to the mounting structure 6 and a servomotor 190 . The belt conveyor 1 can also be rotatably mounted by means of a normally vertically aligned shaft and rotated manually against one or the other stop. This stop can preferably be adjusted by an adjusting element. The belt conveyor 1 is fixed in the end stop. For example, the belt conveyor 1 is provided with a magnet on both sides, which can be placed in the corresponding position of the belt conveyor 1 eg on the plate-shaped guide element 9 powerfully adheres. By changing the operating program 81 (see 1 ) and by automatic or manual adjustment of the belt conveyor 1, the buffer device 10, 10' according to the invention can thus easily be converted from an output buffer to an input buffer and vice versa. In this case, the buffer devices 10, 10' can be configured absolutely identically.

Figure 5b 10 shows the conveyor system 100 of FIG Figure 5a in spatial representation. The process lines 1000 can have any process modules A, B, C, D.

6 FIG. 1 shows a conveyor system 100 with two unimodal or bimodal buffer devices 10, 10′ formed as mirror images of one another. Since the guide elements 9 of both buffer devices 10, 10' are now on the same side of the conveying axis ×100 of the guide system 100, the belt conveyors 1 of both buffer devices 10, 10' are rotated by the angle of inclination α in the same direction. It can be seen that the belt conveyors 1 can be constructed with the same parts of the device. If care is taken to ensure that the assembly elements, for example the suction channel 20, are constructed symmetrically, they can be used in both configurations of the buffer devices 10, 10'. It can be provided that assembly openings for the device parts, for example for the suction unit 21 or the flap motor 22 are provided in the unmirrored and the mirrored assembly position. Device parts designed in this way can be used universally.

6 FIG. 12 further shows that the endless belts 12 are driven by a drive motor or belt motor 15, which is preferably actuated by the control device 8. FIG. The belt motor 15 is connected to the drive shaft 111 of the belt rollers 11 by a clutch 150 . The same drive shaft 111 is provided on both sides of the belt conveyor 1, so that the belt motor 15 can be coupled on both sides without additional effort. Since mirrored or non-mirrored use is possible for functionally relevant device parts, this is possible for practically all device parts of the buffer device 10, 10'. If there is a deviation from the symmetry, there is nevertheless a reduced effort for the mirroring. With buffer devices 10, 10' according to the invention, conveyor systems 100 can therefore be implemented at significantly reduced costs. In addition, an advantageous flexibilization of the conveyor systems 100 is possible.

Reference list:

1

belt conveyor

10, 10'

buffer device

100

conveyor system

101

Interface to process units A, B, C, D

1000

process line

11

tape rolls

111

drive shafts

12

endless belts

13

drive shaft

15

belt motor

150

coupling

16

cover

18

assembly part

19

rotating device

190

actuator

2

suction device

20

suction channel

201

Longitudinal slots in the suction channel

21

suction unit

22

flap motor

221

damper

3

blowing device

30

blow channel

31

blowing unit

32

perforated canal wall

320

wall openings

33

air slide

331

first slide opening

332

second slider opening

333

third slider opening

335

gearing

34

gear

35

control knob

36

guide plate

4

separator

41

control knob

42

separator slide

421

inclined slot opening

422

gearing

423

support spring

43

blocking element

431

cam

44

gear

5

lifting device

51

filing

52

lifting drive

55

guide slot

56

Leaf sensor, preferably optical

6

assembly structure

7

stack

71, 72, ...

flat objects

8th

control device

81

control program

85

quick switch

88

ultrasonic transmitter

89

ultrasonic receiver

9

guide element

91

traverse

92

Slide, fixable

921

locking element

93

leadership sword

94

end stop

a

tilt angle

Fa

lateral force

hT

transfer height

×1

Running axis of the belt conveyor 1

×10, ×10'

Conveyor axis of the buffer device 1

Claims (15)

1. Buffering device (10) for stacking flat objects (71, 72, ...) of paper, cardboard or plastic arriving along a conveying axis (×10) in a depositing position on a deposit (51), comprising

   a) a control device (8) for controlling the stacking process;

   b) a belt conveyor (1) with at least one endless belt (12) driven by belt rollers (11), by means of which incoming flat objects (71, 72, ...) can be transported sequentially in the direction of the deposit position;

   c) a suction device (2) connected to the belt conveyor (1), by means of which incoming flat objects (71, 72, ...) can be sucked against the at least one endless belt (12) and coupled thereto;

   d) a blowing device (3), by means of which an air flow directed towards the deposit (51) can be guided along the side of the at least one endless belt (12) facing the arriving flat objects (71, 72, ...) ;
   characterised in that the device further comprises

   e) at least one guide element (9) along which a flat object (71) coupled to the belt conveyor (1) can be guided along a guide axis (×10), preferably up to a stop (94), into the deposit position;

   wherein the running axis (×1) of the at least one endless belt (12) is inclined by an angle of inclination (α) with respect to the conveying axis (×10), so that a transverse force (Fα) pointing towards the guide element (9) acts on the transported flat objects (71, 72, ...).
2. Buffering device (10) according to claim 1, characterised in that a control loop is provided, with a sensor (56) coupled to the control device (8) and a drive (52) coupled to the control device (8) and provided for driving the deposit (51), which is controllable by means of the control loop in such a way that the respective uppermost flat object (71) of the stack (7) on the deposit (51), which is displaceable by means of the drive (52) along a displacement axis perpendicular to the belt conveyor (1), is regulable to a transfer height (h_T) monitored by the sensor (56).
3. Buffering device (10) according to claim 1 or 2, characterised in that the belt conveyor (1), the suction device (2), the blowing device (3) and the at least one guide element (9) are fixedly, displaceably or rotatably connected to a mounting structure (6).
4. Buffering device (10) according to claim 3, characterised in that the belt conveyor (1) is rotatable by a rotating device (19) connected to the mounting structure (6) in a plane continuously or in at least one step in a range of rotation relative to the conveyor axis (×10) in one and/or the other direction by the preferably selectable angle of inclination (-α, +α).
5. Buffering device (10) according to one of the claims 1 - 4, characterised in that the air transfer through the suction device (2) can preferably selectively be switched on by a flap (221) connected to a flap motor (22), so that the flat objects (71, 72, ...) can selectively be coupled to or uncoupled from the belt conveyor (1), wherein the force with which the flat objects (71) are pressed against the at least one endless belt (12) is preferably adjustable by controlling a suction unit (21) of the suction device (2).
6. Buffering device (10) according to one of the claims 1 - 5, characterised in that the cross-section of the air flow of the blowing device (3) is adjustable in width and/or height by means of an adjusting device (32, 33, 35), which preferably comprises at least one slide (33) .
7. Buffering device (10) according to claim 6, characterised in that the control device (8) comprises a control program (81) by means of which the buffering device (10) can be selectively set for operation as an output buffer for the stacking of flat objects (71, 72, ...) arriving along a conveying axis (×10) on the deposit (21) or for operation as an input buffer for the unstacking of flat objects (71, 72, ...) from the deposit (21) and their discharge along the conveying axis (×10).
8. Buffering device (10) according to claim 7, characterised in that a separating device (4) with a blocking element (43) is provided, which is displaceable into the range of the transfer height (h_T) in order to separate a flat object (71) to be dispensed from subsequent flat objects (72, ...) .
9. Conveyor system (100) with at least one buffering device (10) according to one of the claims 1 - 8, which is connected to a process street (1000) comprising at least one process unit (A; B; C; D) and which serves for the deposit of flat objects (71, 72, ...) arriving along a conveying axis (×10) and/or the unstacking of flat objects (71, 72, ...) from the deposit (21) and their discharge along the conveying axis (×10).
10. Conveyor system (100) according to claim 9, characterised in that on the input side of the process street (1000) a first buffering device (10') operated as an output buffer according to one of the claims 1 - 8 is connected and that on the output side of the process street (1000) a second buffering device (10) operated as an input buffer according to one of the claims 1 - 8 is connected.
11. Conveyor system (100) according to claim 9 or 10, characterised in that the mode of operation of the buffer devices (10, 10') connected to the process line (1000) as output buffer or input buffer is selectively configurable.
12. Conveyor system (100) according to claim 10 or 11, characterised in that the first buffering device (10') and the second buffering device (10) as a whole or at least in the extent of the belt conveyor (1), the suction device (2) and the blowing device (3) are designed at least approximately identical or at least approximately mirror-inverted.
13. Method for operating a buffering device (10) for stacking flat objects (71, 72, ...) of paper, cardboard or plastic arriving along a conveying axis (×10) in a depositing position on a deposit (51), comprising

    a) a control device (8) for controlling the stacking process;

    b) a belt conveyor (1) with at least one endless belt (12) driven by belt rollers (11), by means of which incoming flat objects (71, 72, ...) can be transported sequentially in the direction of the deposit position;

    c) a suction device (2) connected to the belt conveyor (1), by means of which incoming flat objects (71, 72, ...) can be sucked against the at least one endless belt (12) and coupled thereto;

    d) a blowing device (3), by means of which an air flow directed towards the deposit (51) can be guided along the side of the at least one endless belt (12) facing the arriving flat objects (71, 72, ...); and

    e) at least one guide element (9) along which a flat object (71) coupled to the belt conveyor (1) can be guided along a guide axis (×10), preferably up to a stop (94), into the deposit position;

    wherein the running axis (×1) of the at least one endless belt (12) is inclined by an angle of inclination (α) with respect to the conveying axis (×10), so that a transverse force (Fα) pointing towards the guide element (9) acts on the transported flat objects (71, 72, ...).
14. Operating method according to claim 13, characterised in that the belt conveyor (1) is rotated by a rotating device (19) connected to the mounting structure (6) in a plane continuously or stepwise, until the predetermined angle of inclination (-α, +α) relative to the conveyor axis (×10) is reached.
15. Operating method according to claim 13 or 14, characterised in that the control device (8) comprises a control program (81) by means of which the buffering device (10) is selectively set, namely for operation as an output buffer for the stacking of flat objects (71, 72, ...) arriving along a conveying axis (×10) on the deposit (21) or for operation as an input buffer for the unstacking of flat objects (71, 72, ...) from the deposit (21) and their discharge along the conveying axis (×10).

Images