EP2144832A1

EP2144832A1 - Method and device for layered stacking a support

Info

Publication number: EP2144832A1
Application number: EP08717752A
Authority: EP
Inventors: Roland Fritzsche
Original assignee: Dematic GmbH
Current assignee: Dematic GmbH
Priority date: 2007-04-07
Filing date: 2008-03-13
Publication date: 2010-01-20
Also published as: MX2009010829A; DE102007016727B4; US20100178149A1; DE102007016727A1; AU2008235585A1; WO2008122480A1; CA2682537A1

Abstract

Disclosed is an automatic method for layered stacking a support (P), particularly a pallet, with packages (W), especially packages (W) having different sizes, in a predetermined spatial arrangement. Said method comprises the following steps: the order and spatial position of the packages (W) on the support (P) are determined with the aid of a computer; the individual packages (W) are hauled in a required order by means of a conveying mechanism (2); handling means (3, 4) receive the packages (W) that are to be loaded from the conveying mechanism (2) and place the respective package (W) in a desired spatial position on the growing stack (S) on the support (P). The disclosed method is characterized in that the packages (W) are hauled by means of at least two independent conveying mechanisms (2A, B), while at least two handling means (3, 4) are provided in order to alternately receive a package (W) from one conveying mechanism (2A, B) and move the package (W). Also disclosed is a corresponding device.

Description

Method and device for multilayer stacking of a carrier

The invention relates to an automatic method for multilayer stacking a carrier, in particular a pallet, with packages of different dimensions, in a predetermined spatial arrangement, and a corresponding device.

The automatic stacking of a carrier, in particular a pallet or a trolley, with packages for forming a stack, so the palletizing is known per se. In this case, however, packages of uniform size or extent by robots, grippers, etc. are stored on mathematically determined places.

In the process of automatically loading a load carrier with packages of different dimensions to form a stack, on the other hand, it is the so-called automatic mixed-case palletizing.

Different aspects have to be taken into account here, which enormously increase the complexity compared to "simple" stacking, so that a subsequent package can only be stacked or deposited well on a previous package if it has a flat or even surface, which moreover is approximately horizontal should be aligned, and if the package can carry the weight of the deposited on him further packages without damage.

Furthermore, the stack formed should have a certain stability, u. a. so that it does not fall over during transport. A wrapping with foil helps, but can not alone stabilize a faulty stack.

In addition, on the customer side, optimization of the stacks due to the desired unloading order is increasingly desired.

The stacking of different packages or goods of different size or extent is therefore usually still by hand, since the requirements for the stability of the stack, the packing density within the stack and the order of loading and the associated discharge sequence and not least the stackability of the goods are extremely high and not even partially of the known methods and devices are met.

From EP 1 462 394 B1 is z. B. a device for automatically loading a load carrier with a loading stack forming packing units, ie a device for palletizing known. In the device, the packing units are supplied on trays in stock and stored by them on a packing table. There, the packing unit is moved on the table by a pusher along the broad side of the pallet to be loaded, until the loading coordinates in the X direction are reached. Subsequently, another pusher and a loading tongue pushes the packing unit in the direction of the loading depth over the pallet until the loading coordinates in the Z direction are reached. The loading tongue then retracts, stopping the pusher and acting as a scraper, so that the pack unit is deposited "freely falling" on the pallet at the desired position, whereby the stack forming is supported by a loading aid on the remaining three sides. So it is stacked "against the wall".

The pallet or a trolley are only accessible from one side. In addition, the pallet must be adjusted in height after each loading process for loading the next free space if the pallet is loaded in the so-called "mixed-case" method, ie with different packing units The constructive design of the device long waiting times for the change of pallets or trolleys.This again lowers the overall achievable performance and the throughput per hour.

From DE 43 38 801 A1 a method for stacking piece goods of different size and / or quality is known, which are supplied in any desired, changing order, the size and / or the quality of the piece goods registered and these each with known size and / or quality at a certain location within the access area of a stacking handling mechanism for gripping, thereafter being detected by the handling mechanism in a sequence controlled in dependence on the availability of the parcels in or for the access area of the handling mechanism and the instantaneous state of the stack to be formed to be dropped off at a certain point in the stack. The piece goods become before the access area after Size and / or quality are distributed separately over several buffers, from which they are selectively taken according to the current state of the stack and the availability in the buffers.

DE 41 14 215 A1 describes a device for loading pallets with cuboid objects, by a palletizer with movable up and down and pivotable articulated arm, at the end of a suction head or the like is arranged, the cartons are the palletizer on at least one feed conveyor can be fed wherein the palletizer comprises two articulated arms that are independently movable.

From DE 39 06 922 A1 an apparatus for creating a unit of a stack of articles with stacking elements is known to stack a plurality of objects on a surface on a turntable or on the surface thereof. As the articles are stacked on the selected surface, a wrap film or foil is wrapped around the stack at intervals according to the staple or completion of the staple. For this purpose, a device for supplying a wrapping material to the turntable and a cutting device for severing the wrapping material is provided.

In contrast, the object of the present invention is to provide a method and apparatus for automatically stacking a carrier with packages of varying degrees in a predetermined spatial arrangement that flexibly permits high throughput mixed-case stacking.

This object is achieved by the reproduced in claim 1 method and the device specified in claim 15. Advantageous embodiments will become apparent from the dependent claims and the description.

Characterized in that the packages are brought about at least two independent conveyors and that the handling means for mutual package takeover of each one conveyor and displacement are at least twice, each handling means is assigned to a conveyor, it is possible, the stacking of the carrier flexible and with high performance perform. In particular, a wide range of different packages can be stacked continuously. It can therefore be stacked in succession to the carrier in addition to the course, of course, also manageable uniform little demanding packages packages with different dimensions.

As packages come a variety of goods, packaged goods, packaged in groups, such as boxes, boxes, boxes, containers, goods on trays, as well as unpackaged goods of all kinds, etc. in question.

In addition to pallets and trolleys or similar documents for general cargo and their packaging in question come as a carrier.

Conveyor technology refers to conveyors in general, and in particular to roller conveyors, conveyor belts and conveyor systems. These can be fed manually or automatically. The packages are separated and tendered in the correct order for the desired packing sequence on the conveyor. The correct order, etc. is calculated by processing an order. Corresponding software is known.

The packages are therefore delivered separately. For handling the packages can then be taken or handled individually. However, it is also possible to group groups of identical or very similar packaged or unpackaged packages for common handling. This grouping then takes place in the area of taking over the packages from the conveyor by the handling means.

It is particularly advantageous if the handling means can displace the packages in at least two, preferably three, spatial directions during storage on the forming stack on the carrier. This allows a great freedom of positioning of the packages, which is important in order to achieve good space utilization when stacking and to implement the mathematical requirements as accurately as possible. Thus, in particular, such packages can be loaded, are not provided for the known systems. It is also favorable if the packages are aligned before being picked up by the handling means. This allows a standardized takeover of the packages by the handling means. Alternatively or additionally, corresponding optical methods for detecting the orientation of the packages and controlling the handling means may be used.

However, it is also possible to use the handling means even with a corresponding configuration for aligning the packages. This could be done either in a separate step or even in the relocation step from the conveyor to the carrier.

It makes sense if the stack is stabilized on the carrier during and / or after stacking. Thus, the individual layers retain their structure and the stacked carrier can be transported safely. For this purpose, the stack can be stabilized together with the stacked carrier by wrapping with a film, mesh or the like, as is known in the art.

Stabilizing, e.g. Wrapping, can be done either in layers gradually after stacking or after stacking a layer. In this variant, the stabilization may take place within the actual device for stacking, e.g. by layering and wrapping the partially-stacked carrier. This saves time.

Alternatively, then after the end of Bestapelns the stabilization done as a whole, including the stabilization then takes place spatially separated from Bestapeln.

According to the invention, the device for automatic multi-layer stacking of a carrier, in particular a pallet, with packages of varying degrees, characterized in that at least two independent conveyors are provided to procure the packages, and that the handling means for mutual package takeover of each a conveyor and displacement are provided at least twice, wherein each handling means is assigned to a conveyor. It is also particularly preferred here if the handling means are designed to displace the packages in at least two, preferably three, spatial directions during storage on the stack that is being formed on the carrier. For this purpose, the handling means may comprise at least one automatic multi-axis gripping system. Particularly preferred is the use of two multi-axis gripper systems whose working areas overlap. Thus, packages can be alternately removed and stacked by the conveyors or the conveyor. With appropriate control, the carriers can therefore be stacked in parallel at two points.

In particular, multi-axis gripping systems with at least two degrees of freedom of movement are suitable. The multi-axis gripping systems can, for. B. two on a common linear axis in one direction (X) independent of each other Entfahrinheiten with in two other directions (Y and Z) movable package gripping means.

Each of the package gripper means may additionally have at least one rotational degree of freedom of movement, ie be rotatable and also be tiltable in the presence of two axes of rotation.

Particularly suitable handling means are gantry robots or articulated robots, and in particular double gantry robots or double articulated robots. Particularly preferred, as already stated, is the use of two multi-axis gripper systems, so that double portals should be used which have two overlapping work areas.

The handling means may thus comprise automatic multi-axis gripping systems which share a common horizontal displacement path. This allows to easily form overlapping work areas.

The package gripping means may comprise lift forks, combs, grippers, suckers or staple grippers, and combinations of these for gripping the individual packages. In particular, package gripping means are the packages, especially from the bottom supporting and pushing from above, take clamping. This allows a safe rearrangement of the conveyor at high speed, without slipping, shifting or a crash of the packages. Here, the clamping can be done from above via a corresponding movable punch. This can be provided for gentle treatment of the packages with a soft resilient support to the package side. This may be, for example, a foam pad or an air cushion.

The device may additionally comprise a unit for aligning the individual packages. This may include a subunit for horizontal displacement and a subunit for rotation of the individual packages.

A further increase in the speed can be achieved if the carriers are fed in and out in such a way that empty carriers can be tracked at the same time, while stacked carriers are removed. Thus, it is conceivable that the stacked carrier is discharged down and to the side, while at the same time a new empty carrier is supplied at a different height. On the other hand, so the possibly heavily loaded carrier can be dissipated more slowly, without affecting the overall speed of the system.

Depending on the packages to be stacked, it may be necessary to protect them or increase the stackability, etc., layers, e.g. cardboard or cardboard, between, below or above the layers. For this purpose, the sheet material can be stored in a suitable manner and / or delivered and placed with provided on the handling means suckers.

Both the carriers (e.g., pallets) and the sheets (boards) may be delivered and provided via a separate conveyor. The acquisition or transfer of the carrier or layers can be done on the one hand with dedicated technology. However, it is also possible to design and control the already without existing handling means so that they carry out the acquisition itself. Thus, pallets could e.g. Stacks are stored in the gripping area of the handling means, so that the top pallet could be taken in the stack of the gripping mittein the handling means and stored on the lifting table. The same applies to the layers.

In one embodiment, it is provided that the carrier during loading with the Packages on four sides of a, in particular provided with a funnel-shaped inlet, the forming stack or respective layer supporting loading aid is surrounded. This allows a particularly safe and accurate loading with great protection of the environment. This type of loading aid is only possible if the packages are moved in at least three spatial directions during storage on the forming stack on the carrier. Viewed in cross-section, the loading aid is adapted to the dimensions of the carrier or of the stack so that it can be stacked "against the wall".

For the formation or stacking of the next layer of a stack, the handling means can be controlled so that they approach the corresponding Z coordinates. For this purpose, the device is then of course to design so that there is enough space for the forming stack.

Alternatively or additionally, the device may be configured with a unit for lowering / raising the carrier. This allows not only the lowering after stacking a layer, if necessary, also a level control when stacking itself. This leads to a significant increase in performance, since longer ways to store the packages are avoided on average or the travel times can be done in the vertical direction during the positioning in the X and Z directions.

To stabilize the carrier, a stabilizing unit may be provided, e.g. a film winding device (see above). This unit can be inserted directly into the device, e.g. Palletizer, to be integrated. This has the advantage that the carrier with formed stack does not have to be moved separately. Thus, e.g. stabilization already takes place after each lowering of a layer or layer. This has the consequence that even with actually unstably stacked carriers a great stability of the stack can be achieved. This also greatly expands the possibilities of stacking the goods and the selectable order.

Of course, as an alternative to the film winding technique, all other known possibilities of stabilization can be used. These include, for example, shrinking films, nets and other elastic materials, as well as Velcro and adhesive bonds, etc. When stacking carriers, the order of the packages, their two- and three-dimensional arrangement and their determination plays an important role. In principle, optimal stacking is only possible if the placement of the stack is known in advance exactly. There are big problems when this needs to be deviated from, such as short-term changes (just in time) of customer orders, etc. Thus, for example, a particularly heavy package can not be placed or stacked on fragile packages. This problem can be alleviated within the scope of the present system if buffer locations for packages are provided in the operating area of the handling means. This makes it possible to temporarily store packages, if the actually desired and predetermined order of stacking can not be met. It can also be relocated to a limited extent, without the packages would have to be completely transported away spatially, or that must be converted to manual operation.

Further advantages, features and features of the invention will become apparent from the following description of an embodiment with reference to the drawing, in which

Fig. 1 shows a schematic plan view from above of an apparatus for automatic multi-layer stacking of pallets shows and

2 shows a schematic side view on a section along the line A-A through the device from FIG. 1.

In FIGS. 1 and 2, a device designated as a whole by 1 for the automatic multi-layer stacking of pallets P2 with packages W of different dimensions is shown in a predetermined spatial arrangement. It is therefore a device for "mixed-case" palletizing.Of course, with the device 1, only similar packages W can be palletized.

The device 1 comprises two independent conveyors 2A, B for feeding the packages or goods W separated in the required order. These are any conveyors. Preferably, as in the case shown, belt conveyors are used, which pass into the roller conveyor in the roller conveyor. The conveyor 2 are arranged opposite the ground at an elevated level and spaced from each other.

The device 1 further comprises two handling means 3, 4, which take over the respective currently to be loaded packing unit W from the respective conveyor 2A, B and alternately place at the desired spatial position on the forming stack S on each in-service pallet P2.

The handling means 3, 4 are automatic multi-axis gripping systems which have at least three degrees of freedom of movement. These have two on a common horizontal displacement section 5 in a direction X independent traversing units 6, 7 with movable in two other directions Y and Z package gripping means 8, 9, each additionally having a rotational degree of freedom of movement. The package gripping means 8, 9 can thus move the respective product W in three spatial directions X, Y, Z and rotate at the same time. Thus, the goods W can also be aligned by the handling means 3, 4 when moving.

They each include both a gripper 10, 1 1, which is designed to grip the packages from the top pushing and supporting from below by clamping. The grippers 10, 1 1 include a lower fork, which is moved in a known manner below the goods W between the rollers of the conveyor at the gripping point. In addition, the goods W is clamped by a corresponding movable punch from above against the fork. Thus, the commodity W is securely fixed in the gripper 10, 1 1 when moving at high speed.

The handling means are executed in the example shown as a gantry robot R, whose structure 12 is designed so that the conveyor 2A, B respectively enter at one end face 12A in its built-in area and end there. Thus, the delivered goods W can each be taken from the associated handling means 3 and 4 and alternately stored on the pallet P2 and the stack S forming thereon.

The empty pallets P1 are conveyed by a pallet supplier 13, which is arranged between the conveyors 2A, B and approximately parallel to them. Indeed With regard to the height, it is slightly below the level of the conveyors 2A, B, which brings advantages in the subsequent stacking (see below). The pallet supplier 13 leads to a Palettenhubtisch 14, which allows a level control when loading the pallet P2 with the packages.

The ready-stacked pallet P3 is removed by a pallet conveyor 15 which is aligned with the pallet supplier 13 and exits from the area of the gantry robot R on the opposite end face 12B, but is arranged at a lower level than the pallet supplier 13, so that the pallet P2 can be lowered when stacking and, after the end of the stacking process, reaches the level of the pallet conveyor 15 almost automatically.

Thus, at the same time, a new empty pallet P1 can be tracked at the top, while at the bottom the finished stacked pallet P3 is removed. In the optimal case, the difference in height of the pallet conveyor 15 and the pallet supplier 13 corresponds to the height of the stack formed, so that the lifting table 14 does not have to carry out a separate movement for delivering the pallet to the pallet conveyor 15.

Therefore, the pallet change can be done almost continuously without the need for time-consuming additional rearrangements, etc.

The illustrated variant further comprises a film winding unit 16, which is integrated into the device. This is annularly arranged around the lifting table 14, on which the stacking of the pallet P2 takes place. The film winding unit 16 corresponds in structure to known spatially separated film winding devices.

After stacking the pallet P2 with a layer of goods W, the pallet P2 is lowered by the average height of the layer via the lifting table 14. Thus, the layer enters the region of the film winding unit 16 and can be wrapped there in layers for stabilization.

Therefore, the finished stacked pallet is already completely wrapped and does not need to be moved to a spatially separated winding station. At the same time, the integration of the film winding unit 16 allows the permanent stabilization of the forming Stacking, which opens the possibility of automatic stacking of a wider range of goods.

Hereinafter, the method of stacking using the apparatus described above will be described.

First, the list of goods or packages is compiled due to the respective order and determined based on their known size, weight, etc. computer-aided the order and spatial position of the packages in the stack S on the pallet P.

Then the goods from the warehouse etc. are separated in the required order u. a. conveyed by the conveyors 2A, B, the goods being delivered to the two conveyors 2A, B distributed.

In parallel, an empty pallet P1 is placed on the lift table 14 via the pallet supplier 13.

Then, the handling means 3, 4 take over alternately the goods W from the respective conveyor 2A, B. Conveyor 2A operates the handling means 3 and accordingly the handling means 4 are supplied with goods from the conveyor 2B.

The respectively to be loaded package or goods W is stored by the appropriate handling means 3 or 4 at the desired spatial position on the forming stack on the carrier, to which the packages are usually shifted in at least three spatial directions and at the same time - as necessary - rotated.

For the stacking of the first layer, it is possible to arrange the pallet so that only a displacement of the packages in the horizontal, ie in the X and Y direction is necessary.

After stacking the first layer, the pallet is lowered over the lifting table 14 by the average height of the surfaces of the packages, so that the occupancy of the next layer on average with optimized paths when stacking done can.

At the same time, the wrapping unit, if present, can wrap the layer below the palletizing level for stabilization. Alternatively, the wrapping is done completely after the stacking.

In parallel, the stacking of the next layer is started. Subsequently, the process described is repeated until the desired stack is completed.

Now the stacked pallet is in the best case at the level of the discharge conveyor 15 and is transferred from the lifting table 14 on this and transported away.

At the same time, a new empty pallet is delivered above the pallet supplier and held by suitable forks until the lift table has been raised from below for support and installation.

LIST OF REFERENCE NUMBERS

1 device

2 conveyors

3, 4 handling means

5 horizontal displacement section

6, 7 traversing units

8.9 package gripping means

10, 1 1 gripper

12 construction

12A, B front side

13 pallet suppliers

14 lift table

15 pallet conveyor

16 film winding unit

P1, 2, 3 pallets

R portal robot

S stack

W package

Claims

New claims

An automatic method for stacking a carrier (P), in particular a pallet, with packages (W) of different dimensions, in a predetermined spatial arrangement, comprising the steps:

computer-aided determination of the order and spatial position of the packages (W) on the carrier (P);

Finding the isolated packages (W) in a required order by means of conveyor (2);

Taking over the packages (W) to be loaded from the conveyors (2) by handling means (3, 4) which place the respective package (W) at a desired spatial position on the forming stack (S) on the carrier (P);

characterized in that the packages (W) are brought about via at least two independent conveyors (2A, B) and that the handling means (3, 4) to the reciprocal package (W) take over each of a conveyor (2A, B) and displacement at least twice are present, each handling means (3, 4) is assigned to a conveyor (2A, B).

2. The method according to claim 1, characterized in that the handling means (3, 4) displace the packages (W) in at least two spatial directions during storage on the forming stack (S) on the carrier (P).

3. The method according to claim 1 or 2, characterized in that the packages (W) before being picked up by the handling means (3, 4) are aligned.

4. The method according to claim 1 or 2, characterized in that the packages (W) by the handling means (3, 4) are aligned.

5. The method according to any one of the preceding claims, characterized in that the carrier (P) is stabilized during and / or after stacking.

6. The method according to claim 5, characterized in that the stacked carrier (P2, 3) is stabilized by wrapping with a film, mesh or the like.

7. The method according to claim 5 or 6, characterized in that the stacked carrier (P2, 3) is stabilized in layers.

8. The method according to any one of claims 5 to 7, characterized in that the stabilization within the actual device (1) takes place for Bestapeln.

9. The method according to any one of claims 5 to 7, characterized in that the stabilization takes place spatially separated from Bestapeln.

10. The method according to any one of the preceding claims, characterized in that the handling means (3, 4), the packages (W), in particular from below supporting and pushing from above, clamping.

1 1. Method according to one of the preceding claims, characterized in that the carrier (P) are supplied and removed in such a way that empty carriers (P1) can be tracked at the same time while stacked carriers (P3) are removed.

12. The method according to any one of the preceding claims, characterized in that layers are optionally inserted between, above and below layers.

13. The method according to any one of the preceding claims, characterized in that the carrier (P2) when loading with the packages (W) on four sides by a, in particular provided with a funnel-shaped inlet, loading aid is surrounded.

14. The method according to any one of the preceding claims, characterized in that the carrier (P2) when loading with the packages (W) undergoes a level control.

15. Device (1) for automatic multi-layer stacking of a carrier (P), in particular a pallet, with packages (W) of different dimensions, in a predetermined spatial arrangement, with at least one conveyor (2) for supplying the packages separated in the required order (W) and at least one handling means (3, 4) containing the take over the package (W) to be loaded from the at least one conveyor (2) and deposit it at a desired spatial position on the forming stack (S) on the carrier (P), characterized in that at least two independent conveyors (2A, B) are provided to bring the packages (W), and that the handling means (3, 4) to the mutual package (W) take over each of a conveyor (2A, B) and displacement at least twice, wherein each handling means (3, 4 ) is assigned to a conveyor (2A, B).

16. The apparatus according to claim 15, characterized in that the handling means (3, 4) are configured to the packages (W) in at least two, preferably three spatial directions (X, Y, Z) in the deposit on the forming stack ( S) on the support (P) to relocate.

17. The device according to claim 16, characterized in that the handling means (3, 4) comprise at least one automatic multi-axis gripper system (6, 8, 10; 7, 9, 1 1).

18. The device according to claim 17, characterized in that the multi-axis gripping systems have at least two degrees of freedom of movement.

19. Device according to claim 18, characterized in that the multi-axis gripping systems (6, 8, 10, 7, 9, 11) comprise two traversing units independent of one another on a common linear axis (5) in one direction (X) Directions (Y and Z) have movable package gripping means (10, 1 1).

20. The apparatus according to claim 19, characterized in that the package gripping means each additionally comprise at least one rotary degree of freedom of movement.

21. Device according to one of claims 15 to 20, characterized in that the handling means (3, 4) as a gantry robot (R) or articulated robot are executed.

22. The apparatus according to claim 21, characterized in that the handling means (3, 4) are designed as a double gantry robot (R) or double articulated robot.

23. Device according to claim 21 or 22, characterized in that the handling means (3, 4) comprise automatic multi-axis gripping systems (6, 8, 10, 7, 9, 11) which share a common horizontal displacement path (5).

24. Device according to one of claims 19 to 23, characterized in that the package gripping means (10, 1 1) lifting forks, combs, grippers, suckers or staple grippers and combinations of which comprise for detecting the individual packages.

25. Device according to one of claims 15 to 24, characterized in that a unit for aligning the individual packages is present.

26. The device according to claim 25, characterized in that the unit for aligning the packages, a subunit for horizontal displacement and a

Subunit for rotating the individual packages comprises.

27. Device according to one of the preceding claims 15 to 26, characterized in that a unit (14) for lowering / lifting of the carrier is present.

28. Device according to one of the preceding claims 15 to 27, characterized in that a unit (16) for stabilizing the stack forming on the carrier is present during stacking.

29. The device according to claim 28, characterized in that it comprises an integrated winding unit (16) which is designed to wrap the carrier in layers for stabilization.

30. Apparatus according to claim 28 or 29, characterized in that one, In particular provided with a funnel-shaped inlet, loading aid is provided, which surrounds the carrier and the stack forming thereon when loading with the packages on four sides.

31. Device according to one of the preceding claims 15 to 30, characterized in that a unit for stabilizing the stack is present on the stacked carrier after stacking.

32. Apparatus according to claim 31, characterized in that a separate winding device for wrapping the stack on the stacked carrier is present.

33. Device according to one of the preceding claims 19 to 32, characterized in that the package gripping means comprise grippers which are adapted to grip the packages, in particular pressing from above and from below, clamping.

34. Device according to one of the preceding claims 15 to 33, characterized in that it comprises a conveyor system (13, 15) for feeding and discharging the carrier (P1, P3) such that at the same time empty carrier (P1) can be tracked, while stacked carriers (P3) are removed.

35. Device according to one of the preceding claims 15 to 34, characterized in that a unit for supplying layers is present.

36. Device according to one of the preceding claims 15 to 35, characterized in that in the operating area of the handling means buffer spaces for packages are available.