Device and method for stacking multiple layers on a base

Abstract

The invention relates to a device for automatically stacking packages on a base in a specified spatial arrangement in order to form a stack, comprising at least one feed conveyor, each of which comprises two independent units (10), each unit consisting of a sliding plate (13) with an associated pusher (14), in order to transport the packages (W) from the positioning base to the specified position in the stack (S) in the Z-direction. Each sliding plate (13) is in the form of a flat strip-shaped plate which is designed to be movable horizontally and along the side of the stacking location (6) and transversely thereto in order to receive the packages (W) at the X-direction position when the packages (W) are pushed off the positioning base by the pusher and in order to deposit the packages on the base (P) or in the stack (S) in the Z-direction, and each unit consisting of a sliding plate (13) and a pusher (14) can be moved in the X-direction and can be moved independently of the respective other unit (10). The invention also relates to a corresponding method.

Description

[0001] Device and method for multi-layer stacking of a base

[0002] The invention relates to a device and a method for automatically stacking packages on a base in a predetermined spatial arrangement to form a stack according to claim 1 or claim 8.

[0003] The automatic stacking of packages onto a base or carrier, especially a pallet or trolley, to form a stack for later shipping, i.e., "palletizing," is well known. However, this involves placing packages of uniform size or dimensions into mathematically determined locations by robots, grippers, etc.

[0004] The process of automatically loading a load carrier with packages of different characteristics to form a stack is known as automatic “mixed-case” palletizing.

[0005] In today's distribution logistics, picking is becoming increasingly demanding. Therefore, it is necessary to develop picking systems that process orders automatically without manual intervention.

[0006] Thousands of different products (or packages) of varying characteristics (size, shape, weight, dimensions, surfaces, strength, etc.) must be automatically picked using such systems.

[0007] Various aspects must be considered here, which significantly increase the complexity compared to "simple" manual stacking of simple, regular geometries. For example, a subsequent package can only be stacked or placed properly on top of a previous package if the previous package has a flat or level surface, which should also be approximately horizontal, and if the package can support the weight of the additional packages placed on top of it without damage.

[0008] Furthermore, the resulting stack should have a certain degree of stability, among other things, to prevent it from tipping over during transport. While wrapping with film helps, it alone cannot stabilize an incorrectly formed stack. Furthermore, buyers are increasingly requesting stack optimization based on the desired unloading sequence.

[0009] The stacking of different packages or goods of different sizes or dimensions is therefore still mostly done by hand, since the requirements regarding the stability of the stack, the packing density within the stack and the sequence of loading as well as the resulting unloading sequence and, last but not least, the stackability of the goods are extremely high and have not yet been met even partially by the known methods and devices.

[0010] EP 1 462 394 B1 discloses a device for automatically loading a load carrier with packing units forming a loading stack, i.e. a palletizing device. In this device, the packing units are stored on trays and fed individually, from where they are placed on a packing table. There, the packing unit, lying on the table, is pushed along the broad side of the pallet to be loaded by a pusher until the loading coordinates in the X direction are reached. Then, another pusher and a loading tongue simultaneously push the packing unit over the pallet in the direction of the loading depth until the loading coordinates in the Z direction are reached. The loading tongue then retracts, with the pusher stopping and acting as a scraper, so that the packing unit is deposited "freely falling" on the pallet at the desired location. The stack being formed is supported on the other three sides by a loading aid.So, it's essentially stacked "against the wall." Moving the parts on the packing table is time-consuming and, due to limited accessibility, has disadvantages when forming the packing patterns. Furthermore, it is imperative that the loading tongue and the stripper / pusher move simultaneously in the Z direction. Furthermore, only one packing unit can be "processed" sequentially at a time.

[0011] A variant of this is known from EP 2 723663 B1, which operates with a pusher battery and a conveyor. EP 2 870 092 B1 uses a movable carriage instead of a conveyor.

[0012] From WO 2010 / 059923 A1 an automatic robot-assisted stacking device is known in which an intermediate plate is used for forming the first layer of a stack and simultaneous pallet change.

[0013] In contrast, the object of the present invention is to provide a method and a device for automatically stacking packages on a carrier in a predetermined spatial arrangement to form a stack, which allows mixed-case stacking with high throughput in a flexible manner.

[0014] This object is achieved by the device recited in claim 1 and the method according to claim 8. Advantageous embodiments emerge from the subclaims and the description.

[0015] According to the invention, it has been recognized that if two independent units each comprising a sliding plate with an associated pusher are provided to transport the packages from the positioning base in the Z direction to the predetermined position in the stack, wherein each sliding plate is designed as a flat, strip-shaped plate movable horizontally and along the side of the stacking location and transversely thereto, in order to take over the packages when the pusher pushes the packages from the positioning base at the X-direction position and to deposit them in the Z-direction on the base or in the stack, and wherein each pusher is designed to push the packages from the positioning base towards the stack and is movable in the Z direction independently of the at least one sliding plate in order to retain the package when the sliding plate is retracted,and each unit consisting of a sliding plate and pusher is movable in the X-direction and is movable independently of the other unit, it is possible to reliably increase the throughput during stacking by parallelizing the placement of two packages simultaneously at different points on the base or stack.

[0016] In other words, two packages are placed in the stack simultaneously, but due to the independence of the two sliding plate pusher units, they are deposited variably at different, pre-calculated locations within the stack. Therefore, the packages do not have to be delivered strictly according to a common deposit location, which further reduces sequencing effort and increases the flexibility of stack calculation. The surface of the sliding plates can also be provided with friction-reducing properties (e.g., a Teflon surface) or even be designed as an air table to facilitate pushing onto the base. It is particularly advisable to arrange the friction-reducing properties near the tip of the sliding plate.

[0017] The device is particularly efficient if the feed conveyor has a grouping device designed to reposition two consecutive packages next to each other on the feed conveyor as a group. This makes it possible to handle this group of two packages at least partially simultaneously, which in turn increases throughput.

[0018] The consecutive packages can be grouped or paired in the grouping device by accumulating. The leading package can be lifted and lowered laterally, or moved sideways on an accumulating conveyor to be positioned and oriented next to the trailing package.

[0019] The grouping device can, for example, have a pusher acting transversely to the conveying direction, which can push each package to any position transversely to the transport direction. The actual X-pair formation takes place at a movable stop (e.g., raisable and lowerable) located downstream, against which both packages run. For a given pair, each package can be positioned to the left or right of the other package, depending on the pre-calculated space or position in the stack. It is also possible to provide a second pusher opposite.

[0020] In order to handle the grouping of two packages at least partially simultaneously, the device can have a control system that is configured to assign one of the sliding plate pusher units to each pre-positioned package in the grouping and to control both units first together until the packages are picked up by the respective sliding plate and then independently of each other for movement. In other words, the packages in the group are first moved synchronously or simultaneously on the positioning base so that no relative movement takes place. Otherwise, an unwanted change in alignment could occur. Only after the packages have been picked up by the respective sliding plate or have left the positioning base are the units moved independently to reach the different deposit points.

[0021] For this purpose, the units are each guided and driven separately from one another. Preferably, the units are suspended on the side of the positioning base facing away from the support on carriages that are movable in the X direction. They are controlled by the controller to assume the required X position to match the pre-positioning. Both the sliding plate and the pusher are then arranged on the respective carriage. These also have independent drives to execute the required functional movements.

[0022] Since the units are guided and driven separately from each other, only a single package can be handled in a package stacking cycle.

[0023] It's also conceivable to use the cooperative handling of larger packages that would be too large for a single unit. Such packages can then be handled, relocated, and stacked jointly by both units.

[0024] The positioning base itself can be a stationary surface, such as a plate, table, etc., that is appropriately dimensioned. The stationary surface can also be provided with friction-reducing properties or even be designed as an air table.

[0025] However, it is also conceivable that it is formed by a belt conveyor or a transfer carriage.

[0026] In the simplest case, the positioner comprises a pusher that can be moved in the X-direction. It then receives the grouped packages from the infeed or infeed conveyor and pushes them to a pre-calculated X-position on the positioning base. For this purpose, the pusher can be suspended from a gantry-like frame above the positioning base. Thus, one package adjacent to the pusher is actively "pushed" by the pusher, while the adjacent package is passively "pushed."

[0027] Before being moved in the X direction by the positioner, the grouped packages from the infeed can first be aligned with a stop arranged in the X direction. This can be arranged as a guide plate opposite the end of the infeed conveyor and aligned with the edge of the positioning base toward the stacking location (base).

[0028] The positioner can also have a stop that is movable in the X-direction for fine positioning of the packages or groupings arranged on the positioning base. The pusher can then push the packages against the stop that was previously positioned. The stop can also be suspended from a gantry-like frame above the positioning base and can possibly share a travel path or rail, as it is moved from the other side.

[0029] To ensure that irregularly shaped packages, particularly those with a narrow base compared to a wider top, can be placed without any gaps or changes in alignment, an independent invention provides for an adjustable hold-down device on at least one pusher. Preferably, both pushers have a hold-down device. This hold-down device is aligned perpendicular to the pusher surface and is height-adjustable so that it rests against the top of the package during movement, preventing the package from "tipping over." For this purpose, the control system can actuate the hold-down device drive accordingly, since the sequence of the packages and their properties are known from the stacking forecast. This tipping would lead to imprecise placement, i.e., a deviation from the calculated position. The hold-down device is what makes some product groups possible to handle automatically in the first place.Generally, this allows tolerances in the pre-calculated stacking plan to be reduced, thus increasing the stack's packing density and stability. Further advantages include the ability to move the package in the X direction with greater dynamism when it is resting on the sliding plate, as it is held in place by a clamp. Accordingly, the Z movement can be stopped more quickly without the package overshooting the target position.

[0030] The hold-down device is thus controlled to press down on the respective package from above, clamping it first against the positioning base and later also against the sliding plate. During the transition from the positioning base to the sliding plate, the hold-down device is adjusted, if necessary, to maintain the contact pressure, possibly sensor-controlled. The hold-down device can be used in a version of the device with a single unit consisting of a sliding plate and pusher, or in a version with two units.

[0031] It is also conceivable to equip the positioner, which includes a pusher that can be moved in the X direction, with a corresponding hold-down device.

[0032] The stopper that is movable in the X-direction can also be equipped with such a hold-down device.

[0033] The packages are placed in the Y-direction in the usual way by raising and lowering the base.

[0034] Servo motors can be used as drives in the device, which are driven specifically via the control system and appropriate sensors.

[0035] The invention also relates to a corresponding method, wherein packages are provided by at least one feed in a predetermined sequence and are transported to the predetermined position in the stack by means of displacement means adjacent to a discharge end of the feed. The displacement means pre-position the packages in the X-direction on a positioning base using a positioner adjacent to the discharge end of the feed conveyor, which is arranged horizontally and lengthwise to one side of the stacking location, and transport them by means of two independent units, each consisting of a sliding plate with an associated pusher, from the positioning base in the Z-direction to the predetermined position in the stack (or base). They are always supported from below, for which purpose each sliding plate is moved horizontally and lengthwise along the side of the stacking location and transversely in order to

[0036] To pick up the positioning pad at the X-direction position and place it in the Z-direction on the pad or in the stack. Each pusher pushes the packages from the positioning pad toward the stack and is moved in the Z-direction independently of at least one sliding plate to hold the package back as the sliding plate is retracted. It is essential that each unit consisting of the sliding plate and pusher is moved in the X-direction independently of the other unit. It goes without saying that in addition to pallets, trolleys, etc., can also be used as a support.

[0037] Further details of the invention will become apparent from the following description of

[0038] Examples of implementation based on the drawing, in which

[0039] Figs. 1 - 5 show schematic plan views of a device for the automatic multi-layer stacking of pallets in different phases at the beginning of the formation of the first layer;

[0040] Fig. 6 - 12 show schematic side views of the sliding plate pusher units from Figure 1 in different phases when placing packages on the stacking area;

[0041] Fig. 13(A)-(D) show schematic side views of the sliding plate pusher units in different phases when placing packages on the stacking area without hold-down devices for comparison;

[0042] Fig. 14 shows a schematic side view of the hold-down device of Figs. 6-12;

[0043] Fig. 15 is a schematic side view of the positioner and stopper from

[0044] Figure 1 shows;

[0045] Fig. 16 is a schematic view of a spreading-compacting unit of the

[0046] Device from Figure 2 shows;

[0047] Fig. 17 shows a schematic view of a separating layer unit of the device of Fig. 3;

[0048] Fig. 18 a schematic view of a removable floor unit of the

[0049] Device from Figure 4 shows and

[0050] Fig. 19(A),(B) shows a schematic side view of the removable floor unit from Figure 18 and Fig. 20(A),(B) shows a schematic side view of an alternative removable floor unit.

[0051] Figures 1 to 6 show a device, designated as a whole by 1, for the automatic multi-layer stacking of pallets P (carriers) with packages W of different dimensions in a predetermined spatial arrangement. This device is therefore a "mixed-case" palletizing device. Of course, the device 1 can also be used to palletize only similar packages W.

[0052] The device 1 comprises a feed conveyor 2 consisting of several conveyors, which provides the separated packages W in a computer-aided predetermined sequence from a warehouse (not shown).

[0053] A grouping device 20 is integrated in the feed conveyor 2, which is designed to reposition two consecutive packages W1, W2 on the feed conveyor 2 next to each other as a group.

[0054] For this purpose, the grouping device 20 has a conveyor zone 22, upstream of which a controlled pusher 21 is arranged, which is movable in the X direction. In addition, a stop 23 that can be raised and lowered in a controlled manner is arranged at the end of the conveyor zone 22. Thus, as indicated by the dashed lines, incoming packages W2 on the conveyor zone 22 can be shifted laterally by the pusher 21 (in the X direction) and thus positioned next to a trailing package W1 at the stop 23 to form a group. Once the group is formed, the stop 23 is lowered (or raised or removed) and the group can be conveyed further to a positioner 4. It is also possible to provide a second pusher opposite (indicated by the dashed lines) to make group formation more flexible.

[0055] At the end of the feed conveyor 2, the positioning device 4, which includes a positioning pusher 4.1, and a fixed stop 8 are arranged. The packages W1, W2, or the group, run against the stop 8 and are then pre-positioned in the X direction, offset by 90 degrees by the positioning pusher 4.1, on the positioning base 5, which is designed as a smooth surface.

[0056] Thus, the packages W are positioned in the X direction to take up this coordinate of the later position in the stack.

[0057] Pre-positioning is performed in such a way that the location on the positioning base 5 is optimally predetermined. This is done based on the pre-calculated storage positions of the packages W1, W2 of the group, so that the movement of the respective units 10 is optimized in terms of distance and / or time.

[0058] In order to maintain precise positioning or to carry it out despite high movement speeds, a stopper 15 is provided as a stop 8, which is movably controlled in the X direction (coming from the other side) to "stop" the respective package or group, i.e., to serve as a stop 8. The drive is via a toothed belt (not shown) that is arranged on a linear axis and into which the stopper 15 is suspended. The positioning pusher 4.1 and the stopper 15 are suspended from a portal 4A, 15A above the sliding plate 13 (see Figure 15).

[0059] The positioner 4 or positioning base 5 is arranged horizontally (at the same level) and along one side of the stacking area 6 for stack formation. Typically, the carrier P (pallet) to be loaded will be located here.

[0060] A corresponding conveyor is provided below stacking area 6 for feeding empty pallets or removing stacked pallets.

[0061] The respective pallet P is taken from the conveyor by a lifting and lowering unit for lifting and lowering the pallet P in the Y direction and moved upwards to stacking location 6. The lifting and lowering unit is also responsible for level adjustment during stacking itself, i.e., if necessary, carries out a lifting or lowering when stacking a package W and also carries out the adjustment of the balance of the layers at the beginning of a new layer.

[0062] From the positioning base 5, the respective package W is pushed laterally into the desired position in the stack into the stacking position 6 onto the intermediate plate or the removable floor (first layer) or onto the pallet P (further layers) in the Z direction.

[0063] For this relocation of the packages W to the predetermined position in the stack S, the device comprises two independent units 10, each consisting of a sliding plate 13 with an associated pusher 14, in order to transport the packages W from the positioning base 5 in the Z direction to the predetermined position in the stack S.

[0064] Each sliding plate 13 is designed as a flat, strip-shaped plate that is movable horizontally and along the side of the stacking station 6 and transversely thereto, in order to pick up the packages W when the packages W are pushed off the positioning base 5 by the pusher 14 at the X-direction position and to deposit them in the Z-direction on the base P or in the stack S. The sliding plates 13 are thus arranged just below the positioning base 5 and moved.

[0065] Each pusher 14 is designed to push the packages W from the positioning base 5 in the direction of the stack S and is movable in the Z direction independently of the at least one sliding plate 13 in order to hold back the package W when the sliding plate 13 is retracted.

[0066] The two units 10 are independently controllable and movable. Each unit 10, consisting of the sliding plate 13 and the pusher 14, is therefore movable in the X direction and independent of the other unit 10.

[0067] The sliding plates 13 take over the package W moved by the respective pusher 14. The pusher and the sliding plate then move together to the desired position and the sliding plate 13 is retracted, while the pusher 14 remains stationary to hold the package W. This positions the package W. The sliding plates 13 taper flat at the front so that positioning can be carried out as precisely as possible.

[0068] The units 10, or sliding plates 13 and pushers 14, are movably mounted on a frame 11 on the side of the positioning base 5 opposite the base or pallet P and are arranged parallel and next to one another. They can each move back and forth like a slide on a linear axis 11A aligned in the Z direction, and the frame can move in the X direction. Each axis is driven by an electric motor and a toothed belt (not shown), which is arranged on the linear axis and into which the slide or sliding plate 13 is suspended. The pushers 14 are arranged horizontally and along the side of the stacking station 6 or the pallet P along the positioning base 5 and are aligned with one another, and are designed to be movable independently of one another. They are arranged on the side of the positioning base 5 opposite the carrier or are located there in the rest position in order to extend to push off packages.

[0069] The pushers 14 are each movable back and forth like a slide on a linear axis aligned in the Z direction. Each axis is driven by an electric motor and a toothed belt (not shown) that is arranged on the linear axis and into which the slide or pushers 14 are suspended.

[0070] In order to handle the group of two packages W1, W2 partially simultaneously, the device has a controller 100 which is set up to assign one of the sliding plate pusher units 10 to each pre-positioned package W1, W2 of the group and to control both units 10 first together until the packages W1, W2 are taken over by the respective sliding plate 13 and then independently of each other for movement.

[0071] The packages W1, W2 of the group are therefore first moved synchronously or simultaneously on the positioning base 5 (see Figures 2 and 3), first by the positioning pusher 4.1 and stopper 15, then by the units 10, so that there is no relative movement of the packages to each other.

[0072] Only after being taken over by the respective sliding plate 13 or leaving the positioning base 5 are the units 10 moved independently in order to approach the different storage locations on the pallet P (see Figure 5).

[0073] For this purpose, the units 10 are each guided and driven separately from one another. Preferably, the units are suspended on the side of the positioning base 5 facing away from the support on carriages that are movably driven in the X direction and are controlled by the controller 100 to assume the required X position to match the pre-positioning. Both the sliding plate 13 and the pusher 14 are then arranged as a unit on the respective carriage. These also have the independent drives to execute the required functional movements.

[0074] Since the units 10 are each guided and driven separately from one another, only a single package W can be handled in a package stacking cycle, if necessary.

[0075] Both the positioning pusher 4.1, the stopper 15 and the pushers 14 extend from the respective suspension at a height just above the surface of the positioning base 5 and have an enlarged foot at that end in order to handle the packages W better and more safely.

[0076] Depending on requirements, the pallet P is lowered or raised in the Y direction by the corresponding unit.

[0077] Below the stacking station 6, a unit is provided for wrapping the formed stack S with a film.

[0078] Once the entire stack S is completed, the stack S is moved down on the pallet P, wrapped and transported away via the conveyor.

[0079] At the same time, a new empty pallet P is “loaded”.

[0080] Overall, for the automatic stacking of packages W on a pallet P in a predetermined spatial arrangement to form a stack S, the sequence and spatial position of the packages W on the pallet P to create a stack S is determined computer-aided based on the underlying order. Two packages W1, W2 are first grouped and handled together on the positioning base, and only then are they placed or deposited independently on the pallet P.

[0081] As shown in Figures 6 to 13, in order to position irregularly shaped packages W3, particularly those with a narrow base compared to the wider top, without spacing or changing the orientation, an adjustable hold-down device 16 is provided on at least one pusher 14. This hold-down device 16 is aligned perpendicular to the pusher surface 14A and is height-adjustable in order to rest against the top side W3a of the package W3 during movement, so that the package W3 cannot "tip over."

[0082] For this purpose, the controller 100 controls the drive of the hold-down device 16 accordingly, since the sequence of the packages W and their properties are known from the stack prediction.

[0083] This tilting would lead to imprecise placement, as can be seen in Figure 13 in comparison without the hold-down device, i.e. to a deviation D (distance) from the actually calculated position in the stack or on the pallet.

[0084] The hold-down device 16 is thus controlled to press down on the respective package W3 from above (Figure 7), thus clamping it first against the positioning base 5 and later also against the sliding plate 13. During the transition from the positioning base 5 to the sliding plate 13, the hold-down device 16 is adjusted, if necessary, to maintain the contact pressure, possibly sensor-controlled (see Figures 8 and 9 as well as 10).

[0085] The sliding plate 13 can then be retracted (Figure 12) and the package W3 can be positioned exactly.

[0086] Figure 13 shows the placement of package W3* without a hold-down device in (B) - (D) compared to the placement of package W3 with a hold-down device (A) (corresponds to Figure 12). It can be seen that the tilting leads to an incorrect placement by the distance D from the actually calculated position in the Z direction.

[0087] Figure 14 shows the hold-down device 16 on a pusher 14 in greater detail. The pusher 14 contains a mechatronic assembly that provides the hold-down device 16, which can be moved linearly in the vertical direction along the pusher surface 14A. The linear movement is generated by a linear drive 17, which in this case is an electrically driven spindle drive. A toothed belt drive, a rack and pinion drive, a pneumatic linear cylinder, or other drive would also be conceivable.

[0088] All necessary cables and hoses 19 are routed along a sliding arm 18 and terminate at a central location within the device. The sliding arm 18 holds the actual pusher 14 or pusher surface 14A on the positioning support side and is supported on the frame 11, which forms the linear axis 11A.

[0089] The overall dynamics of the displacement movement of the package W can be adapted or increased to the increased frictional force between the package and the positioning base 5 on which it is moved over the pallet P.

[0090] By integrating the device into the existing Pusher 14, no additional linear guides or booms are required.

[0091] The extent to which the pusher 14 or its sliding arm 18 extends beyond the positioning base 5 causes the sliding arm 18 to deflect. This deflection is exponential to the extension length or the length of the sliding arm. This periodically occurring deflection causes the arm to oscillate and vibrate, which reduces accuracy and performance.

[0092] To compensate for the deflection of the sliding arm 18, a tensioning element 12 is provided, which is guided through the sliding arm 18 above the neutral axis A. In this case, a tension rod is used. A rope or chain, etc., would also be conceivable.

[0093] The tension rod 12 is clamped between the rear end 18A of the sliding arm 18 and the pusher-side end 18B of the sliding arm 18, thereby generating a bending moment that counteracts the bending moment of gravity generated by the sliding arm 18 and the load consisting of the pusher surface and the hold-down device 16 attached to its end.

[0094] Since the counteracting bending moment can be adjusted by varying the tensile force at the rear end, it is possible to compensate for different lengths of the sliding arm 18 as well as different weights of the masses mounted at the other end of the sliding arm 18 (pusher 14 or hold-down device 16).

[0095] In the schematic side view of Figure 15 it can be seen that both the

[0096] The positioning pusher 4.1 and the stopper 15 are each suspended on a portal 4A, 15A above the positioning base 5 and feed conveyor 2, respectively.

[0097] They can also both be positioned via controlled movable carriages 4C, 15C on linear guides 4B, 15B, which are attached to the respective portal 4A, 15A.

[0098] On each carriage 4C, 15C, a downwardly extending support arm 4D, 15D is arranged, at the lower end of which a pusher plate 4E or stopper plate 15E is arranged, which carries out the actual interaction with the package W.

[0099] As shown in Figure 15, both the pusher plate 4E and the stopper plate 15E are designed to be height-adjustable so that they can be moved downwards to interact with a package W and upwards to release it.

[0100] The release in the upper position allows the units 10 or the pusher 14 to be arranged so high that there is no interaction with a package and also no interaction with the push arm 18 or pusher 14.

[0101] It is thus possible to reposition the positioning pusher 4.1 or the stopper 15 earlier for the subsequent packages W without being obstructed by the units 10 or the pushers 14 or the push arm 18, before the depositing process of the current package W is completed and the pusher 14 is retracted.

[0102] This means, for example, that the second unit can already begin handling a new package while the other unit is still in the process of storing it.

[0103] This allows the units 10 to be controlled simultaneously and independently of one another, thus increasing the throughput of the device by simultaneously and independently handling packages W.

[0104] If the device is designed to stack trolleys, the stacking process is essentially the same as for pallets. However, it is usually necessary to spread or push apart the side walls of the trolleys, as these tend to shift inward and thus interfere with stacking.

[0105] In addition, during stacking, it may be necessary to increase the density of the packages W in a stacking level. For this purpose, the packages W are compacted by pushing them together from the sides. This also requires the packages to be straightened relative to each other, which leads to a correction of the outer contour of the respective layer.

[0106] Therefore, as shown in Figure 16 and indicated in Figure 2, the device 1 comprises a spreading-compacting unit 30. This spreading-compacting unit 30 combines both the spreading functionality required for trolleys and the compacting functionality in a single common unit.

[0107] For this purpose, the spreading-compacting unit 30 has two plates 31A, B, which are arranged parallel to one another and can be moved together and apart along a rear rail 32 by linear drives. The rail 32 is arranged behind the stacking station 6, so that the plates 31A, B extend laterally along the stacking station 6 from the rear to the front in the direction of the positioning base 5.

[0108] The plates 31A, B can be moved independently of each other or simultaneously.

[0109] The plates 31A, B are cantilevered from the rear, with the front side additionally guided to ensure rigidity. For this purpose, the plates 31A, B each have a receptacle 33A, B on the front side (at the end facing the positioning base), in which a linear guide 34 is movably mounted to enable compensating movements due to changes in distance.

[0110] To ensure that the linear guide 34 does not interfere with stacking, the entire spreading and compacting unit 30 is arranged such that the linear guide 34 is arranged just below the level of the positioning base 5 in a gap between the base and the positioning base 5.

[0111] To prevent packages W from accidentally shifting backward from stacking position 6, a plate-shaped fence 35 is arranged between the plates 31A, B on the rail 32. This fence has slots 36 in which the plates 31A, B can be shifted.

[0112] Together with the plates 31 A, B, the fence 35 acts as a guide on three sides of the stacking location 6 when transferring packages W to a new base when changing a fully stacked base or pallet (see Figure 18 below). When using the compaction functionality to compress layers of packages, the plates 31 A, B are initially placed to the left and right of the stacking location 6 in order not to disrupt the automatic stacking process.

[0113] If a compaction function is triggered, the plates 31A,B are moved towards the stacking location center along the linear guide on the rail 32 through the slots 36.

[0114] When the plates 31A, B are used as spreading devices for trolleys, the plates 31A, B are initially placed in the center of the trolley. As the trolley is moved upward and passes the plates 31A, B according to the invention, the plates 31A, B are moved outward along the linear guide on the rail 32 through the slots 36 and spread the side parts (indicated by dashed lines in Figure 16) of the trolley.

[0115] In order to reduce the interaction between the trolley side parts and the plates 31A, B, the upper and lower outer edges of the plates 31A, B are bevelled.

[0116] If a layer of packages W needs to be compressed / compacted on a trolley, the invention also makes this possible, since the panels are located inside the trolley during the stacking process.

[0117] To increase the stability of a stack or partial stack, it is often useful to place slip sheets on top of or into the stack. To do this, slip sheets are taken from a storage stack behind or next to the stacking location and placed mechanically (e.g., using an articulated-arm robot with a suction gripper) onto a layer of packages in stacking location 6.

[0118] As soon as the quantity of separator sheets available in the supply stack runs low, refilling is required. In order to perform the refilling process, it is currently mandatory to stop the machine to prevent the automatic stacking process from endangering the personnel performing the refilling task. This results in an interruption of the automatic stacking process, which reduces device availability and average throughput. Therefore, the device 1, as shown in Figure 17 and indicated in Figure 3, comprises a separator sheet unit 40.

[0119] Separator layer unit 40 has two storage containers 41A, B, which are alternately or selectively accessible by the indicated automated handling means 40A. This allows the handling means 40A to receive separator layers from the second storage container 41B while the first storage container 41A is being refilled.

[0120] The hazard posed by a machine operating in automatic mode is counteracted by integrating the part of the separating layer unit 40 which acts as an interface to the personnel into the device protective fence 48 (indicated by dotted lines in Figure 3).

[0121] Additionally, the storage bins 41A, B can be covered by gates 42A, B, which prevent personnel from opening them without the device registering this. For this purpose, the gates 42A, B are equipped with access controls 43A, B (door locking). The access controls only allow the gates to be opened after prior authorization. Upon authorization to open the gate, the software determines that only the other storage bin may be controlled by the handling device 40A.

[0122] The gates 42A, B are designed like a rolling gate to prevent personnel from coming into contact with dangerous moving parts of the device. This is achieved by the fact that the gates 42A, B, when open for the handling equipment 40A, forcibly close the opening 44A, B accessible to personnel (see Figure 17A vs. Figure 17B). To this end, the gate 42A, B is moved back and forth on an angled rail 47A, B between the opening 44A, B accessible to personnel and the opening 45A, B accessible to handling equipment.

[0123] In order to facilitate ergonomics during refilling, the storage containers 41A, B are equipped with a drawer mechanism 46 so that they can be pulled out for filling in the open position of the gates 42A, B (out of the device protective fence 48).

[0124] This allows the device to run continuously in automatic mode without any loss of performance in terms of throughput and availability.

[0125] It is understood that, depending on the space available, requirements, and design of the handling means, it is also possible to provide more than two storage containers 41. Thus, it would be conceivable to arrange the storage containers radially in a semicircle, etc., around the handling means in their access area.

[0126] Different separating layers can also be provided in the storage containers as needed. The handling equipment can then access the respective storage container 41A, B alternately as needed.

[0127] It is also possible to provide covers, lids, etc., in the storage containers that are accessible to handling equipment. This allows open containers to be closed in a targeted manner within a single layer of packaging.

[0128] Once a base, e.g. pallet or trolley, has been fully stacked, it is lowered for wrapping as described above. During this time, stacking station 6 is not usable. To prevent this, it is known to use intermediate plates which are arranged at the level of the positioning base 5 above the carrier to be loaded in stacking station 6. These can be moved approximately horizontally between a stacking position and a release position in the X direction. In the stacking position, stacking can continue on these intermediate plates until the new base is ready from below. The packages are then transferred to the base by pulling back the intermediate plates. However, this leads to changes in the position of the packages, as they collide with each other and with lateral stops / scrapers when the intermediate plates are pulled back.

[0129] To prevent this undesired displacement, the device 1 comprises a removable floor unit 50, as shown in Figure 18 and indicated by dashed lines in Figure 3. In comparison to the prior art, the removable floor 51 of the removable floor unit 50 has a "circulating" belt 52 on which the actual stacking or package placement takes place. Figures 19 (A) and 19 (B) show an open position and a closed position of an embodiment of the removable floor 51 of the removable floor unit 50. Figures 20 (A) and 20 (B) show an alternative embodiment.

[0130] The belt 52 is fixed to the outer end 51A of the removable floor 51 and runs around the edge 51D of the removable floor 51 at the other end—the stacking station end 51B. For this purpose, the edge 51D has rollers 59. The outer end 51A has a bevel 53 in this case. A deflection roller 55 for belt deflection is arranged in front of the edge 51C at the outer end 51A.

[0131] When the removable floor 51 is moved back and forth in its guide rails 58 (for further stacking or transfer) while the belt 52 is fixed in position at the outer end 51A and unwinds over the edge 51D, the relative movement between the top side of the belt 52 and the newly placed pallet or base is zero. This results in the packages W lying on the belt 52 being transferred to the base with little or no relative movement, caused by the angle of fall resulting from the thickness of the removable floor 51 and the belt 52. Nevertheless, intentionally planned gaps remain between the packages W.

[0132] Due to geometric constraints within the device, the total length of the removable floor must be as short as possible.

[0133] In order to enable large movements without making the pre-palletizing plate longer than necessary, the slack side of the belt 52 is wound onto a belt drum 54 arranged below the exchangeable floor 51 after the belt 52 has run around the roller 55.

[0134] The belt drum 54 must be actively driven in order to wind up the belt 52, which can be done with a drive 56, which also acts as a servo for driving the removable floor 51.

[0135] The drive 56 drives an open toothed belt 57, the two loose ends 57 A, B of which are fastened to the removable floor 51. The toothed belt 57 runs around a roller 60 at the stacking station end 51 B and is deflected around two further rollers 61, 62 on the belt drum 54.

[0136] The toothed belt 57 rotates the belt drum 54 in a precisely defined gear ratio in order to take up the entire belt slip that has occurred during the movement of the removable floor 51.

[0137] In variant 50* according to Figure 20, the belt 52* is fixed to a fixed point 70 outside the removable floor 51. The belt 52* itself is thus guided on the surface of the removable floor 51* and, with its slack strand 52A*, runs through a cavity 71 in the removable floor 51* to guide the belt 52*. This ensures that the belt 52* cannot sag, and therefore the new base can be brought closer to the removable floor 51*.

[0138] Thus, the surface of the removable floor 51* moves within the thus formed closed loop of the belt 52*. This also results in the relative movement between the upper side of the belt 52* and the pallet or base newly placed underneath it being zero. The fixed point 70 is arranged in this case on the spreading-compacting unit 30 or its fence 35.

[0139] It is understood that combinations of the previously indicated possibilities are also within the scope of the invention.

[0140] List of reference symbols

[0141] 1 device

[0142] 2 feed conveyors

[0143] 4 positioners

[0144] 4.1 Positioning pusher

[0145] 4A Portal

[0146] 4B linear guide

[0147] 4C sled

[0148] 4D support arm

[0149] 4E pusher plate

[0150] 5 Positioning pad

[0151] 6 stacking space

[0152] 8 stop

[0153] 10 units

[0154] 11 frame

[0155] 11A Linear axis

[0156] 12 clamping element

[0157] 13 Sliding plate

[0158] 14 pushers

[0159] 14A pusher surface

[0160] 15 stoppers

[0161] 15A Portal

[0162] 15B linear guide

[0163] 15C sled

[0164] 15D support arm

[0165] 15E stopper plate

[0166] 16 hold-down clamps

[0167] 17 Linear drive

[0168] 18 sliding arm

[0169] 18A rear end

[0170] 18B pusher-side end

[0171] 19 Cables and hoses

[0172] 20 Grouping facility

[0173] 21 pushers

[0174] 22 Conveyor zone 23 Stop

[0175] 30 Spreading-compacting unit

[0176] 31A, B Plate

[0177] 32 rail

[0178] 33A, B recording

[0179] 34 Linear guide

[0180] 35 Fence

[0181] 36 slot

[0182] 40 separating layer units

[0183] 40A Handling equipment

[0184] 41 A, B storage tank

[0185] 42A, B Gate

[0186] 43A, B Access control

[0187] 44A, B opening

[0188] 45A, B opening

[0189] 46 drawer mechanism

[0190] 47A, B rail

[0191] 48 Device protection fence

[0192] 50 removable floor unit

[0193] 50* Removable floor unit

[0194] 51 removable floor

[0195] 51* Removable floor

[0196] 51A outer end

[0197] 51A* outer end

[0198] 51 B stacking station end

[0199] 51 B* stacking station end

[0200] 51 C edge

[0201] 51 D edge

[0202] 51 D* edge

[0203] 52 belt

[0204] 52* Belt

[0205] 52 A* Lostrum 53 Bevel

[0206] 54 Belt drum

[0207] 55 roll

[0208] 56 Drive

[0209] 57 Timing belt

[0210] 57A,B Loose ends

[0211] 58 guide rails

[0212] 59 rolls

[0213] 60 rolls

[0214] 61 roll

[0215] 62 rolls

[0216] 70 fixed point

[0217] 71 cavity

[0218] 100 Control

[0219] A axis

[0220] P Palette

[0221] S stack

[0222] W package

[0223] W1 package

[0224] W2 package

[0225] W3 package

[0226] W3* Package

[0227] W3a top

[0228] D Distance

Claims

Patent claims 1. A device for automatically stacking packages on a base in a predetermined spatial arrangement to form a stack, comprising at least one feed conveyor (2) that provides packages (W) in a predetermined sequence; a lifting and lowering unit for lifting and lowering a base (P) arranged in a stacking location (6) in the Y direction; and displacement means adjacent to a discharge end of the feed conveyor (2) that receive packages (W) from the feed conveyor (2) and transport them to the predetermined position in the stack (S); the displacement means comprising: a positioner (4) adjacent to the discharge end of the feed conveyor (2), which is arranged horizontally and longitudinally to one side of the stacking location (6) to pre-position the packages (W) in the X direction on a positioning base (5), two independent units (10), each consisting of a sliding plate (13) with an associated pusher (14),to transport the packages (W) from the positioning base (5) in the Z direction to the predetermined position in the stack (S), wherein each sliding plate (13) is designed as a flat, strip-shaped plate movable horizontally and along the side of the stacking station (6) and transversely thereto, in order to take over the packages (W) when the pusher (14) pushes the packages (W) from the positioning base (5) at the X-direction position and to deposit them in the Z direction on the base (P) or in the stack (S), and wherein each pusher (14) is designed to push the packages (W) from the positioning base (5) towards the stack (S) and, for this purpose, is movable in the Z direction independently of the at least one sliding plate (13) in order to retain the package (W) when the sliding plate (13) is retracted,and each unit (10) comprising sliding plate (13) and pusher (14) is movable in the X direction and is movable independently of the other unit (10).

2. Device according to claim 1, characterized in that the feed conveyor has a grouping device (20) which is designed to reposition two consecutive packages (W) on the feed conveyor (2) next to each other as a group.

3. Device according to one of the preceding claims, characterized in that the positioner (4) has a stop (15) movable in the X direction for fine positioning in the X direction for the packages (W) or grouping arranged on the positioning base (5).

4. Device according to one of the preceding claims 2 or 3, characterized in that the device has a control (100) which is set up to assign one of the units (10) to each pre-positioned package (W1, W2) of the grouping and to control both units (10) first together until the packages (W1, W2) are taken over by the respective sliding plate (13) and then independently of one another for movement.

5. Device according to one of the preceding claims, characterized in that an adjustable hold-down device (16) is provided on each pusher (14).

6. Device according to one of the preceding claims, characterized in that the positioning base (5) is an immovable surface.

7. Device according to one of the preceding claims, characterized in that the positioner (4) is a pusher (14) displaceable in the X direction.

8. A method for automatically stacking packages on a support in a predetermined spatial arrangement to form a stack, in particular using a device according to one of the preceding claims, wherein packages (W) are provided by at least one feeder in a predetermined sequence and are transported to the predetermined position in the stack (S) by means of displacement means adjacent to a discharge end of the feeder, wherein the displacement means pre-position the packages (W) in the X direction on a positioning support (5) using a positioner (4) adjacent to the discharge end of the feed conveyor, which is arranged horizontally and longitudinally to one side of the stacking station (6), and transport them from the positioning support in the Z direction to the predetermined position in the stack (S) by means of two independent units (10), each consisting of a sliding plate (13) with an associated pusher (14),and always support from below, for which purpose each sliding plate (13) is moved horizontally and along the side of the stacking area (6) and crosswise in order to push the packages (W) when pushing the, To take over packages (W) by the pusher from the positioning base at the X-direction position and to place them in the Z-direction on the base (P) or in the stack (S), and wherein each pusher (14) pushes the packages (W) from the positioning base in the direction of the stack (S) and for this purpose is moved in the Z-direction independently of the at least one sliding plate (13) in order to hold back the package (W) when the sliding plate (13) is retracted, for which purpose and wherein each unit (10) comprising the sliding plate (13) and pusher (14) is moved in the X-direction independently of the other unit.

9. Method for automatic stacking according to claim 8, characterized in that the packages (W) are placed in the Y direction by raising and lowering the base.

10. Method for automatic stacking according to claim 8 or 9, characterized in that two consecutive packages (W) are positioned next to each other in the feeder (2) and then are first moved together until the packages (W1, W2) are taken over by the respective sliding plate (13) and then independently of each other.

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