US20240375803A1

US20240375803A1 - Cutting supply unit and method for its operation

Info

Publication number: US20240375803A1
Application number: US18/644,862
Authority: US
Inventors: Manuel Schuster
Original assignee: Gerhard Schubert GmbH
Current assignee: Gerhard Schubert GmbH
Priority date: 2023-04-24
Filing date: 2024-04-24
Publication date: 2024-11-14
Also published as: EP4455063A1; DE102023110349A1

Abstract

A blank supply unit, for providing flat blanks for production of dimensionally stable outer packaging, includes an input magazine for receiving a stack of blanks, a buffer magazine arranged downstream of the input magazine for receiving stacked blanks, a transfilling unit arranged between the input magazine and the buffer magazine, and a discharge unit for withdrawing a blank from the stacked blanks in the buffer magazine and transporting the blank on to a next processing station for the blank. The transfilling unit is configured for automatic, batch-wise refilling of the buffer magazine with blanks from the input magazine.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. DE 102023110349.0 filed on Apr. 24, 2023, the disclosure of which is incorporated in its entirety by reference herein.

TECHNICAL FIELD

The disclosure relates to the supplying of the carton erector of a packaging machine with flat blanks, in particular of carton material.

BACKGROUND

Outer packaging made of cardboard is produced from prefabricated, flat blanks by so-called erecting, i.e., folding up the side walls, for example, relative to the floor of the blank, and fixing the different sections of the three-dimensionally formed blank relative to one another.
While blanks made of film or thin paper are usually only produced on the packaging line immediately before erecting by cutting a web-type starting material, this is hardly possible in the case of carton blanks.
Instead, the individual blanks, each of which will later form a carton, are stacked in a blank magazine, withdrawn from there by a robot, for example, then fed through a folding die of the carton erector in order to be erected into the required shape, and then placed on a conveying element of the packaging machine.
The blanks are produced and separated externally by the blank supplier, usually from large-format punched sheets whose area corresponds to a multiple of the area of a blank.
However, since the capacity of such a blank magazine is limited, an operator must regularly refill the blank magazine on the packaging machine or exchange an empty blank magazine for a full blank magazine and then manually refill the empty blank magazine after the exchange. To enable the packaging machine to continue working during this time, there are usually two blank magazines so that one of them can continue to supply the packaging machine with blanks while the other is refilled.
Furthermore, in the case of a new packaging order for handling a differently configured blank for a differently configured carton, the guides and supports of the blank magazine must be adapted to the new blank, i.e., mechanically converted, which requires additional manual effort.

SUMMARY

It is therefore the task according to the disclosure to provide a blank supply unit for supplying the carton erector of a packaging machine with flat blanks, including those made of rigid, thicker material, in particular up to 5 mm thick, in particular carton material, in which the manual effort required for refilling is significantly reduced and the timing of which can be chosen in a more flexible way, and, in particular, a manual, mechanical magazine changeover to a new format can be carried out as simply as possible.
This task is solved by the features of the independent claims. Advantageous embodiments result from the dependent claims.
In the context of the present description, a flat blank is understood to be a sheet in the form of a dimensionally stable, flat piece, usually consisting of carton material, which can be re-formed into a three-dimensional package, usually a box or crate, usually open at the top, with or without a lid, by bending it along usually preformed bending lines.
A typical blank supply unit comprises, for example:

- an input magazine for receiving stacked, in particular vertically stacked, blanks, which can be filled and refilled, usually manually, with blanks provided by an external supplier,
- a buffer magazine arranged downstream thereof for receiving stacked, in particular vertically stacked, blanks, from which blanks can be continuously supplied by means of a discharge unit for withdrawing a blank from the stack and conveying it to the carton erector,
- a transfilling unit arranged between them for transfilling stacks or partial stacks from the input magazine into the buffer magazine,
- a control system for controlling at least all the moving parts of the blank supply unit.

According to the disclosure, the transfilling unit is configured for the automatic, batch-wise refilling of the buffer magazine with blanks from the input magazine. This means that there is always a sufficient supply of blanks in the buffer magazine for the operation of the carton erector and thus of the entire packaging machine.
The transfilling unit can be configured in different ways:
In the simplest case, the transfilling unit can have a pusher that pushes a partial stack—more rarely the entire stack—of blanks in the input magazine into the buffer magazine, which for this purpose can be arranged in particular adjacent to the input magazine.
For example, the rear wall of the buffer magazine facing the input magazine can have an upper edge that is positioned at a height such that the pusher pushes the partial stack or stack moved by it over the upper edge of this rear side, and the partial stack or stack then falls into the buffer magazine.
The defined falling-in process can be supported by guide rails in the side walls of the buffer magazine onto which the partial stack is first pushed and which can then fold down at the same time.
Another possibility is that the rear wall and thus its upper edge is controllably height-adjustable relative to the rest of the buffer magazine, so that, when a stack falls into the buffer magazine, the rear wall is only slightly above the height of the top of the stack currently in the buffer magazine, thereby preventing the stack falling into the buffer magazine from tilting. Preferably, the inner side of the upper region of the rear wall inclines obliquely outwards, thereby centering the newly deposited stack in the buffer magazine when the rear wall is subsequently raised to the height of the upper end of the now higher stack in the buffer magazine.
As a rule, the buffer magazine will have a smaller capacity than the input magazine.
In a preferred embodiment, the transfilling unit comprises a transfilling conveyor belt which can not only transport a partial stack or a whole stack of blanks from the input magazine to the buffer magazine, but whose upstream deflector element, in particular an upstream deflection roller, also serves to automatically separate and pick up such a partial stack from the input magazine.
For this purpose, the upstream deflector element can be controllably adjusted between a pick-up position, in which it is at least in contact with the side surface of the stack of blanks in the input magazine facing it, and a non-contacting rest position, in which it is approximately horizontally spaced apart from it.
This makes it possible to bring the upstream deflector element with the belt running over it into contact with the end face of a blank in the stack and, by driving the transfilling conveyor belt in the transfilling direction and thereby applying corresponding pressure from the transfilling conveyor belt against the end face, to slightly lift the end face and therefore this blank.
In order to move the partial stack consisting of this raised blank and all other blanks lying on top of it onto the upper run of the transfilling conveyor belt, the upstream deflector element is displaced against the transfilling direction towards the input magazine and thus under the raised partial stack, doing so at the same speed at which the transfilling conveyor belt is driven in the circulation direction, so that there is no relative movement between the underside of the raised blank and the upper run of the transfilling conveyor belt, while the deflector element lying furthest upstream moves further into the stack.
The downstream deflector element, in particular the deflection roller, is positioned or at least positionable in such a way that a stack of blanks transported on this transfilling conveyor belt can be transported beyond this downstream deflector element and thereby deposited in the buffer magazine.
For this purpose, the aforementioned supporting aids in the form of guide rails can also be provided in the buffer magazine.
Instead of individually displacing the upstream and/or downstream deflector element, in particular the deflection roller, thereby changing their distance and having to be compensated by a compensating device in the transfilling conveyor belt, the entire transfilling conveyor belt can also be movable in and against the transfilling direction, thus enabling a simpler design of this belt unit.
A pusher as described above can nevertheless be provided in order to push a partial stack from the input magazine up onto the upper run of the transfilling conveyor belt, as a result of which it may also be possible to dispense with contact between the upstream deflection roller and the end face of the stack in the input magazine, and in particular the entire transfilling conveyor belt can be designed to be both stationary and/or also with a fixed length.
To transfill a partial stack with a defined height from the input magazine to the buffer magazine, the lower end of the partial stack must be brought to the correct height relative to the transfilling unit, i.e., in the case of a pusher to a height less than one blank thickness below the lower edge of the pusher, in the case of a transfilling conveyor belt to a height at or just above the upper edge of the transfilling conveyor belt.
One possibility is that the input magazine has a lifting device with which at least the floor of the input magazine is controllably height-adjustable to such a height.
Another possibility is to controllably adjust the height of the transfilling unit, for example the pusher or the transfilling conveyor belt or at least its upstream deflection roller, by means of a lifting device.
Especially when only one pusher is used as a transfilling unit, height adjustment of the floor of the input magazine is preferable, because then the displaced partial stack always arrives at the buffer magazine at the same height and the latter can be mounted at a fixed height.
For easy filling of the input magazine, it should have an open side, but preferably a side different to the rear side facing the buffer magazine, i.e., the front side or a longitudinal side.
One or more stacks lying next to one another, for example on a Euro pallet, can be introduced into this open side and/or placed on the floor of the input magazine.
If multiple stacks are present in the input magazine transverse to the transfilling direction, either the input magazine and/or the transfilling unit must be controllably displaceable in the horizontal direction transverse to the transfilling direction so that the stacks lying next to one another in the input magazine can be processed one after the other.
The input magazine can have a floor that is slightly inclined or inclinable towards the transfilling unit by a maximum of 20°, preferably a maximum of 15°, preferably a maximum of 10°, in order to allow the blanks to rest against a correspondingly inclined forward stop or stops.
These stops should be removed to the side or downwards prior to withdrawal of the partial stack from its movement path, as the rear side of the input magazine facing the buffer magazine must generally be open for the withdrawal of a partial stack or the entire stack from the input magazine, at least over the height of the partial stack to be withdrawn.
Instead of filling the input magazine with stacks of blanks, which generally have to be placed on a support such as a Euro pallet for transportation, the input magazine can also be filled with interchangeable input boxes, each of which preferably contains a stack of blanks. Such input boxes, which can replace the stack support and also have side walls, can be delivered in a ready-filled state by the external supplier and are easier for the operator of the packaging machine to handle than loose stacks of blanks.
The discharge unit with which an individual blank is withdrawn from the buffer magazine and, in particular, deposited in the carton erector, is preferably designed so that it can withdraw the bottom blank from the stack in the buffer magazine.
This means that the buffer magazine can be refilled from above time-independently of the withdrawal of individual blanks from the bottom.
The bottom blank is withdrawn either horizontally through a slot in one of the walls of the buffer magazine or through the floor of the buffer magazine, which must then have a very large opening so that the blank—usually engaged from underneath by a suction cup—can be pulled out vertically downwards while slightly bending the blank.
The discharge unit preferably comprises a robot that carries a corresponding tool, such as the aforementioned suction cup.
If blanks are transported and delivered in a stacked state in the form of several stacks placed next to one another, for example on a Euro pallet, the supplier inserts interleaved sheets—for short: intermediate sheets—between them made of paper or carton material distributed over the height and extending over the entire base area of all stacks, thus in particular the entire support, such as the Euro pallet. This makes it harder for the stacks to move relative to each other, thus preventing the individual stacks from slipping and falling over.
However, these intermediate sheets cause problems during automatic withdrawal of partial stacks from such a Euro pallet, for example, when this is inserted as a whole into the input magazine with several stacks placed next to one another.
In that case, the blank supply unit, in particular the transfilling unit, should be configured firstly so that it can withdraw such a partial stack from the input magazine that is placed on such an intermediate sheet, and secondly there should be a removal device that can remove such an intermediate sheet once there are no more blanks on top of it.
Where a pusher is used as a transfilling unit, the removal device can be configured so that it already holds the intermediate sheet when the last stack on it is moved by the pusher and then removes the intermediate sheet, for example by means of a suction cup.
In the case of a transfilling conveyor belt, it may be sufficient if this can be driven against the transfilling direction and thus, in the pick-up position, first bends down any edge of the intermediate sheet that may protrude over the stack, and only then raises and picks up the bottom blank of the partial stack to be picked up by switching to the transfilling direction.
For this purpose, the intermediate sheet should be at approximately the same height as the upper run of the transfilling conveyor belt, which can be achieved by means of a corresponding lifting device at the floor of the input magazine or the transfilling conveyor belt.
The blank supply unit can also have a plurality of buffer magazines so that one can be emptied during operation while the other can be refilled from the input magazine.
Preferably, the blank supply unit and in particular its transfilling unit is configured such that several, in particular all, can be refilled from an, in particular a single, input magazine.
For this purpose, the transfilling unit can be configured to be controllably displaceable transversely to the transfilling direction, in particular transversely to the running direction of the transfilling conveyor belt, in particular in a horizontal direction. If the several buffer magazines are also arranged next to one another in this direction, the transfilling unit, after moving in its transverse direction, can deposit the blank picked up from the input magazine in one or the other buffer magazine.
The problem can also arise that, if the blanks are very short in the transfilling direction in relation to the radius of the upstream deflector element of the transfilling conveyor belt when the transfilling conveyor belt is driven in under the partial stack to be picked up, the center of gravity of the partial stack does not extend above the upper run of the belt and thus the partial stack does not tilt onto the upper run of its own accord due to gravity.
In this case, the transfilling unit can have a hold-down device that can be controllably moved up and down relative to the transfilling unit, which presses the part of the stack that already protrudes obliquely over the upper run of the transfilling conveyor belt downwards against the upper run.
For this purpose, the hold-down device is preferably arranged so that it can be moved towards the upper side of the downstream end, in the transfilling direction, of the transfilling unit, in particular of the transfilling conveyor belt.
For this purpose, the hold-down device can be attached to the input magazine or, preferably, to the transfilling unit.
With regard to a packaging machine for placing articles in a dimensionally stable outer packaging such as a carton produced from a flat blank, this comprises, in addition to several robots along a transfer line for transferring articles into cartons, a carton erector and a blank supply unit for automatically supplying the carton erector with blanks.
According to the disclosure, the blank supply unit of such a packaging machine is designed as described above.
With regard to a method for supplying the carton erector of a packaging machine with individual blanks, the existing task is solved in that

- an input magazine is filled with at least one stack of blanks, this usually being done manually,
- a buffer magazine is automatically refilled with partial stacks or an entire stack from the input magazine by transfilling and is thus constantly kept at least partially filled; after the input magazine is emptied it is refilled, in particular manually, before the buffer magazine is emptied by the packaging machine,
- this is because individual blanks are automatically withdrawn from the buffer magazine one after the other and fed to the carton erector, in particular in cycles following the work cycle of the carton erector.

Preferably, the bottom blank is withdrawn as a single blank from the buffer magazine, as this prevents any disruption to the transfilling and refilling of the buffer magazine from the top.
If transfilling is carried out in the preferred manner by means of a transfilling conveyor belt, the most upstream deflector element, in particular the most upstream deflection roller, of the transfilling conveyor belt is placed against a side surface of the stack in the input magazine in order to engage and pick up a partial stack from the input magazine and, with corresponding contact pressure, the part of the stack located from the contact point and above is automatically lifted by driving the conveyor belt in the transfilling direction.
This partial stack is placed on the upper run of the transfilling conveyor belt by continuing to drive the transfilling conveyor belt with the upper run in the transfilling direction and, at the same time and at the same speed, moving the most upstream deflector element against the transfilling direction into the stack and under the lifted blank, thereby avoiding relative movement between the underside of the lifted blank and the upper run of the transfilling conveyor belt.
The upper partial stack is lifted—either when the blank in the stack is first lifted or when the most upstream deflector element is driven further in—to a height such that a gap remains between the lower run and the remaining stack in the input magazine, so that its uppermost blank is not displaced.
The partial stack picked up by the transfilling conveyor belt can now be transported to the buffer magazine and deposited there.
The capacity of the buffer magazine is preferably chosen to be large enough so that the input magazine can be refilled during the time it takes for a predefined minimum content of the buffer magazine to be used up in supplying the carton erector.
Preferably, the capacity of the buffer magazine is large enough so that, when the buffer magazine is completely full, the time it takes for the content to be used up is at least twice as long, preferably at least three times as long, preferably at least four times as long as the time required to refill the input magazine.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments according to the disclosure are described in more detail below by way of example. The following are shown:

FIG. 1A: A known packaging machine with an inclined magazine for the carton blanks, viewed from above.

FIGS. 1B1, 1B2: The known packaging machine of FIG. 1A viewed in the longitudinal direction with the discharge unit for the blank magazine in two different functional positions.

FIG. 1C: Another design of packaging machine, also viewed in the longitudinal direction, but with the same inclined magazine for carton blanks.

FIGS. 2A1, 2A4, 2A5, 2A7: A blank supply unit according to the disclosure on an otherwise known packaging machine viewed from above in various functional positions analogous to the numbering in FIG. 2B.

FIGS. 2B1, 2B8: The blank supply unit shown in FIG. 2A viewed in the longitudinal direction of the packaging machine in various functional positions.

FIG. 3 : A second embodiment of the blank supply unit in various functional positions viewed in the same direction as FIGS. 2B1 to 2B7.

FIGS. 4A, B, C: A part of a third embodiment of the blank supply unit viewed in the same direction as FIGS. 2 and 3 .

FIG. 5 : A fourth embodiment of the blank supply unit viewed in the same direction as FIGS. 2-4 .

FIG. 6 : A representation similar to the enlargement in FIG. 2B2, but with very short blanks.

DETAILED DESCRIPTION

FIGS. 1A, 1B1, 1B2 show a known packaging machine 100 in the form of a transfer line or picker line viewed from above and in the longitudinal direction 110.
In such a packaging machine 100, irregularly distributed articles A are transported on an article belt 101 which moves in the longitudinal direction 110, i.e., the article running direction, and in some cases—biscuits or packaged articles A for example—may also lie on top of one another. On at least one side, in this case both sides, of the article belt 101, a carton belt 102 runs, on which cartons K are moved in the articles' longitudinal direction 110.
A plurality of robots 109 are arranged one after the other in the longitudinal direction 110, which pick up articles A from the article belt 101 and transfer them into a carton K on the carton belt 102 and in this way fill the cartons K.
In order for the robots 109—of which only two are shown here, but in practice there are usually considerably more arranged one after the other—to know the position of the articles A on the usually permanently moving article belt 101, this is detected in the running direction 110 of the article belt 101 upstream of the first robot 109 by means of an optical sensor 117, usually a scanner 117 covering the entire width of the article belt 101.
In this case, the robots 109 are designed with a serial robot arm in which the robot's upper arm 107 is pivotable about a vertical axis relative to a robot base 108 and, at the free end of the upper arm 107, a lower arm 106 of the robot 109 is also pivotable about a vertical axis. At the free end of the lower arm 106 is the hand 105 of the robot with a suitable tool attached to it, the hand in this case comprising a vertical strut—see FIGS. 1B1 and 1B2—so that the tool is displaceable in height relative to the lower arm 106 and is often also rotatable about a vertical axis.
The robots 109 are suspended by their robot base 108 from a cross-member 104 of the base frame 103 of the packaging machine which runs transversely above the rest of the packaging machine 100.
Alternatively, the robots 109 could also be robots according to FIG. 1C in which the upper arm 107 is pivotable relative to the robot base 108 about a horizontal pivot axis extending in the longitudinal direction 110, and the lower arm 106 is also pivotable relative to the free end of the upper arm 107 about a pivot axis extending horizontally in the longitudinal direction 110. Similarly, the hand 105 of the robot with the tool attached to it can be pivoted about such a horizontal longitudinal axis, so that such a robot 109 has only 3 degrees of freedom (moving in the vertical 112 and transverse directions 111 and pivoting about the longitudinal direction 110), whereas the robots of FIGS. 1A to 1B2 have four degrees of freedom, namely the three spatial directions and rotation of the tool about an upright axis.
FIG. 1C shows bottles that are to be placed in cartons K.
In FIG. 1C, the carton belt 102 is realized not as a conventional, endlessly circulating conveyor belt, but rather in the form of small, unmanned rail vehicles, in this case sleds 115 running along a rail 116 a, b which is arranged on a track body 116 of finite length, once on its upper side and once on its underside.
As a result, cartons K which are to be filled and those which are partially or completely filled can be transported upright on the upper side by a rail vehicle 115 which travels on the upper side of the track body 116 along the rail 116 a located there, while on the underside of the track body 116, along the rail 116 b located there, the empty rail vehicles 115 can be moved back to the start of the track body 116, usually the start of the transfer line, i.e., for example to the first robot 109 in the article transport direction 110.
On both designs of the known packaging machine 100, the same design of blank supply unit 50 is shown, which supplies the carton erector 60 present on each carton belt 102 upstream of the transfer line with flat blanks Z in order to produce a 3 dimensional carton K, usually open at the top, and place it onto the carton belt 102 or onto the rail vehicle 115 in order to transport the cartons K and feed them into the transfer line.
The flat blanks Z—as shown in FIGS. 1B1, 1B2 and 1C—are held so that they stand in an inclined position in a horizontal row or stack outside the base frame 103 of the packaging line 100, standing slightly inclined and pushed by means of a magazine pusher 114 against a stop 113 a of the inclined magazine 113, so that the blank Z resting against the stop 113 is the blank closest to the article belt 102.
This blank Z is removed by a discharge unit 4, here in the form of a robot with three degrees of freedom as described above with reference to FIG. 1C, positioned over an erecting die 61 and pressed through this die 61, as a result of which the flat blank Z is formed into a 3 dimensional carton K that is open at the top.
Before it can be transported further on the carton belt 102, it must be fixed in this erected state, for example by gluing its side walls together.
However, such an inclined magazine 113 must be regularly refilled manually by a machine operator, and, in order to avoid interruptions in the operation of the packaging machine, two blank supply units 50 are often provided one after the other in the longitudinal direction 110 for each carton belt 102, i.e., each with an inclined magazine 113 and carton erector 60. This adds to the overall length of the machine, increases costs and still requires regular attendance by the machine operator.
A blank supply unit 50 according to the disclosure as shown in FIG. 2A1 and the following figures seeks to avoid these disadvantages.
As can best be seen in FIG. 2B1, looking in the longitudinal direction 110 of the packaging machine 100, a buffer magazine 2 for blanks Z is provided in which the blanks Z lie on top of one another, i.e., in a vertical stack 2, and which can be refilled from above at any time, since it is open at the top, and from which the discharge unit 4—again in the form of a robot 109 as described above—withdraws a single bottom blank Z in a downward direction, or, conversely, filling takes place from below and withdrawal from above.
Downward withdrawal is possible by the discharge robot 109 engaging, for example, with a suction cup on the underside of the bottom blank Z which rests only by its corners or edges on supports 2 a of the buffer magazine 2, which can easily be overcome by slight deformation of the engaged bottom blank Z without damaging the blank Z.
Then, as described above, the blank Z is pressed from above by the discharge robot 109 through the die 61 of the carton erector 60, thereby erecting it into the state required for filling.
This buffer magazine 2 is automatically refilled as required, usually at regular intervals, from an input magazine 1, in which blanks Z are also located one above the other, i.e., in a vertical stack S1, and which generally has a larger capacity than the buffer magazine 2 and therefore has to be refilled less frequently, thus requiring less time and manual effort.
For example, a Euro pallet loaded with blanks Z can be set down by a forklift directly in the input magazine 1, of which only the floor plate 1 a is shown in FIG. 2B1 and the following figures, but which also has walls, as can be seen from FIGS. 2A1 to 2A7.
In this case, the input magazine 1 is positioned at a distance from the buffer magazine 2 in the transverse direction 111 of the packaging machine 100, but could also be positioned in the longitudinal direction 110 relative thereto.
The buffer magazine 2 is refilled from the input magazine 1 by means of a transfilling unit 3, for which there are several possibilities.
In FIGS. 2B1 to 2B8, this is a transfilling conveyor belt 5 which is controlled by the control system 50* of the blank supply unit 50, usually being integrated into the control system 100* of the overall packaging machine 100, as shown in FIG. 1A.
This transfilling conveyor belt 5 runs with an approximately horizontal upper run 5.1 generally over two deflection rollers 5 a, 5 b, which are spaced apart and mounted in a belt support frame 5A. At least the deflection roller 5 a adjacent to the input magazine 1 can be displaced at least in the transfilling direction 10, in this case the transverse direction 111 of the packaging machine 100. Specifically, in this exemplary embodiment, the entire transfilling conveyor belt 5 can be displaced in this direction by moving its support frame 5A back and forth in this direction.
This enables a transfilling process as shown in FIGS. 2B1 to 2B8:
The transfilling conveyor belt 5 is brought into contact by its input-side end, here the deflection roller 5 a, with the side surface of the stack S1 facing it in the input magazine 1 as shown in FIG. 2B1, at a certain height, usually a roughly predetermined number of blanks Z below the top blank Z.
By setting the transfilling conveyor belt 5 in motion with its upper run 5.1 in the direction of the buffer magazine 2, i.e., the transfilling direction 10, with sufficient horizontal contact pressure, the transfilling conveyor belt 5 slightly lifts the narrow side of the blank Z with which it is in contact, as shown in FIG. 2B2, so that this is the lowest blank Z of an upper partial stack S1.1, which is thus lifted on one side from the lower remaining stack, the partial stack S1.2, of the stack S1 in the input magazine 1.
This is continued until this end of the contacted blank is at the level of the upper run 5.1 of the transfilling conveyor belt 5 according to FIG. 2B3, which naturally requires the constant repositioning of this guide roller 5 a—in particular horizontally and against the transfilling direction 10—towards the input magazine 1 so as not to lose contact with this bottom blank of the raised partial stack S1.1, preferably until this deflection roller 5 a of the transfilling conveyor belt 5 is located in the wedge-shaped slot between the raised partial stack S1.1 and the remaining stack S1.2 located below it, as shown in FIG. 2B4.
By continuously moving the transfilling conveyor belt 5 in its circulation direction 10 and simultaneously moving the upstream deflector element, in particular the deflection roller 5 a, into the stack S1 at the same speed, but against the circulation direction 10, the upper run 5.1 is rolled further and further along the underside of the partial stack S1.1 against the transfilling direction 10—preferably without relative movement between the underside of the partial stack S1.1 and the upper run 5.1—until the partial stack S1.1 lies on the upper run 5.1 of the transfilling conveyor belt 5 as shown in FIG. 2B5.
FIG. 2A1 also shows that, in this way, either only one buffer magazine 2 lying spaced apart in the transfilling direction 10 can be refilled from the input magazine 1, or two erectors 61 can be present on the packaging machine 100, for example spaced apart in the longitudinal direction 110 of the packaging machine 100, each with a buffer magazine 2 arranged next to it, and both buffer magazines 2 can be refilled, preferably alternately, from the input magazine 1.
For this purpose, the transfilling unit 3 must be controllably movable transversely to the transfilling direction 10 in order to move into a position aligned with the buffer magazine 2 which is not precisely opposite the input magazine 1, after a partial stack S1.1 has been picked up and deposited into it.
At the same time, FIGS. 2B1 to 2B5 show to the left of the buffer magazine 2 how the bottom blank Z of the stack S2 located therein is withdrawn—for example at the same time intervals—by the discharge unit 4, namely the robot 109, it being

- engaged from underneath (FIG. 2B1),
- pulled downwards and thus bent by its middle portion, as long as its edges are still resting on the supports 2 a (FIG. 2B2),
- moved to the erector 60 after withdrawal of the separated blank Z from the buffer magazine 2 (FIG. 2B3),
- positioned by the discharge unit 4, in this case the robot 109, over the erecting die 61 (FIG. 2B4), and
- pressed into, in particular through, the die 61 and thereby erected so as to form a 3 dimensional carton K.

As soon as this has taken place, the entire transfilling conveyor belt 5 according to FIG. 2B6 moves, preferably horizontally, towards the buffer magazine 2, so that its deflection roller 5 facing the latter is located in the transfilling direction 10 close to and, in terms of height, with the upper run 5.1 above the upper end of the side wall of the buffer magazine 2 facing it, as shown in FIG. 2B6.
By further circulation of the conveyor belt 5 about its deflection rollers 5 a, b, the picked-up partial stack S1.1 is dropped into the buffer magazine 2 from above as shown in FIG. 2B7, with an interior space of the buffer magazine 2 tapering conically from top to bottom or other previously described depositing aids (not shown) assisting the exact placement of the blanks Z on top of one another in the buffer magazine 2 as shown in FIG. 2B8.
The transfilling conveyor belt 5 then moves against the transfilling direction 10 back to the input magazine 1 to pick up the next partial stack from it.
This refilling of the buffer magazine 2 preferably already takes place when the uppermost blank Z in the buffer magazine 2 is not yet further away from the upper end of the side wall on the refilling side than the height of the partial stack S1.1 to be refilled.
FIG. 2A1 shows the situation in FIG. 2B1 viewed from above.
It can be seen that the rear side of the input magazine 1 facing the transfilling conveyor belt 5 is essentially open in order to allow the transfilling conveyor belt 5 to rest against the stack S1.
In order to have a limit stop for the stack S1 in the transfilling direction 10, the side walls of the input magazine 1 running in the transfilling direction 10 can have, only on the side facing towards the transfilling conveyor belt 5, a slight inward offset 1 b—as viewed from above—but which it should preferably be possible to fold away outwards in a controlled manner, at least over the height of the upper partial stack S1.1 to be withdrawn.
To ensure that the blanks of the stack S1 rest against these stops 1 b, these vertically extending stops can be inclined slightly forwards towards the top, which, however, makes refilling, e.g., by means of a forklift truck, somewhat more difficult.
FIGS. 2A4, 2A5, 2A7 show the situation corresponding to FIGS. 2B4, 2B5, 2B7 with the transported, refilling partial stack S1.1 in several functional positions.
It can be seen, for example, that the width of the transfilling conveyor belt 5 in the transverse direction 11 relative to the transfilling direction 10 is less than the width of the blank Z to be transfilled.
In FIGS. 2B1 to 2B8, the transfilling conveyor belt 5 is movable in the horizontal transfilling direction 10, but not in height, for example in order to adjust its height to the height of the upper end of the wall of the buffer magazine 2 facing it.
Furthermore, the remaining stack S1.2 in the input magazine 1, which becomes lower due to the withdrawal of the partial stack S1.1, must be moved upwards relative to the transfilling conveyor belt 5, this being done with the aid of a controlled lifting device 7 under the floor plate 1 a of the input magazine.
Alternatively, as shown in FIG. 3 , the transfilling conveyor belt 5 or a differently designed transfilling unit 3 can instead be controllably height-adjustable, while the input magazine 1 is always at the same height, preferably at a height just above the ground, so that it can be reloaded particularly easily, including by means of a non-lifting handling vehicle such as a pallet truck.
After picking up a partial stack S1.1 from the input magazine 1, the transfilling conveyor belt 5, i.e., usually its support frame 5A together with the partial stack S1.1 loaded thereon, must then additionally move upwards to the discharge height with respect to the buffer magazine 2, i.e., with its upper run 5.1 at or above the height of the wall of the buffer magazine 2 facing it.
It should also be clarified that, instead of the aforementioned displacement of the transfilling conveyor belt 5 which has a constant length, i.e., a constant distance between its two ends, as shown here to the left and right, it would also be possible to leave the buffer-side deflection roller 5 b or that end of the transfilling conveyor belt 5 stationary in the discharge position, i.e., at the correct distance from the buffer magazine 2, and instead change the length of the transfilling conveyor belt 5 between the two ends in order to make contact with the stack S1 or space it apart from the stack S1.
FIGS. 4A, 4B, 4C first show a different embodiment of the transfilling conveyor belt 5 in which the conveyor belt 5 also runs over two deflecting rollers 5 a, b, but the upstream end in the transfilling direction 10 runs over the offset of an offset support plate 14 as a deflecting element, and the most upstream deflecting roller 5 a is located downstream thereof.
The same statements as above concerning the corresponding deflection roller apply in particular to such an offset support plate serving as a deflector element.
As a result, a significantly smaller deflection radius can be achieved at the deflection point of the conveyor belt 5, so that contact at the upstream end of the conveyor belt 5 with the end face of the stack S1 can be defined at only the end face of a single blank Z, thus enabling more defined lifting of the upper partial stack S1.1 with otherwise the same procedure as described above, i.e., also driving in this deflection point around the support plate 14 between the lifted partial stack S1.1 and the remaining partial stack S1.2 located below
FIGS. 4A, 4B, 4C also show the special situation in which a so-called intermediate sheet ZB—whether made of cardboard or paper, usually the latter—is inserted in a delivered stack S1 for the input magazine 1 at certain heights between the blanks, which usually protrudes over the edge of the stack S1 and must be removed when the blanks Z above it have been taken away.
Such intermediate sheets ZB are normally used for stabilization, especially if there is not a single stack of blanks on the pallet, for example, but two or more stacks lying next to one another, for example, in order to prevent relative movement between adjacent stacks by connecting them across the entire pallet via the intermediate sheet.
In order to be able to pass the partial stack S1.1 directly over an intermediate sheet ZB as shown in FIGS. 2B1 to 2B8 and/or FIG. 3 , according to FIG. 4A the upstream end of the transfilling conveyor belt 5—regardless of whether it is of the design shown in FIG. 4 or that of the preceding figure—is moved downwards at a slight distance from, i.e., not in contact with, the end face of the stack S1.1 above the intermediate sheet ZB, this end of the conveyor belt 5 being moved downwards to an extent such that the part of the conveyor belt 5 furthest upstream, which can be seen as a point in this side view, is at the level of the end face of the bottom blank Z of this partial stack S1.1 and makes contact with it by moving horizontally against the transfilling direction 10 as shown in FIG. 4B, as a result of which the projecting edge of the intermediate sheet ZB is generally bent slightly downwards.
This partial stack S1.1 is then picked up and placed onto the transfilling conveyor belt 5 as described above, in particular by driving the upstream end into the resulting wedge-shaped gap between the raised partial stack S1.1 and the intermediate sheet ZB as shown in FIG. 4C.
After the partial stack S1.1 has been completely picked up as shown in FIG. 4D and transferred to the buffer magazine 2 as described above, the empty transfilling conveyor belt 5 is moved back towards the input magazine 1 and placed with its lower run 5.2 on the upper side of the intermediate sheet ZB as shown in FIG. 4E.
Then, by driving the conveyor belt 5 in the opposite direction to the transfilling circulation direction, i.e., in this case with the lower run 5.2 from right to left, the intermediate sheet ZB can be removed from the remaining stack S1.2 and ejected as shown in FIG. 4F, so that the transfilling conveyor belt 5 itself can be used as a removal device 13 for the intermediate sheet ZB without requiring an additional, separate removal device.
FIG. 5 shows a transfilling unit 3 of a fundamentally different design.
Instead of a transfilling conveyor belt, a simple pusher 6 is used here, which pushes a partial stack S1.1 horizontally from the input magazine 1 into the immediately adjacent buffer magazine 2 over the upper edge of its wall facing the input magazine 1.
For this purpose, again only the input magazine 1 should be displaceable in height by means of a lifting device 7, while the pusher 6 can always remain at the same height.
If the input magazine 1 has a lifting device 7, this can generally be used to lower its floor 1 a to a height close to the ground in order to facilitate filling of the input magazine 1.
FIG. 6A shows the problem of blanks Z that are very short in the transfilling direction 10.
If the blanks are so short in the transfilling direction 10 that, when the upstream deflector element 5 a is driven in and, depending on the thickness of the upstream deflector element 5 a, the center of gravity SP of the partial stack S1.1—only the centers of gravity of the individual blanks being shown in FIG. 6 for easier visualization—can no longer reach a position above the upper run 5.1 before the partial stack S1.1 is positioned more and more upright by the deflection roller 5 a and pressed against its rear abutment, usually the rear wall of the input magazine 1, additional measures must be taken.
One possibility is to reduce the height of the upstream deflector element 5 a, for example by not using the deflection roller itself as the deflector element, but rather a support plate offset around a much smaller bending radius, as shown in FIGS. 4A-F.
As this may not be possible due to the corresponding parameters of the work order, and the deflection roller 5 a must still be moved into the stack S1 and its diameter cannot be further reduced, the partial stack can be made to lie flat on the upper run 5.1 for example by means of a hold-down device 16, which can press vertically against the downstream end of the partial stack S1.1 in a controlled manner as shown in FIG. 6A until the underside of the stack rests on the upper run 5.1 as shown in FIG. 6B.
This is not critical because, when the transfilling conveyor belt 5 is driven in against the transfilling direction 10, its upper run 5.1 moves in the transfilling direction 10 at an equal and opposite speed, therefore no relative movement takes place between the underside of the hold-down device 16 and the partial stack S1.1.

Claims

What is claimed is:

1. A blank supply unit for providing flat blanks for production of dimensionally stable outer packaging, the blank supply unit comprising:

an input magazine for receiving a stack of blanks,

a buffer magazine arranged downstream of the input magazine for receiving stacked blanks,

a transfilling unit arranged between the input magazine and the buffer magazine, and

a discharge unit for withdrawing a blank from the stacked blanks in the buffer magazine and transporting the blank on to a next processing station for the blank,

wherein

the transfilling unit is configured for automatic, batch-wise refilling of the buffer magazine with blanks from the input magazine.

2. The blank supply unit according to claim 1,

wherein

the transfilling unit comprises a transfilling conveyor belt and downstream and upstream deflection rollers associated with the transfilling conveyor belt,

the downstream deflection roller is positioned or positionable in such a way that the transfilling conveyor belt can deposit a stack of blanks transported thereon in the buffer magazine, and

the upstream deflection roller

is displaceable between a pick-up position in which the upstream deflection roller is at least in contact with a side surface of the stack in the input magazine and a non-contacting rest position.

3. The blank supply unit according to claim 2,

wherein the transfilling unit comprises

a pusher configured

to push a partial stack of blanks in the input magazine lying above a height of an upper run of the transfilling conveyor belt onto the transfilling conveyor belt.

4. The blank supply unit according to claim 2,

wherein

at least the upstream deflection roller of the transfilling conveyor belt is controllably height-adjustable.

5. The blank supply unit according to claim 1,

wherein

the input magazine has a rear side or longitudinal side which is different from a front side facing the transfilling unit and which is open or openable for filling the input magazine.

6. The blank supply unit according to claim 1,

wherein

the input magazine has a floor that is inclined or inclinable towards the transfilling unit.

7. The blank supply unit according to claim 1,

wherein

the input magazine or the transfilling unit is displaceable in a transverse direction relative to a transfilling direction.

8. The blank supply unit according to claim 1,

wherein

the input magazine has at least one interchangeable input box which can be filled with a stack of blanks.

9. The blank supply unit according to claim 1,

wherein

the blank supply unit comprises a removal device for removing an intermediate sheet in the stack of blanks of the input magazine.

10. The blank supply unit according to claim 1,

wherein

the discharge unit is designed so that it can withdraw a bottom blank from the stacked blanks in the buffer magazine.

11. The blank supply unit according to claim 1,

wherein

the blank supply unit comprises an additional buffer magazine, and

the transfilling unit is configured to refill the additional buffer magazine from the input magazine.

12. The blank supply unit according to claim 1,

further comprising

a hold-down device which can be moved up and down in a controlled manner relative to the transfilling unit and is arranged such that the hold-down device can be moved towards an upper side of a downstream end of the transfilling unit in a transfilling direction.

13. A packaging machine for inserting and packaging articles in a dimensionally stable outer packaging, the packaging machine comprising:

a carton erector for producing a carton from a flat blank of carton material,

a plurality of robots along a transfer line for transferring articles into cartons, and

the blank supply unit according to claim 1 for supplying the carton erector with blanks.

14. A method for supplying a carton erector of a packaging machine with individual blanks,

the method comprising:

filling an input magazine with at least one stack of blanks,

automatically refilling a buffer magazine with partial stacks or an entire stack from the input magazine by transfilling,

refilling the input magazine,

automatically withdrawing a single blank from the buffer magazine, and

feeding the blank to the carton erector.

15. The method according to claim 14,

wherein the single blank withdrawn from

the buffer magazine is a bottom blank of a stack of blanks in the buffer magazine.

16. The method according to claim 14,

wherein

a capacity of the buffer magazine is chosen to be large enough so that the input magazine can be refilled by the packaging machine during a time it takes to use up a supply of blanks in the buffer magazine.

17. The method according to claim 14,

wherein

the transfilling is carried out by a transfilling unit including a transfilling conveyor belt and a deflector element associated with the transfilling conveyor belt, and wherein the transfilling comprises:

placing the deflector element in contact with a side surface of a stack of blanks in the input magazine,

driving the transfilling conveyor belt in a circulation direction and moving the deflector element into the stack of blanks, so that a partial stack of the stack of blanks located above the transfilling conveyor belt is automatically picked up onto the transfilling conveyor belt, and

transporting the partial stack to the buffer magazine by the transfilling conveyor belt.

18. The blank supply unit according to claim 1, wherein the transfilling unit comprises a pusher configured to push a partial stack of blanks in the input magazine lying above an upper edge of a rear side of the buffer magazine into the buffer magazine.

19. The blank supply unit according to claim 1, further comprising a lifting device configured to adjust height of the input magazine.

20. The blank supply unit according to claim 10, wherein the discharge unit comprises a robot including a suction cup configured to engage on an underside of the bottom blank, and the robot is configured to withdraw the bottom blank from the stacked blanks in the buffer magazine.