Wigenstedt, Magnus (Pilgatan 7, Mullsjö, S-565 33, SE)
| 1. | A packaging device for packaging substantially rigid articles in a shrinkable packaging material, com¬ prising a receiving means for receiving a succession of articles arranged in a stack to a receiving position; a wrapping means for wrapping packaging material around the stack; and a first shrinking means for shrinking at least part of the packaging material around the stack; the packaging device further comprising at least one holder means provided with two holder supports which are arranged to fix, during at least part of the wrapping of the packaging material and the shrinking of the same, the two outermost articles in the stack and thus maintain a continuous stack. |
| 2. | A packaging device as claimed in claim 1, wherein the holder supports are arranged to accompany, during at least part of the wrapping of the packaging material and the shrinking of the same, which occurs in at least two different positions, the stack when moving between these positions and thus fix the two outermost articles in the stack so as to maintain a continuous stack. |
| 3. | A packaging device as claimed in claim 1 or 2, further comprising moving means for moving the stack between a wrapping position adjacent to the wrapping means and a shrinking position adjacent to the shrinking means. |
| 4. | A packaging device as claimed in claim 1, 2 or 3, further comprising a second shrinking means, the first shrinking means being arranged to shrink the packaging material around both ends of the stack and the second shrinking means being arranged to shrink the packaging material around the central portion of the stack. |
| 5. | A packaging device as claimed in claims 14, fur ther comprising a discharging means for discharging the stack from the packaging device. |
| 6. | A packaging device as claimed in claims 15, wherein the holder means is arranged on the moving means. |
| 7. | A packaging device as claimed in claims 16, wherein at least one of the holder supports is arranged to perform a squeezing motion towards the second holder support. |
| 8. | A packaging device as claimed in claims 17, wherein the receiving means receives the articles in an axial direction. |
| 9. | A packaging device as claimed in claims 38, wherein the moving means moves the stack in a direction transversely to the longitudinal extent of the stack. |
| 10. | A packaging device as claimed in claims 39, wherein the moving means is a rotatable drum. |
| 11. | A packaging device as claimed in claims 110, wherein the packaging material is a shrinkable plastic film and shrinkage occurs by heat. |
| 12. | A packaging device as claimed in claim 11, wherein the wrapping means is provided with two rolls of shrinkable plastic film arranged on opposite sides of the wrapping position. |
| 13. | A packaging device as claimed in claims 11 and 12, wherein said holder means further comprises the first shrinking means. |
| 14. | A packaging device as claimed in any one of the preceding claims, wherein the device comprises at least two receiving means, preferably adapted to receive diffe¬ rent types of articles. |
| 15. | A method of packaging substantially rigid articles in a shrinkable packaging material, comprising the steps of receiving a succession of articles arranged in a stack to a receiving position; wrapping packaging material around the stack; and shrinking the packaging material around the stack; the wrapping and shrinking of the packaging material occurring at least in two different positions, and the articles in these two positions, during at least part of the wrapping and shrinking of the packaging material, being fixed so as to maintain a continuous stack. |
| 16. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claim 15, wherein the wrapping and shrinking of the packaging material occur in at least two different posi¬ tions, and wherein the articles in these two positions, during at least part of the wrapping and shrinking of the packaging material, are fixed so as to maintain a con tinuous stack. |
| 17. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claim 15 or 16, further comprising the step of moving the stack from a receiving position to a wrapping position. |
| 18. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1517, further comprising the step of moving the stack, after wrapping the packaging mate rial around the stack, from a wrapping position to a shrinking position for shrinking of the packaging mate¬ rial around the stack. |
| 19. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1518, further comprising the step of moving the stack, after shrinking the packaging material around the stack, from a shrinking position to a discharge position for discharging the stack from the packaging device. |
| 20. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1519, further comprising the steps of shrinking the packaging material around both ends of the stack; and shrinking the packaging material around the central portion of the stack, the steps being performed sepa¬ rately. |
| 21. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1520, further comprising the steps of moving the stack, after wrapping the packaging mate rial around the stack, from a wrapping position to a first shrinking position for shrinking of the packaging material around both ends of the stack; and moving from the first shrinking position to a second shrinking position for shrinking the packaging material around the central portion of the stack. |
| 22. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1521, further comprising the step of fixing the stack by a squeezing motion acting at least on one of the two ends of the stack. |
| 23. | A method of packaging substantially rigid articles in a shrinkable packaging material according to claims 1522, wherein the step of shrinking the packaging material around the stack occurs by heat . |
Background Art
There are many different systems and devices for packaging, and, for instance, packaging machines using wrapping paper, cardboard and plastic materials and com- binations of such materials are previously known. Also packaging machines which automatically seal packages by gluing belong to prior art.
When packaging a plurality of articles, for instance can lids, in one and the same package, special require- ments are, however, placed on the packaging device and the packaging method. This type of bulk packaging, like in production in bulk, also places increased require¬ ments that the packaging be performed quickly and with¬ out machine stoppage, so as to provide as cost-effective packaging as possible. The properties of the articles to be packaged also have an effect on how packaging can and should take place in an optimal manner.
Particularly stringent requirements are placed when packaging articles that are to be used in contact with foodstuffs, where the articles must have a high degree of cleanliness in the packaging process as well as in the subsequent handling of the packaged articles . For example for handling of can lids, it is known to use packages of paper, which are sealed for transport. An automated sys- tern for such packaging is disclosed in US 6,244,019 by the same applicant.
However, it has been found that the use of paper packages causes certain drawbacks. The packages will be relatively sensitive to moisture and the like, resulting in a risk that the packages split up and that the enclos¬ ed articles are damaged or contaminated. Moreover it is relatively complicated and expensive to provide automated
processes for packing and unpacking this type of pack¬ ages .
In other contexts, it is also known to use plastic materials. For example, US 2004/0011005 Al shows an exam- pie of a packaging apparatus for packaging a plurality of paper products in one package of a plastic material . It is shown how a continuous flow of paper products, such as napkins, arriving at the apparatus are first divided into a subset and how such a subset is then compressed by means of a press plunger to press air out of the paper products and thus reduce the volume of the subset. Sub¬ sequently a squeezer projects from a drum arranged at the side of the press plunger and the subset is pressed through a packaging material, which is held on the press plunger, into the squeezer. Then the squeezer is moved to a station for sealing the packaging material by glue, after which the packaged subset is discharged. However, US 2004/0011005 Al is suited to package compressible pro¬ ducts and is not suitable for packaging substantially rigid, non-compressible articles. For example, a subset of rigid articles would not stay in the squeezer after being pressed into the same since such a subset cannot exert an expansive pressure on the inside of the squeezer after pressing-in in the same way as the napkins intended in US 2004/0011005 Al can do in the compressed state.
Nor is US 2004/0011005 Al suitable to ensure that the articles of a subset are not laterally displaced relative to each other since the articles are expected to orient themselves automatically without being acted upon from the outside in the longitudinal axis of the subset. Such displacement of one or more substantially rigid articles of a subset may result in a serious disturbance in the packaging process such as machine stoppage or, if the article in question falls out of the subset, remain- ing articles not being packaged in the correct way and in the correct number.
Moreover the device according to US 2004/0011005 Al is provided with a means for sealing a packaging mate¬ rial with a binder, such as adhesive. The use of a binder makes the packaging device complicated and requires con- tinuous supply of adhesive for the packaging device to function. The dosing device for adhesive must also be reliable so that an adequate seal is provided while at the same time adhesive does not come into contact with the articles that are to be packaged and contaminate them or even make them adhere to one another. The device according to US 2002/0011005 Al is not convenient for other types of sealing techniques than gluing. The need for sealing by gluing specifically indicates that said device is not suitable for use with foodstuffs, due to the risk that the foodstuffs can then be subjected to contact with a glue line or glue residue .
There is thus a need for an improved packaging device and an improved method of packaging, taking the above problems into consideration, especially for more demanding articles, such as rigid, flat articles, articles with special requirements as to cleanliness, for instance for use in the food industry, and/or articles that may require both packing and unpacking in automated processes. An example of such a type of article is can lids for use in sealing of beverage cans and the like.
Summary of the Invention
It is an object of the invention to alleviate at least some of the above-mentioned problems by providing an improved packaging device for packaging substantially rigid articles.
Another object of the invention is to provide an improved method for packaging substantially rigid articles, which method alleviates at least some of the above-mentioned problems .
These objects and other objects that will be evident from the following description are achieved by a packag¬ ing device and a method which have the features as defin¬ ed in the appended claims. Preferred embodiments are defined in the dependent claims.
The invention is based on the knowledge that packag¬ ing of substantially rigid articles can be facilitated by the articles being fixed in order to maintain a con¬ tinuous stack during the packaging process. In particu- lar, the invention is based on the knowledge that it is possible to maintain a continuous stack of articles by exerting a fixing effect only on the two outermost articles in the stack.
By stack is here meant a continuous length of articles which are arranged side by side. The stack can be arranged horizontally as well as vertically or in some other direction. Particularly the articles are arranged so that a predetermined side of each of the articles is parallel to a corresponding side of the other articles in the stack and so that the centre of each of the articles is arranged on a common axis.
According to a first aspect of the present inven¬ tion, a packaging device is provided for packaging sub¬ stantially rigid articles in a shrinkable packaging mate- rial, comprising a receiving means for receiving a suc¬ cession of articles arranged in a stack to a receiving position; a wrapping means for wrapping packaging mate¬ rial around the stack; and a first shrinking means for shrinking at least part of the packaging material around the stack; the packaging device further comprising at least one holder means provided with two holder supports which are arranged to fix, during at least part of the wrapping of the packaging material and the shrinking of the same, the two outermost articles in the stack and thus maintain a continuous stack. As a result, an improv¬ ed packaging device is provided, which minimizes the risk of machine stoppage and packaging of an incorrect number
of articles and also allows a great and cost-effective flow of articles to be packaged.
It is particularly preferred for the holder means to comprise holder supports, which are arranged to accom- pany, during at least part of the wrapping of the packag¬ ing material and the shrinking of the same, which occurs at least in two different positions, the stack when mov¬ ing between these positions and thus fix the two outer¬ most articles in the stack so as to maintain a continuous stack. This enables a very compact and space-effective device and handling, which is also suitable for handling stacks of a great length, such as about 1 m or more, and/ or stacks with a great variation in length.
A packaging device according to the invention also means that the length of the entire stack including the two outermost articles in the stack is wrapped in a pack¬ aging material while at the same time the compressive force exerted by the holder supports on the outermost articles in the stack ensures that all articles keep their place in the stack and that the disturbance in the packaging process are minimized.
In an embodiment of the invention, the packaging device further comprises moving means for moving the stack between a wrapping position adjacent to the wrap- ping means and a shrinking position adjacent to the shrinking means. The invention according to this embo¬ diment makes it possible to provide a quicker flow of stacks of articles through the packaging device since the stack can be moved from the wrapping position to the shrinking position where the shrinking means performs the shrinkage of the packaging material, which in a shorter time makes the wrapping position accessible for the next stack to be packaged.
In another embodiment of the invention, the packag- ing device also comprises a second shrinking means, the first shrinking means being arranged to shrink the pack¬ aging material around both ends of the stack and the
second shrinking means being arranged to shrink the pack¬ aging material around the central portion of the stack. By two shrinking means adapted to shrink the packaging material in different parts of the stack, the shrinking means can be adjusted to shrink in an optimal manner that part of a packaging material which is arranged around the outer ends of the stack and that part of the packaging material which is arranged along the stack.
In a further embodiment of the invention, the pack- aging device further comprises a discharge means for dis¬ charging the stack from the packaging device. The provi¬ sion of a discharge means makes it possible to discharge the stack after the completed packaging of the stack of articles . In yet another embodiment of the invention, at least one of the holder means and the first shrinking means is arranged on the moving means. This embodiment of the invention allows the stack of articles to be advanta¬ geously arranged in relation to the holder means and/or the first shrinking means even when the stack reaches the wrapping position and allows one of said means to accom¬ pany the stack during packaging of the same until it is fixed by the packaging material, which ensures that no further orientation of the stack is required. The holder supports can be passive, in which case they are adjustable to a current stack length and are then locked in this position, so that they keep the stack in place during wrapping and shrinking of the packaging material and during optional movement between different positions for this, but where no active compression of the stack occurs in the locked position. Alternatively, the holder supports can be active, in which case they continuously exert a compressive force on the stack. This can be achieved in various ways, for instance, by arrang- ing at least one of the holder supports to be resilient on a supporting structure, which in turn can be locked in
a compressing position. However, also active compression by pneumatics, hydraulics or the like is conceivable.
Especially in one embodiment of the invention, at least one of the holder supports is arranged to perform a squeezing motion towards the other holder support. In this way, a squeezing effect is provided, which fixes the stack between the holder supports without the holder supports having to grasp the terminal edge of the stack; only the outsides of the stack have to be accessible for the holder supports. This allows the shrinkage of the packaging material to occur also around the ends of the stack, thus fixing the ends of the stack still more and, after completed packaging, ensuring that no articles fall out of the wrapped stack. Furthermore the invention in this embodiment allows stacks of different lengths to be packaged by the same packaging device without necessitat¬ ing that the packaging device be adjusted in a specific way, by the squeezing motion being capable of having an extent so that the holder support in question can fix stacks of varying lengths.
In a further embodiment of the invention, the receiving means receives that articles in an axial direc¬ tion. The invention according to this embodiment facili¬ tates the provision of a continuous stack of articles since the articles reach the receiving means one after the other and, thus, the need for lateral orientation of the articles can be minimized.
In another embodiment of the invention, the moving means moves the stack in a direction transversely to the longitudinal extent of the stack. The invention according to this embodiment allows that the width of the packaging device does not have to exceed a multiple of the length of the stack, but instead can be kept compact.
In a further embodiment of the invention, the moving means is a rotatable drum. This embodiment of the inven¬ tion also allows a compact design of the invention since the packaging device does not require a great lateral
extent either, while at the same time the rotation of the drum around an axis allows exact movement between diffe¬ rent positions during the packaging process. In this man¬ ner, for instance the drum can be arranged to move the stack between three, or preferably four, different work¬ ing positions. In a first position for instance, the stack can be received and the packaging material can be wrapped around the stack, in a second position shrinking of the packaging material can take place at the end parts of the stack, in a third position the remaining interme¬ diate part of packaging material can be shrunk, and in a fourth position the now packaged stack can be discharged for palletizing or similar continued handling. However, it is of course possible to perform two or more of these operations in the same position and thus reduce the num¬ ber of steps. Furthermore it is possible to use more than four steps to perform additional operations or to divide one of the operations above into several partial opera¬ tions . It is also possible to arrange one or more of the above-stated means directly on the drum, so that they will accompany the drum as it rotates. In particular, it is advantageous to arrange the holder means at each stack-holding station of the drum in order to hold the stack intact during at least some critical parts of the packaging process.
It is possible to arrange the second shrinking means on the drum or outside the drum, as long as it does not shrink the packaging material until in the second shrink- ing position.
In one more embodiment of the invention, the pack¬ aging material is a shrinkable plastic film and shrinkage occurs by heat. Shrinkage of shrinkable plastic film by heat means that an additional material, for instance a binder, is not necessary to seal the packaging material around the stack. Shrinkage by heat also has the advan¬ tage that no movement of the stack has to take place
since it is sufficient for the heat, which can be sup¬ plied in various ways, to reach the shrinkable plastic film.
In another embodiment of the invention, the wrapping means is provided with two rolls of shrinkable plastic film arranged on opposite sides of the wrapping position. This embodiment of the invention allows the stack to be wrapped in a simple way in the shrinkable plastic film when moving the stack to the receiving position. In a further embodiment of the invention, said holder means comprises the first shrinking means. By integrating the first shrinking means with the holder means, it is ensured that orientation of the stack in the holder means results in the stack being in a certain position also relative to the first shrinking means, and no movement of the stack to reach the first shrinking means is necessary.
The device according to the invention can advanta¬ geously comprise at least two receiving means, from which articles can alternately be moved on. Preferably the num¬ ber of receiving means can be the same as the number of positions of the drum, or alternatively half this number. For a drum with four positions, thus two or four receiv¬ ing means can advantageously be provided. Furthermore the receiving means can be designed to receive different types of articles, such as lids of different dimensions, different geometries (for instance round, elliptic or square), different materials etc. In discharging, these different articles may in that case be separated, which makes it possible to use the packaging device for two or more parallel flows.
According to a further aspect of the invention, a method is provided for packaging substantially rigid articles in a shrinkable packaging material, comprising the steps of receiving a succession of articles arranged in a stack to a receiving position, wrapping packaging material around the stack, and shrinking the packaging
material around the stack, the articles, during at least part of the wrapping and shrinking of the packaging mate¬ rial, being fixed so as to maintain a continuous stack. This results in reliable and cost-effective packaging of the articles, and essentially the same advantages as dis¬ cussed above in connection with the first aspect of the invention are achieved also for this aspect.
The invention is applicable to packaging of articles of different types which have significant torsional rigi- dity and are stackable, such as lids, cans, food packages and other articles of consumption. In particular the invention is advantageous for more demanding articles, such as rigid, flat articles, articles with special reguirements as to cleanliness, for instance for use in the food industry, and/or articles which need to be packed and unpacked in automated processes. An example of such a type of article is can lids for use in sealing of beverage cans and the like.
Brief Description of the Drawings
The invention will now be described in more detail with reference to the accompanying schematic drawings which illustrate preferred embodiments of the invention and in which Fig. 1 is a schematic side view of a system compris¬ ing an embodiment of the invention;
Fig. 2 is a schematic side view of a wrapping means according to an embodiment of the invention;
Fig. 3a is a schematic side view of a moving means 12 according to an embodiment of the invention;
Fig. 3b is another schematic view of the moving means 12 according to an embodiment of the invention;
Fig-. 4a is a schematic side view of a holder means according to an embodiment of the invention; Fig. 4b is another schematic side view of a holder means according to an embodiment of the invention;
Fig. 5a is a schematic top plan view of an alterna¬ tive embodiment of a system according to the invention; and
Fig. 5b is a side view of the system in Fig. 5a.
Detailed Description of the Invention
Fig. 1 shows a packaging device 1 designed accord¬ ing to an embodiment of the invention and comprising a receiving means 2 with a receiving position 3 for receiv- ing one of a plurality of articles 4 arranged in succes¬ sion in a stack 5. The receiving means 2 preferably receives the articles 4 in an axial direction, for instance by the articles 4 being moved to the receiv¬ ing position 3 in a succession as a separated length of articles 4. In this way, the articles 4 are already when arriving at the receiving position 3 arranged in a stack 5. To reduce the risk that the stack 5 falls apart, the articles 4 can advantageously be form-fitted to one another, as is the case with, for instance, plastic or metal lids.
Advantageously, a plurality of receiving means 2 and receiving positions 3 can be provided, from which the articles to be packaged are then alternately fed. Fig. 1 shows an embodiment with two receiving means, but additional receiving means, such as four, can also be arranged.
Moreover Fig. 1 shows a transferring means β, which in this embodiment of the invention is arranged on a con¬ veyor or linear unit 7. The transferring means 6 raises the stack 5 from the receiving position 3 of the receiv¬ ing means 2 to a wrapping means 8 for wrapping a packag¬ ing material 9 around the stack 5. In this embodiment the packaging material 9 is wound on two rolls 10 and 11. A preferred embodiment of the wrapping means 8 is further commented on in Fig. 2. The wrapping means 8 is arranged adjacent to a moving means 12, in a preferred embodiment designed as a rotatable drum, which comprises at least
one holder means 13 arranged to fix, during at least part of the packaging, by compressive force the two outermost articles 4 in the stack 5 and thus maintain a continuous stack 5. In the preferred embodiment according to Fig. 1, the moving means 12 comprises four holder means 13. In this way, the moving means 12 can at the same time fix four stacks 5 and by rotation process the stacks in four different processing positions. The capacity of the mov¬ ing means 12 can be varied by the number of holder means 13 and processing positions in other embodiments of the invention being fewer or more than four. In the embodi¬ ment in Fig. 1, clockwise rotation of the moving means 12 occurs in steps, which moves the stack 5 from a wrapping position 14 to a first shrinking position 15, in which the packaging material 8 is shrunk by a first shrinking means 14 (not shown) around the ends of the stack 5. Sub¬ sequently the stack 5 is moved by further rotation of the moving means 12 on to a second shrinking position 16 where shrinkage of the packaging material 8 by a second shrinking means 17 occurs along the length of the stack. If a plurality of receiving means are arranged and adapted to receive different types of articles, also the holder means of the drum can advantageously be adjusted to these articles, in which case each holder means is dedicated to a certain type of article.
The packaging material preferably is a shrinkable plastic film which is shrunk by being subjected to hot air, in this embodiment hot air from a hot air unit 18. The packaging material can also be made of other mate- rials, such as paper, and shrinkage can occur in other ways than by hot air, for example mechanically.
After performing these two shrinking operations of the packaging material, the stack 5 of articles 4 is now completely packaged. The moving means 12 now rotates to a fourth processing position where the fixing of the pack¬ aged stack performed by the holder means 13 ceases and a
discharge means 19 discharges the stack from the packag¬ ing device 1.
Fig. 2 is a side view of a wrapping means 8 accord¬ ing to an embodiment of the invention comprising two rolls 10 and 11 of packaging material 9 from which rolls two ends of the packaging material 9 are unwound towards each other to a welding apparatus 20 comprising two sepa¬ rable weld jaws 21. The packaging material 9 runs from the rolls 10 and 11 to the welding apparatus 20 via one or more wheels 22. The weld jaws 21 are each provided with two welding means 23 between which a cutting means 24 is arranged. The stack 5 to be wrapped in packaging material 9 is put down, according to the embodiment shown in Fig. 2, between the two separated weld jaws 21 from above, after which the packaging material 9 abuts against the underside and the sides of the stack 5. Subsequently the weld jaws are brought together and compress the pack¬ aging material 9 from the two rolls 10 and 11, after which the four welding means 23 in the two weld jaws pro- vide two parallel but separated weld joints of the pack¬ aging material 9, which joins the packaging material from the two rolls 10 and 11. Finally, before the weld jaws 21 are separated from one another, the cutting means 24 cuts the packaging material between the two weld joints, so that the stack 5 wrapped in packaging material 9 is released from the rolls 10 and 11. Subsequently the wrap¬ ping means 8 is again available to receive a new stack 5. It should be noted that the thus described wrapping of packaging material 9 around a stack requires that the packaging material 9 from the two rolls 10 and 11 be already joined as the wrapping starts, which joining can be done by manually passing down packaging material 9 between the separated weld jaws 21, after which the weld jaws are pressed together and weldings and cutting as described above are performed.
Fig. 3a is a side view of a moving means 12 accord¬ ing to an embodiment of the invention comprising four
holder means 13 suspended between two end walls 25 (of which one is to be seen) .
Fig. 3b is another side view of the same moving means 12 as in Fig. 3a comprising four holder means 13 (of which two are to be seen) , suspended between two end walls 25. The end walls 25 are joined to a main shaft 26 which can be rotated by means of a motor 27. Each holder means 13 is provided with two holder supports 28 which are slidable along the longitudinal axis of the moving means to be able to fix a stack 5. The holder means 12 are articulated to the end walls 25 in such a manner that rotation of the main shaft 26 and the end walls 25 only causes movement of the individual holder means 13 without rotating them about their own longitudinal axis. Fig. 4a is a side view of a holder means 13 accord¬ ing to an embodiment of the invention, the holder means 13 being provided with two stack supports 29 which are adapted to support a stack 5 during packaging of the same. Fig. 4b is another side view of the holder means 13 according to Fig. 4a. Fig. 4b also shows two holder sup¬ ports 28 belonging to the holder means and oriented towards one another, which are slidably arranged on the holder means by a slide means 30 each. Due to the slide means 30, the holder supports 28 are movable in the longitudinal direction of the holding means, which allows the holder supports 28 to be moved towards one another and thus fix the two outermost articles 4 in the stack 5 by compressive force. In this manner, the holder supports 28 can be moved towards one another and fix a stack 5 by a squeezing motion.
Moreover the holder supports 28 are each provided with a connecting means 31, to which a supply device for supplying hot air can be connected. In this way, the shrinkage of the packaging material 8 can be provided while the stack 5 is fixed between the holder supports 28.
As discussed above, the packaging device is prefer¬ ably arranged in an automated system, which automatically advances, for instance, can lids which are to be packag¬ ed, packages them in stacks and then moves the packaged stacks on, for instance for automated packaging on pallets. Alternatively, it is however also possible to manually handle supply of stacks to the packaging device and/or discharge of the packaged stacks. Such a system is schematically shown in Figs 5a and 5b. In the semiautomatic alternative embodiment shown in Fig. 5, the operator manually performs the introductory handling of the stacks which are to be packaged and thus places them manually in the wrapping means 108 and the rotatable drum and the moving means 112, which functions in essentially the same way as described above. The wrap¬ ping means 108 is in this embodiment preferably adapted to insert the stacks essentially horizontally, so as to provide a more ergonomic working environment for the ope¬ rator, and are suitably fed via two film rolls 110, which can be arranged in a high and a low position, respective¬ ly. To facilitate the supply of the articles, such as can lids, and to separate the stacks that are to be packaged, for instance a buffer table 102 can be provided, to which the articles to be packaged are preferably supplied con- tinuously. Moreover a carriage or shuttle 103 can be pro¬ vided to separate stacks from the buffer table and supply them to be left in the wrapping means and the drum.
The manual supply of the articles that are to be packaged can be combined with automated palletizing of the completely packaged stacks. Alternatively, this can also take place manually, as will be discussed below. It is also possible to provide automated supply of the articles that are to be packaged, but manual palletizing of the completely packaged stacks. In automated palletizing, for instance the packaged stacks can be conveyed to palletizing equipment, such as the equipment disclosed in EP 1453749 and US 5769601 by
the same applicant. These two documents are herewith incorporated by reference.
In manual palletizing, the packaged articles can be discharged in a discharge trough 130 from which they can be manually removed and arranged on a pallet 131.
A system where supply and/or palletizing occur manually can be made less expensive to manufacture than fully automatic systems while, however, greater efforts are necessary in operation. It will be appreciated that many modifications of the above-described embodiment of the invention are con¬ ceivable within the scope of the invention as defined by the appended claims. The term moving device also relates to a type of device other than the drum illustrated in the drawings. For instance, within the scope of the invention it is also possible to have a moving device, which uses linear motion, between processing positions, for instance in the form of a conveyor belt.
In the same way, it is also possible to have, within the scope of the invention, a receiving means, which receives a plurality of articles by external propulsion, for instance in the form of a conveyor consisting of rotating wheels. This also applies to the wrapping means, which within the scope of the invention, for instance, can also be designed in the form of a slip-on device which slips on a packaging material at one side of the stack. Also the shrinking means can, within the scope of the invention, be designed in other ways, for instance in the form of a device for pulling out the packaging mate- rial in one direction, with subsequent shrinking in another direction. It should further be noted that also the holder means can, within the scope of the invention, be designed in a different manner, for instance in the form of a grip or clamp. Finally it should be understood that motions performed by movable parts within the scope of the invention can be accomplished in various ways, for
instance by means of linear motors, step motors, hydrau¬ lics, compressed air, gear wheels, chain or belt drive.