EP0269809B1 - Device for making a package unit completely enveloped by a shrink foil - Google Patents

Abstract

Apparatus for the production of a packaged unit completely enclosed by a heat shrinkable foil where the unit is made up of a plurality of layers of items of the same general shape stacked one layer on another with a final layer being inset relative to the subjection layers forming inset spaces for receiving support members of a lifting device in the final package condition of the unit. Initially, a shrinkable foil is placed over the stack and is shrunk onto it. Next, the stack is inverted so that the final layer is located at the bottom. The apparatus reduces the space requirement for producing the packaged unit with the stack being moved as little as possible and increasing production output. The tool for shaping the foil on the stack are combined with at least one of the foil applying unit and a frame of the shrinkage unit and with the conveying device for the stack.

Description

The invention is directed to a device for producing a packaging unit completely covered with shrink film according to the preamble of claim 1.

It is known (DE-PS 2 760 249 & FR-A 2 346 229) to arrange the turning device between a single shrink film applicator and a single shrinking device in systems of this type with a lower power requirement to reduce the outlay on apparatus, so that after the application the first shrink film only passes through the turning device without turning the relevant stack and then the first shrink film can be shrunk in the shrinking device, whereupon the stack moves back to the turning device, is turned there, moved back into the shrink film application device and covered there with the second shrink film and then under again simply passing the turning device is transported back into the shrinking device for shrinking on the second shrink film. For profiling the niches in this known system, however, two profiling devices must also be provided, namely one in front of the shrinking device for profiling the niches, if these are on top, and one after the shrinking device for profiling the niches, if these after turning the stack are below.

From DE-OS 2 702 613 it is known, by lowering a corresponding area of the conveying and standing track, to move the narrower special layer located on this standing track against a stop on one side, so as to ensure the profiling and the other side through that Swing in a pressure flap to form.

Another possibility of forming the stacking niches in the shrink film hoods is shown in DE-PS 2 839 089. There, a stack is conveyed on leaving a shrinking furnace on a conveyor and, with the shrink film hood partially drawn into the niches, is fed to a station which has roller sets that can enter the niches. The roller sets are initially used as conveying elements, the stack is placed on a lowerable, rollable area, this is lowered by the roll dimension, the rollers then move into the niches, whereupon the stack is lowered so that the roller sets open the shrunk hood areas press the bottom of the excess of the stack.

With the older, but not prepublished EP 0 250 697, a further device has been proposed, in which a single shrink film application device and a single shrinking device are designed as a combination device, and in which the shaping tools of the profiling device are permanently assigned to a subsequent turning device, the shaping tools being used by Drive means arranged on the turning device after the application and shrinking of the first shrink film in the form position in the niches, after turning the stack in the release position and after returning the stack to the combined shrink film application and shrinking device and covering and shrinking the second shrink film there and then feeding it again Turning device for re-profiling the niches can be moved back into the form position and subsequently for releasing the stack laterally into the release position. This device is characterized by a small footprint and little equipment. In certain applications, however, it is possible that the arrangement of the shaping tools in the area of the turning device will not result in a perfect profiling of the niches, since the film may already have cooled to a large extent during the transport from the shrinking device to the turning device required before profiling that the film pulls diagonally over the niches due to the strong shrinking forces developed during cooling and can thus be injured when the molds are attacked. Depending on the shrink film used in each case, these phenomena can have different degrees of severity.

The object of the invention is to provide a solution with which, while maintaining the possibility of a compact design, a perfect shaping of the niches without risk of damage to the shrink film is possible.

With a device of the type described in the introduction, this object is achieved according to the invention in that the shaping tools of the profiling device are arranged in the region of their conveying and standing path in the shrinking device designed as a vertically movable shrinking frame.

With the invention, with the possibility of a compact design, a particularly good profiling of the niches is achieved, since the profiling device can be activated by the shrink frame immediately after the application of heat, i.e. the stack no longer has to travel any distances and the film has not yet cooled, so that injuries to the film when the niches are formed can be reliably avoided. In practice, the control can be made so that the shrink frame e.g. is first lowered over the stack with the film hood to be shrunk down in the direction of the transport path and then moved upward again with the application of heat, with this upward movement of the shrink frame, i.e. after the release of the niche area, the molding tools of the profiling device are inserted into the niches.

It is particularly expedient if the shrink film application device and the shrink frame are designed as a combination device. This configuration achieves a particularly compact design, the shaping tools of the profiling device then being arranged accordingly in the combination device.

One embodiment provides that molding tools of the profiling device are additionally provided in the opposite upper area of the shrinking device. It is thereby achieved that not only the lower stack area to be treated can be processed with molding tools, but also the upper one as soon as the heat application by the shrinking frame in the upper area of the stack has ended. This is particularly important if an upper special layer was first formed on a stack, in order to later serve as a standing area for palletless packaging and to provide the niches for the forks of fork-lift trucks. If this special layer, which is initially on top, is shrink-wrapped by means of a shrink hood, it is useful to ensure the niche formation here already by means of molding tools.

The invention also provides that the molding tools are designed as roller sets which are known per se and can be inserted into the niches on the stack and which ensure particularly good shaping of the niches.

It is particularly expedient if the region of the conveying and standing track which can be raised and lowered is shorter and / or narrower than the special layer in the region of the shrinking device. With this design it can be achieved that a shrink film hood placed over the stack can also cover large areas of the bottom surface of such a stack, since this liftable and lowerable web area only acts on parts of the bottom surface. The shrinking can therefore not only take place in the area of the niches, but also extend into the floor area of the special layer which is then below.

It goes without saying that such a configuration makes it irrelevant whether it is a matter of so-called palletless stacks or stacks stacked on pallets. In this case, the covered hoods can cover large areas on the bottom surface of the pallet.

In order to ensure a position that is as perfect as possible, the invention provides that the molding tools are guided in their pressing or shaping movement by means of constrained guides, in particular link surfaces, which are arranged fixedly on the lifting and lowering device. For the invention, it is initially irrelevant whether only the lifting and lowering device executes the necessary movements, or whether the molding tools themselves are also designed to be raised and lowered, as is additionally provided by an expedient embodiment of the invention. The molds can e.g. be positively guided by means of rollers over corresponding slide tracks, be it over their entire path relative to the stack or at least over partial distances.

It can be expedient to arrange the roller sets of the molding tools on spring-loaded rockers, wherein these rockers can be designed such that they can be raised and lowered, as a result of which the molding tools can be moved in two dimensions. With such a configuration, it is possible to compensate for the position of a stack that is not exactly positioned, without the operability being influenced thereby.

• Fig. 1 eine Seitenansicht auf eine Ausführungsmöglichkeit eines Teils der Vorrichtung nach der Erfindung teilweise geschnitten,
• Fig. 2 eine Aufsicht auf die Vorrichtung gemäß Pfeil in Fig. 1,
• Fig. 3 eine stirnseitige Ansicht der Vorrichtung gemäß Pfeil 111 in Fig. 1,
• Fig. 4 ein Formwerkzeug der Profiliervorrichtung,
• Fig. 5 eine stirnseitige Ansicht dieses Formwerkzeuges sowie
• Fig. 6 eine schematische Übersicht der Arbeitsabläufe der Gesamtvorrichtung mit zwei unterschiedlichen Varianten in den Abb. 6.9 bis 6.11. bzw. 6.9' bis 6.11'.

The invention is explained below with reference to the drawing, for example. This shows in:

• 1 is a side view of an embodiment of a part of the device according to the invention, partially cut,
• 2 is a plan view of the device according to the arrow in FIG. 1,
• 3 shows an end view of the device according to arrow 111 in FIG. 1,
• 4 a molding tool of the profiling device,
• Fig. 5 is an end view of this mold and
• 6 shows a schematic overview of the work processes of the overall device with two different variants in FIGS. 6.9 to 6.11. or 6.9 'to 6.11'.

1 to 5 initially only show elements of the common conveying and standing path F which is arranged in the area of a shrink film applicator (not shown) with a simultaneous shrinking device. The essential elements of this part of the overall device consist of a belt conveyor B on a scissor lift table S (not shown in more detail) and the belt conveyor B in the conveying direction of surrounding rollers R. In the conveying direction, in front of and behind the belt conveyor, profiling devices P are arranged, the function of which, particularly in connection with below 4 and 5 is described in more detail.

The belt conveyor B is manufactured in a known manner, i.e. it has an electromotive drive (not described in more detail), tape guide and tensioning rollers and the like. More. The belt conveyor B can be moved up and down out of the plane of the conveyor track F by a considerable amount via the scissor lifting table S, as is indicated schematically in FIG. 6. The size of the belt conveyor is such that it is shorter than the special layer of a packaging unit, as seen in the conveying direction, as well as narrower, in such a way that when the special layer is placed on the conveyor track, the lateral short conveyor rollers R support the stack edges.

The profiling devices P are shown in FIGS. 4 and 5 and initially generally designated 1. Each of these profiling devices 1 has a frame 2 designed as a rocker with guide rollers 3 and 4, which interact with the flanges and the web of essentially U-shaped profiles (FIG. 5). On the side facing the conveyor track F, each profiling device carries a roller set 6 with two rollers 7 in the example shown.

Each frame 2 can be raised and lowered via a reciprocating piston 8 (FIG. 3), as is shown by the double arrow 9 in the upper part of FIG. 4. The articulation point of the piston-cylinder unit 8 is designated by 10 in FIG. 5. The lower, A fixed articulation point to, for example, a cross strut 11 has the reference number 12 in FIG. 3.

It is essential for the invention that the profiling device 1 is guided over guide surfaces 13 and 14, which are shown schematically in FIG. 4, at the upper ends of the flanges of the aforementioned U-profiles, the guide surface 14, which enables a greater pivoting movement, to be provided on the side facing the belt conveyor B. , while the opposite slotted surface 13, which allows a slightly smaller expansion of the spreading angle of the rockers 2, is arranged on the side facing away from the belt conveyor.

The profiles 7 can thus be seen to perform a pivoting movement, as is shown in the upper part of FIG. 4 by a double arrow, which bears the reference symbol 15 and which is to represent the different pivoting-out path due to the different arrow length.

The mode of operation of the invention is now described in more detail with reference to FIG. 6. As far as letters have been used above to identify individual assemblies, this is retained in the description of the functional sequence according to FIG. 6.

A stack of goods 16 is shown in FIG. 6.1 with a special layer 17 lying on top. A shrink frame designated 18 surrounds this stack of goods, heat application flames 19 only being indicated; this is not important.

Position 6.2 shows the stack of goods 16 in the raised position with a first film hood 20 covered by means of a shrink film applicator 21. In this raised position, the shrink film applicator is now moved and the shrink frame 18 is lowered, where appropriate, whereupon the shrink frame begins to apply heat, so that part of the shrink hood 20, designated 22 in Fig. 6.3, shrinks under the floor. The shrink frame 18 and the shrink film application device 21 can expediently be designed as a component as a so-called combination device.

Fig. 6.3 shows that after applying the heat to the entire shrink film, a profiling device P 'can be provided, which presses the still warm, shrunk-on hood into the corners between the stack 16 and the special layer 17.

In Figure 6.4 it is only indicated by dashed lines that according to this procedure the stack of goods 16 is introduced into a turning device, which is not important here, this turning device is generally designated with 23.

After leaving the turning device 23, the mode of operation of which is indicated by the arrows shown there, the stack of goods 16 with its special layer 17 is positioned on the belt conveyor B and raised from the aligned position shown in FIG. 6.5 to the raised position according to FIG. 6.6. A second shrink film hood 20 '(counter hood) is applied by means of the shrink film applicator 21, which is not shown there, the shrink frame 18 moves downward and begins to apply heat from the bottom up until the second hood has shrunk, as shown in FIG. 6.7.

6.8 shows the stack 16, lowered into the plane of the conveyor F.

In principle, two variants can now be used, namely on the one hand as shown in Figures 6.9 to 6.11 or as in the alternative illustrations 6.9 'to 6.11 _' .

In the variant according to FIGS. 6.9 'to 6.11', the stack of goods 16 can remain in the conveying plane F ', then the roller sets 6 are raised according to arrow 9 (FIG. 6.9'), they form the corner and are then lowered again ( Fig. 6.10 _' ), so that finally the stack of goods 16 can leave the device (Fig. 6.11').

In the variant according to FIGS. 6.9 to 6.11, the stack of goods 16 can be lowered from the conveying plane F (FIG. 6.9) in such a way that the roller sets 6 form the corners accordingly. The stack 16 is then raised again to the level F (FIG. 6.10), in order to finally leave the entire device for further processing (FIG. 6.11).

The guidance over the link surfaces 13 and 14 and the spring load (24) of the rockers or the frame 2, which carry the form rollers 7, not only ensures that the rollers 7 form the niches in the end layer 17 of the stack 16 cleanly, but also that centering takes place when the stack of goods is not precisely positioned, so that the stack of goods 16 can always be set in a very optimal position, in particular relative to the shrink frame 18.

The profiling devices can also be provided laterally on the belt conveyor B transversely to the conveying direction.

Claims (8)

1. Apparatus for carrying out a method of manufacturing a package, which contains items stacked on top of one another in several layers and is completely wrapped in shrink foil, wherein at first a plurality of layers of items of the same base area are stacked on top of one another, on which a special layer of items is then stacked in such a manner that at least two parallel niches are formed for lifting elements of a lifting appliance subsequently to engage in, then a first shrink foil is applied to the whole stack and is then shrunk close to the stack by the application of heat, whereupon the whole stack is rotated by 180° so that the special! layer with the niches ends up at the bottom, whereupon a second shrink foil is applied to the stack and then shrunk close to the stack by the application of heat, and after shrinking of the second shrink foil the shrink foils are shaped in the niches, the apparatus also comprising shrink foil applying apparatus (21), shrink apparatus (18), turning apparatus (23) and profiling apparatus (P) for shaping the shrink foils in the niches, and comprising 3 conveying and standing belt (F) passing through all the apparatus, characterised in that the shaping tools (7) of the profiling apparatus (1) are mounted in the shrink apparatus formed as a height-adjustable shrink frame (18) in the region of its conveying and standing belt (F).

2. Apparatus according to claim 1, characterised in that the shrink foil applying apparatus (21) and the shrink frame (18) are formed as combined apparatus.

3. Apparatus according to claim 1 or 2, characterised in that, in addition, shaping tools (7) of the profiling apparatus (1) are also provided in the opposite upper region of the shrink apparatus.

4. Apparatus according to claim 1 or one of the subsequent claims, characterised in that the shaping tools (7) are formed as roller sets (6) known per se and insertable into the niches in the stack (16).

5. Apparatus according to claim 1 or one of the subsequent claims, with a liftable and lowerable region of the conveying and standing belt, characterised in that the liftable and lowerable region (B) of the conveying and standing belt is shorter and/or narrower in the region of the shrink apparatus

6. Apparatus according to claim 1 or one of the subsequent claims, characterised in that the pressing or shaping movement of the shaping tools (7) is guided via guides, in particular crank surfaces (13, 14), mounted in a fixed manner on the lifting and lowering apparatus (S).

7. Apparatus according to claim 6, characterised in that the shaping tools (7) are formed so that they can be raised and lowered and the fixed slide surfaces (13, 14) are provided in the longitudinal and/or transverse conveying direction.

8. Apparatus according to claims 6 or 7, characterised in that the roller sets (6) of the shaping tools (7) are mounted on spring-loaded (24) rocker arms (2).

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