Device for making a package unit completely enveloped by a shrink foil

DESCRIPTION

The invention is directed to a device for manufacturing a fully lined packaging unit with shrinkable plastic sheet according to the preamble of claim 1.

It is known (document DE-PS 27 60 249 and document FR-A-2346229), in installations of this type with small power consumption for the reduction of instrumental expenditure, to arrange the turning device between a single device for applying plastic sheets Shrinkable and a single shrinking device, so that after the application of the first shrinkable plastic sheet the flip device only passes without turning over the corresponding stack and then the first shrinkable plastic sheet in the shrinking device can be shrunk, after which the stack is retracted to the flip device, there it turns around, it is moved back to the device for applying shrinkable plastic sheets and there it is coated with the second shrinkable plastic sheet and then it is transported back to the shrinking device by simple step renewed by the turning device for shrinking the second shrinkable plastic sheet. For profiling of the cavities, two profiling devices must also be provided in this installation so additionally known only, ie one before the shrinking device for profiling the cavities, when these are up, and another after the shrinking device for the cavities profiling, when these are after the battery is turned down.

From DE-OS 27 02 613 it is known, by lowering a corresponding area of ​​the transport and position track, to move the narrower special layer that is located on this position track against a stop to one side, so guarantee profiling and form the other side by turning a clapper.

Another possibility, to form the stack cavities in the shrinkable plastic sheet hoods, is shown in DE-PS 28 3 089. There a battery is subsequently transported on a conveyor after leaving a shrinking furnace and is led to a station with the shrinkable plastic sheet hood partially inserted into the cavities, which has roller bearings, which can enter the cavities. On the other hand, the roller sets are first used as transport elements, the stack is deposited in a downward rolling area, this is lowered in the dimension of the rollers, and the rollers then enter the cavities, after which then The battery is lowered until the sets of rollers press the shrunk hood areas on the lower part of the projection of the battery.

With the previous but not previously published document EP 0 250 697, a further device has been proposed, in which there are configured a single device for applying plastics sheets and a single device shrinking as a combination device, and in which the tools of shape of the profiling device will be fixed fixed to a flip device connected next, for which purpose the shape tools are movable by means of the actuation means arranged in the flip device after the application and shrinkage of the first shrinkable plastic sheet in the position of forming in the cavities, after the battery is turned into a release position and after the battery has been returned to the device, combining the application of shrinkable and shrinkable plastic sheet and the local and shrunk coating of the second shrinkable plastic sheet and after the renewed lead to the turning device for the subsequent profiling of the cavities back to the position of conformation and then of the lateral evacuation of the stack back to the position of release. This device stands out for a small need for space and a small instrumental expense. In certain cases of use it is, however, possible that impeccable profiling of the cavities does not take place due to the arrangement of the shape tools in the area of ​​the turning device, since the sheet can already be largely cooled in the required transport from the shrinking device to the turning device before profiling, with the consequence that the sheet is stretched diagonally over the cavities due to the large shrinking forces developed in the cooling and thus can be damaged in the grip of the shape tools. These phenomena may weigh differently depending on the shrinkable plastic sheets used in each case.

Misioán of the invention is the creation of a solution, with which it is possible, with the preservation of the possibility of a compact constructive form, an impeccable conformation of the cavities without danger of damage to the shrinkable plastic sheet.

With a device of the type mentioned at the beginning this mission is solved according to the invention so that the shape tools of the profiling device will be arranged in the shrinking device configured as a shrink frame movable in height in the area of ​​its transport track and position.

With the invention a particularly good profiling of the cavities is achieved with the possibility of a compact construction, since the profiling device is immediately activated after the heat input by the shrinking frame, that is to say the battery must not go any further way. and therefore the sheet is still not cooled, so that sheet damage in the cavity forming can be safely avoided. In practice, the command can also be achieved so that, for example, the shrink frame is lowered down first on the stack with the sheet hood to shrink in the direction of the transport track and then moved upwards again with application. of heat, to which effect already in this upward movement of the shrinking frame, that is after the release of the cavity area, the shape tools of the profiling device are introduced into the cavities.

It is especially advantageous that the device for applying shrinkable plastic sheets and the shrinking frame are configured as a combination device. For this configu2

020 241 an especially compact construction form is achieved, for which purpose the shape tools of the profiling device are then arranged in correspondence in the combination device.

In one embodiment it was provided that there were also tools for forming the profiling device in the upper opposite area of ​​the shrinking device. This ensures that it can be worked with the shape tools, not only the lower area of ​​the stack to be handled, but also in the overflow, as soon as the thermal input by the shrinking frame is finished in the upper area of ​​the stack. This is essential in particular when a special top layer was formed on a stack in the first place, to be used later in packaging without a loading platform as a positioning surface and to provide the cavities for the introduction of the forklift poles with a fork lift. If this special layer that is in the first place above shrinks by means of a shrinkable hood, it is useful to guarantee the formation of cavities by the shape tools.

The invention also provided that the shape tools are configured as sets of rollers themselves known, intraducibies in the cavities in the stack, which guarantee a particularly good conformation of the cavities.

It is especially convenient that the upward and downward area of ​​the transport and positioning track in the area of ​​the shrinking device be shorter and / or narrower than the special layer. With this configuration, it is possible to achieve that a shrinkable plastic laminating hood placed on the stack can also cover large areas of the base surface of such a pile, since this upward and downward track area only drives parts of the base surface. Therefore, the lower shrinkage can take place not only in the area of ​​the cavities, but also to reach the base area of ​​the special layer that is then underneath.

It is understood that in such a configuration it is indifferent whether it is a so-called stack without a loading platform or a stack stowed on loading platforms. In this case the covered hoods can cover large areas on the base surface of the loading platform.

In order to guarantee the best possible position, the invention provides that the shape tools are guided in their tightening movement or formed by forced guides stationary in the up and down device, in particular colisa surfaces. For the invention, on the other hand, it is in the first place indifferent if only the raising and lowering device performs the necessary movements, or if the shape tools themselves are also configurable on the other hand up and down, as additionally provided for a convenient configuration of the invention. . In addition, the shape tools can be guided, for example, by means of rollers through the corresponding colisa tracks, be it for their entire path in relation to the stack or at least on partial sections.

It may be convenient to arrange the roller sets of the shape tools on spring loaded rocker arms, for which purpose these rocker arms can be configured up and down, so that the shape tools are movable in two dimensions. By means of such a configuration, it is possible to compensate for the position of a battery that is not exactly positioned, without this affecting the operating capacity.

The invention is explained more closely in the following by way of example with the help of drawing. This shows in:

Fig. 1 a side elevation partially cut on a possibility of realization of a part of the device according to the invention,

Fig. 2 a plan view from above of the device following arrow III in fig. one,

Fig. 3 a view of the front side of the device following arrow III in fig. one,

Fig. 4 a shape tool of the profiling device,

Fig. 5 a front view of this shape tool, and

Fig. 6 a schematic overview of the working developments of the total device with two different variants in Figures 6.9 to 6.11 or 6.9 'to 6.11'.

In figures 1 to 5, only elements of the joint transport and positioning track F are represented first, which is arranged simultaneously with the shrinking device in the area of ​​a shrinkable plastics laminating application device not closely reproduced. The essential elements of this part of the total device consist of a belt conveyor B on a lifting platform S by pantograph not closely represented and the sliding rollers R laterally enclosing the conveyor B by belt in the direction of transport. In the direction of transport in front of and behind the conveyor by tape conveyor, the profiling devices P are arranged, whose function is described more closely ahead, in particular in conjunction with figures 4 and 5.

The belt conveyor B is constructed in the known manner, that is to say it has an electromotorized drive not described more closely, tape guide rollers and tension rollers, and similar elements. On the pantograph platform S the belt conveyor B is movable out of the plane of the transport track F in a considerable amount up and down, as this is schematically represented in fig. 6. But the size of the belt conveyor has been chosen so that, seen in the direction of transport, it was configured not only shorter than the special layer of a packaging unit, but also narrower, so that in the deposit of the special layer on the conveyor belt the short lateral transport rollers R support the edges of the stack.

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The profiling devices P are represented in figures 4 and 5 and firstly designated in general with 1. Each of these profiling devices 1 has a frame 2 configured as a rocker, with guide rollers 3 and 4 that collaborate with flanges and the core of profiles in the essential U-shaped (fig. 5). Each profiling device has a set of rollers 6 with two rollers 7 on the side shown towards the transport track F in the example shown.

Each frame 2 can be raised and lowered by an elevator piston 8 (fig. 3), as shown in the upper part of figure 4 with the double arrow 9. The articulation point of the cylinder and piston unit 8 is indicated by 10 in fig. 5. The stationary articulation point, lower, in for example a cross brace 11 bears in fig. 3 reference mark 12.

Essential for the invention is a hole 1 of the profiling device 1 on colisa surfaces 13 and 14, schematically drawn in fig. 4, at the upper ends of the flanges of the aforementioned U-profiles, for which purpose the surface 14, of colisa that allows a greater turning movement is provided on the turned side towards the belt conveyor B, while the surface 13 of opposite colisa that allows a somewhat smaller broadening of the extension angle of the rockers 2 is arranged on the separate side of the belt conveyor.

Perceptibly, the profilers 7 can thus make a turning movement, as shown in the upper part of fig. 4 by a double arrow, uqe bears the reference mark 15 and that for the different arrow lengths must represent the different turning path.

The operation of the invention is described hereinafter more closely with the aid of fig. 6. As previously, letters have already been used for the marking of isolated construction groups, these are preserved in the description of the performance development following Figure 6.

In Fig. 6.1 a stack 16 of material with a special layer 17 located at the top is shown. A shrinking frame 18 marked with 18 surrounds this material stack, for which purpose the heat supply flames 19 are only indicated, since this is not the case here.

Position 6.2 shows the stack 16 of material in a raised position with a first hood 20 of openwork sheet by means of a device 21 for applying shrinkable plastic sheets. In this raised position the shrinkable plastic sheet application device is now moved and the shrinking frame 18 is lowered down if necessary, after which the shrinking frame begins with the application of heat, so that a part of the hood 20 shrinkable, indicated with 22 in fig. 6.3, shrinks under the base. On the other hand, the shrinking frame 18 and the device 21 for applying shrinkable plastic sheets can be conveniently configured in a construction piece such as the so-called combination device.

Fig. 6.3 shows that after the application of heat over the entire shrinkable plastic sheet, a profiling device P 'can be provided, which crushes the shrunk hood still hot in the corners between the stack 16 of material and the special layer 17.

In Fig. 6.4 it is indicated so only in dashed lines that by this method of procedure the stack 16 of material is introduced into a turning device, which here is not more closely treated; This flip device is generally indicated with 23.

After leaving the flip device 23, whose working form is indicated by the arrows drawn there, the stack 16 of material is positioned with its special for 17 on the belt conveyor B and is lifted from the aligned position reproduced in fig. 6.5 to the raised position follow figure 6.6. By means of the reproduced field, more closely, device 21 of application of shrinkable plastic sheets is applied, a second hood 20 'of shrinkable plastic sheet (counter-hood) is applied, the frame 18 shrinks downwards and the heat application starts from the bottom up until the second hood is shrunk, as shown in fig. 6.7.

Fig. 6.8 shows the battery 16 lowered to the plane of the conveyor F.

From now on, the movement can basically be followed in two variants, that is, on the one hand, as reproduced in figures 6.9 to 6.11 or, on the other hand, as it is in alternative figures 6.9 'to 6.11'.

In the variant, figures 6.9 'to 6.11' follow the stack 16 of material can remain in the transport plane F ', then the roller sets 6 are lifted following the arrow 9 (fig. 6.9') and these form the corners and they are again lowered (fig.6.10 '), so that finally the stack 16 of material can leave the device (fig. 6.11').

In the variant, figures 6.9 to 6.11 follow the stack 16 of material can be lowered from the transport plane F (fig. 6.9), such that the sets of rollers 6 correspond to the corners. Then the battery 16 is then lifted back to the plane F (fig. 6.10), to finally finally abandon the entire device for further treatment (fig. 6.11).

By guiding the colisa surfaces 13 and 14 and the spring load (24) of the rockers or frames 2, which have the rollers 7 in shape, it is not guaranteed that the rollers 7 cleanly form the cavities in the final layer 17 of the stack 16, but also that a centering takes place in a stack of material not exactly positioned, so that the stack 16 of material can always be adjusted in a completely optimal position, in particular in relation to the shrinking frame 18.

The profiling devices may also be provided transverse to the transport direction laterally to the belt conveyor B.

020 241