PROCESS FOR PALLETISING PACKS OF CONTAINERS WOUND BY A STABILISING WRAP, AND RELATIVE EQUIPMENT

Technical Field

This invention relates to a process for palletising packs of containers wound by a stabilising wrap, e.g. the traditional bottles wound with a heat shrunk plastic film.

This invention also relates to a piece of equipment that permits to achieve the process according to the invention.

Background Art To transport bottles of water or other liquids the known process is to collect a certain number of bottles, normally six, and wrap them together with heat shrunk plastic film.

Once heated, the plastic film shrivels and adheres perfectly to the bottles, forming a stabilized wrap that keeps them together. Packs made in this way can then be sent to a palletising station where they are placed on top of a pallet to form a set of overlapping horizontal layers.

Around the palletised load is then applied an external cover to keep the packs stable on the pallet when they are being handled and transported and even to protect them from water and dust if the case may be. To increase the stability of the palletised load during transport, the packs of the upper layers can be arranged so they are supported by at least two different packs, practically avoiding the formation of single piles of packs, which can easily topple over.

However, the overall stability of the palletised load is still rather limited in that the base of the packs, substantially flat, is free to slide on top of the packs of the layer underneath.

To increase the sturdiness and stability of the load, therefore, a sheet of cardboard, conventionally called "interleaf, is placed between a layer of packs and the one immediately above it. In effect, when palletising, the interleaf is arranged horizontally on top of a layer of packs and then another layer of packs is put on top of the interleaf, and so on.

By using interleafs it is also possible to transmit horizontal forces between the packs of one layer and those immediately on top and, therefore, to distribute more evenly the thrusts and stresses the load is subject to during transport. Despite this, the use of interleafs has numerous drawbacks. First of all the cost of these sheets of cardboard is not negligible because if they are to work efficiently they must have certain resistance and rigidity characteristics that only certain types of cardboard can guarantee. The need to place one interleaf between each layer of packs and the next also requires the use of additional machinery inside the palletising station which complicates the system quite a lot and, as it works intermittently, it slows down the overall palletizing cycle times considerably.

Inconveniently, among other things, these machines are also an additional cost in terms of installation, maintenance and overall system running. Another drawback which is particularly felt in this sector occurs when the bottles being transported contain liquids whose temperature is below the dew- point of the environment surrounding them, e.g. freshly bottled source water. In these cases, in fact, the humidity in the air remains trapped inside the external cover and condenses on the surface of the cold containers. This condensed water wets the cardboard interleafs, softening and ruining them, often definitively; due to this phenomenon, the interleafs lose their stabilizing characteristics with the risk of compromising the integrity of the whole palletised load. Object of the Invention The main aim of this invention is to provide a process for palletising packs of containers wound by a stabilising wrap, and relative equipment, that permit to obtain particularly stable and sturdy palletised loads without having to use cardboard interleafs.

Another object of this invention is to reduce notably the overall palletising and transport costs, both in terms of less packaging materials used and in terms of less expense for installation, maintenance and running the system.

Another object of this invention is to provide a process for palletising packs of containers wound by a stabilising wrap, and relative equipment, that allow to

overcome the mentioned drawbacks of the known technique as part of a simple, rational, easy, effective use and low cost solution.

The objects listed above are reached by this process for palletising packs of containers wound by a stabilising wrap, characterised by the fact that it comprises the following phases: supplying a plurality of packs of containers wound by a stabilising wrap, each container comprising at least one cavity obtained in the bottom and at least one projecting part obtained at the top, said cavity and said projecting part being substantially complementary to each other; - placing said packs on top of a pallet in an interlocking configuration where said packs are distributed in a plurality of horizontal layers arranged one on top of the other and the projecting parts of the containers of at least one of the packs underneath are coupled inside the cavities of the containers of at least two different packs on top. Brief Description of the Drawings

Further characteristics and advantages of this invention will appear more evident from the description of a preferred but not only embodiment of a process for palletising packs of containers wound by a stabilising wrap, and relative equipment, illustrated indicatively by way of non limiting example in the accompanying drawings, wherein: figure 1 is an axonometric view of a palletised load obtained with the process according to the invention; figure 2 is a side view of a pack of containers employed in a first embodiment of the process according to the invention; figure 3 is a side view of a pack of containers employed in a second embodiment of the process according to the invention; figure 4 is a side view of the packs of figure 3 piled up following the process according to the invention; figure 5 is a side, schematic and partial view of the equipment according to the invention; figure 6 is a plan, schematic and partial view of the equipment according to the invention;

figure 7 is a front, schematic and partial view of the equipment according to the invention; figure 8 is an axonometric view of a perforation punch mounted on the equipment according to the invention; figure 9 is an axonometric view of the second plate mounted on the equipment according to the invention.

Embodiments of the Invention

With particular reference to such figures, a palletised load obtained with the process according to the invention has been globally indicated by 1. In particular, the palletised load 1 consists of a pallet 2 on which a plurality of packs 3 of containers 4 stand.

Each pack 3 consists of a plurality of containers 4 wound by a stabilising wrap

5.

In the particular embodiment of this invention illustrated in the figures, the packs 3 are composed of six containers 4, grouped in two parallel and side by side rows of three containers 4 each, and the stabilising wrap 5 is a sheet of heat shrunk plastic film wound around the containers 4.

However alternative embodiments of this invention are not excluded where e.g. in each pack 3 a different quantity of containers 4 is grouped with a different arrangement and/or with the use of a stabilising wrap 5 of a different nature.

The containers 4 consist of, e.g., plastic bottles for water or other drinks.

In the bottom of the containers 4, in particular, a substantially circular cavity 6 is obtained.

At the top, on the other hand, the containers 4 extend into a neck 4a that ends in a projecting part 7 defined by the cap that closes the bottle.

The cavities 6 and the projecting parts 7 are shaped substantially complementary to one another, i.e. dimensioned to allow the insertion substantially to measure of one projecting part 7 inside one cavity 6.

The process, object of the invention, comprises the following phases: - supplying a plurality of the above mentioned packs 3 ; placing the packs 3 on top of the pallet 2 in an interlocking configuration wherein the packs 3 are distributed in a plurality of horizontal layers 8a,

8b, 8c arranged one on top of the other and the projecting parts 7 of the containers 4 of at least one of the packs 3 underneath are coupled inside the cavities 6 of the containers 4 of at least two different packs 3 on top. In practice, the arrangement of the packs 3 in the interlocking configuration is such that none of the packs 3 is coupled above or below just one pack 3 but, to the contrary, is standing on, or supports, at least two different packs 3. In one particular embodiment of the process according to the invention, the stabilising wrap 5 is made in a substantially deformable material that allows a more or less elastic deformation of the bottom face of the stabilising wrap 5 by the cavities 6 of the containers 4.

In this case, the base of the packs 3 is defined by the bottom face of the stabilising wrap 5, as illustrated in detail in figure 2; while the packs 3 are being placed on the pallet 2, the bottom face of the stabilising wrap 5 deforms and is pulled inside the cavities 6 of the containers 4 when the projecting parts 7 of the containers 4 underneath are inserted.

In an alternative embodiment of the invention illustrated in detail in figures 3 and 4, the process according to the invention contemplates an additional phase that consists of perforating the stabilising wraps 5 of the packs 3 by the cavities 6. Practically speaking, this additional phase comprises the insertion of a plurality of perforation punches 9 in the cavities 6 of the containers 4 and, simultaneously, the heating of these punches.

The contact between the heated perforation punches 9 and the stabilising wrap 5 makes it possible to create on the bottom face of the stabilising wrap 5 a series of folds 10 substantially matching the edge of the cavities 6 (figure 3).

Once arranged in the interlocking configuration, the projecting parts of the containers 4 underneath are inserted into the cavities 6 of the containers 4 on top without the need to deform the stabilising wrap 5 (figure 4). One possible piece of equipment 11 for perforating the stabilising wraps 5 of the containers 4 grouped in the packs 3 is illustrated in detail in figures 5 to 9.

This equipment comprises a base frame 12 with a resting surface 13 for one or more packs 3.

In the particular embodiment of the invention illustrated in the figures 5 to 9, the equipment 11 is able to perforate the stabilising wraps 5 of two adjacent packs 3 simultaneously.

It is not excluded, however, that it can be adapted to perforate just one pack 3 at a time or three or more packs 3 simultaneously.

The equipment 11 has forward movement means 14 of the packs 3 along a forward movement direction A that is substantially parallel with the resting surface 13.

The forward movement means 14, e.g., consist of one pair of conveyor belts that are arranged parallel and side by side and their top surface defines the resting surface 13.

The conveyors 14, in detail, are placed at a reciprocal distance such to allow the end portions of the packs 3 to be supported while the rest of the bottom face of the packs 3 juts out over the floor. On top of the resting surface 13 and along the conveyors 14 are arranged two sides 15 for the lateral containment of the packs 3.

The reciprocal distance between the conveyors 14, likewise the reciprocal distance between the sides 15, is adjustable according to the format of the packs

3 being processed. The conveyors 14 and the sides 15, in fact, are mounted on the base frame 12 by the interposition of first and of the second adjustment means of the reciprocal distance respectively. The first and the second adjustment means are not illustrated in detail in the figures.

With reference to the forward movement direction of the packs 3 along the forward movement direction A, the conveyors 14 have an inlet end that is in proximity of a feeding line 16, by means of which the packs 3 reach the equipment 11, and an outlet end that is in proximity of a moving away line 17, by means of which the perforated packs 3 are sent to the next palletising stations. At the inlet end of the conveyors 14 are contemplated first stopping means 18 of the front face of the packs 3.

In this paper, the front faces and the rear faces of the packs 3 are considered

with reference to the forward movement direction of the packs along the forward movement direction A.

The first stopping means 18, in detail, consist of a first vertical plate 19 positionable transversally to the forward movement direction A and associated with a first lifting actuator 20 mounted on the base frame 12.

With reference to the forward movement direction of the packs 3 along the forward movement direction A, downstream from the first stopping means 18, are arranged punching means 21 associated with the base frame 12 and suitable for perforating the stabilising wraps 5 by the cavities 6 of the containers 4. These punching means comprise a supporting plate 22 substantially horizontal that sustains the perforation punches 9 insertable inside the cavities 6. The supporting plate 22 is arranged below the resting surface 13 and is associated with movement means that allow it to slide lengthways, along the forward movement direction A. Such movement means comprise a slide 23 that is engaged sliding along a pair of longitudinal guides 24 associated integrally with the base frame 12 and on which the supporting plate 22 is mounted.

The slide 23 runs along the longitudinal guides 24 thanks to a chain drive 25. Between the slide 23 and the supporting plate 22 are interposed bringing close and moving away means for moving the supporting plate 22 close to or away from the resting surface 13 and from the packs 3 moving above it. Such bringing close and moving away means are composed of a second lifting actuator 26 mounted substantially vertically on the slide 23 and sustaining the supporting plate 22. The perforation punches 9 mounted on the supporting plate 22 consist of a set of substantially vertical pins on the top of which a perimeter cutting edge 27 is obtained suitable for coming into contact with the stabilising wrap 5. The cutting edges 27 of the pins 9 are shaped substantially to match the edges of the cavities 6 of the containers 4 and suitable for creating on the stabilising wrap 5 the folds 10 as illustrated in figures 3 and 4.

The cutting edges 27 are substantially open, i.e. they have at least one interrupted section 28 that allows the corresponding fold 10 to remain attached

to the rest of the stabilising wrap 5.

The perforation punches 9 are also associated with heating means, of the type of an internal electrical heating element or the like, not illustrated in the figures.

The heating means allow to heat the cutting edges 27 so the perforation punches 9 can penetrate the stabilising wrap 5 easily without causing notches that could inconveniently weaken the wrap.

Advantageously, the punching means 21 comprise second stopping means of the front face of the packs 3.

Such second stopping means consist of a substantially vertical second plate 29 positionable transversally to the forward movement direction A and associated with a third lifting actuator 30 mounted on the slide 23.

On the second plate 29 are mounted detection means 31 for detecting contact with the front face of the packs 3.

The detection means 31 are composed of e.g. two push buttons 32 projecting from the face of the second plate 29 turned towards the inlet end of the conveyors 14.

Advantageously, the two push buttons 32 are arranged on laterally opposite sides to the second plate 29 so as to guarantee contact with both the lateral portions of the front face of the packs 3. Each push button 32 is connected to a position sensor 33 by means of which an electronic signal is sent to a processing and control unit, not illustrated in the figures, that controls operation of the equipment 11.

Along the moving away line 17, near the outlet end of the conveyors 14, is lastly arranged an ejector device 34 which removes from the moving away line 17 the packs 3 which have not undergone a correct perforation operation.

The equipment 11 works in the following way.

The packs 3 reach the equipment 11 via the feeding line 16.

The first plate 19 is initially lifted and allows the forward movement of two packs 3 to be stopped so they can be compacted and arranged one adjacent to the other, with the front and rear faces at right angles to the forward movement direction A.

Once packs 3 are compacted, the first plate 19 descends and the two packs 3

move forward on the conveyors 14.

As the packs 3 move forward the slide 23 starts moving as well. The forward movement speed of the conveyors 14 and of the slide 23 is controlled so that contact between the front face of the front pack 3 and the surface of the second plate 29 is very gradual.

Purely as an example, the speed of the slide 23 can initially be set at a value equivalent to 80% of the forward movement speed of the packs 3 until they reach the second plate 29. Once the packs 3 and the second plate 29 have come into contact, the speed of the slide 23 is taken to a value equal to the forward movement speed of the packs 3.

It should be noted how the use of the mobile slide 23 allows the equipment 11 to perforate the packs 3 without interruption and without necessarily stopping their forward movement; in practice, in fact, it is not the packs 3 that slow then- speed to position themselves on the supporting plate 22, but it is the supporting plate 22 that reaches the translation speed of the packs 3.

When the packs 3 and the slide 23 move forward at the same speed, proceed first of all by checking the correct position of the packs 3 in relation to the second plate 29 by means of the signals detected by the push buttons 32. If, e.g., a correct positioning is detected, command the supporting plate 22 to lift and then command perforation of the stabilising wraps 5.

The supporting plate 22 now descends together with the second plate 29, the slide 23 returns to its initial position, in proximity of the inlet end of the conveyors 14 so the next two packs 3 can be perforated, while the packs 3 that have just been perforated are released so they can continue their forward movement up to the moving away line 17 from where they reach the next palletising stations.

If, however, the push buttons 32 detect an incorrect positioning of the packs 3 the stabilising wraps 5 are not perforated, the slide 23 is made to return to its initial position and the packs 3 that are on the conveyors 14 are made to move forward up to the ejector device 34 that removes them from the moving away line 17 so they can go through the equipment 11 again. It has in point of fact being ascertained how the described invention achieves

the proposed objects.

The invention thus conceived is susceptible to numerous modifications and variations, all of which falling within the scope of the inventive concept. Furthermore all the details can be replaced with others that are technically equivalent.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements without because of this moving outside the protection scope of the following claims.