PACKAGING ASSEMBLY Technical Field

The present invention relates to a packaging assembly. Background Art In the field of machines for packaging various types of articles, particularly for cylindrical rolls of paper, for example absorbent or toilet paper, a first task that these machines must perform is to package a predefined number of rolls, in order to provide the packaging unit, which typically the end consumer finds on shop shelves. Subsequently, the need is known to proceed to a further wrapping of a preset number of packs, by means of a suitable film, in order to obtain a bag that can be handled and transported more easily, for example by means of pallets; in some cases, the resulting bag can also be sold directly, for example in discount stores, where the end consumer can purchase goods in the quantities that are handled usually only by wholesale dealers.

In the field of automatic machines, therefore, packaging assemblies supplied with packs of rolls, appropriately arranged in the desired final configuration and passed between a series of so-called tie-shaped tools, are therefore known. Such tie-shaped tools are substantially suitably shaped metal plates, which are capable of folding the film unwound from a feeder in order to form a substantially tubular shape. The resulting tube is open at one end in order to receive the packs to be wrapped and is closed at the other end.

The assembly is further provided with a pusher or with other movement systems, capable of handling the packs and of accompanying them within the tube thus formed, making them enter from the open side and pushing them until they are proximate to its other closed end, beyond the tie-shaped tools. Here, once the pusher has retracted, a heat-sealing assembly acts which is constituted by a pair of heat-sealing devices, which can perform a translational motion along a direction that is substantially

transverse with respect to the advancement direction of the pack being processed. The two devices become active once the pack has passed beyond them, in order to close behind such pack the two folded and open flaps of the film by means of the devices, which by performing a translational motion move mutually closer until they touch each other, subsequently remaining for a few seconds in position on the flaps in order to provide their heat- sealing, and finally return to the initial position, waiting for the subsequent pack.

The drawbacks that arise by adopting this type of constructive solution are linked to the reciprocating motion that characterizes the heat- sealing devices. The system in fact is unable to ensure high productivity, since the high speeds required would generate continuous accelerations and decelerations, to which the mechanical components would be subjected, stressing them beyond their mechanical (or structural) limits. Further, in order to allow the heat-sealing of the flaps, the pack must in practice "stop" along the line for the time needed for the two devices to complete their heat-sealing cycle, therefore also excluding for the main advancement line of the pack an advantageous continuous operation.

Systems are known which solve the described drawbacks at least partially: they have a pack dosage assembly, a system for the stepwise conveyance of such groups of packs, and a plurality of heat-sealing devices that can move by means of racks along a closed path that is formed by a system of guides. Each pair, during continuous motion along the path, moves into contact, on opposite sides, with the bag, heat-sealing the ends thereof that were folded in the preceding processing steps.

This type of heat-sealing potentially allows to have continuous operation for the bag advancement line, such bags being followed along a portion of their stroke by the heat-sealing devices, which move along the substantially straight portion of the annular path to which they are constrained; the result is a packaging assembly that can ensure processes

with higher productivity than the type described previously.

However, not even this solution is free from drawbacks: resorting to an annular path (or otherwise closed path, obtained by means of a mechanical system of guides) in fact excludes any possibility to vary the trajectory of the heat-sealing devices. Such devices cannot be reconfigured once the machine has been built, leaving the users of the apparatus solely with the possibility to adjust the closure position of the pairs of such heat- sealing devices, depending on the size of the bags to be provided. The impossibility to change the trajectory prevents the possibility to adapt to the different formats and speeds of the bags: this would have the purpose of optimizing their entry.

As regards the maximum attainable speeds, while it is true that the continuous system has assuredly higher limits, it must nonetheless be noted that beyond certain speeds the only feasible way to achieve further productivity increases is to increase the number of pairs along the path, but of course increasing the number of heat-sealing devices inevitably leads to an increase in the overall cost of the machine in addition to an increase in its structural complexity.

Disclosure of the Invention The aim of the present invention is to solve the above-mentioned drawbacks, by providing a packaging assembly that is capable of heat- sealing a film around a preset number of packs of product prepared adequately, which offers a wide range of trajectories that can be followed by the heat-sealing devices. Within this aim, an object of the invention is to provide a packaging assembly in which the trajectories of the heat-sealing devices can be configured at will during design or during format changing.

Another object of the invention is to provide a packaging assembly that has a satisfactory structural simplicity and low costs. Another object of the invention is to provide a packaging assembly

that ensures high reliability in operation.

Another object of the invention is to provide a packaging assembly that can be obtained easily starting from commonly commercially available elements and materials. Another object of the invention is to provide a packaging assembly that is relatively simple to provide in practice and safe in application.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a packaging assembly, characterized in that it comprises movement means arranged along a predefined path for an element to be packaged by means of a film made of polymeric material that arrives from a feeder, said packaging assembly comprising a station for folding the film onto the element, downstream of which there is a unit for heat-sealing the folded flaps of the film, said heat-sealing unit comprising at least one pair of heat-sealing elements, which are arranged on opposite sides with respect to said predefined path and are functionally associated with respective actuation and control assemblies, said heat-sealing elements acting, during the heat-sealing step, each along at least two mutually independent directions, performing heat-sealing on the elements to be packaged even in motion. Brief description of the drawings

Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the packaging assembly according to the invention, illustrated by way of non- limiting example in the accompanying drawings, wherein:

Figures 1 to 6 are schematic side elevation views of the operation of the packaging assembly according to the invention;

Figures 7 and 8 are enlarged- scale views of a detail of the packaging assembly, illustrating the heat-sealing unit, and show the movement of the heat-sealing elements;

Figures 9 and 10 are front elevation views of the same detail of Figures 7 and 8;

Figure 11 is a functional diagram of a detail of the movement means. Ways of carrying out the Invention With reference to the figures, a packaging assembly according to the invention, generally designated by the reference numeral 1, comprises movement means 2, which are arranged along a predefined path 3 for an element to be packaged 4, by means of a film 5 made of polymeric material, that arrives from a feeder 6. The element 4 to be packaged can be constituted for example by a preset number of packs of products, which must be wrapped by the film 5 in order to make transport easier.

The packaging assembly 1 further comprises a folding station 7, for folding the film 5 onto the element 4, downstream of which there is, for the folded flaps of the film 5, a heat-sealing unit 8, which comprises at least one pair of heat-sealing elements 9, which are arranged on opposite sides with respect to the predefined path 3 and are functionally associated with respective actuation and control assemblies 10; the heat-sealing elements 9 act, during heat- sealing, each along at least two mutually independent directions, and the heat- sealing on the elements to be packaged 4 can be performed even during motion.

More particularly, each actuation and control assembly 10 comprises at least one pair of traction apparatuses 11, constituted for example by motorized belts: one of the apparatuses 11 acts along a substantially transverse direction with respect to the predefined path 3, while the other one acts along a direction that is substantially parallel thereto.

In this manner, the two heat- sealing elements 9 can perform a translational motion along the direction that is perpendicular to the advancement direction of the element 4, in order to come into contact with each other and provide the closure and heat-sealing of the previously folded

flaps of the film 5, and can simultaneously perform a translational motion, parallel to the product advancement direction, to "follow" the trajectory traced by the flaps of the film 5 without interfering with the advancement motion of the element 4 being processed. In other words, the system allows to provide any motion for the heat- sealing elements 9 and therefore to impart any advancement motion to the element 4 in input, thus adapting to different formats, while the annular path described in packaging assemblies of the background art is a function of the structural elements that compose the system and therefore cannot be modified or changed in its configuration, except on penalty of substantial transformations of the machine as a whole.

Indeed in order to allow reconfiguration of the spatial trajectories of the heat- sealing elements 9, advantageously the packaging assembly 1 according to the invention comprises a control and management unit, which is provided with respective memory components and is associated with the actuation and control assemblies 10, and by means of which it is possible to program suitable operating sequences of the traction apparatuses 11 on such memory components, in order to determine, as mentioned, the desired spatial trajectory of the heat-sealing elements 9. The folding station 7 comprises a plurality of laminar elements, known as tie-shaped tools, which are arranged along the path of the film 5 and whose surfaces are mutually coupled according to a spatial configuration that allows to fold the film 5 until it assumes a substantially tubular shape. Conveniently, the movement means 2 of the element 4 comprise an assembly 12 for the transport of the film 5, which is arranged substantially downstream of the folding station 7, and has at least one surface portion that can move along a direction that is substantially parallel to the predefined path 3 in order to transport by friction the element 4 wrapped by the film 5, which is interposed between the movable surface portion and a suitable

abutment.

In particular, the transport assembly 12 comprises at least one first conveyor belt 13a and at least one second conveyor belt 13b. The element 4, wrapped by the film 5, is interposed between the two belts 13a, 13b and is transported by them: the first conveyor belt 13a in fact constitutes the movable surface portion, while the second conveyor belt 13b constitutes the appropriately provided reference.

Advantageously, both the first conveyor belt 13a and the second conveyor belt 13b comprise respective guiding pulleys, and a first pulley 14a (and respectively 14b) that faces and lies proximate to the corresponding heat-sealing element 9 is coupled slidingly to the heat-sealing element 9 along a direction that is substantially transverse with respect to the predefined path 3.

The Figure 11 is a functional diagram which is related to what has just been described and in which, in addition to the first pulleys 14a, 14b that can perform a translational motion, a possible constructive solution is shown and mentioned merely by way of non-limiting example for second pulleys 15a, 15b, which is arranged opposite the first pulleys 14a, 14b and is jointly connected thereto by means of a rigid connection 16a, 16b. In this manner, the translational motion of the heat-sealing element 9 along the advancement direction of the element to be packaged 4, entails a consequent movement of the first pulleys 14a, 14b and of the second pulleys 15a, 15b to increase the useful surface 17a, 17b of the corresponding conveyor belt 13a, 13b. This increase in the useful surface 17a, 17b is matched by a reduction of the length of the portions 18a, 18b of the belt 13a, 13b that lead to the second pulleys 15a, 15b; this reduction is possible by way of the movement caused by the rigid connection 16a, 16b between the first pulleys 14a, 14b and the second pulleys 15a, 15b, such movement occurring along a direction that is parallel to the useful surface 17a, 17b and to the portions 18 a, 18b.

It should be noted that the transport assembly 12 must be supplied with adequately prepared elements 4 and then move them with the method described above. This supply of elements 4 can be performed by a pusher that is capable of moving them to the folding station 7, upstream of the inlet of the transport assembly 12. The elements 4 are fed to the inlet of the transport assembly 12 by way of other movement units, for example additional conveyance lines arranged laterally. Further, in the transport assembly 12, the elements 4 can be wrapped by the film 5 and transported by the first conveyor belt 13a and by the second conveyor belt 13b. It should thus be noted that the transport assembly 12 conveniently allows to reduce the stroke of the pusher with respect to the stroke that was provided for it in the machines of the background art, where in practice it had to push the element 4 along the entire length of the tube of film 5 formed earlier. In the packaging assembly 1 according to the invention, the transport assembly 12 in fact provides, at least for a portion of the overall stroke, the movement by traction of the element 4 along the predefined path 3 jointly with the film 5, simultaneously providing the desired wrapping.

The method for packaging elements to be packaged 4 associated with a packaging assembly 1 comprises a first step for feeding the movement means 2, which are arranged along the predefined path 3, with at least one element to be packaged 4, a second step for folding the film 5 on the element to be packaged 4, along a substantially folded shape, in the folding station 7, and a third step for heat-sealing the folded flaps of the film 5 by means of the heat-sealing unit 8. According to the method associated with the packaging assembly 1, the third heat- sealing step consists in performing the translational motion, along two mutually independent directions, of a pair of heat- sealing elements 9.

In particular, the third heat- sealing step consists in performing the translational motion of the pair of heat-sealing elements 9 along a first

direction that is substantially transverse to the predefined path 3 to heat-seal the folded flaps of the film 5 and along a second direction that is substantially parallel to the predefined path 3 in order to follow the advancement motion of the element 4 during heat-sealing. In practice it has been found that the packaging assembly according to the invention fully achieves the proposed aim, since resorting to heat- sealing elements 9, which are actuated by traction apparatuses 11 that act independently of each other along two different directions, allows to provide any spatial trajectory for the heat- sealing elements 9, thus allowing an effective closure of the wrapping of film 5 on the element 4, whatever the size of the element 4.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent ones.

It is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. BO2007A000650 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.