The present invention relates to a packaging assembly. Background art In the field of packaging machines, for various types of article and particularly for rolls of paper of the tissue type (for example absorbent paper or toilet paper), machines are widespread which are capable of packaging a predefined number of rolls in order to define the packaging unit that is usually sold to the end consumer. According to a known constructive solution, these machines first of all have devices for feeding and moving the rolls, which are thus arranged in a group that has the desired configuration, typically constituted by several rows and/or layers of rolls.

The rolls thus arranged are then delivered to a traction device, for example by means of a lifting unit (typically constituted by a pusher that can move along its own axis).

Commonly, the above-mentioned traction device is constituted by a plurality of grip means, which can move along a substantially annular closed path and are capable of accommodating and retaining laterally the rolls along the typically straight portion of the path.

During traction, a crossfolding element, in cooperation with a folding element that acts on the opposite side with respect to the lifting unit, folds a flap of film in order to wrap the rolls; an element for heat-sealing the folded flaps of film that protrude from the pack then intervenes to provide final closure of such pack.

The crossfolding element is constituted substantially by a plate, which is arranged below the traction device proximate to the rolls and is capable of moving along their advancement direction (and in the opposite direction), in order to fold the flaps of film around the group of rolls that has just been received from the grip elements, and of then retracting, in order to allow to receive the next group of rolls.

The Applicant of the present application is the proprietor of Italian patent application BO2008A000107, which discloses a constructive solution that resorts to a heat- sealing element arranged downward with respect to the rolls and to the complementary folding element, with the possibility to move along the roll advancement direction as well as at right angles thereto.

In this manner, the heat-sealing element can trace a closed path in order to follow along a useful portion the group of rolls and thus heat-seal the protruding flaps of film during its traction, without the need to impose a halting step.

According to this embodiment, the crossfolding element is conveniently elongated along the roll advancement direction in order to define a sliding plane capable of offering an abutment to such rolls even during heat-sealing and beyond. Downstream of the region of action of the heat-sealing element, the crossfolding element is inserted below a fixed plane, which acts as a support in the last step of traction, up to delivery to the downstream units.

To allow the heat-sealing element to rest on the protruding flaps in order to perform heat-sealing, the crossfolding element has a plurality of longitudinal slots, in which the teeth of the heat-sealing head, which is substantially comb-shaped, can be inserted and can slide.

This embodiment, however, is not free from drawbacks. First of all, the provision of a plate that has such plurality of longitudinal slots requires long and onerous hours of mechanical machining, thus negatively affecting production costs.

Further, the presence of the longitudinal slots can cause the formation of small folds or wrinkles of the film in the lower part of the package, with negative consequences on its aesthetic appearance.

It should also be noted that the comb-like provision of the heat- sealing head, in order to allow mating with the crossfolding element, is the source of high heat dissipations caused by the presence of the teeth cited above, which in practice generate a significant dispersion of heat toward the surrounding environment.

In order to ensure the good outcome of the heat-sealing process, a high consumption of heat power is therefore necessary, and a substantial fraction of such power is dissipated.

Disclosure of the Invention

The aim of the present invention is to solve the above-mentioned drawbacks, by providing a packaging assembly in which the adoption of a movable heat-sealing element is accompanied by simple and cheap provision of the devices associated therewith.

Within this aim, an object of the invention is to provide a heat-sealing assembly that ensures retention of the aesthetic quality of the packaged product without causing deteriorations such as the formation of folds or wrinkles in the film.

Another object of the invention is to provide a packaging assembly that allows to resort to a heat-sealing element whose shape is adapted to ensure high energy efficiency without excessive dissipations of the generated heat. 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 safe in application.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a packaging assembly, which comprises means for moving at least one element for gripping at least one product to be packaged along an active segment of a predefined closed path, and an element for heat-sealing the flaps of film wrapped around the product, which can move and operate along at least one useful portion of said active segment, characterized in that it comprises an abutment element, which constitutes a support for the products and an aid for their transport, said abutment element being movable along said useful portion of said active segment substantially synchronously with said heat-sealing element. 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 9 are schematic side elevation views of the operation of the packaging assembly according to the invention. 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 for at least one element 2 for gripping at least one product 3 to be packaged, along an active portion A of a predefined closed path 4. It should be noted from the outset that the packaging assembly 1 according to the invention can comprise any number of grip elements 2 that can move along the closed path 4, such number being variable as a function of the various constructive, functional and economic requirements.

According to one possible embodiment, shown in the accompanying figures, the closed path 4 has a shape which is composed of two semicircles interposed between two parallel straight segments, and the active segment A for pulling the products 3 is defined on the one of the straight segments, the lower one (the rest of the closed path 4 is instead used for the return stroke).

The products 3 are for example rolls of paper of the tissue type, i.e., toilet paper, absorbent paper or the like; the desired final configuration of the rolls, which are arranged along several rows and layers, is obtained in the preceding steps of the wrapping cycle and must be maintained by the grip elements 2 during traction, while the subsequent processing steps are performed. Along the active segment A, the products 3 are first wrapped by a sheet of plastic film, whose flaps are then folded by means of a folding unit and a crossfolding unit 5, which cooperate with each other and are arranged on opposite sides with respect to a station 6 for receiving the products 3. More specifically, the crossfolding unit 5 is arranged at an initial portion of the active segment A.

An element 7 for heat-sealing the protruding flaps of film then acts on the products 3 thus wrapped and can move along at least one useful portion of the active segment A (arranged downstream of the initial portion cited above) in order to perform heat-sealing. Once heat-sealing has ended, the products 3 are available for delivery to the subsequent apparatuses after traveling along an end portion of the active segment A, which is arranged downstream of the useful portion and leads to a sending station 8.

According to the invention, the packaging assembly 1 comprises an abutment element, which constitutes a support for the products 3 and an aid for their transport and can move along the useful portion of the active segment A substantially synchronously with the heat-sealing element 7.

As is particularly evident from the accompanying figures, the products 3 are clamped laterally by the grip elements 2 and are supported in a lower region, along the useful portion of the active segment A ₅ by the abutment element, which contributes to the transport of the products 3, and by moving jointly with them and substantially synchronously with the heat- sealing element 7 prevents the formation of folds on the flap of film.

Advantageously, the heat-sealing element 7 comprises a heat- sealing head 9, which can move along a direction which is substantially transverse to the direction of a carriage 10. In turn, the carriage 10 can move along a track 11 , which is arranged parallel to the active segment A of the closed path 4.

More particularly, according to a possible embodiment, described by way of non-limiting example of the application of the invention, the heat- sealing head 9, which is substantially box-like (or has a similar simple configuration, as described hereinafter), oscillates about the carriage 10, being fixed to an end of an arm 12, which in turn is pivoted at its other end to the carriage 10. The abutment element comprised in the packaging assembly 1 according to the invention is therefore adapted to interact with the heat- sealing head 9, which can move along two mutually incident (or perpendicular) directions.

This possibility, as disclosed in Italian patent application BO2008A000107, allows to heat-seal the products 3 without stopping the products 3 and at the same time containing the total time required to perform the wrapping cycle.

The heat-sealing head 9 can be constituted substantially by a bar, or by a wire, or by another variously shaped component; regardless of the chosen solution, as highlighted hereinafter, the presence of a movable abutment element allows to perform optimum heat-sealing while maintaining low the dissipations of heat toward the environment.

The scope of the protection defined by the present invention also includes the provision of packaging assemblies 1 in which the motion of the heat-sealing head 9 along the direction that lies transversely to the direction of the carriage 10 is provided by way of technical solutions that are different from the one described earlier, such as for example resorting to a cylinder that can move substantially at right angles to the direction of motion of the carriage 10. With reference to the preferred embodiment described above, the heat-sealing head 9, as can be deduced from the accompanying figures, can move into contact with the protruding flaps of film by way of the rotation of the arm 12, for example arranging itself in the configuration of Figure 2.

Subsequently, as is evident for example from Figures 3 and 4, the heat-sealing head 9 can remain in contact with the products 3, while by way of the sliding of the carriage 10 on the track 11 it accompanies its motion along the active segment A in order to perform heat-sealing.

Conveniently, the abutment element is constituted by a movable plate 13, which is adapted to support the products 3 and has an end edge that faces the heat-sealing head 9 and is proximate thereto.

Preferably, the movable plate 13 is arranged downstream of the heat- sealing head 9, as in the embodiment shown in the accompanying figures.

More particularly, the movable plate 13 is jointly fixed, by way of a connecting rib 14, to the carriage 10, and thus can move jointly with the heat-sealing head 9 along the direction defined by the track 11, i.e., along the active segment A. Vice versa, the movable plate 13 is not influenced by the movements of the heat-sealing head 9 along the direction of approach to the active segment A and to the products 3.

Advantageously, the packaging assembly 1 according to the invention comprises a fixed plate 15, which is adapted, like the movable plate 13, to support the products 3 at the end portion of the active segment A.

The movable plate 13 can slide on the fixed plate 15 at the side of the plate 15 that lies opposite the products 3.

In this manner, the products 3 delivered to the grip elements 2 at the receiving station 6 abut initially against the crossfolding unit 5, which is adapted to support them. Subsequently, the products 3, drawn by the grip elements 2, move beyond the crossfolding unit 5 and abut against the movable plate 13 while they follow the useful portion of the active segment

A. Finally, the movable plate 13 moves below the fixed plate 15, and it is therefore on the latter that the products 3 abut during the end portion of the active segment A.

The operation of the packaging assembly according to the invention is as follows.

At the receiving station 6, one grip element 2 takes one product 3 in order to entrain it along the active segment A of the closed path 4, up to the sending station 8.

Along the initial portion of the active segment A, the crossfolding unit 5, which is substantially laminar, moves with a reciprocating translational motion along a direction which is parallel to the advancement direction of the product 3. The described motion allows, in the outgoing stroke, the crossfolding unit 5 to fold the flaps of film wrapped around the product 3, and in the return stroke, to follow them, supporting them in a lower region along the initial portion of the active segment A, as shown for example in Figures 5, 6, 7 and 8. Once the initial portion has been passed, the heat-sealing element 7 acts on the product 3, while support is provided by the abutment element, which accompanies the product 3 and prevents the formation of folds on the flaps. The abutment element is arranged, as already noted, downstream of the heat-sealing head 9 and is capable of following the movement of the latter along the direction defined by the track 11 (which is parallel to the active segment A).

The presence of the movable plate 13 allows to ensure adequate support to the products 3 during their entrainment without the need to resort to complex embodiments for the devices being considered, such as for example the crossfolding unit 5.

The crossfolding unit 5 in fact has a limited extension along the advancement direction of the products 3, differently from the corresponding units provided in devices of the background art, and therefore does not require solutions (such as the provision of recesses or slots) to avoid interference with the heat-sealing head 9, which works substantially in a (limited) region of discontinuity between the crossfolding unit 5 and the movable plate 13.

As already noted, the products 3, once they have passed the useful portion as well, abut against the fixed plate 15, below which the movable plate 13 slides, supporting them to the sending station 8.

It is easy to note that the described solution ensures support of the products 3 by resorting to a series of apparatuses that are easy to provide in practice, while the heat-sealing head 9, which as mentioned enters a region of discontinuity between the cross-folding unit 5 and the movable plate 13, can have a box-like shape, or in any case a different shape, which is very simple and acts on a delimited and homogeneous heat-sealing region.

This simple configuration, and therefore the lack of sources of heat dispersion such as wings or teeth, allows the heat-sealing element 7 to ensure adequate heating of the heat-sealing head 9 with low energy consumption.

Finally, it should be noted that the already noted lack of slots or other longitudinal discontinuities along which the products 3 are made to slide further contributes to avoid the danger of forming folds or wrinkles of the film such as to deteriorate the aesthetic appearance of the resulting wrapping.

In practice it has been found that the packaging assembly according to the invention fully achieves the proposed aim, since the adoption of an abutment element that can move substantially synchronously with the heat- sealing element allows to avoid the need to resort to structurally complex embodiments for the other devices associated therewith.

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 elements. In the exemplary embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

Moreover, 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.

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.