WO2010013267A1

WO2010013267A1 - Folding assembly, particularly for products to be packaged

Info

Publication number: WO2010013267A1
Application number: PCT/IT2008/000522
Authority: WO
Inventors: Francesco Maria Bernardi
Original assignee: Dp S.R.L.
Priority date: 2008-07-31
Filing date: 2008-07-31
Publication date: 2010-02-04

Abstract

A folding assembly (1), particularly for products to be packaged, comprising an apparatus (2) for moving at least one element (3) for folding flaps of film wrapped around a product to be packaged, the product being movable along a predefined path (A). The movement apparatus (2) comprises at least one supporting element for the at least one folding element (3); the supporting element is able to rotate about an axis (C) which is perpendicular to the predefined path (A) of the product in order to move the folding element (3) along a trajectory (B). A useful portion (Bl) of the trajectory (B) faces, and is proximate to, a respective useful portion (Al) of the predefined path (A) of the product in order to allow the folding of the flaps.

Description

FOLDING ASSEMBLY₅ PARTICULARLY FOR PRODUCTS TO BE

PACKAGED

Technical field

The present invention relates to a folding assembly, particularly for products to be packaged. 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 the rolls, which are then taken by handling means, for example conveyor belts or platforms. Apparatuses capable of diverting the flow of part of the rolls in order to arrange them as a whole along several rows or layers are provided along such means.

Once the rolls have been arranged in the desired configuration, in practice they are ready to perform the wrapping cycle, to perform which the rolls are delivered to a traction device, for example by means of a lifting unit (constituted typically by a pusher that can move along its own axis).

Commonly, the above-mentioned traction devices are constituted by a plurality of grip means that can move along a substantially annular path.

Suitable elements act along such path to allow the wrapping of the rolls and the subsequent heat-sealing of the folded flaps of film. The wrapping cycle first of all entails the action of a first upper folding unit, which, assisted by a lower crossfolding unit, provides the upper and lower wrapping of the rolls, which are thus arranged inside a "tube" of film (open at the end faces, which correspond to the lateral surfaces of the pack). Two end folding units then intervene and act on the two sides of the pack (moving parallel to it) to provide the first lateral fold; such end folding units must complete their action before the pack enters the range of action of the lateral crossfolding units, which provide the second lateral fold (which is opposite to the first one). Provision of the first lateral fold occurs during the movement of the packs along the path: to perform folding and accompany the product with the folded flap within the lateral crossfolding units, the end folding units are provided with a reciprocating rectilinear motion.

More specifically, after waiting for the delivery of the packs to the grip means, by means of the lifting unit, and after the action of the lower crossfolding units, the end folding units move and overlap the edge of the pack, providing the fold.

Halting in order to allow reversal of travel occurs when such folding units are adjacent to the flush level of the crossfolding units, without making mutual contact, but in any case approximating a continuous wall for containing the flaps.

The rolls can thus move beyond the end folding units, which retract into the initial position to wait for the subsequent pack. However, this solution is not free from drawbacks. The movement described above of the end folding units applies excessive stress to the motors and to the mechanical components that provide it, due to the particularly substantial accelerations caused by the reciprocating motion and due to the need to comply with the timing of the other machine elements with which they interact. Further, the accelerations and decelerations that are introduced are a source of intense vibration, particularly if high productivity and therefore low cycle times are required; this requires the adoption of damping elements and sets a maximum limit to the speeds that can be reached by the machine.

Finally, it should be noted that in order to stop the folding units and allow the subsequent reversal of motion, it is necessary to impart thereto a deceleration ramp during which the pack moves beyond them, with consequent sliding of the folded flap on the surface of the folding unit in the opposite direction with respect to the direction of the fold; in practice, while the folding units are motionless, the pack performs a translational motion against the fold.

Disclosure of the Invention

The aim of the present invention is to solve the above-mentioned drawbacks, by providing a folding assembly that allows to contain the stresses on the involved mechanical elements without requiring them to have a high mechanical performance.

Within this aim, an object of the invention is to provide a folding assembly in which the motion of the involved elements provides for a moderate generation of vibrations.

Another object of the invention is to provide a folding assembly that allows to provide a fold that has a high quality level, avoiding the risk of deterioration of the wrapping as a consequence of unwanted sliding on the pack.

Another object of the invention is to provide a folding assembly that allows to contain the time required to execute a folding cycle. Another object of the invention is to provide a folding assembly that ensures high reliability in operation.

Another object of the invention is to provide a folding assembly that can be obtained easily starting from commonly commercially available elements and materials. Another object of the invention is to provide a folding assembly that has low costs and is safe in application.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a folding assembly, particularly for products to be packaged, comprising an apparatus for moving at least one element for folding flaps of film wrapped around a product to be packaged, the product being movable along a predefined path, characterized in that said movement apparatus comprises at least one supporting element for said at least one folding element, said supporting element being able to rotate about an axis which is perpendicular to the predefined path of the product to move said folding element along a trajectory, a useful portion of said trajectory facing and being proximate to a respective useful portion of the predefined path of the product in order to allow the folding of the flaps. 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 folding assembly according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a schematic plan view of the folding assembly and illustrates a plurality of different positions assumed by the folding elements;

Figure 2 is a schematic side elevation view of the folding assembly. Ways of carrying out the Invention

With reference to the figures, a folding assembly according to the invention, generally designated by the reference numeral 1, comprises an apparatus 2 for moving at least one element 3 for folding flaps of film wrapped around a product to be packaged.

The products are for example rolls of paper of the so-called "tissue type", i.e., toilet paper, absorbent paper or the like, for which wrapping in a film of a material such as plastics or paper is provided. This constructive solution is therefore referenced in the continuation of this description, but the application (which in, any case falls within the scope of the protection defined by the present application) of the folding assembly 1 according to the invention to different types of product to be packaged is not excluded.

The rolls can move along a predefined path A, along which the desired wrapping is first performed by means of the film and subsequently the heat-sealing of the folded flaps is performed in order to complete the wrapping cycle.

More specifically, the rolls are delivered to the units that provide their movement along the path A by a lifting unit, which has a translational motion along a direction which is perpendicular to the path A.

At the delivery of the rolls, a first device intervenes which is capable of folding the film to wrap such rolls at the top and bottom, substantially forming a tube of film. Then the rolls move along the predefined path A and the folding element 3 acts thereon in order to provide the first lateral fold. According to the invention, the movement apparatus 2 comprises at least one supporting element for the folding element 3, which can rotate about an axis C which is perpendicular to the path A of the product.

The supporting element moves the folding element 3 unidirectionally along a trajectory B, which comprises a useful portion Bl, which faces and is proximate to a respective useful portion Al of the. predefined path A of the product, in order to allow to fold the flaps.

Conveniently, the folding assembly 1 comprises two folding elements 3, which are arranged along the trajectory B and can move substantially synchronously thereon in substantially opposite directions, as can be seen in Figure 1.

In particular, the supporting element is constituted substantially by a rod 4, which rotates about the axis C at a central pivot 5 that is arranged on its centerline. The rod 4 therefore rotates about the central pivot 5 and supports the two folding elements 3 at end portions 4a thereof, each of which therefore traces a closed curved trajectory.

The use of two folding elements 3 allows to perform the folding of the flaps of a product with one of the elements 3 (which travels along the useful portion B l) while the other one is engaged in the return stroke.

Therefore, as soon as the first element 3 has ended folding, the next one becomes available upstream of the useful portion Bl in order to proceed with the folding of the flaps on the subsequent product.

To perform folding on the next product, therefore, it is not necessary to wait for the time required for the return stroke; this leads to the possibility to contain the cycle time, with evident advantages on the productivity that can be achieved by using the folding assembly 1 according to the invention.

Further, it should be stressed that the scope of protection defined by the present description also comprises folding assemblies 1 that have three or more folding elements 3 : this embodiment can be adopted, for example, if this is required by specific production requirements.

According to a solution of particular practical interest, each folding element 3 is provided with a block 6 which has a substantially box-like shape and comprises at least one folding surface 6a and a sliding surface 6b, which is substantially perpendicular to the first one. . During the movement of the folding element 3 along the trajectory B, the folding surface 6a strikes the flap of film (substantially at the beginning of the useful portion B l) that protrudes from the product and folds it thereon. Subsequently, the folding element 3 moves along the useful path Bl at a higher speed than the product along the useful portion Al of the path A.

The folding element 3 thus moves beyond the product and the sliding surface 6b slides along the flap that has just been folded in order to stretch it and maintain such fold, thus preventing the formation of surface wrinkles of the wrapping and avoiding the danger of any lifting of the flap. According to an embodiment of substantial practical interest, shown in the accompanying figures by way of non-limiting example of the application of the invention, the folding assembly 1 comprises means for controlling and modifying the position and orientation of each folding element 3 with respect to the axis C, and the rod 4, to which each folding element 3 is articulated by means of an end pivot 8, which is arranged at the end portion 4a.

Modifying the position and orientation along the trajectory B allows to define a substantially translational motion for the folding elements 3 along the useful portion Bl . The folding elements 3 can thus move parallel to the product, which in turn moves along the substantially straight useful portion Al of the predefined path A.

In particular, the control and modification means comprise a lever 7, which is rigidly connected to the folding element 3 (and to the block 6) and is articulated to the rod 4 at a first end 7a thereof, which is fixed to the end pivot 8.

In order to provide the rigid connection between the folding element 3 and the lever 7, brackets 9 extend from the end pivot 8, and a plate 10 that supports the block 6 is fixed to the brackets 9. The lever 7 is adapted to control and modify the orientation of each folding element 3 with respect to the rod 4, in the manner described hereinafter.

The lever 7 has, at a second end 7b that lies opposite the first end 7a, a first slider 11, which can slide in a first slotted profile 12 that is formed on a plate 13 which is arranged parallel to the plane that contains the trajectory B.

The first slider 11 can be constituted by a roller, by a probe, by a skid or by any other solution that allows the first slotted profile 12 to mate with it and guide it. The orientation (angular position) of the folding element 3 is thus defined, during the rotation of the rod 4 about the axis C, by the sliding of the first slider 11 in the first slotted profile 12, which causes the rotation of the lever 7 to which the folding element 3 is rigidly connected.

More precisely, the presence of the first slotted profile 12 imposes a variation of the angular position of the block 6 during its rotation about the axis C, and by means of a suitable definition of the first slotted profile 12 it is possible to impose to the block 6 and to the first folding element 3 a constant angular position at the useful portion Bl of the trajectory B. In this manner, the sliding surface 6b remains parallel to the flap that is folded on the product.

Advantageously, in order to allow to modify the (radial) position of each folding element 3 with respect to the rod 4 and to the axis C, the rod 4 is constituted by a central segment 4b, which is provided with the central pivot 5, and two end segments 4c, each of which supports a respective folding element 3 that can slide in a radial direction with respect to the central segment 4b.

The control and modification means comprise a second slotted profile 14, which is formed on the plate 13 and is adapted to guide a second slider 15 (which, in a manner similar to what has been shown for the first slider, can be a roller, a probe, a skid, or others), which is fixed to each end segment 4c in order to vary the length of the rod 4 and thus modify the position of each folding element 3 with respect to it and with respect to the axis C.

More particularly, the central segment 4b has protrusions 16, which are arranged on opposite sides with respect to the pivot 5 and can slide with respect to tracks 17 (as shown more clearly in Figure 2) formed in the end segments 4c.

During the rotation of the rod 4, the second slider 15 moves along the second slotted profile 14, the points of which are arranged at a variable distance from the axis C: the second slider 15 thus imposes a movement of the end segment 4c, to which the second slider 15 is fixed. This movement is allowed and guided in a radial direction by the mutual sliding of the protrusion 16 with respect to the walls of the track 17 (more specifically, the walls of the track 17 slide along the protrusion 16). Ultimately, the desired variation of the length of the rod 4 and of the distance of the folding element 3 from the rotation axis C is achieved, and it is thus possible to keep the sliding surface 6b constantly in contact with the flap that is folded along the useful portion Bl.

The combined action of the lever 7 (which is controlled by the first slotted profile 12) and of the end segment 4c (which is controlled by the second slotted profile 14) thus defines the movement of each folding element 3 during its rotation about the axis C. By appropriately shaping the first profile 12 and the second profile 14 it is thus possible to achieve a rectilinear motion (with constant orientation) of the folding element 3 that accompanies the movement of the product along the useful portion Al of the predefined path A.

According to an alternative embodiment, the folding element 3 comprises at least one layer of elastically deformable material.

The presence of such layer allows to apply the folding assembly 1 according to the invention also if the trajectory B is substantially circular and there are no devices adapted to define, for the folding element 3, a substantially translational motion at the useful portion Bl.

If the trajectory B is in fact substantially similar to a circumference, and if the useful portion Al. is straight, as in the previously described embodiment, the presence of the elastically deformable layer allows an at least partial interpenetration between the folding element 3 and the product at the interference between the useful portion. Bl, which is substantially circular as mentioned, and the useful portion Al.

More particularly, the layer of elastically deformable material is constituted substantially by a brush, which is fixed to the block 6 at the sliding surface 6b.

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

Following the rotation of the rod 4 about the axis C, the folding element 3 traces the trajectory B, and at the useful portion Bl, which faces and is proximate to the useful portion Al of the path A of the product, provides and maintains the fold of the flap of film on such product.

According to the first described embodiment, shown in the accompanying figures, the presence of the means for controlling and modifying the angular position of the folding element 3 allows to provide a translational motion for the folding element 3 at the useful portion B 1.

In this manner, the operation in practice can be likened to the operation of assemblies of the background art, and allows the folding element 3 to follow the movement of the products along the useful portion Al, but without the stop and the change of direction provided in known assemblies, in which the folding elements are provided with a reciprocating rectilinear motion.

The units that constitute the folding assembly 1 according to the invention in fact have a substantially circular unidirectional motion and therefore do not have problems linked to intense vibrations and more generally to intense mechanical stresses generated by operation with a reciprocating rectilinear motion.

If instead the folding assembly 1 has brushes which are fixed to the folding elements 3, as provided in the second described embodiment, the trajectory B of the elements 3 can be substantially circular and again unidirectional, thus allowing to avoid the problems linked to reciprocating motion.

The presence of the brushes in fact allows interpenetration between the folding element 3 and the product, at the interference between the circular trajectory B and the rectilinear useful portion Al of the path A of the product.

In practice it has been shown that the folding assembly according to the invention fully achieves the proposed aim, since the presence of the rotatable supporting element allows to define, for the folding element, a trajectory that comprises a useful portion that faces and is proximate to the respective useful portion of the predefined path of the product, so as to contain the stresses on the involved mechanical elements and without requiring very high mechanical performance from them.

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 shown, 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.

Claims

1. A folding assembly (1), particularly for products to be packaged, comprising an apparatus (2) for moving at least one element (3) for folding flaps of film wrapped around a product to be packaged, the product being movable along a predefined path (A), characterized in that said movement apparatus (2) comprises at least one supporting element for said at least one folding element (3), said supporting element being able to rotate about an axis (C) which is perpendicular to the predefined path (A) of the product to move said folding element (3) along a trajectory (B)₃ a useful portion (Bl) of said trajectory (B) facing and being proximate to a respective useful portion (Al) of the predefined path (A) of the product in order to allow the folding of the flaps.

2. The folding assembly according to claim 1, characterized in that it comprises two of said folding elements (3), which can move substantially synchronously along said trajectory (B) in substantially opposite directions.

3. The folding assembly according to claims 1 and 2, characterized in that each of said folding elements (3) comprises at least one folding surface (6a) and at least one sliding surface (6b), which is substantially perpendicular to the first surface, said folding surface (6a) striking, substantially at the beginning of said useful portion (Bl), the flap of film that protrudes from the product in order to fold it, said sliding surface (6b) being able to slide along the flap that is folded on the product in order to maintain and flatten the fold, said folding element (3) being movable along said useful portion (Bl) at a higher speed than that of said product along said useful portion (Al).

4. The folding assembly according to one or more of the preceding claims, characterized in that said supporting element is constituted substantially by a rod (4) that rotates about said axis (C) at a central pivot (5) that is arranged on its centerline, said rod (4) supporting, at its end portions (4a), said two folding elements (3).

5. The folding assembly according to claim 1, characterized in that it comprises means for controlling and modifying the position and orientation of each of said folding elements (3) with respect to said axis (C), said control and modification means defining a substantially translational motion for said folding elements (3) along said useful portion (Bl), parallel to the product, which can move along said useful portion (Al) of the predefined path (A), which is substantially straight.

6. The folding assembly according to claim 5, characterized in that said control and modification means comprise a lever (7), which is rigidly connected to said folding element (3) and is articulated to said rod (4) at a first end (7a) thereof, said lever (7) being adapted to control and modify the orientation of each of said folding elements (3) with respect to said rod (4).

7. The folding assembly according to claim 6, characterized in that said lever (7) has, at a second end (7b) that lies opposite the first end (7a), a first slider (11), which can slide in a first slotted profile (12) formed on a plate (13) which is parallel to the plane that contains said trajectory (B), the sliding of said first slider (11) in said first slotted profile (12) causing the rotation of said lever (7) with respect to said rod (4) and the modification of the orientation of each of said folding elements (3).

8. The folding assembly according to one or more of the preceding claims, characterized in that said rod (4) is constituted by a central segment (4b), provided with said central pivot (5), and two end segments (4c), each of which supporting a respective folding element (3), each of said end segments (4c) being able to slide radially with respect to said central segment (4b), in order to modify the position of each of said folding elements (3) with respect to said rod (4) and said axis (C).

9. The folding assembly according to one or more of the preceding claims, characterized in that said control and modification means comprise a second slotted profile (14), which is formed on said plate (13) and is adapted to guide a second slider (15), which is fixed to each of said end segments (4c) in order to vary the length of said rod (4) and modify the position of each one of said folding elements (3) with respect to it and with respect to said axis (C).

10. The folding assembly according to claim 1 and as an alternative to claim 5, characterized in that said folding element (3) comprises at least one layer of elastically deformable material, in order to allow an at least partial interpenetration between said folding element (3) and the product, at the interference between said useful portion (Bl), which is substantially circular, of said trajectory (B) of said folding element (3) and the substantially straight useful portion (Al) of the predefined path (A) of the products.

11. The folding assembly according to one or more of the preceding claims, characterized in that said at least one layer of elastically deformable material is constituted substantially by a brush which is arranged at said sliding surface (6b).