WRAPPING HEAD FOR WRAPPING LOADS, PARTICULARLY PALLETIZED LOADS, AND METHOD OF OPERATION THEREOF

Abstract

A wrapping head for wrapping loads, particularly palletized loads, including a framework, connectable to the operating end of a handler, and supporting a reel of film made of extensible material, and diverting means, for transferring the film, unwound from the reel, towards the load. The head also includes means for cutting the film, along its feed direction, so as to obtain a first portion of film and a second portion of film that are distinct and separate from each other, and deflection means for the first portion of film, suitable to superimpose the first portion on the second portion, thus attaining, at the outlet of said wrapping head, a double-layer material band.

Claims

1. A wrapping head for wrapping loads, particularly palletized loads, comprising a framework, connectable to the operating end of a handler, and supporting a reel of film made of extensible material, and diverting means for transferring the film, unwound from the reel, towards the load, further comprising means for cutting the film, along its feed direction, so as to obtain a first portion of film and a second portion of film that are distinct and separate from each other, and deflection means for the first portion of film, suitable to move said first portion, parallel to itself, in order to at least partly superimpose said first portion on said second portion.

2. The wrapping head according to claim 1, wherein said deflection means are provided with adjustment means for partly or completely superimposing the first portion on the second portion, thus attaining, at the outlet of said wrapping head, a band of material that is partly or completely double-layer.

3. The wrapping head according to claim 1, wherein said deflection means comprise a first deflector and a second deflector, around which the first portion of the film is wound.

4. The wrapping head according to claim 3, wherein said first deflector is configured so as to deflect the first portion of the film from a first feed direction to an intermediate feed direction which is tilted, with respect to said first feed direction, by a first deflection angle.

5. The wrapping head according to claim 4, wherein said second deflector is configured so as to further deflect the first portion of the film from said intermediate feed direction to a second feed direction which is tilted, with respect to said intermediate feed direction, by a second deflection angle, said second feed direction substantially corresponding to the feed direction of the second portion of film.

6. The wrapping head according to claim 5, wherein said first deflection angle and said second deflection angle are substantially equal and with opposite sign.

7. The wrapping head according to claim 6, wherein said first deflection angle is substantially equal to 90° and said second deflection angle is substantially equal to −90°.

8. The wrapping head according to claim 4, wherein said first deflector has essentially elongated shape, and it defines a respective first longitudinal axis tilted, with respect to said first feed direction, by a first tilt angle.

9. The wrapping head according to claim 8, wherein said second deflector has essentially elongated shape, and it defines a respective second longitudinal axis tilted, with respect to said intermediate feed direction, by a second tilt angle.

10. The wrapping head according to claim 9, wherein said first tilt angle is substantially equal to half the supplementary angle of the first deflection angle and wherein said second tilt angle is substantially equal to half the supplementary angle of the second deflection angle.

11. The wrapping head according to claim 10, wherein said first tilt angle is substantially equal to 45° and said second tilt angle is substantially equal to −45°.

12. The wrapping head according to claim 4, wherein said deflection means can be activated or deactivated in a selective manner during the operation of said head, so as to select carrying out a normal single-layer wrapping cycle, or a double-layer wrapping cycle.

13. The wrapping head according to claim 12, wherein said second deflector is selectively movable between a first position, in which it does not carry out any deflection of the first portion of the film, and a second position, in which it carries out the deflection of the first portion of film, so as to bring the first portion to be superimposed on the second portion, thus attaining, at the outlet of said wrapping head, a band of double-layer material.

14. The wrapping head according to claim 13, wherein the passage of said second deflector from said first position to said second position, and vice versa, occurs by means of a rigid translation of said second deflector according to a direction parallel to the symmetry axis of the reel of film.

15. The wrapping head according to claim 14, wherein said deflection means comprise translation means for translating said second deflector, between said first position and second position, said translation means comprising a guide member fixed to said framework, to which a slider is in turn connected in a slidable manner, said slider associated with said deflector, said slider being actuated to slide along said guide member by linear actuation means.

16. The wrapping head according to claim 3, wherein said first deflector is selectively movable between an inactive position and an operative position, such that when said first deflector is situated in said inactive position, the wrapping head can be used according to a conventional use mode, in which the film is wound, around the load, in a single layer, while when said first deflector is situated in said operative position, the wrapping head is usable according to the use mode in which the film, previously cut, can be wound, around the load, in a double layer.

17. The wrapping head according to claim 16, wherein the passage of said first deflector from said inactive position to said operative position, and vice versa, occurs by means of a rigid translation according to a direction that forms a right angle with the symmetry axis of the reel of film.

18. The wrapping head according to claim 1, wherein said cutting means are movable and/or adjustable upward or downward, with respect to the height of the reel, so as to obtain a first portion of film and a second portion of film of different heights, the height being intended as the dimension of the film perpendicular to the unwinding and feeding direction thereof.

19. A method for wrapping loads, comprising the steps of: supplying a reel of film made of extensible material; unwinding the film from the reel; characterized in that it comprises cutting the film along its feed direction, so as to obtain a first portion of film and a second portion of film that are distinct and separate from each other; deflecting said first portion of film, parallel to itself, so as to at least partly superimpose said first portion of film on said second portion of film, thus at least partly attaining a band of double-layer material; and wrapping the load with said band.

20. The wrapping method according to claim 19, wherein said step of deflecting said first portion of film comprises a step of deflecting said first portion from a first feed direction to an intermediate feed direction which is tilted, with respect to said first feed direction, by a first deflection angle.

21. The wrapping method according to claim 20, wherein said step of deflecting said first portion of film comprises a step of further deflecting said first portion from said intermediate feed direction to a second feed direction which is tilted, with respect to said intermediate feed direction, by a second deflection angle, said second feed direction substantially corresponding to the feed direction of said second portion of film.

22. The wrapping method according to claim 21, wherein said first deflection angle is substantially equal to 90° and said second deflection angle is substantially equal to −90°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Further aspects and advantages of the present invention will be clearer from the following detailed description of several currently preferred embodiments, illustrated as a merely non-limiting example in the enclosed drawings, in which:

[0045] FIG. 1 is a perspective view of the wrapping head according to the present invention, in a specific operative step;

[0046] FIG. 2 is a further perspective view of the wrapping head, in which the film has been removed for greater clarity;

[0047] FIG. 3 is a top view of the wrapping head;

[0048] FIG. 4 is another top view of the wrapping head, with some parts removed for greater clarity;

[0049] FIG. 5 is a detail of FIG. 2;

[0050] FIG. 6 is a further perspective view of the wrapping head from a different angle, with some parts removed and with the handler, with which the head is associated, illustrated in a schematic manner with dashed line;

[0051] FIG. 7 is a schematic front view of a wrapping station comprising the wrapping head according to the invention;

[0052] FIG. 8 is a front, schematic and detailed view of the deflection means for the wrapping head, in an initial step in which the first portion of the film is not yet superimposed on the second portion of the film;

[0053] FIG. 9 is a front, schematic and detailed view of the deflection means for the wrapping head, in a subsequent step in which the first portion of the film is superimposed on the second portion of the film, thus attaining a double-layer wrapping material; and

[0054] FIG. 10 is a schematic and detailed top view of the deflection means for the wrapping head.

DETAILED DESCRIPTION OF THE INVENTION

[0055] With reference to the FIG. 1, reference number 1 overall indicates a head for wrapping loads, more particularly palletized loads, according to the present invention.

[0056] In the following description, by way of a non-limiting example, reference will be made to a head 1 included in a wrapping station 2 (FIG. 7) in which the load 3, in particular a palletized load, is driven to rotate around a vertical or substantially vertical axis, on a suitable rotatable support platform 4, and the wrapping head 1 is fixed with respect to the load 3, and only executes vertical or substantially vertical movements.

[0057] However, the present invention can also be applied to a wrapping station 2 in which the load 3 is locally stationary, while the wrapping head 1 is supported, and driven, to rotate around the aforesaid stationary load 3.

[0058] The wrapping head 1 comprises a support framework 5.

[0059] The support framework 5 comprises a first plate 6, lower during use, and a second plate 7, upper during use, opposite the first plate 6.

[0060] The first plate 6 and the second plate 7 can be joined together by means of elongated connection elements 8, of any type (see for example FIG. 6).

[0061] As shown in the same FIG. 6, in an entirely schematic manner and only for the purpose of improved comprehension, the framework 5 of the head 1 is connectable to the operating end 9 of a handler 10, e.g. a robot.

[0062] The handler 10 can for example be a robot of anthropomorphic type, or a Cartesian robot, or a robot of another type.

[0063] The robot 10 has the task of imparting, to the support framework 5 of the head 1, the necessary movements in order to execute the correct wrapping of the palletized load 3, according to a specific wrapping program, as is better clarified hereinbelow.

[0064] The connection between the operating end 9 of the robot 10 and the framework 5 is carried out by means of the brackets 11 fixed, for example, to the elongated connection elements 8.

[0065] In particular, two brackets 11 can be provided, of which one is upper during use and the other lower during use; each bracket 11 can be provided with eyelets 12, by means of which it is possible to obtain the connection to the operating end 9.

[0066] The framework 5 supports a reel 13 of a film 14 made of extensible material suitable for the wrapping of loads, in particular palletized loads, e.g. an extensible plastic material of type known in this application type.

[0067] The wrapping head 1 can also comprise a pre-stretch group 15 of the film 14 unwound from the reel 13, and intended for the wrapping of the load 3.

[0068] The pre-stretch group 15 is supported by the framework 5.

[0069] The pre-stretch group 15 comprises a first roller 16 and a second roller 17, rotatably supported by the framework 5, with the respective rotation axes parallel.

[0070] The rotation axes of the rust roller 16 and of the second roller 17 are perpendicular to the planes where respectively the first plate 6 and the second plate 7 lie.

[0071] In one embodiment of the invention, the first roller 16 and the second roller 17 have cylindrical or substantially cylindrical shape; nevertheless, in other embodiments, the first roller 16 and the second roller 17 could have a different shape.

[0072] The lateral surfaces of the first roller 16 and of the second roller 17 are coated with material adapted to attain high friction with the film 14; for example, the lateral surfaces of the first roller 16 and of the second roller 17 can be coated with rubber, or another material with suitable properties.

[0073] Such coating of the first roller 16 and of the second roller 17 could also be affected by surface machining, which has the purpose of further increasing the friction with the film 14.

[0074] The film 14, unwound from the reel 13, is wound on the first roller 16 and then on the second roller 17, in this order, before then continuing towards the palletized load 3.

[0075] The first roller 16 and the second roller 17 comprise respective first driving means 18 and second driving means 19, controlled by a control unit for operating the wrapping head 1, not represented in the figures.

[0076] The control unit is configured for commanding the first driving means 18 and the second driving means 19 such that the rotation speed of the second roller 17 is greater than that of the first roller 16.

[0077] In this manner, the tangential speed difference of the second roller 17 with respect to that of the first roller 16, to which the film 14 adheres due to their special coating, causes a certain stretching of the material with respect to its state when it is wound in the reel 13.

[0078] Such stretching of the material of the film 14 can be carried out for at least two reasons.

[0079] The first reason is the reduction of the consumption of material used for wrapping the palletized loads 3, due to the greater length of the film 14 given the same weight of employed material.

[0080] The second reason is that the suitably stretched material adheres in an improved manner to the external surface of the palletized load 3, causing a wrapping of improved quality. The presence of the pre-stretch group 15 in the wrapping head 1 according to the present invention is however entirely optional.

[0081] The wrapping head 1 also comprises diverting means 20 for sending the film 14, unwound from the reel 13 and suitably elongated by the pre-stretch group 15, towards the load 3.

[0082] In one embodiment of the invention, such diverting means 20 comprise a plurality of bars 20a, 20b, 20c, 20d, supported by the framework 5 with respective longitudinal axes parallel to the axis of the reel 13.

[0083] In other words, the film 14, coming from the pre-stretch group 15, carries out, before reaching the palletized load 3, a specific path in which it is deflected by the bars 20a, 20b, 20c, 20d multiple times, being partially wound around the surface of the latter.

[0084] The bars 20a, 20b, 20c, 20d can be rotatably idly supported with respect to the framework 5, or they can be fixed with respect to the framework 5 itself.

[0085] According to one aspect of the invention, the wrapping head 1 comprises means 21 for cutting the film 14 along the feed and advancement direction of the film 14 itself, so as to obtain, due to such cutting, a first portion 22 of film 14 and a second portion 23 of film 14 that are distinct and separate from each other, which advance together towards the load 3.

[0086] With reference to the path of the film 14 from the reel 13 to the load 3, the cutting means 21 are interposed between the pre-stretch group 15 and the diverting means 20. The cutting means 21 can for example comprise a blade, a heated body or other devices suitable for precisely separating the two aforesaid portions 22, 23 of the film 14.

[0087] Preferably, but not exclusively, the cutting means 21 are supported by the framework 5, at about half the height with respect to the reel 13, so as to obtain a first portion 22 of film 14 and a second portion 23 of film 14 of equal height (by height it is intended the dimension of the film 14 perpendicular to the direction of unwinding and feeding of the same).

[0088] According to another version of the invention, the cutting means 21 are movable and/or adjustable upward or downward, with respect to the height of the reel 13, so as to obtain a first portion 22 of film 14 and a second portion 23 of film 14 of different heights, always intending with height the dimension of the film 14 perpendicular to the direction of unwinding and feeding of the same.

[0089] According to another aspect of the invention, the wrapping head 1 comprises deflection means 24 for deflecting the first portion 22 of film 14, suitable to superimpose such first portion 22 on the second portion 23 of film 14, thus attaining, at the outlet of the wrapping head 1, a band 25 of double-layer material.

[0090] The deflection means 24 are supported by the framework 5 of the head 1.

[0091] With reference to the feed path of the film 14 from the reel 13 towards the palletized load 3, the deflection means 24 are provided downstream of the cutting means 21.

[0092] In addition, the deflection means 24 are interposed between the bars 20a, 20b, 20c and the final bar 20d of the diverting means 20 (see on this matter FIG. 4, which shows the head 1 with some parts removed, and where a possible path P of the film 14 is illustrated, in an entirely schematic manner, with dashed line, only for the purpose of improved comprehension).

[0093] The deflection means 24 modify the first feed direction D1 of the first portion 22 of film 14, so as to bring the latter substantially corresponding to the second feed direction D2 of the second portion 23 of film 14 (see FIGS. 8 and 9).

[0094] In other words, the deflection means 24 attain the movement of the first feed direction D1 of the first portion 22 of film 14 in a second feed direction D2, parallel to the first feed direction D1.

[0095] Due to the possibilities of adjusting the deflection means 24, the first portion 22 of film 14 can be superimposed at least partly on the second portion 23 of film 14 and can come to be completely superimposed on the second portion 23 of film 14 substantially corresponding to the feed direction of the second portion 23 of film 14.

[0096] It must be observed that the deflection means 24 attain the aforesaid movement of the first portion 22 of film 14, without overturning or folding, maintaining such first portion 22 parallel to itself.

[0097] The deflection means 24 comprise a plurality of deflectors 26, 27.

[0098] The deflectors 26, 27 are positioned one after the other, with reference to the feed direction of the first portion 22 of film 14, and are configured for attaining the aforesaid deflection of the first feed direction D1 of the first portion 22 of film 14.

[0099] In the embodiment of the invention illustrated in the figures, the deflection means 24 comprise two deflectors 26, 27, and more particularly a first deflector 26 and a second deflector 27, around which the first portion 22 of the film 14 is wound.

[0100] The first deflector 26 is configured so as to deflect the first portion 22 of the film 14 from a first feed direction D1 to an intermediate feed direction D3 which is deflected, with respect to the first feed direction D1, by a first deflection angle α1.

[0101] The second deflector 27 is configured so as to further deflect the first portion 22 of the film 14 from the aforesaid intermediate feed direction D3 to the aforesaid second feed direction D2, which is deflected, with respect to the intermediate feed direction D3, by a second deflection angle α2. According to one version of the invention the second deflection angle α2 substantially corresponds to the first deflection angle α1, but with opposite sign; for example if the first deflection angle α1 is 120°, then the second deflection angle α2 is −120°, bringing the portion 22 of the film 14 back to a final angle of 0°.

[0102] In some embodiments of the invention, the deflection means 24 could comprise further deflectors: in other words, the same result could be obtained with a number of deflectors greater than two, if the specific needs require it (e.g. for the type of wrapping material used, or for other reasons).

[0103] In the embodiment of the invention illustrated in the figures, the first deflection angle α1 is 90° and the second deflection angle α2 is −90°.

[0104] The overall deflection that the first portion 22 of film 14 sustains, traversing the deflection means 24, is thus the result of the algebraic sum of the first deflection angle α1 and of the second deflection angle α2, and is thus 0°, i.e. there is a translation with respect to the first feed direction D1, in particular, a translation of the first portion of film 22 parallel to itself, but moved lower, as shown in FIG. 9.

[0105] According to one aspect of the invention, the first deflector 26 is selectively movable between an inactive position and an operative position.

[0106] When the first deflector 26 is situated in the inactive position, the wrapping head 1 can be used according to a conventional use mode, in which the film 14 is wound, around the load 3, in a single layer.

[0107] In this situation, the cutting means 21 can be deactivated, in order to use the single-layer film 14 directly as it is unwound from the reel 13.

[0108] If, however, the first deflector 26 is situated in the operative position, the wrapping head 1 is usable according to the use mode in which the film 14, previously cut, can be wound around the load 3 in a double layer.

[0109] The passage of the first deflector 26 from the inactive position to the operative position is schematically shown in FIG. 10.

[0110] In such figure, the first deflector 26 is represented with dashed line when it is situated in the inactive position, and it is instead shown with solid line when it is in the operative position.

[0111] The passage of the first deflector 26 from the inactive position to the operative position, and vice versa occurs by means of a rigid translation according to a direction which forms a right angle with the symmetry axis of the reel 13.

[0112] For this purpose, the deflection means 24 comprise a linear actuator 28, associated with the aforesaid first deflector 26.

[0113] The linear actuator 28 can be of any type suitable for this purpose, e.g. electromechanical, pneumatic, oil-pressure etc.

[0114] The linear actuator 28 can be fixed, for example, to the first plate 6 of the framework 5.

[0115] The first deflector 26 can for example be connected to a carriage 29 slidable on guides 30 fixed to the first plate 6; the carriage 29 is, in turn, connected to the movable member 31 of the aforesaid linear actuator 28.

[0116] The first deflector 26 has essentially elongated shape.

[0117] The first deflector 26 has one end connected to the aforesaid linear actuator 28.

[0118] The first deflector 26 defines a respective first longitudinal axis 32.

[0119] The first deflector 26 has the lateral surface with shape suitable for allowing the wrapping of the film 14 around it, and also the sliding of the film 14 itself in the feed direction.

[0120] The first deflector 26 can for example have cylindrical shape, or in any case be provided with a lateral surface with suitable curvature.

[0121] The first deflector 26 could also comprise, or be constituted by, a rotatable roller.

[0122] The first longitudinal axis 32 of the first deflector 26 is deflected, with respect to the first feed direction D1, by a first deflection angle β1.

[0123] In particular, according to the embodiment of the figures, the first deflection angle β1 is substantially equal to 45°.

[0124] According to another aspect of the invention, the deflection means 24 are activatable and deactivatable in a selective manner, during the operation of the head 1; in other words the user can decide, during the operation of the head 1, to carry out a normal single-layer wrapping cycle, or, if necessary, to pass, in a very quick and easy manner, to a double-layer wrapping mode, for a stronger and more rigid wrapping in specific zones of the load.

[0125] More particularly, the second deflector 27 is selectively movable between a first position, in which it does not carry out any deflection of the first portion 22 of film 14, and a second position, in which it carries out the deflection of the first portion 22 of film 14, so as to bring such first portion 22 in superimposition on the second portion 23, thus attaining, at the outlet of the wrapping head 1, a band 25 of double-layer material.

[0126] As shown in FIGS. 8 and 9, the passage of the second deflector 27 from the first position to the second position, and vice versa, occurs by means of a rigid translation of the second deflector 27 according to a direction parallel to the symmetry axis of the reel 13 (i.e. during use, and in most wrapping applications, according to a vertical or substantially vertical direction).

[0127] For this purpose, the deflection means 24 comprise means 33 for translating the second deflector 27 between the aforesaid first position and second position.

[0128] The translation means 33 can be of any type suitable for this purpose.

[0129] For example, the translation means 33 can comprise a guide member 34 fixed to the framework 5, to which a slider 35 is in turn connected in a slidable manner.

[0130] As shown in the detail of FIG. 5, a support 36 is fixed to the slider 35; such support 36 is in turn associated with the second deflector 27.

[0131] The slider 35 is actuated to slide along the guide member 34 by linear actuation means which can be of any type suitable for the application, e.g. electromechanical, pneumatic, oil-pressure, etcetera.

[0132] It must be observed therefore that the deflection of the first portion 22 of the film 14 can be adjusted and in this manner also the superimposition of the first portion 22 with respect to the second portion 23 can be adjusted. The second deflector 27, being moved by means of the translation means 33, can render the superimposition of the first portion 22 with respect to the second portion 23 partial or complete.

[0133] In addition, given that also the cutting means 21 are movable and adjustable upward or downward, with respect to the height of the reel 13, also the two portions 22, 23 of the film 14 can be varied.

[0134] Hence, the maximum flexibility is obtained for making the wrapping 2 for the load 3, with portions 22, 23 equivalent or not equivalent and partial or complete superimpositions.

[0135] The second deflector 27 has essentially elongated shape, and defines a respective second longitudinal axis 37.

[0136] As with the first deflector 26, also the second deflector 27 has the lateral surface with shape suitable for allowing the wrapping of the film 14 around it, and also the sliding of the film 14 itself in the feed direction.

[0137] The second deflector 27 can for example have cylindrical shape, or in any case be provided with a lateral surface with suitable curvature.

[0138] The second deflector 27 could also comprise or be constituted by a rotatable roller.

[0139] The second longitudinal axis 37 of the second deflector 27 is deflected, with respect to the intermediate feed direction D3, by a second deflection angle β2.

[0140] In particular, according to the embodiment of the figures, also the second deflection angle β2 is substantially equal to −45°.

[0141] As can be observed in the particular case of FIG. 9, in order to obtain the desired result, the rust deflection angle β1 of the first deflector 26 is substantially equal to half of the rust deflection angle α1, like the second deflection angle β2 of the second deflector 27 is substantially equal to half of the second deflection angle α2.

[0142] In other cases, for example with a first deflection angle α1 of 120° and a second deflection angle α2 of −120°, the deflection angle β1 of the first deflector 26 is substantially equal to half of the supplementary angle of the first deflection angle α1, i.e. it is substantially equal to 30°, and the same calculation holds true for the deflection angle β2 of the second deflector 27, which is substantially equal to half of the supplementary angle of the second deflection angle α2, i.e. it is substantially equal to −30°, with respect to the intermediate feed direction D3.

[0143] In one embodiment of the invention, the deflection means 20 can comprise a further bar 20e, supported by the framework 5 and placed downstream of the bar 20d, with reference to the feed direction of the film 14, which allows directing, with a suitable winding angle, the first portion 22 of the film 14 towards the first deflector 26.

[0144] In light of that described above, the operation of the wrapping head 1 according to the invention is intuitive.

[0145] In a preliminary step of arranging the head 1, if in the wrapping it is desired to use, for some zones of the load 3, the double-layer wrapping mode, the first deflector 26 is translated into its operative position.

[0146] As is observed, for example, in FIGS. 1, 8, 10, when the first deflector 26 is situated in its operative position, it is approached to the second deflector 27, which is situated in its first position; more particularly, as shown in FIG. 8, the second deflector 27 is situated (with reference to the plane of the floor, on which the load 3 is supported) at a height slightly greater than that of the first deflector 26, in a manner such that the first portion 22 of film 14 is wound, in succession, on the external surface of the first deflector 26 and of the second deflector 27 so as to substantially not sustain any deflection with respect to the first feed direction D1, due to the mutual positioning between the first deflector 26 and the second deflector 27.

[0147] In this operating configuration, the head 1 can carry out the wrapping of the load 3 with a single layer of film 14.

[0148] More particularly, the first portion 22 and the second portion 23, even if previously separated by the cutting means 21, are fed parallel, or substantially parallel, to each other, and hence wound around the load 3 essentially as if they constituted a film that is intact, even if with a longitudinal cut.

[0149] When it is desired, however, to carry out the wrapping of the load 3 with double-layer mode—e.g. in some portions of the load, such as the base—the second deflector 27 is translated from the first position to the second position, as shown in FIG. 8 (in which the second deflector is represented with a dashed line) and in FIG. 9.

[0150] In particular—with reference to a normal situation of use of the head 1—in the passage from the first position to the second position, the second deflector 27 carries out a downward translation.

[0151] In substance, the second deflector 27 travels a section equal to the distance between the upper edge of the first portion 22 of the film 14 and the upper edge of the second portion 23 of the film 14.

[0152] In this manner, the first portion 22 of the film 14, being wound around the first deflector 26, is deflected from the first feed direction D1 to the intermediate feed direction D3, which is deflected, with respect to the first feed direction D1, by the first deflection angle α1 (which is, in particular, substantially equal to 90°).

[0153] In addition, the same first portion 22 of the film 14, being wound around the second deflector 27, is deflected from the intermediate feed direction D3 to the second feed direction D2 which is deflected, with respect to the intermediate feed direction D3, by the second deflection angle α2, substantially equal to −90°.

[0154] In this manner, the first portion 22 of film 14 is superimposed on the second portion 23, and both are fed along the second feed direction D2, attaining a band 25 of double-layer material.

[0155] If it is desired, after having carried out, around the load 3, a certain number of windings with the aforesaid band 25 of double-layer material, the second deflector 27 can be brought back to its first position of FIG. 8, in a manner such that the first portion 22 and the second portion 23 of film can be newly fed one parallel to the other in the single-layer configuration.

[0156] Also forming the object of the present invention is a method for wrapping loads, in particular palletized loads.

[0157] The method according to the present invention comprises the steps of:

[0158] supplying a reel 13 of film 14 made of extensible material;

[0159] unwinding the film 14 from the reel 13;

[0160] cutting the film 14 along its feed direction, so as to obtain a first portion 22 of film 14 and a second portion 23 of film 14 that are distinct and separate from each other; deflecting the first portion 22 of film 14, so as to superimpose the first portion 22 of film 14 on the second portion 23 of film 14, so as to attain a band 25 of double-layer material; and

[0161] wrapping the load 3 with such band 25 of double-layer material.

[0162] According to one aspect of the invention, such step of deflecting the first portion 22 of film 14 comprises, more in detail, a step of deflecting the first portion 22 from a first feed direction D1 to an intermediate feed direction D3, which is deflected, with respect to said first feed direction D1, by a first deflection angle α1.

[0163] According to another aspect of the invention, the aforesaid step of deflecting the first portion 22 of film 14 further comprises a step of deflecting the first portion 22 from the aforesaid intermediate feed direction D3 to a second feed direction D2 which is deflected, with respect to the intermediate feed direction, by a second deflection angle. The second feed direction D2 coincides with the feed direction of the second portion 23 of film 14.

[0164] In one embodiment of particular practical interest of the method according to the invention, the first deflection angle α1 is substantially equal to 90° and the second deflection angle α2 is substantially equal to −90°.

[0165] The invention as conceived allows attaining important technical advantages.

[0166] As seen, first of all the wrapping head 1 according to the present invention has the considerably advantage of being able to modify, even during the winding of a load, the working mode, passing from the single-layer configuration to the double-layer wrapping configuration, and vice versa, in relation to the different packaging requirements.

[0167] Only by way of a non-limiting example, the double-layer wrapping mode can be used when the base of the load 3 is wrapped, while the single-layer wrapping mode can be used when the central portion of the same load 3 is wrapped.

[0168] In addition thereto, it is underlined that, due to the solution according to the present invention, the double-layer wrapping is carried out with consumption of further material with respect to the single-layer solution, since the same film 14 is used, longitudinally cut into two portions 22, 23 and superimposed on each other.

[0169] In addition, it is observed that, also in the double-layer wrapping mode, the wrapping is carried out by always directing towards the load 3 the same face of the film 14.

[0170] Indeed, the double deflection sustained by the first portion 22 (for winding on the first deflector 26 and then on the second deflector 27) in substance determines a double overturning of the film 14 which, at the outlet of the deflection means 24, has the same orientation that it had before traversing the aforesaid deflection means 24.

[0171] This circumstance is important since it is known that, usually, the two faces of the film 14 used in this application type are not identical, but rather the one preferably directed towards the load 3 has better adhesion characteristics. For example, such better adhesion characteristics are due to the presence of a glue on the face of the film 14 directed towards the load 3.

[0172] These results are obtained with a structurally simple and inexpensive technical solution, that is also easy to use and versatile.

[0173] It was thus seen that the invention attains the proposed objects.

[0174] The invention thus conceived is susceptible of numerous modifications and variations, all falling within the scope of the inventive concept.

[0175] In addition, all the details can be substituted by technically equivalent elements.

[0176] In practice, the materials used, as well as the contingent shapes and sizes, can be of any type in accordance with the requirements without departing from the protective scope of the following claims.