EP4025505A1

EP4025505A1 - Wrapping head for wrapping loads, particularly palletized loads, and method of operation thereof

Info

Publication number: EP4025505A1
Application number: EP20785599.0A
Authority: EP
Inventors: Davide Balzani
Original assignee: E80 Group SpA
Current assignee: E80 Group SpA
Priority date: 2019-09-06
Filing date: 2020-09-04
Publication date: 2022-07-13
Also published as: IT201900015842A1; CA3153058A1; WO2021044368A1; US20220340315A1

Abstract

A wrapping head (1) for wrapping loads, particularly palletized loads, comprising a framework (5), connectable to the operating end (9) of a handler (10), and supporting a reel (13) of film (14) made of extensible material, and diverting means (20), for transferring the film (14), unwound from the reel (13), towards the load (3). The head (1) also comprises means (21) for 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, and deflection means (24) for the first portion (22) of film (14), suitable to superimpose the first portion (22) on the second portion (23), thus attaining, at the outlet of said wrapping head (1), a double-layer material band (25).

Description

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

TECHNICAL FIELD OF THE INVENTION The present invention regards a head for wrapping loads, more particularly palletized loads, and the respective wrapping method.

STATE OF THE PRIOR ART

As is known, the palletized loads consist of one or more goods arranged on a pallet for the purpose of facilitating the movement and the transport thereof.

In order to prevent falls or overturning of goods, during the transport of a palletized load it is provided to laterally enclosed or wrap the load itself with a layer of extensible material, for example in the form of a plastic material film.

The wrapping of a palletized load is generally carried out by means of automatic or semiautomatic wrapping stations, comprising means for moving a wrapping head, which carries one or more reels of such extensible material that can be unrolled and wound around the load.

There are different types of wrapping stations.

In some types of stations, the palletized load is maintained stationary, while the wrapping head is rotated around the load.

In other types of stations, the palletized load is driven to rotate around a longitudinal axis thereof, while the wrapping head is situated in a fixed position at a predetermined distance from the rotatable load, and is translatable vertically and parallel to the load, so as to cover the entire lateral surface thereof.

In this manner, the extensible material of the reel can be unrolled from the wrapping head, coming to form a series of spiral windings around the palletized load, starting from a lower or upper end thereof, up to obtaining a stabilizing covering of the load.

At the end of the wrapping, the extensible material employed is cut by means of suitable means mounted on the wrapping head, and the film flap thus obtained is fixed to the palletized load, e.g. welded by means of a suitable buffer.

The wrapping stations briefly described above are susceptible of improvements, mainly with the purpose of increasing, during the transport or during other logistical operations, the stability and the strength of the wrapped load.

As is known, in fact, a palletized load is subjected, during the transport, to strong stresses, accelerations or decelerations, both longitudinally and transversely.

In particular, if the reel of plastic material film to be wound around the palletized load has a height comparable to that of the load to be palletized, a typical example is that of the reels of film with height of 1000 mm., and loads to be palletized that are 1200-1500 mm. high, the spiral winding of the film on the load achieves the relatively high height superimpositions of the layers of the film, for example also on the order of 300 mm.

Such superimposition of the layers of the film is above all verified at the central portion of the load, since the alternating vertical movement of the wrapping head determines the execution of multiple passages at such zone.

As a consequence thereof, it can happen that the film exerts an excessive pressure in the aforesaid central portion of the load, obtaining a so-called hourglass effect, i.e. with a narrower central part, with the consequent crushing-deformation of possible pliable goods situated in that zone.

The strong vertical stresses sustained by the load during the transport can temporarily cancel the weight force of the goods of the palletized load, with the consequent reduction of the friction force between one layer of goods and the next, and possible accidental movements between the layers.

In addition, the portion of the load most subject to goods slipping on the pallet is that in direct contact with the pallet, so that the pallet delimits an abutment surface of the goods that is nearly flat and with low friction level, while in the upper layers the goods, usually having non-perfectly regular shapes, tend to offer greater slipping resistance. Presently, therefore, in order to overcome the abovementioned drawbacks, and in order to make a suitable wrapping of the palletized load, it is provided to quite firmly wrap with the plastic material film at the base of the load, achieving multiple windings around the pallet and around the lower layer of the goods.

Such practice of firmly and repeatedly wrapping the base of the palletized load with the plastic material film, in addition to not resolving the aforesaid problem of the “hourglass” effect of the palletized load, involves - as can be understood - a considerable increase of the consumption of employed film, as well as a corresponding increase of the consumer costs of the palletized goods.

The state of the art comprises several documents which illustrate machines and methods for wrapping loads.

The document WO 2006/032065 A1 describes an apparatus for wrapping goods on a pallet, which comprises a base section for receiving a pallet and distribution means for dispensing a material in order to wrap the goods on a pallet, the distribution means including rotary means in order to allow the material to be twisted while it is applied to the goods on the pallet.

The document US 2009/293425 A1 describes systems for tracing the use of the material for monitoring and optimizing the use of the extensible film on a wrapping machine. Different uses are also supplied for the data collected from the material tracing system, and different data presentation modes are also supplied.

The document US 2018/111709 describes an apparatus, associable with a wrapping machine, comprising at least one unwrapping unit for the wrapping machine for wrapping a load with a film and shuttle means movable along a path and adapted to receive and support an unwrapping unit to be substituted and to be disassembled from the wrapping machine and/or from a new unwrapping unit to be mounted on the wrapping machine.

The document US 2011/088359 A1 presents a wrapping machine for wrapping a tape with at least two extensible films around a product, which comprises a dispenser for dispensing the two extensible films with longitudinal superimposition.

The patent US 5 077 956 A describes a method for wrapping a palletized load with a tape of plastic material film whose width is a fraction of the height of the load. The method is provided for a fixed table machine with a stationary load in which the reel of film is moved around the load and consequently unwound in order to form at least one revolution of the tape, after which the tape of film is transversely cut, the latter terminal part of the film tape is combined with the wrapped load and the new first terminal part of the film is fixed and the wrapped load is removed. During at least one step of the wrapping, the reel of film is moved in a path, forming a horizontal ring, and in this step the tap of unwound film is deflected and offset in vertical direction in order to prevent irregular folds in the film.

OBJECTS OF THE INVENTION

The technical task of the present invention is that of improving the state of the art in the field of wrapping palletized loads.

In the context of such technical task, one object of the present invention is to make a wrapping head for wrapping loads which allows overcoming the previously lamented drawbacks.

Another object of the present invention is to provide a wrapping head for wrapping loads capable of suitably stabilizing a palletized load with a more limited consumption of plastic material film with respect to the known solutions.

Still another object is to devise a wrapping head for wrapping loads with versatile use, in order to satisfy different load wrapping requirements.

Still another object of the present invention is to implement a wrapping head for wrapping loads that is structurally simple and inexpensive.

A further object of the present invention is to provide a wrapping head for wrapping loads with simple and reliable operation.

Such task and such objects are achieved by a wrapping head for wrapping loads, more particularly palletized loads, according to claim 1.

The wrapping head comprises a framework, connectable to the operating end of a handler, and supporting a reel of film made of extensible material.

The head also comprises diverting means for transferring the film, unwound from the reel, towards the load.

According to one aspect of the invention, the head comprises 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.

In addition, the head comprises means for deflecting 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. In addition, the deflection means for the first portion of film are adjustable so as to obtain a partial or complete superimposition of the two film portions.

This solution allows at least partly obtaining a wrapping of the load that is more solid and thick, when desired, by using the normal film unwound from the reel, with which one obtains, due to the aforesaid expedients, a double-layer band, even without using a greater quantity of material.

According to a further aspect of the invention, the aforesaid deflection means can be activated and deactivated in a selective manner at the user’s discretion, i.e. they can be activated only when requested, during the operation of the head.

This signifies that the user can decide, during the operation of the head, to carry out a normal single-layer wrapping cycle, or, if necessary, to pass in a very simple and quick manner to a double-layer wrapping mode, for a stronger and more rigid wrapping in specific zones of the load.

Such task and such objects are also reached by a method for wrapping loads, more particularly palletized loads, according to claim 19.

The wrapping method according to the invention comprises the steps of supplying a reel of film made of extensible material, unwinding the film from the reel, 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 deflecting the first portion of film, so as to superimpose such first portion of film on the second portion of film, thus attaining a double-layer material band, and wrapping the load with such band.

According to one aspect of the invention, the aforesaid step of deflecting the first portion of film comprises a step of deflecting such first portion from a first feed direction to an intermediate feed direction, which is deflected, with respect to such first feed direction, by a first deflection angle.

According to another aspect of the invention, the aforesaid step of deflecting the first portion of film comprises a step of further deflecting such first portion from the intermediate feed direction to a second feed direction, which is deflected, with respect to such intermediate feed direction, by a second deflection angle; in particular, the second feed direction coincides with the feed direction of the second portion of film. The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS 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: figure 1 is a perspective view of the wrapping head according to the present invention, in a specific operative step; figure 2 is a further perspective view of the wrapping head, in which the film has been removed for greater clarity; figure 3 is a top view of the wrapping head; figure 4 is another top view of the wrapping head, with some parts removed for greater clarity; figure 5 is a detail of figure 2; figure 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; figure 7 is a schematic front view of a wrapping station comprising the wrapping head according to the invention; figure 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; figure 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; figure 10 is a schematic and detailed top view of the deflection means for the wrapping head.

EMBODIMENTS OF THE INVENTION

With reference to the figure 1, reference number 1 overall indicates a head for wrapping loads, more particularly palletized loads, according to the present invention. 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 (figure 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.

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.

The wrapping head 1 comprises a support framework 5.

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.

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 figure 6).

As shown in the same figure 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.

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

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.

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.

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.

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. 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.

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

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.

The rotation axes of the first 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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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. 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).

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.

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.

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

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.

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 figure 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).

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 figures 8 and 9).

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 Dl.

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.

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.

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

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.

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.

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 Dl, by a first deflection angle al.

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 a2. According to one version of the invention the second deflection angle a2 substantially corresponds to the first deflection angle al, but with opposite sign: for example if the first deflection angle al is 120°, then the second deflection angle a2 is -120°, bringing the portion 22 of the film 14 back to a final angle of 0°.

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).

In the embodiment of the invention illustrated in the figures, the first deflection angle al is 90° and the second deflection angle a2 is -90°.

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 al and of the second deflection angle a2, and is thus 0°, i.e. there is a translation with respect to the first feed direction Dl, in particular, a translation of the first portion of film 22 parallel to itself, but moved lower, as shown in figure 9.

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

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.

In this situation, the cutting means 21 can be deactivated, in order to use the singleday er film 14 directly as it is unwound from the reel 13.

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.

The passage of the first deflector 26 from the inactive position to the operative position is schematically shown in figure 10.

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.

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.

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

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

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

The first deflector 26 has essentially elongated shape.

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

The first deflector 26 defines a respective first longitudinal axis 32. 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.

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

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

The first longitudinal axis 32 of the first deflector 26 is deflected, with respect to the first feed direction Dl, by a first deflection angle bΐ.

In particular, according to the embodiment of the figures, the first deflection angle bΐ is substantially equal to 45°.

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.

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.

As shown in figures 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).

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

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

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.

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

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.

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.

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. 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.

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

The second deflector 27 can for example have cylindrical shape, or in any case be provided with a lateral surface with suitable curvature. The second deflector 27 could also comprise or be constituted by a rotatable roller.

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 b2.

In particular, according to the embodiment of the figures, also the second deflection angle b2 is substantially equal to -45°. As can be observed in the particular case of figure 9, in order to obtain the desired result, the first deflection angle bΐ of the first deflector 26 is substantially equal to half of the first deflection angle al, like the second deflection angle b2 of the second deflector 27 is substantially equal to half of the second deflection angle a2.

In other cases, for example with a first deflection angle al of 120° and a second deflection angle a2 of -120°, the deflection angle bΐ of the first deflector 26 is substantially equal to half of the supplementary angle of the first deflection angle al, i.e. it is substantially equal to 30°, and the same calculation holds true for the deflection angle b2 of the second deflector 27, which is substantially equal to half of the supplementary angle of the second deflection angle a2, i.e. it is substantially equal to - 30°, with respect to the intermediate feed direction D3.

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.

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

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 doubledayer wrapping mode, the first deflector 26 is translated into its operative position.

As is observed, for example, in figures 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 figure 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 Dl, due to the mutual positioning between the first deflector 26 and the second deflector 27.

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

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 figure 8 (in which the second deflector is represented with a dashed line) and in figure 9.

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.

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.

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 Dl, by the first deflection angle al (which is, in particular, substantially equal to 90°).

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 a2, substantially equal to -90°.

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.

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

The method according to the present invention comprises the steps of: supplying a reel 13 of film 14 made of extensible material; unwinding the film 14 from the reel 13; 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 wrapping the load 3 with such band 25 of double-layer material.

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 Dl, by a first deflection angle al.

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.

In one embodiment of particular practical interest of the method according to the invention, the first deflection angle al is substantially equal to 90° and the second deflection angle a2 is substantially equal to -90°.

The invention as conceived allows attaining important technical advantages.

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.

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.

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.

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.

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.

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.

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

It was thus seen that the invention attains the proposed objects.

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

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

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.

Claims

1. Wrapping head (1) for wrapping loads, particularly palletized loads, comprising a framework (5), connectable to the operating end (9) of a handler (10), and supporting a reel (13) of film (14) made of extensible material, and diverting means (20) for transferring the film (14), unwound from the reel (13), towards the load (3), characterized in that it comprises means (21) for 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, and deflection means (24) for the first portion (22) of film (14), suitable to move said first portion (22), parallel to itself, in order to at least partly superimpose said first portion (22) on said second portion (23).

2. Wrapping head according to claim 1, wherein said deflection means (24) are provided with adjustment means for partly or completely superimposing the first portion (22) on the second portion (23), thus attaining, at the outlet of said wrapping head (1), a band (25) of material that is partly or completely double-layer.

3. Wrapping head according to claim 1 or 2, wherein said deflection means (24) comprise a first deflector (26) and a second deflector (27), around which the first portion (22) of the film (14) is wound.

4. Wrapping head (1) according to claim 3, wherein said first deflector (26) is configured so as to deflect the first portion (22) of the film (14) from a first feed direction (Dl) to an intermediate feed direction (D3) which is tilted, with respect to said first feed direction (Dl), by a first deflection angle (al).

5. Wrapping head (1) according to claim 4, wherein said second deflector (27) is configured so as to further deflect the first portion (2) of the film (14) from said intermediate feed direction (D3) to a second feed direction (D2) which is tilted, with respect to said intermediate feed direction (D3), by a second deflection angle (a2), said second feed direction (D2) substantially corresponding to the feed direction of the second portion (23) of film (14).

6. Wrapping head (1) according to claim 5, wherein said first deflection angle (al) and said second deflection angle (a2) are substantially equal and with opposite sign.

7. Wrapping head (1) according to claim 6, wherein said first deflection angle (al) is substantially equal to 90° and said second deflection angle (a2) is substantially equal to -90°.

8. Wrapping head (1) according to one of the claims 4-7, wherein said first deflector (26) has essentially elongated shape, and it defines a respective first longitudinal axis (32) tilted, with respect to said first feed direction (Dl), by a first tilt angle (bΐ).

9. Wrapping head (1) according to claim 8, wherein said second deflector (27) has essentially elongated shape, and it defines a respective second longitudinal axis (37) tilted, with respect to said intermediate feed direction (D3), by a second tilt angle (b2).

10. Wrapping head (1) according to claim 9, wherein said first tilt angle (bΐ) is substantially equal to half the supplementary angle of the first deflection angle (al) and wherein said second tilt angle (b2) is substantially equal to half the supplementary angle of the second deflection angle (al).

11. Wrapping head (1) according to claim 10, wherein said first tilt angle (bΐ) is substantially equal to 45° and said second tilt angle (b2) is substantially equal to -45°.

12. Wrapping head (1) according to one of the claims 4-11, wherein said deflection means (24) can be activated or deactivated in a selective manner during the operation of said head (1), so as to select carrying out a normal single-layer wrapping cycle, or a double-layer wrapping cycle.

13. Wrapping head (1) according to claim 12, wherein said 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 the 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 the first portion (22) to be superimposed on the second portion (23), thus attaining, at the outlet of said wrapping head (1), a band (25) of double-layer material.

14. Wrapping head (1) according to claim 13, wherein the passage of said second deflector (27) from said first position to said second position, and vice versa, occurs by means of a rigid translation of said second deflector (27) according to a direction parallel to the symmetry axis of the reel (13) of film (14).

15. Wrapping head (1) according to claim 14, wherein said deflection means (24) comprise translation means (33) for translating said second deflector (27), between said first position and second position, said translation means (33) comprising a guide member (34) fixed to said framework (5), to which a slider (35) is in turn connected in a slidable manner, said slider (35) associated with said deflector (27), said slider (35) being actuated to slide along said guide member (34) by linear actuation means.

16. Wrapping head (1) according to one of the claims 2-15, wherein said first deflector (26) is selectively movable between an inactive position and an operative position, such that when said first deflector (26) is situated in said 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, while when said first deflector (26) is situated in said 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.

17. Wrapping head (1) according to claim 16, wherein the passage of said first deflector (26) 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 (13) of film (14).

18. Wrapping head (1) according to one of the preceding claims, wherein said 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, the height being intended as the dimension of the film (14) perpendicular to the unwinding and feeding direction thereof.

19. Method for wrapping loads (3), comprising the steps of: supplying a reel (13) of film (14) made of extensible material; unwinding the film (14) from the reel (13); characterized in that it comprises 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 said first portion (22) of film (14), parallel to itself, so as to at least partly superimpose said first portion (22) of film (14) on said second portion (23) of film (14), thus at least partly attaining a band (25) of double-layer material; and wrapping the load (3) with said band (25).

20. Wrapping method according to claim 19, wherein said step of deflecting said first portion (22) of film (14) comprises a step of deflecting said first portion (22) from a first feed direction (Dl) to an intermediate feed direction (D3) which is tilted, with respect to said first feed direction (Dl), by a first deflection angle (al).

21. Wrapping method according to claim 20, wherein said step of deflecting said first portion (22) of film (14) comprises a step of further deflecting said first portion (22) from said intermediate feed direction (D3) to a second feed direction (D2) which is tilted, with respect to said intermediate feed direction (D3), by a second deflection angle (a2), said second feed direction (D2) substantially corresponding to the feed direction of said second portion (23) of film (14).

22. Wrapping method according to claim 21, wherein said first deflection angle (al) is substantially equal to 90° and said second deflection angle (a2) is substantially equal to -90°.