Gripping elements for handling a stretchable film for packaging a product

Abstract

A gripping elements system (1) for handling a stretchable film (2) comprises a first gripping element (3), arranged transversely to said film (2), a second gripping element (4), arranged transversely to said film (2), a third gripping element (5) and a fourth gripping element (6) arranged parallel to respective opposite longitudinal edges (8, 9) of the film (2), wherein each gripping element (3; 4; 5; 6) comprises a body (1; 20; 29; 41) inside which at least one chamber (27; 28, 28a; 34, 35, 36) is defined communicating with the environment outside the system (1) via a plurality of holes (13; 23; 26; 31, 32, 33); wherein said at least one chamber is connected to a connecting element (14; 24; 38; 50) by which said at least one chamber (27; 28, 28a; 34, 35, 36) can be connected to a sucking device, wherein the holes (13; 23; 26; 31, 32, 33; 43, 44, 45; 56; 62, 64, 66) of said plurality of holes have a diameter comprised between 1 mm and 5 mm.

Description

Gripping elements system for handling a stretchable film for packaging a product

[0001] The invention relates to a gripping elements system for handling a stretchable film, for example made of plastics, in order to wrap a product therewith, in particular a product placed on a tray, to create light packaging, which also leaves the product visible, if the film is transparent.

[0002] Systems of gripping elements for handling a stretchable film are known from the prior art that comprise: a first gripping element and a second gripping element that are devised to grasp the film, unwind the film from a reel and wrap the film around a product to be packaged; a third gripping element and a fourth gripping element that are devised to grasp the opposite longitudinal edges of the film, tension the film in a direction substantially perpendicular to said opposite longitudinal edges and wrap the film around the product to be packaged.

[0003] The gripping elements have the shape of pincers comprising a fixed jaw and a movable jaw, between which the film can be clamped.

[0004] The jaws are normally covered with a slip-proof material, for example rubber, or synthetic rubber, which is used to ensure the grip on the film.

[0005] A gripping elements system of the type mentioned above is described in European patent EP 3177533.

[0006] The pincers-shaped gripping elements mentioned above and described in EP 3177533, whilst allowing effective manipulation of the film, have some drawbacks.

[0007] First of all, the slip-proof material with which the jaws of the pincers are covered must have sufficiently great friction to retain the film but at the same time the friction cannot be excessive because it can create problems during the step of releasing the film, making this operation uncontrollable.

[0008] The interaction between the slip-proof material and the film can change according to the features of the film, which can be more or less slippery, more or less thick, but can also change because of environmental conditions like temperature and humidity, which alter the physical properties of the film and of the slip-proof material; in extreme cases of low temperatures the need to preheat the film before use also arises.

[0009] Further, slip-proof material is subject to wear, which constitutes a further problem in the constancy of operation of the system and requires periodic replacement interventions, with resulting loss of time and money.

[0010] Further, the pincers require precise tolerances in the mechanical parts in order to operate correctly, but these precise tolerances generate complications first in the assembly step and then in the maintenance step.

[0011] Further, repeated opening and closing of the movable jaws of the pincers can cause, over time, wear to the coupling between the movable jaw and the fixed jaw and wear to the mechanisms that control opening and closing of the movable jaw, until complete replacement of the gripper is required, with significant waste of time and money.

[0012] Lastly, the presence of the movable jaw in each gripping element and the presence of mechanisms that control the movement thereof makes the gripping elements system complex and expensive to make.Summary of the invention

[0013] One object of this invention is to simplify the systems of gripping elements for handling a stretchable film by making the systems simpler and less expensive to implement, ensuring a secure grip on the stretchable film in all steps of handling the film and in all conditions.

[0014] A further object of this invention is to improve the durability of the gripping elements.

[0015] The objects of the invention are achieved by a gripping elements system for handling a stretchable film according to claim 1 and claims 2 to 21.

[0016] Owing to the invention, the structure of the gripping elements is significantly simplified, because the gripping elements do not have moving parts for gripping the film.

[0017] The absence of moving parts substantially eliminates the problems of wear present in the aforementioned prior-art gripping elements, ensuring much longer durability for the gripping elements compared with known prior-art gripping elements.Brief description of the drawings

[0018] The invention will now be disclosed below merely by way of non-limiting example, with reference to the enclosed drawings, in which:Figure 1 is a schematic perspective view of a gripping elements system according to the invention;Figure 2 is a perspective view of a first gripping element according to the invention;Figure 3 is an exploded perspective view of the first gripping element of Figure 2;Figure 4 is a perspective view of a second gripping element according to the invention; Figure 5 is an exploded perspective view of the second gripping element of Figure 4; Figure 6 is a perspective view of a third gripping element according to the invention; Figure 7 is an exploded perspective view of the third gripping element of Figure 6;Figure 8 is a perspective view of is a perspective view of a fourth gripping element according to the invention;Figure 9 is an exploded perspective view of the fourth gripping element of Figure 8;Figure 10 is a perspective view of a version of a gripping element according to the invention; Figure 11 is a perspective view of a further version of a gripping element according to the invention;Figure 12 is a view like that of Figure 11, in which a part of the gripping element has been removed.

[0019] Figure 1 shows a schematic perspective view of a system 1 of gripping elements according to the invention, for handling a film 2 of stretchable material, for example stretchable plastics.

[0020] The system 1 comprises:- a first gripping element 3, arranged transversely to the film 2, whose function is to retain the film 2 before the start of a step of wrapping a product, to enable the film to pass whilst being unwound from a reel (not visible in the figures), to cooperate with wrapping the film around the product to be packaged and possibly cut the film, at the end of the step of wrapping the product;- a second gripping element 4, which is also arranged transversely to the film 2, the function of which is to unwind a set quantity of film 2 from the reel, in the direction indicated by the arrow F in figure 1, by grasping a free end of the film 7, initially retained by the first gripping element 3, and cooperating with the first gripping element 3 to wrap the film around a product to be packaged;- a third gripping element 5 and a fourth gripping element 6, arranged parallel to respective opposite longitudinal edges 8 and 9 of the film 2, the function of which is to tension the film 2 by stretching the film in a direction substantially perpendicular to the direction indicated by the arrow F and wrapping the film around the product to be packaged.

[0021] The first gripping element 3, the second gripping element 4, the third gripping element 5 and the fourth gripping element 6 grasp and retain the film 2 by a vacuum gripping system, as will be explained in greater detail below.

[0022] In figures 2 and 3, the first gripping element 3 is illustrated in a perspective view (Figure 2) and in an exploded perspective view (Figure 3).

[0023] The first gripping element 3 comprises a body 10 that has a plurality of protrusions 11, having a substantially rectangular plan shape, spaced apart by spaces 12.

[0024] The body 10 consists of a first part 10a and a second part 10b having corresponding shapes. The first part 10a and the second part 10b are provided with respective protrusions I la and 1 lb that mate with one another to form the protrusions 11 of the body 10, when the first part 10a and the second part 10b of the body 10 are joined together.

[0025] Inside the body 10, when the first part 10a and the second part 10b are joined together, a chamber 27 is defined.

[0026] Each protrusion 11b of the second part 10b of the body 10 is provided with a plurality of holes 13, which place the chamber 27 in communication with the exterior.

[0027] The chamber 27 communicates with a first connecting element 14, by means of which the chamber 27 can be connected to a sucking device suitable for creating a vacuum in the chamber 27.

[0028] The first gripping element 3 further comprises a plate 15, which is so connected to the body 10 that between the body 10 and the plate 15 a slit 16 remains through which the film 2 can pass.

[0029] When the film 2 is inserted into the slit 16, if the chamber 27 is connected to the sucking device, the vacuum that is created in the chamber 27 sucks the film 2, through the holes 13, makes the film 2 stick to the body 10 and retains the film 2 against the body 10, as long as the connection between the chamber 27 and the sucking device is maintained.

[0030] The holes 13 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 13 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, in particular during the step of wrapping the film 2 around the product, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0031] In fact, with holes 13 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the first gripping element 3 may lose the grip on the film 2, whereas with holes with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smallerdimensions than the dimensions of the holes 13 can be fixed below the plane of the holes to avoid in all cases the effect of sucking the film 2.

[0032] The first gripping element 3 can also comprise a knife element 17, drivable by a lever 18, controlled by a cam 19.

[0033] The knife element 17 is used to cut the film 2, at the end of the step of wrapping a product, to separate the portion of film 2 wrapped around the product from the rest of the film 2.In figures 4 and 5, the second gripping element 4 is illustrated in a perspective view (Figure 4) and in an exploded perspective view (Figure 5).

[0034] The second gripping element 4 comprises a body 20 that has a plurality of protrusions 21, having a substantially rectangular plan shape, spaced apart by spaces 22.

[0035] The protrusions 21 are so positioned and sized as to be able to be inserted into the spaces 12 of the body 10 of the first gripping element 3.

[0036] Similarly, the spaces 22 are so positioned and sized that the protrusions 11 of the body 10 of the first gripping element 3 can be inserted into the spaces 22.

[0037] The body 20 consists of a first part 20a and a second part 20b having corresponding shapes. The first part 20a and the second part 20b are provided with respective protrusions 21a and 21b that mate with one another to form the protrusions 21 of the body 20, when the first part 20a and the second part 20b of the body 20 are joined together.

[0038] Inside the body 20, when the first part 20a and the second part 20b are joined together, a first chamber 28 is defined.

[0039] Each protrusion 21b of the second part 20b of the body 12 is provided with a plurality of holes 23, that place the first chamber 28 in communication with the exterior.

[0040] The first chamber 28 can be placed in communication with a second connecting element 24, by means of which the first chamber 28 can be connected to a sucking device suitable for creating a vacuum in the first chamber 28.

[0041] The first gripping element 3 further comprises a plate 25, to which a perforated element 26 is fitted and that can be connected to the second part 20b of the body 20.

[0042] When the plate 25 is connected to the second part 20b of the body 20, between the second part 20b and the plate 25 a second chamber 28a is defined that communicates with the exterior through the perforated element 26.

[0043] The second chamber 28a can also be placed in communication, independently of the first chamber 28, with the second connecting element 24, by which the second chamber28a can be connected to a sucking device suitable for creating a vacuum in the second chamber 28a.

[0044] When the second gripping element 4 is brought into contact with the film 2, if the chamber 28 is connected to the sucking device, the vacuum that is created in the chamber 28 sucks the film 2, through the holes 23, makes the film stick to the body 20 and retains the film against the body 20, as long as the connection between the chamber 28 and the sucking device is maintained.

[0045] The holes 23 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 23 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, in particular during the step of unwinding the film 2 from the reel and of wrapping the film 2 around the product, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0046] In fact, with holes 23 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the second gripping element 4 may lose the grip on the film 2, whereas with holes with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smaller dimensions than the dimensions of the holes 23 can be fixed below the plane of the holes to avoid, in all cases, the effect of sucking the film 2. Creating a vacuum in the second chamber 28a is designed to enable the second gripping element 4 to lock in position a tray containing a product to be wrapped, which has been brought into contact with the perforated element 26, whereas the third gripping element 5 and the fourth gripping element 6 take the opposite longitudinal edges 8 and 9 of the film 2 below the tray, in a step of completing wrapping the product.

[0047] In figures 6 and 7, the third gripping element 5 is illustrated in a perspective view (Figure 6) and in an exploded perspective view (Figure 7).

[0048] The third gripping element 5 comprises a body 29 on a face 30 of which a first group of holes 31 is present that is flanked by a second group of holes 32 and by a third group of holes 33 that are placed on sides opposite the first group of holes 31. The body 29 consists of a first part 29a and a second part 29b having corresponding shapes.

[0049] The first part 29a comprises the first group of holes 31, the second group of holes 32 and the third group of holes 33.

[0050] The second part 29b comprises a first chamber 34 flanked by a second chamber 35 and by a third chamber 36 placed on sides opposite the first chamber 34.

[0051] When the first part 29a and the second part 29b are joined together the first group of holes 31 is at the first chamber 34 and places the first chamber 34 in communication with the exterior; the second group of holes 32 is at the second chamber 35 and places the second chamber 35 in communication with the exterior; the third group of holes 33 is at the third chamber 36 and places the third chamber 36 in communication with the exterior.

[0052] The first chamber 34 communicates, via a first conduit 37, with a third connecting element 38.

[0053] Similarly, the second chamber 35 communicates, via a second conduit 39, with the third connecting element 38 and the third chamber 36 communicates, via a third conduit 40, with the third connecting element 38.

[0054] The third connecting element 38 can be connected to a sucking device suitable for creating a vacuum in the first chamber 34, in the second chamber 35 and in the third chamber 36.

[0055] The connections between the first chamber 34, the second chamber 35, the third chamber 36 and the third connecting element 38 can be opened or closed independently of one another, by respective valve elements, which are not shown, placed at the coupling of the first conduit 37, of the second conduit 39 and of the third conduit 40, in the third connecting element 38.

[0056] When the third gripping element 5 comes into contact with the film 2, a vacuum created in the first chamber 34, in the second chamber 35 and in the third chamber 36 makes the film 2 stick to the body 29 of the third gripping element and retains the film against the body 29 as long as said vacuum is maintained.

[0057] Depending on the dimensions of the portion of film 2 that has to be grasped by the third gripping element, the vacuum is created only in the first chamber 34, or also in the second chamber 35 and in the third chamber 36.

[0058] The holes 31, 32, 33 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 31, 32, 33 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, in particular during the step of tensioning the film 2 and of wrapping the film 2 around the product, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0059] In fact, with holes 31, 32, 33 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the third gripping element 5 may lose the grip on the film 2, whereas with holes 31, 32, 33 with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smaller dimensions than the dimensions of the holes 31, 32, 33 can be fixed below the plane of the holes to avoid in all cases the effect of sucking the film 2. In figures 8 and 9, the fourth gripping element 6 is illustrated in a perspective view (Figure 8) and in an exploded perspective view (Figure 9).

[0060] The fourth gripping element 6 comprises a body 41 on a face 42 of which a first group of holes 43 is present that is flanked by a second group of holes 44 and by a third group of holes 45 that are placed on sides opposite the first group of holes 43.

[0061] The body 41 consists of a first part 41a and a second part 41b having corresponding shapes.

[0062] The first part 41a comprises the first group of holes 43, the second group of holes44 and the third group of holes 45.

[0063] The second part 41b comprises a first chamber 46 flanked by a second chamber 47 and by a third chamber 48 placed on sides opposite the first chamber 34.

[0064] When the first part 41a and the second part 41b are joined together the first group of holes 43 is at the first chamber 46 and places the first chamber 46 in communication with the exterior; the second group of holes 44 is at the second chamber 47 and places the second chamber 47 in communication with the exterior; the third group of holes 45 is at the third chamber 48 and places the third chamber 48 in communication with the exterior.

[0065] The first chamber 46 communicates, via a first conduit 49, with a fourth connecting element 50.

[0066] Similarly, the second chamber 47 communicates, via a second conduit 51, with the fourth connecting element 50 and the third chamber 48 communicates, via a third conduit 52, with the fourth connecting element 50.

[0067] The fourth connecting element 50 can be connected to a sucking device suitable for creating a vacuum in the first chamber 46, in the second chamber 47 and in the third chamber 48.

[0068] The connections between the first chamber 46, the second chamber 47 and the third chamber 48 and the fourth connecting element 50 can be opened or closedindependently of one another, by respective valve elements, which are not shown, placed at the coupling of the first conduit 49, of the second conduit 51 and of the third conduit 52, in the fourth connecting element 50.

[0069] When the fourth gripping element 6 comes into contact with the film 2, creating a vacuum in the first chamber 46, in the second chamber 47 and in the third chamber 48 makes the film 2 stick to the body 41 of the third gripping element and retains the film against the body 41 as long as said vacuum is maintained.

[0070] Depending on the dimensions of the portion of film 2 that has to be grasped by the third gripping element, the vacuum is created only in the first chamber 46, or also in the second chamber 47 and in the third chamber 48.

[0071] The holes 43, 44, 45 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 43, 44, 45 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, in particular during the step of tensioning the film 2 and of wrapping the film 2 around the product, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0072] In fact, with holes 43, 44, 45 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the fourth gripping element 6 may lose the grip on the film 2, whereas with holes 31, 32, 33 with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smaller dimensions than the dimensions of the holes 43, 44, 45 can be fixed below the plane of the holes to avoid in all cases the effect of sucking the film 2. In Figure 10, a first version of a gripping element 53 according to the invention is illustrated in a perspective view.

[0073] The gripping element 53 comprises a tubular element 54, closed at both ends and fixed to a support plate 55.

[0074] The tubular element 54 is provided with a plurality of holes 56, distributed substantially evenly over most of the length thereof.

[0075] The holes 56 place the interior of the tubular element 54 in communication with the exterior.

[0076] The interior of the tubular element 54 communicates with a fifth connecting element 57, by means of which the interior of the tubular element 54 can be connected to a sucking device suitable for creating a vacuum inside the tubular element 54.

[0077] When the tubular element 54 is brought into contact with the film 2, if the interior of the tubular element 54 is connected to the sucking device, the vacuum that is created inside the tubular element 54 sucks the film 2, through the holes 56, makes the film stick to the tubular element 54 and retains the film against the tubular element 54 as long as the connection between interior of the tubular element 54 and the sucking device is maintained.

[0078] The holes 56 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 56 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0079] In fact, with holes 56 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the gripping element 53 may lose the grip on the film 2, whereas with holes 56 with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smaller dimensions than the dimensions of the holes 56 can be fixed below the plane of the holes to avoid in all cases the effect of sucking the film 2. In figures 11 and 12, a second version of a gripping element 58 according to the invention is illustrated in perspective views.

[0080] The gripping element 58 comprises a tubular element 59, closed at both ends, fixed to a U-shaped support element 60.

[0081] The tubular element 59 comprises a central section 61, provided with a first group of holes 62, flanked, on opposite sides, by a first lateral section 63, provided with a second group of holes 64, and by a second lateral section 65, provided with a third group of holes 66. The interior of the central section 61 does not communicate with the interior of the first lateral section 63 and of the second lateral section 65.

[0082] The interior of the central section 61 can be connected, by a sixth connecting element 67, to a sucking device.

[0083] Similarly, the interior of the first lateral section 63 can be connected, by a seventh connecting element 68, to a sucking device and the interior of the second lateral section 65 can be connected, by an eighth connecting element 69, to a sucking device.

[0084] On a side 70 of the support element 60, a first window 71 is made, that, when the tubular element 59 is fixed to the support element 60, is at the first group of holes 62.

[0085] On the side 70, a second window 72 and a third window 73 are further made, that, when the tubular element 59 is fixed to the support element 60, are at the second group of holes 64 and the third group of holes 66, respectively.

[0086] The connections between the interior of said central section 61, the interior of said first lateral section 63 and the interior of said second lateral section 65 can be opened or closed independently of one another.

[0087] When the gripping element 58 comes into contact with the film 2, creating a vacuum inside said central section 61, said first lateral section 63 and said second lateral section 65 makes the film 2 stick to the tubular element 59 and retains the film against the tubular element 59 as long as said vacuum is maintained.

[0088] Depending on the dimensions of the portion of film 2 that has to be grasped by the gripping element 58, the vacuum is created only in the central section 61 of the tubular element 59, or also in the first lateral section 63 and in the second lateral section 65 of the tubular element 59.

[0089] The holes 62, 64, 66 are arranged in parallel rows that are staggered in relation to one another. The diameter of the holes 62, 64, 66 is comprised between 1 mm and 5 mm, so as to ensure a secure grip on the film 2, and so as to make the release of the film 2 easy and not to generate unappealing wrinkles on the surface of the film.

[0090] In fact, with holes 62, 64, 66 with a diameter of less than 1 mm, the grip on the film 2 is not secure, with the risk that the gripping element 58 may lose the grip on the film 2, whereas with holes 62, 64, 66 with a diameter greater than 5 mm, there is the risk that the film 2 is sucked back inside the holes, making release of the film 2 problematic and generating unappealing wrinkles on the surface of the film 2. A net with meshes having smaller dimensions than the dimensions of the holes 62, 64, 66 can be fixed below the plane of the holes to avoid in all cases the effect of sucking the film 2.

[0091] The gripping element 53 and / or the gripping element 58 can be used instead of the first gripping element 3, of the second gripping element 4, of the third gripping element 5 and of the fourth gripping element 6.

Claims

CLAIMS1. Gripping elements system (1) for handling a stretchable film (2) comprising a first gripping element (3), arranged transversely to said film (2), a second gripping element (4), arranged transversely to said film (2), a third gripping element (5) and a fourth gripping element (6) arranged parallel to respective opposite longitudinal edges (8, 9) of the film (2), characterized in that each gripping element (3; 4; 5; 6) comprises a body (1; 20; 29; 41) inside which at least one chamber (27; 28, 28a; 34, 35, 36) is defined communicating with the environment outside the system (1) via a plurality of holes (13; 23; 26; 31, 32, 33; 43, 44, 45; 56; 62, 64, 66); wherein said at least one chamber is connected to a connecting element (14; 24; 38; 50) by which said at least one chamber (27; 28, 28a; 34, 35, 36) can be connected to a sucking device, wherein the holes (13; 23; 26; 31, 32, 33) of said plurality of holes have a diameter comprised between 1 mm and 5 mm.

2. Gripping elements system (1) according to claim 1, wherein the body (10) of said first gripping element (3) has a plurality of protrusions (11), having a substantially rectangular plan shape, spaced apart by spaces (12).

3. Gripping elements system (1) according to claim 2, wherein said body (10) comprises a first part (10a) and a second part (10b) having corresponding shapes, in which the first part (10a) and the second part (10b) are provided with respective protrusions (I la; 1 lb) that mate with one another to form the protrusions (11) of the body (10), when the first part (10a) and the second part (10b) of the body (10) are joined together.

4. Gripping elements system, according to claim 3, wherein a chamber (27) is defined inside the body (10), when the first part (10a) and the second part (10b) are joined together; wherein each protrusion (1 lb) of the second part (10b) of the body (10) is provided with a plurality of holes (13), which place the chamber (27) in communication with the exterior; wherein the chamber (27) communicates with a first connecting element (14), by means of which the chamber (27) can be connected to a sucking device suitable for creating a vacuum in the chamber (27).

5. Gripping elements system (1) according to one of the preceding claims, wherein the first gripping element (3) further comprises a plate (15), which is so connected to the body (10) that between the body (10) and the plate (15) a slit (16) remains through which the film (2) can pass.

6. Gripping elements system according to one of the preceding claims, wherein the first gripping element (3) comprises a knife element (17), drivable by a lever (18), controlled by a cam (19).

7. Gripping elements system (1) according to one of claims 1 to 6, wherein the body (20) of said second gripping element (4) has a plurality of protrusions (21), having a substantially rectangular plan shape, spaced apart by spaces (22).

8. Gripping elements system (1) according to claim 7, wherein said body (20) comprises a first part (20a) and a second part (20b) having corresponding shapes, wherein the first part (20a) and the second part (20b) are provided with respective protrusions (21a; 21b) that mate with one another to form the protrusions (21) of the body (20), when the first part (20a) and the second part (20b) of the body (20) are joined together.

9. Gripping elements system (1), according to claim 8, wherein a first chamber (28) is defined inside the body (20) , when the first part (20a) and the second part (20b) are joined together; wherein each protrusion (21b) of the second part (20b) of the body (20) is provided with a plurality of holes (23), that place the chamber (28) in communication with the exterior; wherein the chamber (27) communicates with a first connecting element (14), by means of which the chamber (27) can be connected to a sucking device suitable for creating a vacuum in the chamber (27).

10. Gripping elements system (1), according to claim 8, or 9, characterized in that it further comprises a plate (25), connected to the second part (20b) of the body (20), to which a perforated element (26) is fitted, wherein between the second part (20b) and the plate (25) a second chamber (28a) is defined that communicates with the exterior through the perforated element (26), wherein the second chamber (28a) can also be placed in communication, independently of the first chamber (28), with the second connecting element (24), by whichthe second chamber (28a) can be connected to a sucking device suitable for creating a vacuum in the second chamber (28a).

11. Gripping elements system (1) according to one of the preceding claims, wherein the third gripping element (5) comprises a body (29) on a face (30) of which a first group of holes (31) is present flanked by a second group of holes (32) and by a third group of holes(33) that are placed on sides opposite the first group of holes (31).

12. Gripping elements system (1) according to claim 11, wherein the body (29) comprises a first part (29a) and a second part (29b) having corresponding shapes, wherein the first part (29a) comprises the first group of holes (31), the second group of holes (32) and the third group of holes (33); wherein the second part (29b) comprises a first chamber (34) flanked by a second chamber (35) and by a third chamber (36) placed on sides opposite the first chamber (34); wherein, when the first part (29a) and the second part (29b) are joined together, the first group of holes (31) is at the first chamber (34) and places the first chamber(34) in communication with the exterior; the second group of holes (32) is at the second chamber (35) and places the second chamber (35) in communication with the exterior; the third group of holes (33) is at the third chamber (36) and places the third chamber (36) in communication with the exterior.

13. Gripping elements system (1) according to claim 12, wherein the first chamber (34) communicates, via a first conduit (37), with a third connecting element (38), the second chamber (35) communicates, via a second conduit (39), with the third connecting element (38) and the third chamber (36) communicates, via a third conduit (40), with the third connecting element (38), wherein the third connecting element (38) can be connected to a sucking device suitable for creating a vacuum in the first chamber (34), in the second chamber (35) and in the third chamber (36).

14. Gripping elements system (1) according to claim 13, wherein connections between the first chamber (34), the second chamber (35), the third chamber (36) and the third connecting element (38) can be open or closed independently of one another.

15. Gripping elements system (1) according to one of the preceding claims, wherein the fourth gripping element (6) comprises a body (41) on a face (42) of which a first group ofholes (43) is present that is flanked by a second group of holes (44) and by a third group of holes (45) that are placed on sides opposite the first group of holes (43).

16. Gripping elements system (1) according to claim 15, wherein the body (41) comprises a first part (41a) and a second part (41b) having corresponding shapes, wherein the first part (41a) comprises the first group of holes (43), the second group of holes (44) and the third group of holes (45); wherein the second part (41b) comprises a first chamber (46) flanked by a second chamber (47) and by a third chamber (48) placed on sides opposite the first chamber (46); wherein, when the first part (41a) and the second part (41b) are joined together, the first group of holes (43) is at the first chamber (46) and places the first chamber (46) in communication with the exterior; the second group of holes (44) is at the second chamber (47) and places the second chamber (47) in communication with the exterior; the third group of holes (45) is at the third chamber (48) and places the third chamber (48) in communication with the exterior.

17. Gripping elements system (1) according to claim 16, wherein the first chamber (46) communicates, via a first conduit (49), with a fourth connecting element (50), the second chamber (47) communicates, via a second conduit (51), with the fourth connecting element (50) and the third chamber (48) communicates, via a third conduit (52), with the fourth connecting element (50); wherein the fourth connecting element (50) can be connected to a sucking device suitable for creating a vacuum in the first chamber (46), in the second chamber (47) and in the third chamber (48).

18. Gripping elements system (1) according to claim 17, wherein connections between the first chamber (46), the second chamber (47), the third chamber (48) and the third connecting element (50) can be opened or closed independently of one another.

19. Gripping elements system (1) according to claim 1, characterized in that it comprises a gripping element (53), that comprises a tubular element (54), closed at both ends and fixed to a support plate (55), wherein the tubular element (54) is provided with a plurality of holes (56), distributed substantially evenly over most of the length thereof; wherein the holes (56) place the interior of the tubular element (54) in communication with the exterior; wherein the interior of the tubular element (54) communicates with a fifth connecting element (57),by means of which the interior of the tubular element (54) can be connected to a sucking device suitable for creating a vacuum inside the tubular element (54).

20. Gripping elements system (1) according to claim 1, characterized in that it comprises a gripping element (58) that comprises a tubular element (59), closed at both ends and fixed to a U-shaped support element (60); wherein the tubular element (59) comprises a central section (61), provided with a first group of holes (62), flanked, on opposite sides by a first lateral section (63), provided with a second group of holes (64), and by a second lateral section (65), provided with a third group of holes (66), wherein the interior of the central section (61) does not communicate with the interior of the first lateral section (63) and of the second lateral section (65); wherein the interior of the central section (61) can be connected, by a sixth connecting element (67), to a sucking device; in which the interior of the first lateral section (63) can be connected, by a seventh connecting element (68), to a sucking device and the interior of the second lateral section (65) can be connected, by an eighth connecting element (69), to a sucking device.

21. Gripping elements system (1) according to claim 20, wherein on one side (70) of the support element (60) a first window (71) is made, that, when the tubular element (59) is fixed to the support element (60), is at the first group of holes (62); wherein a second window (72) and a third window (73) are moreover made on the side (70), that, when the tubular element (59) is fixed to the support element (60), are at the second group of holes (64) and the third group of holes (66), respectively.

22. Gripping elements system (1) according to one of the preceding claims, wherein said holes (13; 23; 26; 31, 32, 33; 43, 44, 45; 56; 62, 64, 66) are arranged in parallel rows that are staggered in relation to one another.

23. Gripping elements system (1) according to one of the preceding claims, wherein a net with meshes having smaller dimensions than the dimensions of the holes (13; 23; 26; 31, 32, 33; 43, 44, 45; 56; 62, 64, 66) is fixed below the plane of the holes.

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