Wrapping machine

Abstract

 A machine (1) for wrapping polymeric film, comprising a fixed frame (2), a platform (3), which can rotate on the frame (2) and is actuated by a respective motor, a shaft (4), which can also perform a translational motion, for supporting a roll of polymeric film (5), a substantially oscillating contrast element (7), which is associated with the frame (2), and an assembly (14) for gripping and cutting the polymeric film (5), which is associated with the platform (3). The contrast element (7) presses the polymeric film (5) so that it adheres against the outer surface of the product (P) to be wrapped after the cutting operation.

Description

[0001] The present invention relates to a machine for wrapping polymeric film for packaging products stored on pallets or other supports.

[0002] Some products, particularly goods stacked on pallets, require a more or less accurate packaging with ribbons of polymeric film.

[0003] Originally, this ribbon was wrapped manually around the object to be packaged by moving around it while holding the roll of film in one's hand or by placing the object on a rotating platform and merely moving the roll downward during rotation.

[0004] These two solutions have evolved until machines have been provided which wrap the product automatically.

[0005] The constructive solution of interest is the one that provides for a rotating platform on which the product (optionally placed on a pallet) is arranged; a fixed station is provided to the side of the platform, and the roll of polymeric film is fitted on the station so that it can perform a translational motion along a suitable vertical guide.

[0006] Substantially, it is possible to combine a rotary movement with a vertical translational motion: both movements can be adjusted in terms of speed.

[0007] Once wrapping has ended (the rotating platform is stationary and the polymeric film is stretched between the roll and the wrapped product), an operator must cut the ribbon, leaving loose the end connected to the roll and making the end connected to the product adhere to the outer surface of the wrapping.

[0008] This last operation entails a long time and a high cost for wrapping in relation to the necessary presence of the operator: therefore, during a wrapping operation he cannot store a product wrapped earlier or remove from store a product to be wrapped subsequently, since he must monitor the entire wrapping operation in order to work during the final step.

[0009] The aim of the present invention is to obviate the above-mentioned drawbacks and meet the mentioned requirements, by providing a wrapping machine which works autonomously without requiring the aid of the operator except for the starting and stopping commands.

[0010] Within this aim, an object of the present invention is to provide a wrapping machine which is simple, relatively easy to provide in practice, safe in use, effective in operation, and has a relatively low cost.

[0011] This aim and this and other objects which will become better apparent hereinafter are achieved by a wrapping machine, of the type which comprises a fixed frame, a platform which rotates on said frame and is actuated by a respective motor, and a shaft, which can also perform a translational motion, for supporting a roll of polymeric film, characterized in that it comprises a substantially oscillating contrast element, which is associated with said frame, and an assembly for gripping and cutting the polymeric film, which is associated with said platform, said contrast element pressing the polymeric film so that it adheres against the outer surface of the product to be wrapped after the cutting operation.

[0012] Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of a wrapping machine, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a wrapping machine according to the invention;

Figure 2 is a perspective view of an assembly for gripping and cutting the polymeric film of a wrapping machine according to the invention in the open configuration;

Figure 3 is a perspective view of a portion of an assembly for gripping and cutting the polymeric film of a wrapping machine according to the invention in the closed configuration;

Figure 4 is a plan view of a wrapping machine according to the invention, during a preliminary step of product wrapping;

Figure 5 is a plan view of a wrapping machine according to the invention during product wrapping;

Figure 6 is a plan view of a wrapping machine according to the invention, during a final step of product wrapping;

Figure 7 is a plan view of a wrapping machine according to the invention during the gripping of the polymeric film at the end of product wrapping;

Figure 8 is a plan view of a wrapping machine according to the invention during the cutting of the polymeric film at the end of product wrapping;

Figure 9 is a plan view of a wrapping machine according to the invention during the arrangement of the product for removal at the end of the wrapping of the product.

[0013] With reference to the figures, the reference numeral 1 generally designates a wrapping machine.

[0014] The machine 1 comprises a fixed frame 2 and a platform 3, which can rotate on the frame 2 and is actuated by a respective motor arranged substantially below the platform 3. The frame 2 also supports a shaft 4 for supporting a roll of polymeric film 5: the shaft 4 can perform a translational motion parallel to itself, along a substantially vertical axis, and is guided by a column 6, which is also rigidly coupled to the frame 2.

[0015] The machine 1 also comprises a contrast element 7, which in turn is constituted by a vertical shaft 8, which is pivoted about its longitudinal axis to the fixed frame 2; an area 9 for accommodating and actuating the shaft 8 contains suitable movement means, which are designed to turn the shaft about its own axis. The shaft 8 supports, at its upper end, a substantially horizontal arm 10 (in the embodiment shown in the figures, the arm 10 is constituted by a profiled element which has a substantially central angular portion, so that its end region lies at a lower level than the anchoring to the shaft 8).

[0016] A tubular body 12 is pivoted to the free end 11 of the arm 10, has a substantially vertical axis and constitutes the portion suitable to press the polymeric film 5 against the surface of the wrapped product P.

[0017] The tubular body 12, according to a preferred embodiment, is a roller which can rotate about its own longitudinal axis and is made of a material which is easily and elastically compressible, such as for example sponge rubber or other expanded polymeric materials.

[0018] An actuator 13 (a pneumatic cylinder in the embodiment shown in the figures) is fixed between the tubular body 12 and the arm 10 in order to move the tubular body 12 with respect to the arm 10.

[0019] An assembly 14 for gripping and cutting the polymeric film 5 is associated with the platform 3 and comprises two oscillating jaws 15, which have an end 15a which is rigidly coupled to the platform 3 (and pivoted to it). The jaws 15 are actuated rotationally by at least one respective actuator (which can be a motor but also a fluid-operated actuator, such as for example a pneumatic cylinder) arranged below the supporting surface of the platform 3 so that they can rotate from a first mutually open configuration of maximum distance between the free ends 15b of the jaws 15 to a second configuration for mutual coupling with consequent forced contact of the respective grip faces 16.

[0020] The jaws 15 are pivoted to the platform 3 with their end 15a by way of a respective substantially transverse pivot, in which at least one end head is associated with the end head of the contiguous pivot (with which the other jaw 15 is associated) by way of an elastic means 17.

[0021] In the embodiment shown in the figures, the elastic means 17 is an axially-acting spring, which is fixed to respective transverse arms 18 which are rigidly coupled to the head of each pivot: the presence of the spring is intended to hinder the rotation of the pivots (and therefore of the jaws 15) starting from the first configuration of the jaws 15 (open) to the position in which the arms 18 are parallel with points for fixing the spring at the maximum mutual distance and facilitate the rotation from this intermediate position until the second configuration (jaws 15 coupled) is reached.

[0022] In another embodiment, the springs might also be two, arranged at the two sides of the jaws 15 at both heads of each pivot, in order to improve the balance and stability of the assembly 14.

[0023] The jaws 15 are provided with respective grip faces 16, which have complementarily shaped surfaces: these surfaces 16, in the embodiment shown in the figures, have a plurality of slots and rails which are arranged complementarily in the two jaws 15 for correct coupling when the jaws 15 are arranged in the second configuration for coupling and gripping the film 5.

[0024] Respective means 19 for cutting the film 5 are fitted on the lateral edges of the jaws 15: in the embodiment shown in the figures, the means 19 are constituted by two blades 19, which perform the cold cutting of the film. The cutting surfaces of the blades 19 are substantially co-planar, in order to ensure the cutting of the film 5 when the jaws 15 are coupled (second configuration). In an alternative embodiment (not shown in the figures), the cutting means 19 are constituted by an incandescent element (for example a filament or a Teflon-coated heated bar), which is substantially aligned with the grip faces 16; in another embodiment (not shown in the figures), the hot or cold cutting means 19 can be associated with the contrast element 7, substantially at the free end 11 of the arm 10 and/or of the tubular element 12.

[0025] The wrapping of a product P with polymeric film 5 by means of the wrapping machine 1 consists in resting the product P to be wrapped on the rotating platform 3, while the end flap of the polymeric film 5 is clamped within the gripping and cutting assembly 14.

[0026] The motor must then start the rotation of the platform 3, consequently wrapping the product P with the film 5: during this step, the supporting shaft 4 of the roll of film is made to perform a translational motion along the column 6 vertically by an extent equal to the height of the product P in order to ensure its complete wrapping.

[0027] When the product P is completely wrapped, the contrast element 7 rests forcibly against the outer surface of the product P, ensuring the adhesion of the end portion of the film 5 to said surface.

[0028] By means of a small rotation of the platform 3, the grip and cutting assembly 14 is aligned with the film 5, which is stretched between the contact point of the contrast element 7 and the roll.

[0029] In this position, the grip and cutting assembly 14 grips tight, so as to lock the flap of film 5 that arrives from the roll and cut the part comprised within the jaws 15 beyond said grip portion.

[0030] The contrast element 7 then presses the flap of film that arrives from the product P against the outer surface of the product, and the platform performs a small rotation, during which the film 5 remains clamped between the jaws 15: the forced retention of the flap on the product P by the contrast element 7 facilitates the complete tearing of the film 5, which is tensioned during said small rotation, separating the flap that arrives from the roll from the flap pressed against the product P.

[0031] At this point it is possible to remove the correctly wrapped product P from the platform 3 and arrange a new product P (which in turn will have to be wrapped with the film 5).

[0032] It has thus been shown that the invention achieves the intended aim and objects.

[0033] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

[0034] All the details may further be replaced with other technically equivalent ones.

[0035] In the exemplary embodiments given, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

[0036] Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

[0037] In practice, the materials used, as well as the shapes and dimensions, may be any according to requirements without thereby abandoning the protective scope of the appended claims.

[0038] The disclosures in Italian Patent Application No. BO2005A000258 from which this application claims priority are incorporated herein by reference.

[0039] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A wrapping machine, of the type which comprises a fixed frame (2), a platform (3), which rotates on said frame (2) and is actuated by a respective motor, and a shaft (4), which can also perform a translational motion, for supporting a roll of polymeric film (5), characterized in that it comprises a substantially oscillating contrast element (7), which is associated with said frame (2), and an assembly (14) for gripping and cutting the polymeric film (5), which is associated with said platform (3), said contrast element (7) pressing the polymeric film (5) so that it adheres against the outer surface of the product (P) to be wrapped after the cutting operation.

2. The machine according to claim 1, characterized in that said contrast element (7) comprises a vertical shaft (8), which is pivoted about its own longitudinal axis to said fixed frame (2), said shaft (8) being provided with a substantially horizontal arm (10), to the free end (11) of which a tubular body (12) having a substantially vertical axis is connected, said tubular body constituting the portion suitable to press the polymeric film (5) against the surface of the wrapped product (P).

3. The machine according to the preceding claims, characterized in that said tubular body (12) is a roller which can rotate about its own longitudinal axis and is made of a material which is easily and elastically compressible.

4. The machine according to claims 1 and 2, characterized in that said tubular body (12) is pivoted to the free end (11) of said arm (10), an actuator (13) being fixed between said tubular body (12) and said arm (10) for moving said tubular body (12) with respect to said arm (10).

5. The machine according to claim 1, characterized in that said assembly (14) for gripping and cutting the polymeric film (5) comprises two oscillating jaws (15), which have an end (15a) which is pivoted to the platform (3), are actuated rotationally by at least one respective actuator, and are able to turn from a first mutually open configuration of maximum distance between the free ends (15b) of said jaws (15) to a second configuration for mutual coupling, with consequent forced contact of the respective grip faces (16).

6. The machine according to claim 5, characterized in that said jaws (15) are pivoted to said platform (3) by way of a respective pivot, each pivot having at least one end head which is associated with the end head of the contiguous pivot by way of an elastic means (17).

7. The machine according to claim 6, characterized in that said elastic means (17) is an axially-acting spring, which is fixed to respective transverse arms (18) which are rigidly coupled to the head of each pivot, the rotation of the pivots being hindered by the spring from said first configuration of the jaws (15) to the position in which the arms (18) are parallel, with spring fixing points at the maximum mutual distance, and being facilitated from said position until said second configuration is reached.

8. The machine according to claim 7, characterized in that said springs are two and are arranged at the two sides of said jaws (15) at both heads of each pivot.

9. The machine according to claim 5, characterized in that said jaws (15) comprise respective grip faces (16), which have complementarily shaped surfaces for correct coupling when they are arranged in said second configuration, and respective means (19) for cutting the film (5).

10. The machine according to claim 1, characterized in that it comprises means (19) for hot-cutting the film (5).

11. The machine according to claim 1, characterized in that it comprises means (19) for cold-cutting the film (5).

12. The machine according to claim 1, characterized in that it comprises cutting means (19), which are arranged on said contrast element (7), substantially in the region comprised between said arm (10) and said tubular body (12).

13. The machine according to claim 5, characterized in that said respective actuators are fluid-operated cylinders.

14. The machine according to claim 5, characterized in that said respective actuators are of the electromechanical type.

15. A method for wrapping a product (P) with polymeric film (5) by means of a wrapping machine (1) according to claim 1, which comprises the steps of:

- resting the product (P) to be wrapped on said rotating platform (3) while an end flap of the polymeric film (5) is clamped within said grip and cutting assembly (14),

- actuating said motor so as to turn said platform (3), consequently wrapping the product (P) with the film (5), said roll supporting shaft (4) being moved vertically by an extent equal to the height of the product (P),

- actuating said contrast element (7), forcing it into contact against the outer surface of the wrapped product (P),

- aligning, with a small rotation of the platform (3), said grip and cutting assembly (14) with said film (5), which is stretched between the resting point of the contrast element (7) and said roll,

- tightening the grip of said grip and cutting assembly (14), locking the flap of film (5) that arrives from the roll and cutting it beyond said grip portion,

- pressing the flap of film (5) that arrives from the wrapped product (P) against the outer surface of said wrapped product (P) by means of said contrast element (7) during a small rotation of the platform (3),

- removing the wrapped product (P).

Drawing