EP3331762B1

EP3331762B1 - Device for wrapping products

Info

Publication number: EP3331762B1
Application number: EP16778872.8A
Authority: EP
Inventors: Antonio Grassi
Original assignee: Bema SRL
Current assignee: Bema SRL
Priority date: 2015-08-07
Filing date: 2016-08-05
Publication date: 2020-03-11
Anticipated expiration: 2036-08-05
Also published as: ITUB20153017A1; US20180134425A1; WO2017025874A1; EP3331762A1

Description

TECHNICAL FIELD OF THE INVENTION.

The present invention refers to a device for wrapping products, such as bottles, containers, also those made of metal, usually with cylindrical or prismatic shape, etcetera, which are grouped together in two or more products according to different types. One example includes loads of six plastic bottles arranged in two three-bottle rows, so as to allow an easier transport thereof.

STATE OF THE PRIOR ART.

In the systems according to the state of the art, the grouped products are moved along a conveyor belt where they are wrapped with a sheet of heat-shrinking plastic material in a manner such that the ends of the sheet are superimposed, then the products thus wrapped are subjected to a heating step.
The plastic material sheet, due to the heat-shrinking characteristics, is joined at the end, is shrunk, adhering to the products and defining a stable package.
This mode of packaging has different problems: it is necessary to provide for a heating oven, with consequent complication and increased energy cost, increased cost of the heat-shrinking plastic material, impossibility for certain types of containers and contained product to exceed certain temperature levels, and hence impossibility to effectively carry out the heat-shrinkable action on the plastic material.
It has therefore been proposed to substitute the heat-shrinkable plastic material with a stretch film.
In the German patent application No. DE3910823 , an apparatus is illustrated for packaging a certain number of bottles or similar products with a stretch film, which allows a wrapping without a tray or cardboard support for the products.
The products which arrive from a conveyor belt are retained by means of guide rods, which are engaged around the neck of the products and in at least one recess in the bottom. The wrapping station is designed so that the products, together with the guide rods, are wrapped with the stretch film from a coil with a horizontal wrapping axis that rotates around the products themselves.
Also the European patent No. EP2470438B1 illustrates a similar packaging system, in which an assembly of bottles is pressed by two jaws to form a compact set and a film coil rotates around the group of bottles and on the gripping jaws. WO 2015/028894 A1 discloses a packing system according to preamble of claim 1. WO 03/084816 A1 discloses a packing system which comprises a handling robot for wrapping an article.
These wrapping systems have different drawbacks, including a considerable structural complication and a considerable bulk due to the need to rotate the coil around the group of products, and there is also the need to stop the products on the conveyor belt due to the time necessary for the wrapping step.
In addition, it is impossible to continuously operate due to the machine stop times required for substituting the wrapping film coil or for eliminating possible jamming or possible malfunctions tied to the coil or film.

OBJECTS OF THE INVENTION.

One object of the present invention is to improve the state of the art.
Another object of the present invention is to increase the productivity of the product wrapping devices, making their packaging quicker and more continuous.
Still another object of the present invention is to propose a device for wrapping products provided with a wrapping and gripping assembly that allows decreasing the device stop time due to depletion or jamming of the wrapping film.
A further object of the present invention is to propose a device for wrapping products which allows a change of the coil in an automatic and practical manner, reducing the tooling and relative device stop times, in the scope of a simple, rational solution, with easy and effective use and with limited costs.
In accordance with one aspect of the present invention, a device is provided for wrapping sets of products according to claim 1.
In accordance with another aspect of the present invention, a system is provided for wrapping sets of products according to claim 10.
The dependent claims refer to preferred and advantageous embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS.

Further characteristics and advantages of the present invention will be more evident from the detailed description of a preferred but not exclusive embodiment of a device for wrapping products, illustrated as a non-limiting example in the enclosed drawing tables in which:

figure 1 is an overall perspective view of a system provided with several devices for wrapping sets of products according to the present invention;
figure 2 is an enlarged perspective view of a device for wrapping sets of products pursuant to figure 1;
figure 3 is an enlarged perspective view of a detail of the device for wrapping sets of products pursuant to the preceding figures;
figure 4 is another enlarged perspective view of the detail pursuant to figure 3; and
figures 5 to 12 illustrate a sequence of wrapping a set of products, achieved with a device according to the present invention.

EMBODIMENTS OF THE INVENTION.

With reference to figure 1, reference number 10 schematically indicates a system provided with three devices 1 for wrapping sets of products 2 such as bottles, packs, boxes and the like.
In the following description, a system 10 will be illustrated with three devices 1 for wrapping a set of six bottles with a stretch film; nevertheless, it must be considered that any number of devices 1 can be used, starting from one device, and that in addition the products to be wrapped can be of any type or number.
The system 10 comprises a first conveyor belt 3, on which the products 2 to be wrapped with the stretch film arrive, already grouped together; in this embodiment, there are six bottles grouped in two rows of three.
A second conveyor belt 4 is also present, on which the products 2 wrapped in the stretch film are deposited so as to form packages 5; from this second conveyor belt 4, the packages 5 are sent to possible subsequent treatment and/or palletization stations which are not described further herein since they are not part of the present invention.
It must be observed that the advancing direction of the first conveyor belt 3 and second conveyor belt 4 can be any direction; in addition, in the illustrated embodiment, the two conveyor belts 3 and 4 are parallel to each other, but it must be considered that the aforesaid conveyor belts can have any mutual arrangement, i.e. for example perpendicular, or oblique, thus making the system 10 very flexible as an installation possibility. In addition, if a sufficient number of devices 1 is provided, all the operations for wrapping the products 2 can be carried out on a single belt.
Each wrapping device 1 essentially comprises a handling robot 6, provided with a handling end 7; such robot 6 in the embodiment illustrated in the figures is of anthropomorphous type, but it could be of another type, such as Cartesian or polar with at least three or four axes. Also provided are a wrapping head 8, fixed to the handling end 7 of the robot 6, and gripping means 9 for gripping the products 2, these too fixed to the handling end 7 of the robot 6.
Figures 3 and 4 illustrate the wrapping head 8 in detail.
The wrapping head 8 is provided with a coil 11 of stretch film 12 for wrapping the products 2 and comprises a box-shaped body 13 that contains means for actuating in rotation the coil 11, means for pre-stretching 14 the wrapping film, means for applying 15 the same film on the products 2 and means for cutting 16 the film to complete the application of the film on the products, these means not described in more detail herein since they are not the object of the present invention.
The gripping means 9 are fixed to the handling end 7 of the robot 6 by means of brackets 17; in turn, the brackets 17 are connected to the box-shaped body 13 of the wrapping head 8, so as to form with the aforesaid head 8 a wrapping and gripping assembly 20 that can be automatically substituted by the robot 6.
In figure 1, it can in fact be observed that next to each robot 6, at least one wrapping and gripping assembly 20 is positioned which is waiting to be picked up by the robot 6. When the wrapping head 8 receives a signal that the coil 11 is terminating the stretch film 12, the robot 6 completes the products 2 wrapping cycle that is underway and rests the assembly 20 in a free parking zone.
The robot 6 comprises, on the end 7, attachment means 21 which are provided for hooking or unhooking on command to/from corresponding fixing means, e.g. a shank 22, positioned on the assembly 20.
Therefore, by means of the attachment means 21, the robot 6 unhooks the assembly 20 with the depleted coil 11 and immediately picks up another assembly 20 with the full coil 11 of stretch film 12.
It is therefore clear that the time for changing the wrapping and gripping assembly 20 is much less than that for substituting the coil 11 and inserting the film 12 in the pre-stretching means 14.
On the other hand, when the assembly 20 with the depleted coil 11 has been parked in the parking zone, an operator has all the time available for changing the depleted coil with a full coil and for inserting the film 12 in the pre-stretching means 14, since the wrapping device 1 is already operational, having picked up an assembly 20 with a new coil 11 full of stretch film 12.
The gripping means 9 comprise two jaws 18 provided with rod-like elements 19 capable of compacting together the products 2; the rod-like elements 19 also have a shape and a structure that allows them to be extracted when they are situated inside the wrapping formed by the film 12 in the package 5.
More in detail, the rod-like elements 19 are suitably shaped based on the particular shape of the products 2 to be grasped, so as to correctly compact them and retain them without risking deformation, squashing or other damage.
If desired, the rod-like elements 19 can be substituted by the jaws 18 as a function of the type of product to be treated, e.g. bricks, half-liter or 1.5 liter bottles, boxes, etcetera. For such purpose, means can be provided for unhooking or disengaging (such as screw means, bayonet means, snap means, etcetera) the rod-like elements 19 from the jaws 18, e.g. quick unhooking or disengagement means.
As an alternative or in addition thereto, the device can be provided with a control unit having means for storing or setting the size of the products and, more particularly, means for associating (e.g. by means of suitable software) each product with a respective treatment sequence or scheme; the control unit is also set to drive the device or better yet the jaws 18, in a manner such to suitably compact the products as a function of the actual size of the products themselves, i.e. so as to compact each product according to the respective treatment sequence or scheme, which is, if desired, different from the treatment sequence or scheme of other products. In substance, once the type of product to be treated is established or set in the control unit, the control unit would drive the jaws 18 in a manner such to compact the products by the desired amount, suitably pushing the jaws 18 or making them complete a predetermined travel thereof.
The two jaws 18 are opened or closed in opposite manner, according to a substantially horizontal direction "X", by means of the drive means 23.
The drive means 23 can be made in different ways. In the embodiment illustrated in figures 3 and 4, the drive means 23 comprise substantially horizontal guides 24 and toothed belts 25 driven by an electric motor 26. The two jaws 18 are slidable on the substantially horizontal guides 24 and are fixed to a branch of each toothed belt 25, which determine the opposed opening or closing movement of the jaws 18.
The gripping means 9 also comprise rotation means 27 which allow the rotation of the products 2 when they are gripped by the jaws 18.
Also the rotation means 27 can be made in different ways, and in the embodiment illustrated in the figures they comprise two gearmotors 28 that rotate around the axis "X" in a concurrent and synchronized way in speed and phase, due to an electrical axis between the two motors, i.e. by means of suitable sensors and electric adjustment means of the motors.
It is thus possible to carry out the rotation of the products 2 gripped by the jaws 18, wrapping the stretch film 12 around the set of products 2.
In particular, the shaped rod-like elements 19 are adapted to discharge the tension due to the wrapping of the film 12 around the products 2. In such a manner, the latter do not show any squashing, deformation or other damage that would otherwise be caused by the tightening of the film 12, during the wrapping step.
It must be observed that, due to the robot 6, the products 2 are moved from the incoming first conveyor belt 3 to the second outgoing conveyor belt 4, while the operation of wrapping the stretch film 12 on the products 2 themselves takes place.
An advantage is therefore obtained with regard to time, as well as the possibility to place the two belts 3 and 4 with the maximum arrangement freedom.
Figures 5 to 12 illustrate a wrapping sequence of a group of products 2.
In figure 5, the jaws 18 are observed arranged above a set of products 2. It must be noted that the conveyor belt 3 does not have to stop since the robot 6 is capable of being adapted to the translation speed of the products 2 on the belt 3; in figure 6, the jaws 18 in open position approach each other, being lowered on the set of products 2 and in figure 7 the jaws 18 are closed, compacting the set of products 2, then the application means 15 apply the free flap of the stretch film 12 on the set of products 2.
In figure 8, the robot 6 has lifted the assembly 20 to allow the rotation of the set of products 2 and starts the rotation of the set of products around the axis "X" which allows wrapping the stretch film 12 around the set of products 2; in figures 9 and 10, the rotation of the set of products 2 continues, while the robot 6 moves the set of products 2 towards the second conveyor belt 4.
In figure 11, the wrapping of the stretch film 12 around the set of products 2 has been completed and the cutting means 16 cut the film 12, completing the packaging of the products.
Then, the robot 6 lowers the set of products 2 on the second conveyor belt 4; also in this case, it must be observed that the conveyor belt 4 can be moving since the robot 6 is capable of being adapted to the translation speed of the belt 4.
In figure 12, the jaws 18 are opened, the rod-like elements 19 which are situated inside the wrapping formed by the film 12 can be removed and the package 5 of products 2 can be released on the outgoing conveyor belt 4; the robot 6 can return towards the first conveyor belt 3 in order to start a new wrapping operation.
The described device attains the pre-established objects in the scope of a solution with reduced bulk and a high productivity due to this new wrapping type.
Indeed it must be observed that it is possible to have multiple robots 6 on same conveyor line, thus increasing the number of treated products in accordance with requirements.
In addition, the presence of a sufficient number of robots 6 allows the already-described possibility to carry out all the operations for wrapping the products 2 on a single belt. Each robot 6 picks up a set of products 2 from one position on the single belt in order to carry out the wrapping operations thereon; once such operations have terminated, the robot once again deposits the set of products 2 on the single belt in the same position as the initial pick up, or alternatively at another free position.
The invention thus conceived is susceptible of numerous modifications and variants, all falling within the scope of the inventive concept.
In addition, all details can be substituted by other 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

Device (1) for wrapping sets of products (2) through a stretch film (12), comprising a wrapping and gripping assembly (20) which includes a wrapping head (8) for wrapping said stretch film (12) and gripping means (9) for gripping and rotation of said sets of products (2) according to a substantially horizontal direction (X), characterized in that it comprises a handling robot (6), provided with a handling end (7), to which said wrapping and gripping assembly (20) is fixed and in that said gripping means (9) comprise two jaws (18) able to take the set of products (2).
Device according to claim 1, wherein said handling robot (6) comprises attachment means (21) placed on said handling end (7) and said wrapping and gripping assembly (20) comprises fixing means (22), said attachment means (21) being provided for hooking or unhooking on command to said fixing means (22).
Device according to any one of the preceding claims, wherein said wrapping head (8) is adapted to receive a coil (11) of stretch film (12) for wrapping the products (2) and comprises a box-shaped body (13) which contains means for actuating in rotation the coil (11), means for pre-stretching (14) the wrapping film (12), means for applying (15) the same film (12) on the sets of products (2) and means for cutting (16) the film to complete the application of the film (12) on the sets of products (2).
Device according to any one of the preceding claims, wherein said gripping means (9) comprise drive means (23) to open or close said gripping means (9) according to said substantially horizontal direction (X) and to compact the sets of products (2).
Device according to claim 1, wherein said jaws (18) comprise rod-like elements (19) having a shape and a structure that allows them to be extract from the inside of the wrapping made from the film (12) on the set of products (2).
Device according to the preceding claim, wherein said rod-like elements (19) are suitably shaped based on the particular shape of the products (2) to be grasped, and are adapted to discharge the tension due to the wrapping of said film (12) around the products (2), so as to preserve the latters from any squashing, deformation or other damage during the wrapping step.
Device according to any one of the preceding claims, wherein said gripping means (9) comprise rotation means (27) for the rotation of the products (2) when they have been gripped by said gripping means (9).
Device according to the preceding claim, wherein said rotation means (27) comprise two gearmotors (28) in rotation around said axis (X) in a concurrent and synchronized way in speed and phase, thanks to an electric axis between the two motors, namely through appropriate sensors and electric adjustment means of the motors.
Device according to any one of the preceding claims, comprising
- hooking or unhooking means, optionally quick, of rod-like elements (19) from said jaws (18) and/or

- a control unit having means for connecting each product to a respective scheme or treatment sequence, said control unit being in charge of steering said jaws (18) so as to compact each product according to its respective scheme or treatment sequence.
System (10) for wrapping sets of products (2) with a stretch film (12) comprising one or more devices (1) according to any one of the preceding claims.
System according to the preceding claim, comprising at least a first conveyor belt (3) with the incoming products (2) and at least a second conveyor belt (4) with the outgoing products (2) wrapped in the stretch film (12).