ES2565546T3 - Machine to apply a packing cover on an object - Google Patents

Abstract

Covering machine (10) for an object (14), comprising an adjustment unit (13) that is capable of adjusting a heat shrinkable film cover with its open end on an object placed in a coverage area (15) of the machine , air blowing nozzles being present for blowing air into the cover at least during the action of the adjustment unit, in which the adjustment unit comprises grips (37) to grip the edge of said open end of the cover, the blowing nozzles (59) being arranged directly on these grips, characterized in that the flow of air directed towards the blowing nozzles (59) also flows into the grips to cool the grips.

Description

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DESCRIPTION

Machine to apply a packing cover on an object

The present invention relates to a machine for wrapping objects, such as packages, with a film cover. In particular, packages may consist of objects that are stacked on a pale.

In prior art machines, called cover machines, these machines are known which are designed to fit a cover formed by a tube of thermo-contraflective film on the package to be covered. The film is then heated to cause heat shrinkage around the package. These machines usually form or unwind the film tube directly above the reception area of the package from a coil that is placed next to this area or next to the machine. Suitable means are provided for transporting the film to form a cover therewith and transfer it over the package.

A problem associated with these machines is to quickly insert the cover over the package. Usually, a grab frame grabs the free edge of the cover and stretches it along the package. In order to prevent the cover from rubbing excessively along the sides of the package, it has also been proposed to introduce air into the cover during the insertion movement. For this purpose, suitable nozzles are provided in the base of the machine or in the grip frame. These nozzles are usually small in size and the amount of air introduced is usually limited to a small local area. This does not always produce a satisfactory result. Larger nozzles have been proposed, but these prevent insertion and heat shrinkage operations.

Document US 2002/170270 describes small nozzles that are mounted on the grips of the film. The air flow is, however, limited and the dimensions of the nozzles in no case impair the adjustment of the film.

In addition, the known machines are slightly slow and the aesthetic quality of the heat-resistant cover is often unsatisfactory, especially in the case of product packages that cause rapid cooling of the film when it accidentally touches them. In this case, in fact, the heat-resistant cover has wrinkles, dents and irregularities. This is particularly the case, for example, with glass bottle packages. Among other things, precisely the packaging of bottles is one of the sectors where rapid execution of the hedging operation is required due to the high processing speed of the plants that produce the bottles.

The heat induced in the film grip elements due to the heat shrinkable cycle of the film can cause the film to melt in these grip elements. This also limits the speeds of operation of the machine and results in defects in the packaging, in particular, in the case of mobile heating racks.

The general object of the present invention is to provide a cover machine that is capable of achieving improved cover insertion and a more satisfactory end result.

In view of this object, the idea that has arisen in accordance with the present invention is to provide a machine as claimed in claim 1.

In order to more clearly illustrate the innovative principles of the present invention and their advantages compared to the prior art, an example of embodiment that applies these principles will be described below, with the help of the attached drawings. In the drawings:

- Figure 1 shows a schematic, perspective and partial view of a cover machine designed in accordance with the invention;

- Figure 2 shows a schematic cross-sectional view of a drive frame present in the machine according to Figure 1;

- Figure 3 shows a schematic, perspective and partial view of a machine grip;

- Figure 4 shows a schematic cross-sectional view of a grip according to Figure 3 in another operating position thereof;

- Figures 5 and 8 are schematic side elevational views of successive sequences of operating steps of the machine according to Figure 1.

With reference to the figures, Figure 1 shows, generally indicated by 10, a cover machine provided in accordance with the principles of the present invention.

The machine 10 comprises an adjustment unit 13 which is capable of adjusting, from the top down, a heat shrinkable film cover 12 on an object 14 (for example, formed by a package of objects,

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such as bottles, boxes, bricks, etc., which are arranged in a pale) placed (advantageously on top of an appropriate known raised base 50, which may be equipped with means for moving the package in and out of the machine) in a coverage area 15 of the machine.

The cover 12 is advantageously transferred to the adjustment unit by known means of supply (generally indicated 11 in Figure 4) which can, for example, form the cover from a strip or tube of film (if necessary with means suitable welding), as is known by the person skilled in the art. These means for supplying and for forming, where necessary, the cover can be of any known type and, therefore, will not be described or shown here further.

The vertical adjustment unit 13 comprises a transport frame 33 and, advantageously, a heat shrink frame 34 arranged in the upper part (advantageously both in the form of a closed rectangle located in a horizontal plane), whose frames are driven by motor to slide vertically in sequence on the object that is placed in the coverage area (as shown schematically in Figures 4-7).

Advantageously, the sliding is carried out by means of support slides 51, 52 driven by suitable motors that slide along a pair of vertical uprights 21.

Advantageously, above the coverage area, there is also a protective frame 35 that defines the entrance from above in this area for the cover. This protective frame, which is made, for example, of metal mesh or the like, externally defines an area 36 that receives the heat shrink frame when it is not in operation (in its elevated position) to avoid contact between the cover and the means of heating 39 (for example, gas water heaters) present in the heat shrink frame and protect the cover during insertion on the object by means of the transport frame 33.

As can be clearly seen in Figure 1, the transport frame 33 supports vertical grips 37 that are operated to grip the edge of the heat shrinkable film cover. Advantageously, the grips 37 have means for position adjustment that depend on the transverse dimensions of the cover, to be able to place them close to the edges of the cover. These means can be formed by suitable grids and transverse support elements for the grips, as can be clearly seen in Figure 1. In the solution shown, the transport frame 33 advantageously has an external peripheral structure 61 in which elements are arranged opposite cross-sections 55 that slide parallel to each other by means of grind 53 that are placed in the frame at the ends of the cross-members. The grips 37 are slidably mounted on the transverse elements. Suitable locking means (for example, of the thread type) allow the grips and the transverse elements to be locked in the desired position depending on the dimensions of the cover. Known motor driven means (not shown) can be provided for automatic or semi-automatic adjustment.

The grips are advantageously four in number and are arranged opposite each other in pairs on opposite sides of the cover.

As can be clearly seen in cross sections in Figures 2 and 4, the grips 37 have jaws 56 and 57 that can be opened or closed by means of a suitable actuator 58 and which are designed to be arranged with one of them outside the edge of cover 12 and the other inside, to grip and retain the cover, when it is operated.

Advantageously, in order to grab the film, the outer jaw 56 is designed to rotate on an axis 60 (as shown in broken lines in Figure 2), while the inner jaw 57 is fixed.

Nozzles are arranged directly on the grips 37 to emit air inside the cover. In particular, the internal jaw 57 has its free end 59 which forms a mouth with a wide groove that extends parallel to the jaw closing surface and, in this case, towards the axis of rotation 60. This also defines the plane of the superimposed film wall.

In particular, as can be seen more clearly in Figures 3 and 4, the outer jaw 56 is advantageously formed as a hollow box-shaped element (triangular in shape) having a jaw wall 63 that is located above an opening 64 directed towards the jaw 57. The jaw 57 is formed open towards the jaw 63 (to have a generally C-shaped cross section). Flexible tubes 62 carry pressurized air inside the jaw 57 in the form of a box. As can be seen more clearly in Figure 4, when the grip is closed, the air is able to pass from one jaw to the other and exit from the groove 59 to the cover 12. As for the rest, the inside of the jaws is closed by sealing, the two jaws forming a single box-shaped container.

The transport frame advantageously comprises means for blowing the air to be supplied to the grips. These blowing means may comprise a fan 38 (which can be accelerated for the regulation of air flow) that blows air through tubes that exit at the front end of the grips 37.

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Advantageously, as can be clearly seen in Figure 2, it is the same external peripheral frame 61 that is formed in a box to transport the air flow from the fan 38 to the areas close to the grips where the flexible tubes 62 are present for connect the inside of the peripheral frame 61 and the grips.

As can be seen in Figure 4, each grip can also advantageously rotate around axis 60 during operation of an actuator 65 to move from the first vertical operating position shown in Figure 1 to the second operating position (shown in Figure 4) inclined towards the inside of the roof, for the reasons that will be evident next.

It has been found that the correct inflation is considerably improved by blowing air directly from the grips (in particular, from the main grip point of the cover) and that the oscillations that can damage the quality of the final product are reduced.

During the operation stages of the machine, firstly, the cover is supplied so that it is grasped by the grips 37 with the frame 33 arranged at the top (and the heat shrink frame, when present, seated inside the element protector 35). After which, the air is supplied to the grips and the cover is inflated. The frame 37 then begins its movement of movement to insert the cover on the object 14 to be covered (figure 5).

At the end of the movement of movement (in particular, when the cover is correctly inserted on the object 14, for example, to the base defined by a pale - see figure 6), the transport frame 33 stops and the heat shrink frame 34 begins its downward movement, with the heating means that are activated and directed towards the outer surface of the adjusted cover, while advantageously the air blowing inside the cover continues (figure 7).

The descent continues down to the base of the package. In this position, it has been found that it is useful for the grips to rotate as shown in Figure 4 to tension the film and place its end portion under the package. The heat shrinkage can, therefore, form a solid film cord that is also useful for attaching the pale to the package.

During the backward upward movement of the heat shrink frame, heat can be maintained for a more complete and uniform heat shrinkage of the film.

Once the racks have returned to the elevated position, the package can be removed and a new object can be arranged to be wrapped in the coverage area (figure 8).

At this point, it is clear how predefined objects have been achieved. With the machine described, wrapping operations are carried out more quickly and the result is always of satisfactory quality. In addition, the movement of the heat shrinkable media can be carried out more quickly due to the fact that the cover stably touches the package only after it has been heat shrunk. In addition, low energy consumption can be maintained. The machine is compact and has small dimensions. Finally, the quality of the final product is improved due to the innovative features that characterize the insertion, retention and heat shrinkage of the roof over the object. Air that flows directly into the grips (if necessary, also inside the outer jaw before leaving the mouth in the inner jaw) cools the grips and avoids the potential risk of the film sticking to the grips, especially after repeated heat shrinkage cycles, and when, at the base of the package, the heat shrink frame is maintained longer in order to form a cord of heat shrinkable film. As can be clearly seen in Figure 4, cooling can also advantageously affect the piston that drives the grip that is disposed within said grip, to protect it from overheating. Also the transport frame can be cooled by the flow of air directed towards the grips.

As the blow nozzles are located directly on the grips, they are correctly placed inside the cover without the need for an additional different position adjustment.

Obviously, the above description of an embodiment that applies the innovative principles of the present invention is provided by way of example of these innovative principles and should therefore not be considered as limiting the scope of the rights claimed in this document. For example, the proportions of the various parts of the machine may vary depending on the specific requirements and the dimensions of the products to be wrapped. In addition, the heat shrinkage of the film can also be carried out in a different station, with a heating frame or with a special heated chamber or oven. In this case, it is possible to dispense with the heat shrink frame 34 and also, if required, the protective frame 35, if deemed unnecessary to guide the cover.

Claims (11)

5 10 fifteen twenty 25 30 35 1. Covering machine (10) for an object (14), which comprises an adjustment unit (13) that is capable of adjusting a thermo-contrast film cover with its open end on an object placed in a coverage area (15) of the machine, with air blowing nozzles being present to blow air into the cover at least during the action of the adjustment unit, in which the adjustment unit comprises grips (37) to grip the edge of said open end of the cover, the blowing nozzles (59) being arranged directly in these grips, characterized in that the flow of air directed towards the blowing nozzles (59) also flows inside the grips to cool the grips. 2. Machine according to claim 1, characterized in that the adjustment unit comprises a transport frame (33) that is driven by motor to slide vertically around the object placed in the coverage area and that supports said holding grips ( 37) to transport the cover over the object. 3. Machine according to claim 1, characterized in that the grips have a jaw (57) that is placed inside the cover and has a free end provided with said blow nozzles (59). 4. Machine according to claim 3, characterized in that said jaw (57) is designed hollow and open at its free end to form the blow nozzle (59). 5. Machine according to claim 2, characterized in that the transport frame (33) is designed as a box-shaped element for transporting air from a blower fan to said grips. 6. Machine according to claim 5, characterized in that a flexible tube (62) is connected between the inside of the frame (33) and the blow nozzle. 7. Machine according to claim 1, characterized in that the grips are supported on the frame (33), so that its position can be adjusted to adapt to the transverse dimensions of the cover. Machine according to claim 1, characterized in that the adjustment unit comprises a heat shrink frame (34) that is driven by motor to slide vertically around the object placed in the coverage area, the heat shrink frame supporting means of heating directed towards the outer surface of the cover adjusted by means of the adjustment unit (13) on an object placed in the coverage area. 9. Machine according to claim 8, characterized in that above the coverage area there is a protective frame (35) defining the entrance in this area for the cover, the protective frame externally defining an area to receive the frame of heat shrink when it is not operational, to avoid contact between the cover and the heating means of the heat shrink frame. 10. Machine according to claim 3, characterized in that the grips have an additional jaw (56) that is placed outside the cover, and within which the air flow passes, directed towards the free end of the jaw ( 57) provided with said blow nozzles. 11. Machine according to claim 1, characterized in that the grips have a drive actuator (58) which is contained therein to be cooled by the flow of air flowing into the grips.