DESCRIPTION

Devices are known which are used for transporting boxes containing food items that need to be carried in horizontal position, such as just baked pizzas, and in particular straps are known which are used for transporting boxes containing food items, such as pizzas, cakes, etc., while keeping them in horizontal position.

Just baked pizzas are introduced in boxes made up of a sheet of food cardboard, cut and bent for the purpose described above. These boxes are usually transported using one hand, or both hands if they are very large or heavy.

When several boxes must be transported together, these are stacked on one another in such a way as to form a pile, which makes it consequently difficult to keep them in horizontal position without letting them fall or slide.

If the content of the box or of the stacked boxes is hot, it is quite uncomfortable or even impossible to transport it/them with one hand or with both hands in contact with the bottom of the single box or of the lower box of the pile.

Paper bags with square bottom are known which are used for transporting square boxes in horizontal position.

These paper bags pose several drawbacks, including their high production cost which is due both to the raw material used and to the processing cycles needed to form the various parts of the bag and glue them together.

The subject of the present patent is a new process for making straps suited to be used for transporting substantially plane food containers, individually or stacked on one another, which must be kept in horizontal position during transport.

It is one object of the present invention to develop a process for making the new strap with reduced production costs.

It is another object of the present invention to develop a process for producing the new strap with just a few simple operations.

Said specific production process comprises several steps.

The process includes a first step, during which the following are used:

- at least one storage unit with at least two reels, each holding a film made of a plastic material, such as polyethylene or other suitable products, the height of said reels being equal to the width of the strap to be obtained;

- devices for unwinding said films from said at least two reels, and wherein a first film is superimposed to a second film having the same width;

- devices for moving said at least two films forward on an advance surface.

The second step includes the following operations:

- transverse heat sealing of said two superimposed upper and lower films, at such a distance from the front edges of said films that the sum of the lengths of said films is at least equal to the width of said containers, summed to the thickness of two or more containers and of the respective connection sections;

- simultaneous or successive cutting of the two films, wherein the cut obtained is positioned immediately before said seal.

The successive step includes:

- the use of devices for holding, for example by suction, and lifting the upper film in proximity to the edge obtained from the cutting operation just performed during the first step; - the rotation, at least partial, of said edge of the upper film;

- the use of devices for applying and fixing, through a heat sealing operation, the ends of two tapes arranged so as to form an arc, the first one onto the lifted upper film, in proximity to the front edge, the second one onto the lower film, always in proximity to the corresponding front edge. Successively the band obtained in this way, once the edge of the upper film has been lowered and re-positioned on the lower film, will advance towards a device intended to move it forward for the packing step.

Alternatively, according to the invention, only one tubular polyethylene film may be used, and its side edges may be cut in order to obtain two distinct and superimposed films, always in order to obtain said strap.

Alternatively, according to the invention, the handles may not be obtained through the application of said tapes, but through the execution, for example by means of a die cutting operation, of two holes, one per each film, in proximity to the edges, wherein said holes should be sufficiently large to allow the user to introduce his/her hands therein.

A practical embodiment of the invention is illustrated in the attached drawings by way of example without limitation.

Figure 1 shows the functional diagram of said process and the various essential components used.

There are two reels (Bi, Bs), placed side by side or on top of each other, each holding a polyethylene film (Fs, Fi), wherein said two films, the upper one (Fs) and the lower one (Fi), are superimposed and moved forward through the advance devices (A), and wherein the two films (Fs, Fi) are successively cut and heat sealed through a convenient cutting and heat sealing device (Ts). Owing to the action of said advance devices (A), the two superimposed films (Fs, Fi) reach the lifting device (S), which is suited to lift, for example by suction, the upper film (Fs); the terminal portions of two tapes intended to be used as handles (Ms, Mi) are successively applied to the films through two or more heat sealing devices (TM).

Figure 2 shows the container holding strap that has been obtained, comprising the two handles (Ms, Mi), the front edges (A2), the centre seal

(R) made with the heat sealing device (TS), while Figure 3 shows the same strap in the variant provided with holes (FM) suited to be used as handles. These are the schematic outlines which are sufficient to the expert in the art to carry out the invention, consequently during the production process variants may be developed which do not affect the substance of the innovative concept introduced herein.

Therefore, with reference to the above description and the attached drawings, the following claims are expressed.