DESCRIPTION

This invention relates to a silo or box for storage or transportation of empty plastic bottles.

As is known, in plastic bottle filling processes, plastic bottles are blow molded from preforms or parisons.

After molding, the bottles may be conveyed either directly to the filling lines or to storage silos, wherefrom they are withdrawn to be transferred to the filling lines with the help of unscramblers, which receive bulk bottles and arrange them in rows.

In many cases, bottles are manufactured in factories that are specialized in the manufacture of plastic items and then shipped in shipping boxes of vehicles, in bulk storage arrangement, to the bottle filling factories.

The storage silos or boxes are made up of parallelepipeds of square or rectangular cross section, which are open at their tops and closed at their bottom by movable walls for bottle discharge.

Both in storage silos and in bottle shipping boxes, strips or ribbons are hooked to the side walls in such arrangement as to form a plurality of parallel plane grids.

In prior art, these strips or ribbons are placed over a plane surface. Prior art drawbacks are associated to the plane arrangement of strips, which form bridges, whereby bottles do not fall during unloading of the box or silo after removal of the bottom wall.

The object of this invention is to obviate the above drawbacks and particularly facilitate bottle fall after removal of the bottom wall. The advantages achieved by using the box or silo of the present invention consist in that it prevents the formation of bridges which hinder the fall of bottles, as well as bottle crushing during transportation or storage.

These objects and advantages are achieved by a silo or box for storage or

transportation of empty plastic bottles of this invention, which is characterized by the annexed claims.

Characteristics and advantages will be more apparent from the following description of a few embodiments, which are shown by way of example and without limitation in the accompanying drawings, in which:

- Figure 1 is a front view of a box of rectangular section taken from the shorter side;

- Figure 2 is a side view of the box of Figure 1 ;

- Figure 3 shows the inclination of a ribbon or strip and the attachment thereof to the box structure;

- Figure 4 is a front view of a bottle storage silo of square section;

- Figure 5 is a side view of the silo of Figure 4;

- Figure 6 shows the inclination of the ribbon or strip and the attachment thereof to the silo structure; - Figures 7 and 8 are top views of the respective arrangements of belts over two adjacent planes;

- Figure 9 is a top view of the strip arrangement in a troncopyramidal discharge hopper.

Referring to Figures 1 and 2, numeral 1 designates a quadrangular silo or box for storage or transportation of empty plastic bottles, which is composed of 4 posts Ia at the vertices of the quadrangular section of the silo 1 and a plurality of profiles Ib placed transverse to said posts Ia and equally spaced to generate a strong and light¬ weight structure.

The silo 1 thus obtained is peripherally closed by plastic walls or sheets for retaining empty bottles.

As further shown in Figures 4 and 5, the lower portion of the silo 1 may be a discharge hopper having a removable bottom wall to allow the bottles to fall by gravity.

Alternatively, the lower portion may be only closed by a sliding panel, to be

inserted in corresponding guides, attached to the posts Ia.

Still from Figures 4 and 5, the covering sheet is shown to have windows 10 of transparent material to allow inspection within the silo 1 by the operator in charge of unloading and/or transportation. The profiles Ib form a given number of layers or planes, which number depends on the size of the silo 1; referring to Figures 7 and 8, a series of strips 3 or ribbons are stretched between one profile Ib and the corresponding opposite profile, and the same is repeated for the profiles Ib perpendicular thereto, so that the strips 3 are in crossed relationship to form a wide mesh grid. By repeating the above process at all planes, a plurality of grids is finally provided, lying on parallel horizontal planes, which have the function of preventing any excessive pressure from being exerted on the lower layers of any column of bottles, thence any bottle crushing.

As further shown by Figures 7 and 8, the strips 3 are alternated between the various layers or planes formed by the profiles Ib, to create a misaligned arrangement of grids, which are offset from the bottle falling direction, thereby preventing the underlying layers from being crushed.

The number of strips 3 may also change depending on the size of empty bottles.

Referring to Figures 3 and 6, each strip 3 is shown to be inclined with respect to the horizontal plane defined by the four coplanar profiles Ib.

In other words, each strip 3 is placed with its bottom side (the longer side being stretched between the two profiles IB) inclined with respect to the horizontal plane of the longitudinal axis of the strip 3.

Preferably, the inclination angle a of the strips 3 is of 20 to 35 ^° . Still from Figures 3 and 6, two examples of attachment of the strips 3 are shown: in the first example (Figure 3), two inclined flaps 4 are clamped against the inner and outer sides of the profile Ib respectively, using two screws 5; the strip 3 will be held between the inner flaps of the two opposite profiles Ib.

The other example (Figure 6) shows a substantially identical attachment arrangement, except that a plate is provided instead of the outer flap of each profile, which is secured to the profile Ib using an additional screw 7; on the inner side, there is still a strip supporting flap 4. The silo 1 so formed can support a part of the weight of the columns of empty bottles on the strips 3 and allows complete unloading of the silo 1 itself when the bottom sliding panel is opened.

As mentioned above, the lower portion of the silo 1 may consist of a troncopyramidal discharge hopper (see Figure 4); Figure 9 shows the arrangement of the strips 3 in such hopper, shorter and fewer strips being provided, if any, due to the reduced section of the hopper.

The above strip attachment arrangement between the profiles Ib may be susceptible of changes, without departure from the scope of the invention, as claimed below. Reference was made in the example to a silo 1 having profiles Ib, because this reduces the weight of the silo 1 ; however, if four solid walls are used instead of the profiles Ib, the strips 3 will be secured and stretched between opposite walls and still inclined as described above.

Once again, the attachment thereof may be achieved using techniques known to those skilled in the art.