Description

BOX WITH LATERAL COLLAPSIBLE WALLS

The present patent application relates to a plastic moulded box with parallelepiped structure and rectangular base provided with lateral collapsible walls, in which the two longitudinal walls are higher than half of the width of the transversal walls. For space reasons plastic moulded box with parallelepiped structure provided with collapsible walls are largely used, in which the collapsible walls are hinged to the perimeter borders of the bottom wall and designed to be alternatively brought from vertical operative position to horizontal idle position (forming a compact pile) against the bottom wall of the box. Normally, the walls of this type are collapsed according to a sequence of operations in which the transversal walls are collapsed first, until they touch the upper side of the bottom wall of the box, and then the longitudinal walls are collapsed until they touch the external side of the transversal walls.

For a long time the said boxes have been provided with longitudinal walls slightly shorter than the width of the transversal walls.

Because of this, once they are brought in idle position, the two longitudinal walls lay on the same horizontal plane, thus giving the box a perfectly regular shape that is especially useful during packaging and stacking with similar boxes. More recently, a different solution has been devised to provide this type of boxes with four walls higher than the width of the transversal walls.

To that end, the two longitudinal walls of the box had to be perfectly aligned on the same horizontal plane, once they are collapsed in idle position.

This was done in spite of the mutual interference of the top of the longitudinal walls caused by the fact that the longitudinal walls are higher than half of the width of the transversal walls.

In view of the above, boxes with collapsible walls have been provided

with longitudinal walls having crenellated longitudinal top profiles designed to match exactly by mutual penetration when the box is collapsed in compact position.

It is worthless saying that the height of the crenellated profile of each longitudinal wall is the difference between the total height of the longitudinal wall and half of the width of the transversal walls of the box.

Nevertheless, the said solution has not proved to be fully satisfactory, not only because of the fact that the presence of the two crenellated top profiles is rather anti-aesthetic and reduces the lateral loading capacity of the box, but also because of the lower rigidity of the two longitudinal walls in the crenellated longitudinal areas.

The specific purpose of the present invention is to devise a box with collapsible walls, in which the longitudinal walls (same as the transversal ones) are higher than half of the width of the transversal walls, without affecting the structural continuity of the longitudinal walls and without reducing the general rigidity of the walls.

The inventive idea that has permitted to achieve the aforementioned purposes consists in providing the top of the two longitudinal walls of the box of the invention with a longitudinal shaped band with basically sinusoidal section.

Preferably, the height of the shaped bands is the dimensional difference between the total height of each longitudinal wall and half of the transversal walls of the box.

It must be noted that, although having a profile with similar shape, the two shaped bands of the longitudinal walls do not have the same dimensions.

This fact is of crucial importance to permit perfect alignment of the two longitudinal walls (on the same horizontal plane) when they are both collapsed in horizontal position against the bottom wall of the box.

In this phase, the longitudinal wall with the smaller shaped band is collapsed first in horizontal position, in such a way that the external side of the band is positioned upwards.

Then, the second longitudinal wall is collapsed, ensuring that the

internal side of the shaped band is exactly overlapped (completely embracing it) on the corresponding external side of the shaped band of the first wall.

In other words, the two longitudinal walls are maintained on the same horizontal plane by means of the male-female coupling of the shaped bands. For purposes of clarity, the description of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, whereby:

- figure 1 is a partial axonomethc view of the box with the two longitudinal walls in vertical position and the two transversal walls in collapsed position; - figure 2 is identical to fig. 1 , except for the fact that only one longitudinal wall is in vertical position;

- figure 3 is a view of the box of the invention in idle position after all lateral walls have been collapsed.

With reference to the aforementioned figures, the invention consists in a plastic moulded box with parallelepiped structure (1 ) of the type provided with lateral walls designed to be collapsed on the bottom wall (2), being hinged to corresponding perimeter borders of the bottom wall (2).

In the box (1 ) of the invention, the two longitudinal walls (3, 4) and the two transversal walls (5) are higher than half of the width of the transversal walls (5).

Both longitudinal walls (3, 4) are provided on top with corresponding longitudinal shaped bands (31 , 41 ) with basically sinusoidal profile, each of them being bordered by a lower groove (31 a, 41 a).

The box-shaped band (31 ) obtained on top of the first longitudinal wall (3) - that is to say the wall designed to be collapsed first - has a slightly lower height and length than the box-shaped band (41 ) of the second longitudinal wall (4).

Because of this, the external side of the box-shaped band (31 ) of the first longitudinal wall (3) is exactly engaged (by means of male-female coupling) into the internal side of the corresponding shaped band (41 ) of the second longitudinal wall (4), when the second longitudinal wall (4) is collapsed in horizontal position on the first longitudinal wall (3).

Additional solutions have been necessary in order to guarantee that the two longitudinal walls (3, 4) are perfectly aligned on the same horizontal plane when they are collapsed in idle position.

The first longitudinal wall (3) is laterally bordered by two stiffening edges (32) obtained on the vertical borders, but not for the entire height; in fact, the upper end of each edge (32) is positioned at about half of the height of the longitudinal rib (31 a) provided in lower position on the top box-shaped band (31 ).

The lateral ends of the box-shaped band (31 ) are closed for their entire height by corresponding partitions (33) provided with cylindrical pins (33a) on top and towards the inside of the box.

It must be noted that, although having the same vertical direction, each partition (33) occupies a more internal position than the adjacent stiffening edge (32); it being also provided that a transversal notch (34) is obtained in intermediate position between them, ending into a circular hole (35) on the surface of the longitudinal wall (3).

As shown in the enclosed figures, the two lateral notches (34) of the first longitudinal wall (3) are perfectly aligned with the rib (31 a) that borders in lower position the box-shaped band (31 ). The function of the cylindrical pins (33a) provided on top and at the two ends of the box-shaped band (31 ) is to be exactly engaged - when the entire first longitudinal wall (3) is collapsed in horizontal position on the previously collapsed transversal walls (5) - into corresponding holes with vertical axis (50) suitably provided above the two short raised sections (51 ) where the transversal walls (5) are pivoted.

The second transversal wall (4) is provided with stiffening edges (42) on the vertical borders.

The edges (42) extend for the entire height of the vertical borders, so that they are joined on top with very short edges (43) with identical height obtained at the two ends of the upper horizontal border of the shaped band (41 ) of the second longitudinal wall (40).

The short edges (43) are joined on the opposite side, with the

interposition of corresponding cylindrical pins (43a), with the ends of a longitudinal rib (44) that protrudes from the upper horizontal border of the shaped band (41 ) of the second longitudinal wall (4).

A vertical niche (45) with concavity towards the inside of the box (1 ) is provided in intermediate position between each longitudinal end of the shaped band (41 ) and the opposite section of the stiffening edge (42).

The internal cavity of each niche (45) is exactly compatible with the shape and dimensions of each partition (33) provided at the ends of the box- shaped band (31 ) of the first longitudinal wall (3). When the second longitudinal wall (4) is collapsed in horizontal position on the first longitudinal wall (3), other consequences are simultaneously produced, in addition to the aforementioned coupling between the shaped bands (31 , 41 ).

In particular, the longitudinal rib (44) provided on top of the box- shaped band (41 ) of the second longitudinal wall (4) is exactly engaged into the corresponding groove (31 a) provided at the base of the shaped band (31 ) of the first longitudinal wall (3).

Simultaneously, the short edges (43) provided at the ends of the upper horizontal border of the second longitudinal wall (4) are exactly engaged into corresponding notches (34) obtained on the two vertical borders of the first longitudinal wall (3), thus favouring the engagement of the cylindrical pins (43a) of the second longitudinal wall (4) into corresponding holes (35) on the first longitudinal wall (3).

The niches (45) provided at the sides of the box-shaped band (41 ) of the second longitudinal wall (4) are exactly lowered onto the partitions (33) provided at the sides of the shaped band (31 ) of the first longitudinal wall (3). Following the said matching, the stiffening edge (42) provided on each side of the second longitudinal wall (4) is brought in perfect alignment with the corresponding stiffening edge (32) of the first longitudinal wall (3).