A cardboard seat

The present patent application for industrial invention relates to a cardboard seat.

After being used only for packaging in the past, cardboard has recently found new applications because of the constant research for environmentally sustainable design.

Cardboard is undoubtedly one of the most environmentally-friendly materials because it is completely recyclable, biodegradable and made with natural elements and additives.

In particular, thanks to its versatility, sturdiness and capability to adjust to the most diverse shape, cardboard has proved to be one the most appropriate materials for the realization of environmentally-friendly interior decoration items.

Technological innovation, feasibility studies and machinery improvement have made cardboard seats stronger and stronger, with high stability, good performance and refined details.

The market currently offers various types of cardboard seats that are obtained by folding and/or gluing a punched cardboard sheet.

Some parts of the seat must be fixed with glue when the edges of the punched sections cannot be fitted together.

In such a case, in addition to having to choose the correct type of glue carefully in order not to prevent seat recycling and to avoid visible thickness between glued parts, the seat inevitably maintains its three-dimensional condition, without the possibility of being dismounted to return to the bi- dimensional condition of the original punched cardboard sheet.

It must be noted that "bi-dimensional" indicates a condition in which two dimensions largely prevail on the third dimension.

While they are always ready for use, without having to be assembled, seats of this type can no longer resume their two-dimensional condition, thus impairing storage and transportation and requiring large packaging volumes in case of big seats.

Instead, seats obtained from folding a punched cardboard sheet can easily resume their original bi-dimensional condition, thus solving the aforementioned problems related with storage and transportation of seats obtained by gluing sections of the original punched cardboard sheet.

In other words, the advantage of said "folding" seats is that they occupy a very reduced space during storage, require minimum packaging volumes and minimize transportation costs.

However, it must be noted that the stability of a glued seat is normally higher than the stability of a folding seat, given the fact that in the latter case stability is obtained by fitting the various cardboard sections together.

In any case, being a folding chair, in presence of an anomalous stress, some of its portions can fold uncontrollably, thus impairing the stability of the chair.

The purpose of the present invention is to remedy the drawbacks of the prior art, by devising a cardboard seat that is strong, stable, easy and fast to assemble.

The cardboard seat of the invention is obtained by folding a single cardboard sheet that is the base structure of the seat of the invention.

The base structure is composed of four consecutive quadrangular sections separated by a folding line.

Each of said consecutive four sections is folded by approximately 90° with respect to the adjacent section in order to close the base structure along a quadrangular direction; said cardboard seat also comprises fixing means adapted to hold the structure in three-dimensional condition provided on a first transversal side of the base structure and on an imaginary line.

For explanatory reasons, the description of the cardboard seat according to the present invention continues with reference to the attached drawings, which only have illustrative, not limiting value, wherein:

- Figure 1 is a plan view of the base structure used to obtain the cardboard seat according to the invention; - Figure 2 is an axonometric view of the base structure of Fig. 1 ;

- Figure 3 is an exploded axonometric view of the cardboard seat according to the invention.

- Figure 4 is an axonometric view of the cardboard seat according to invention.

- Figures 5 and 6 are respectively an axonometric view and a side view of the end portion of an end section provided in the cardboard seat according to the invention.

Referring to Fig. 1 , the cardboard seat of the invention is obtained using a base structure (A) with substantially rectangular shape, and comprising two parallel longitudinal long sides (B,C), of which a first longitudinal long side (B) and a second longitudinal long side (C), as well as two parallel transversal sides (D,E), of which a first transversal short side (D) and a second transversal short side (E).

Said base structure (A) is composed of five quadrangular sections (1 ,

2, 3, 4, 5) and four lines (L1 , L2, L3, X), each line separating two adjacent quadrangular sections.

Said lines consist in three folding lines (L1 , L2, L3) and one imaginary line (X).

More precisely, with reference to Fig. 1 , the five quadrangular sections

(1 , 2, 3, 4, 5) of the base structure (A) comprise:

- a first quadrangular section (1 ) defined by the first transversal side (D) of the base structure (A), a first portion (B1 ) of the first longitudinal long side (B), a first portion (C1 ) of the second longitudinal long side (C) and a first folding line (L1 );

- a second quadrangular section (2) defined by said first folding line (L1 ), a second portion (B2) of the first longitudinal long side (B), a second portion (C2) of the second longitudinal long side (C) and a second folding line (L2);

- a third quadrangular section (3) defined by said second folding line

(L2), a third portion (B3) of the first longitudinal long side (B), a third portion - a fourth quadrangular section (4) defined by said third folding line (L3), a fourth portion (B4) of the first longitudinal long side (B), a fourth portion (C4) of the second longitudinal long side (C) and an imaginary line (X) against which said first transversal short side (D) of the base structure (A) is stopped;

- a fifth quadrangular section (5) defined by said imaginary line (X), a fifth portion (B5) of the first longitudinal long side (5), a fifth portion (C5) of the second longitudinal long side (C) and said second transversal side (E) of the base structure (A).

Said folding lines make it possible to overturn a quadrangular section

(1 , 2, 3, 4, 5) by approximately 90° with respect to the adjacent quadrangular section. It must be noted that in the seat obtained from said base structure (A), the first (1 ) and third section (3) are disposed in substantially horizontal position, whereas the second (2), fourth (4) and fifth section (5) are disposed vertically.

Referring to Fig. 2, a V-sectioned groove is provided in each folding line (L1 , L2, L3) of the base structure (A) in order to obtain perfect overturning between two adjacent quadrangular sections (1 , 2, 3, 4, 5).

As shown in Fig. 4, the third section (3) rests on the ground, the first section (1 ) acts as seat, and the fifth section (5) acts as backrest.

The first transversal side (D) is provided with fixing means adapted to cooperate with corresponding housings obtained in the imaginary line (X), against which said first transversal short side (D) is stopped.

As shown in Fig. 1 , said fixing means consist in end sections (6) inserted in said housings, which specifically consists in slots (7).

Each end section (6) comprises an intermediate portion (61 ) and an end portion (62).

As shown in Figs. 5 and 6, said intermediate portion (61 ) is exactly inserted into the corresponding slot (7), therefore having length equal to the horizontal dimension of said slot (7) and width equal to the thickness of the base structure (A). Said end portion (62) protrudes with respect to said slot (7) wherein the end section (6) is inserted, and is provided with two opposite grooves (64) with diverging concavity.

Said opposite grooves (64) house a ring (63) adapted to prevent the backward sliding of each end section (6) from the slot (7).

More precisely, said ring (63) is dimensioned in such way that the horizontal dimension (63a), when measured in its external border, is higher than the horizontal dimension of the slot (7) where the end section (6) is inserted.

It must be noted that, in spite of the fact that the slot (7) has a horizontal or vertical direction, in order to prevent the backward sliding of each end section (6) from the slot (7), said ring (63) must be provided with maximum dimension (63a), when measured in its external border, higher than the maximum dimension of the slot (7).

Still referring to Figs. 5 and 6, the cardboard seat of the invention can advantageously comprise a washer (65) disposed between said two opposite grooves (64) and the surface of the base structure (A) from which the end portions (62) of the end sections (6) protrude.

Said washer (65) is centrally provided with a slot that receives the end portion (62) of a single end section (6).

Referring to Fig. 2, the cardboard seat of the invention can advantageously be provided with two stiffening edges (8) in order to give stability and sturdiness to the seat of the invention.

The seat of the invention comprises centering and fixing means for said stiffening edges (8) adapted to make it easier to assemble the edges in the seat, and guarantee the stable position of the stiffening edges (8) with respect to the seat, when the latter is in assembled condition.

Referring to Fig. 2, said centering means consist in a series of tabs situated on the edge and a series of housings situated on said base structure.

More precisely, said series of tabs comprises a first tab (81 ), a second tab (82), a third tab (83) and a fourth set of three tabs (84). Said housings are situated on the first four quadrangular sections (1 , 2, 3, 4) of the base structure (A) and consist in through slots (9) obtained on the longitudinal long sides (B, C) of the base structure (A).

Specifically, said through slots (9) are previously obtained on cardboard strips (90) glued on said longitudinal long sides (B, C) of the base structure (A).

Although the attached drawings and description refer to a seat with backrest obtained with a fifth quadrangular section (5), the present invention also relates to a stool without backrest obtained with the same base structure (A), but without the fifth quadrangular section (5).