Folding furniture

Abstract

The invention relates to a piece of furniture (1) that folds between a use position (P1) in which the furniture is unfolded with a support surface (2) substantially under tension and a storage position (P2) in which the furniture is folded with the support surface substantially relaxed. The furniture comprises a central part (3), at least two upper bars (4) designed to serve as a frame for the support surface, each comprising an upper end (4a) connected to the support surface and a lower end (4b) connected to the central part, and at least two lower bars (5) designed to serve as feet for said frame, each comprising an upper end (5a) connected to the central part. The furniture also comprises reinforcement links (6) for the upper and lower bars in the use position. Figure to be published: Fig. 1

Description

Title of the invention: Folding furniture technical field

[0001] The invention falls within the field of folding furniture and more particularly folding furniture such as stools, seats or tables. Previous technique

[0002] Such furniture is intended to be transported by one person. It is therefore advantageous for it to be compact and as light as possible in order to be transported as easily as possible without sacrificing robustness.

[0003] In particular, there are folding stools with three relatively compact telescopic legs when folded, as described in US patent 11882942B2. However, for this type of stool, the cross-section of the bars must be sized according to their bending / compression stress, which generally makes them quite heavy. To achieve a weight reduction compared to a telescopic design, one solution is to choose a structure that only subjects the bars to compression. In this case, elements working in pure tension must be added to maintain the stability of the structure, as described in US patents 2139673, 4290643A, and EP3261492B1.

[0004] However, the structure of these stools is generally made up of mixed elements, that is to say, links subjected to tension and bars subjected to compression, which are sensitive to variations in the angles between them when the user sits on the stool, particularly due to variations in the user's position, differences in weight and body shape, and parasitic torsional stresses that the user may exert around the vertical axis. Therefore, to resist these deformations, the structure must be reinforced, which generates additional weight. Summary of the invention

[0005] The objective of the invention is therefore to solve the aforementioned problems.

[0006] To this end, the invention relates to a folding piece of furniture comprising a flexible support surface, said furniture being foldable between a use position in which the furniture is unfolded with the support surface substantially under tension and a storage position in which the furniture is folded with the support surface substantially relaxed, said furniture comprising a central part, at least two upper bars designed to serve as a frame for the support surface, each comprising an upper end connected to the support surface and a lower end connected to the central part, and at least two lower bars designed to serve as feet for said frame, each comprising an upper end connected to the central part, said furniture comprising consolidation links of the upper and lower bars in the position of use connecting each lower end of a lower bar to a lower end of at least one other lower bar and each upper end of an upper bar to a lower end of at least one lower bar, characterized in that the lower end of at least one upper bar has a concave surface and the upper end of at least one lower bar has a concave surface, and in that the central part has a convex surface such that the concave surfaces of said at least one upper bar and of said at least one lower bar each form a spherical connection (7a) with the convex surface of the central part in the position of use.

[0007] The idea behind the invention is to eliminate as many bending stresses as possible on the bars when the support surface bears a load, for example, a user sitting on the furniture, and to maximize both the compressive stresses on the bars in the central part and the tensile stresses on the links at the ends of the bars. The invention thus allows for greater angular freedom of movement of the bars in the central part under stress, and therefore a reduced risk of permanent deformation or even breakage of the bars, resulting in greater robustness of the furniture.

[0008] The folding furniture according to the invention may also have the following features:

[0009] - the upper and lower bars are oriented so as to converge towards the same central point located in the central part;

[0010] - the central part comprises an upper part on which the lower ends upper bars are connected and a lower part to which the upper ends of the lower bars are connected, said upper part and said lower part cooperating with each other by means of a central joint with free angular movement in the position of use;

[0011] - the upper and lower parts are not articulated to each other at with the help of the central link in the storage position;

[0012] - the upper part and the lower part are designed to articulate together by engaging when the furniture moves from the storage position to the use position;

[0013] - the upper and lower parts of the central part include each one has a magnetic element so that they are attracted to each other by magnetic attraction;

[0014] - the central joint is formed by a convex male part arranged on the part upper or lower part of the central part and a concave female part respectively arranged on the lower or upper part of the part central, the male part being designed to snap into place with the female part in the position of use;

[0015] - the lower end of at least one upper bar or the upper end of at least one minus one lower bar are respectively in fixed connection with the upper part and the lower part of the central part;

[0016] - the lower ends of the upper bars and the upper ends of the bars lowers include elastic means designed to elastically connect said at least one upper and lower bar with the central part;

[0017] - additional bars extend upwards from the upper extremities of at least two upper bars and between which extends a backrest surface in the position of use so as to form a backrest substantially perpendicular to the support surface.

[0018] The folding furniture according to the invention can be used for example as a seat, chair, table, hammock, bed or stool. Brief presentation of the drawings

[0019] The present invention will be better understood and other advantages will become apparent upon reading the detailed description of an embodiment taken by way of non-limiting example and illustrated by the accompanying drawings, in which:

[0020] [Fig-1] Fig. 1 is a schematic representation of a folding piece of furniture according to the stool-type invention in a position of use;

[0021] [Fig.2] Fig.2 is a schematic representation of a folding piece of furniture according to the invention of a stool-type device in a storage position;

[0022] [Fig.3] Fig.3 is a schematic representation of the upper part and of the lower part of the central part with two upper and lower bars in spherical connection according to the invention, the upper part being seen in frontal section;

[0023] [Fig.4] [Fig.4] is a schematic side view representation of the part upper and lower part of the central part according to the invention with two upper and lower bars in spherical connection;

[0024] [Fig.5] The [Fig.5] is a schematic representation of the lower end of a upper bar according to the invention;

[0025] [Fig.6] Fig.6 is a schematic representation of a first step in a kinetics of the engagement of the upper part with the lower part of the central part of a piece of furniture according to the invention;

[0026] [Fig.7] Fig.7 is a schematic representation of a second step in the kinetics of the engagement of the upper part with the lower part of the central part of a piece of furniture according to the invention.

[0027] [Fig.8] Fig.8 is a schematic representation of a folding piece of furniture according to the invention of the chair type in the position of use comprising a backrest. Description of a method of implementation

[0028] The invention relates to a folding piece of furniture, such as a stool, a bed, a seat, a chair, a table, or a hammock. The folding piece of furniture 1 according to the invention is designed to be lightweight and compact so as to be easily transported and stored.

[0029] Fig. 1 represents a piece of furniture 1 according to the invention of the stool type comprising a support surface 2 according to the invention, here a seat, composed of a flexible material such as fabric, plastic, leather and may also have elastic properties.

[0030] The furniture 1 according to the invention is also foldable between a use position PI, visible in [Fig.1], in which the furniture 1 is unfolded to put substantially under tension the support surface 2 and a storage position P2, visible in [Fig.2], in which the furniture 1 is folded to relax the support surface.

[0031] The term "substantially tensioned support surface" is understood as a state of the support surface that allows a user to use the furniture for its intended function, i.e., a seat for a chair, etc. Similarly, the term "substantially relaxed support surface" is understood as a state of the support surface that does not allow a user to use the furniture for its intended function.

[0032] By way of non-limitation, the transition from storage position P2 to usage position PI will be made automatic by an elastic deployment system of the furniture 1.

[0033] The furniture 1 according to the invention comprises, in particular, a frame supporting the support surface, legs supporting the frame, and a central part 3 connecting the frame and the legs in the use position PL

[0034] The frame is formed here by at least two upper bars 4, each comprising a lower end 4b connected to the central part 3 and an upper end 4a connected to the support surface. In the example shown in [Fig. 1], there are three upper bars 4, which gives the support surface 2 a substantially triangular shape. The bars are tubes made of a substantially rigid material such as, for example, aluminum tubes.

[0035] The feet are here formed by at least two lower bars 5, each comprising an upper end 5a connected to the central part 3. In the example shown in [Fig. 1], there are three lower bars 5. The feet are designed here to be placed on the ground.

[0036] The number of bars can be modified according to the type of furniture desired. For a table, for example, four upper bars (4) and four lower bars (5) could be considered.

[0037] As shown in [Fig. 3], the lower ends 4b of the upper bars 4 and the upper ends 5a of the lower bars 5 may include elastic means 12 designed to elastically connect the bars with the central part 3 and thus maintain the bars in compression with the central part 3. This arrangement allows for the automated deployment of the furniture 1 described above. For example, a compression spring 12a may be provided, fixed at one end inside the bar, and a link 12b connecting the other end of the spring to the central part 3, so that the bars automatically deploy into the operating position PI by releasing the spring.

[0038] In an embodiment of the invention visible in [Fig.3], the link may also pass through the central part 3 to be connected to another spring arranged in another bar.

[0039] The furniture 1 also includes consolidation links 6 for the upper bars 4 and the lower bars 5, as shown in Figures 1, 2, and 8. The consolidation links 6 connect each lower end 5b of a lower bar 5 to a lower end 5b of at least one other lower bar 5, and each upper end 4a of an upper bar 4 to a lower end 4b of at least one lower bar 5. The consolidation links 6 help maintain the geometric shape of the structure and contribute to its mechanical strength when the furniture 1 is in its operating position PL.

[0040] The consolidation links 6 and the support surface 2 therefore work mainly in tension on the upper bars 4 and the lower bars 5 while the upper bars 4 and the lower bars 5 work here mainly in compression on the central part 3.

[0041] With this arrangement, the bars are mainly subjected to buckling, which allows the use of smaller bar sections than for mechanical dimensioning in bending while maintaining the same resistance.

[0042] It may also be provided that at least one consolidation link 6 is adjustable in tension by adjusting its length between two bar ends, just like the support surface 2.

[0043] The lower end 4b of at least one upper bar 4 shall have a concave surface and the upper end 5a of at least one lower bar 5 shall also have a concave surface, while the central part 3 shall have a convex surface such that the concave surfaces of said at least one upper bar and of said at least one lower bar each form a spherical connection 7a with the convex surface of the central part in the position of use. By convex surface, it is understood that the central part shall have either a fully convex surface, for example in the form of a sphere, or a partially convex surface, for example with Convex surface portions. Whether the surface of the central part is entirely or partially convex, the convex surface must allow the formation of spherical connections with the concave surfaces of the lower and upper bars.

[0044] These spherical connections 7a allow the said at least one upper bar and lower bar to be articulated with the central part 3 in the manner of a ball joint.

[0045] Each spherical connection 7a may consist of a concave upper spherical surface arranged at the end of a bar, as shown in [Fig.5], and a convex lower spherical surface arranged on the central part 3, visible in [Fig.3].

[0046] More specifically, and as shown in Figures 6 and 7, the lower end 4b of at least one upper bar and / or the upper end 5a of at least one lower bar may be provided with a fixed connection 7b to the upper part 3a and the lower part 3b, respectively. This means that the upper bars 4 and the lower bars 5, with their fixed connections 7b, are not spherically connected to the upper part 3a and the lower part 3b, respectively. For example, one upper bar may be provided with a fixed connection and all other upper bars and lower bars with spherical connections; one lower bar may be provided with a fixed connection and all other lower bars and upper bars with spherical connections; or one upper and one lower bar may be provided with a fixed connection and all other upper and lower bars with spherical connections.

[0047] It may also be provided that the upper bars 4 and the lower bars 5 are oriented so as to converge towards a single central point PC located in the central part 3. Each bar will then have a longitudinal axis, here four axes A1, A2, A3 and A4, which intersect at the central point PC. Thanks to this arrangement, it is possible to obtain almost pure compression of the upper bars 4 and the lower bars 5 on the central part 3 and to obtain the smallest possible cross-sections of very strong bars, again with the aim of minimizing weight. This focusing of the compressive forces at a single central point PC is made possible by the presence of spherical joints at the ends of the upper bars 4 and the lower bars 5. All the spherical joints 7a can indeed have the same single central point PC as their geometric center.

[0048] The central part 3 may also include an upper part 3a to which the lower ends of the upper bars 4 are connected and a lower part 3b to which the upper ends 5a of the lower bars 5 are connected, said upper part 3a and said lower part 3b cooperating with each other by means of a central joint 8 with free angular movement in the operating position PI.

[0049] The central part 3 may, for example, include a ball, in which the central point PC is located, and to which parts 3a and 3b, each comprising the spherical joints 7a of the ends of the bars, are connected. The ball may be fixed by a fixed joint in the upper part 3a or the lower part 3b such that, respectively, the lower part 3b or the upper part 3a includes a housing for receiving the ball in a ball joint.

[0050] Thanks to the use of the central joint 8 coupled with the joints of the bars on the central part 3, and when a user sits on the support surface, deformations throughout the furniture 1 do not change the way the structural elements are stressed. If the angles between the bars change by several degrees, then the compressive forces on the bars continue to converge all towards the single central point PC, here the center of the spherical joints. The bars therefore always work in near-pure compression, and the joints and support surface 2 always work in near-pure tension. Thus, the structural elements can be dimensioned as precisely as possible, which allows for a significant weight saving compared to a structure that must resist the bending caused by the geometric deformations of the structure.

[0051] It may also be provided that the lower part 3b and upper part 3a are able to be assembled / disassembled via the central joint 8 in order to facilitate the unfolding / folding of the unit 1 into the storage position P2. In this case, the upper part 3a and the lower part 3b will no longer be articulated to each other by means of the central joint in the storage position P2, while they will be articulated to each other by means of the central joint in the use position PL

[0052] To articulate or disarticulate the upper part 3a and the lower part 3b using the central joint 8, an interlocking means may be used, as seen in figures 4 and 6 in which the central joint is not engaged and in [Fig.7] in which the central joint is engaged.

[0053] By way of example, and as shown in [Fig. 3], the engagement means for the central joint 8 is presented here in the form of a male part 8a, for example a convex surface located on the upper part 3a or on the lower part 3b of the central part 3, and a female part 8b, for example a concave surface located respectively on the lower part 3b or on the upper part 3a. In the case shown in [Fig. 3], the female part 8b may be grooved to facilitate the engagement of the male part 8a in the female part 8b.

[0054] Also, it may be provided that the upper part 3a and the lower part 3b of the central part 3 each comprise a magnetic element 9, for example a magnet, so as to be attracted to each other by magnetic attraction and thus maintain the connection between the lower and upper parts during handling of the furniture, as shown in figures 6 and 7.

[0055] In an embodiment of the invention shown in [Fig. 8], the furniture 1 may be in the form of a chair comprising supplementary bars 10 extending upwards from the upper ends 4a of at least two upper bars 4 and between which extends a backrest surface 11 in the use position PI so as to form a backrest substantially perpendicular to the support surface 2. The supplementary bars 10 may in this case include elastic links allowing the supplementary bars 10 to be extended perpendicularly by elastic release of the elastic links. In the case where the furniture 1 comprises at least four upper bars 4, the backrest may include reinforcing links 6 connecting each upper end lia of the supplementary bars 10 to an upper end 4a of an upper bar and extending perpendicularly to the backrest.

Claims

Demands

1. Folding furniture (1) comprising a flexible support surface (2), said furniture being foldable between a use position (PI) in which the furniture is unfolded with the support surface substantially under tension and a storage position (P2) in which the furniture is folded with the support surface substantially relaxed, said furniture comprising a central part (3), at least two upper bars (4) designed to serve as a frame for the support surface, each comprising an upper end (4a) connected to the support surface and a lower end (4b) connected to the central part, and at least two lower bars (5) designed to serve as feet for said frame, each comprising an upper end (5a) connected to the central part,said furniture comprising consolidation links (6) of the upper and lower bars in the position of use connecting each lower end (5b) of a lower bar to a lower end of at least one other lower bar and each upper end of an upper bar to a lower end of at least one lower bar, characterized in that the lower end of at least one upper bar has a concave surface and the upper end of at least one lower bar has a concave surface, and in that the central part has a convex surface such that the concave surfaces of said at least one upper bar and of said at least one lower bar each form a spherical connection (7a) with the convex surface of the central part in the position of use.

2. Folding furniture according to claim 1, characterized in that the upper and lower bars are oriented so as to converge towards the same central point (PC) located in the central part.

3. Folding furniture according to claim 1 or 2, characterized in that the central part comprises an upper part (3a) to which the lower ends of the upper bars are connected and a lower part (3b) to which the upper ends of the lower bars are connected, said upper part and said lower part lower cooperating with each other by means of a central joint (8) with free angular movement in the position of use.

4. Folding furniture according to any one of claims 1 to 3, characterized in that said upper part and said lower part are not articulated to each other by means of the central linkage in the storage position.

5. Folding furniture according to any one of claims 1 to 4, characterized in that said upper part and said lower part of the central part are designed to articulate together when the furniture moves from the storage position to the use position.

6. Folding furniture according to any one of claims 1 to 5, characterized in that the upper and lower parts of the central part each comprise a magnetic element (9) so as to be attracted to each other by magnetic attraction.

7. Folding furniture according to any one of claims 1 to 6, characterized in that the central joint is formed by a convex male part (8a) arranged on the upper or lower part of the central part and a concave female part (8b) respectively arranged on the lower or upper part of the central part and in that the male part is designed to snap into the female part in the position of use.

8. Folding furniture according to any one of claims 1 to 7, characterized in that the lower end of at least one upper bar and / or the upper end of at least one lower bar are respectively in fixed connection (7b) with the upper and lower parts of the central part.

9. Folding furniture according to any one of claims 1 to 8, characterized in that the lower ends of the upper bars and the upper ends of the lower bars comprise elastic means designed to elastically connect said at least one upper and lower bar with the central part.

10. Folding furniture according to any one of claims 1 to 9, characterized in that it comprises additional bars (10) extending upwards from the upper ends of at least two upper bars and between which extends a backrest surface (11) in the position of use so as to form a backrest substantially perpendicular to the support surface.

11. Folding furniture according to any one of claims 1 to 10 designed to be used as a seat or table or hammock or bed or stool.

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