Foldable item of furniture

Abstract

The invention relates to an item of furniture (1) that is foldable between a position of use (P1), in which the item of furniture is unfolded with a support surface (2) substantially held taut, and a storage position (P2), in which the item of furniture is folded with the support surface substantially relaxed. The item of furniture comprises a central portion (3), at least two upper bars (4), designed to act as a frame for the support surface, each upper bar comprising a top end (4a) connected to the support surface and a bottom end (4b) connected to the central portion, and at least two lower bars (5) designed to act as legs for the frame, each lower bar comprising a top end (5a) connected to the central portion. The item of furniture also comprises reinforcing links (6) for securing the upper bars and the lower bars in the position of use.

Description

Folding furniture

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

[0002] Such furniture is designed to be carried by one person. Therefore, it is advantageous for it to be compact and as lightweight as possible in order to be transported as easily as possible without sacrificing sturdiness.

[0003] One example is a relatively compact, three-legged telescopic folding stool, 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 stresses, 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 puts compression stress on the bars. In this case, elements working in pure tension must be added to maintain the structure's stability, 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, tensile links and compressive bars, which are sensitive to variations in the angles between them when the user sits on the stool. This is due in particular to variations in the user's position, differences in weight and body shape, and the parasitic torsional stresses that the user may exert around the vertical axis. Therefore, to resist these deformations, the structure must be reinforced, which results in added weight.

[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 minimize bending stress on the bars when the support surface bears a load, for example, a user sitting on the furniture, and to maximize both the compressive stress on the bars in the central section and the tensile stress on the links at the ends of the bars. The invention thus allows for greater angular movement of the bars in the central section under stress, thereby reducing the risk of permanent deformation or even breakage of the bars, and consequently increasing the 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 to which the lower ends of the upper bars are connected and a lower part to which the upper ends of the lower bars are connected;

[0011] - elastic means are provided to elastically connect at least one of said upper bars and at least one of said lower bars with the central part so that said at least one upper bar and at least one lower bar can automatically move from a folded position in which their concave surface no longer forms the spherical connection with the convex surface of the central part to an unfolded position in which their concave surface forms the spherical connection with the convex surface of the central part;

[0012] - upper ball joint connections are provided, each designed to connect the upper end of an upper bar to the support surface;

[0013] - each upper ball joint is formed of a female part fixed to the support and a male part fixed to an upper end of an upper bar;

[0014] - the male part has a geometric center and a through passage passing through the geometric center, the consolidation links connecting the upper end of an upper bar and the lower end of a lower bar extend through the passage;

[0015] - lower ball joint connections are provided, each designed to connect the lower end of a lower bar to at least one consolidation link connecting a lower end of another lower bar;

[0016] - each lower ball joint is formed of a female part fixed to said consolidation link connecting a lower end of another lower bar and a male part fixed to a lower end of a lower bar;

[0017] - the male part has a geometric center and a through passage passing through the geometric center and in that each consolidation link connecting an upper bar with a lower bar extends through the passage;

[0018] - the female part of each lower ball joint has a groove and in that each consolidation link connecting the lower ends of two lower bars extends through the groove to surround the female part;

[0019] - 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 central part;

[0020] - additional bars extend upwards from the upper ends 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.

[0021] The folding furniture according to the invention can be used for example as a seat, chair, table, hammock, bed or stool.

[0022] The folding furniture according to the invention may also have the following features according to a first embodiment:

[0023] - the upper and lower parts of the central section are designed to cooperate with each other when the furniture is in the position of use to form a central joint;

[0024] - the upper and lower parts of the central section are designed to be separated from each other when the furniture is in the storage position;

[0025] - the upper and lower parts of the central part each include a magnetic element so that they are attracted to each other by magnetic attraction;

[0026] - the central joint is formed of a convex male part arranged on the upper or lower part of the central part and a concave female part respectively arranged on the lower or upper part of the central part.

[0027] The folding furniture according to the invention may also have the following features according to a second embodiment:

[0028] - the upper and lower parts are designed to cooperate mechanically together between a pre-assembly position in which the elastic means are in a first state of tension, and an assembly position in which the elastic means are in a second state of tension superior to said first state of tension.

[0029] - the upper and lower parts of the central part may respectively be in the form of an upper hemisphere and a lower hemisphere, angularly indexed to each other by a notch;

[0030] - the central part includes a toothed ring arranged between the two upper and lower parts so as to facilitate angular indexing and rotation around the axis of the upper and lower parts relative to each other between the mounting and pre-mounting position;

[0031] - the central part includes a cavity inside which extends a support having a first support part and a second support part extending respectively into the upper and lower parts, designed so that, during the mechanical cooperation between the lower and upper parts, the support means put the elastic means into tension. Brief presentation of the drawings

[0032] 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:

[0033] This is a schematic representation of a folding piece of furniture according to the invention, of the stool type, in a position of use;

[0034] This is a schematic representation of a folding piece of furniture according to the invention, of the stool type, in a storage position;

[0035] Laest is a schematic representation of the upper and lower parts of the central part with two upper and lower bars in spherical connection according to a first embodiment of the invention, the upper part being seen in frontal section;

[0036] Laest is a schematic representation in side view of the upper and lower parts of the central part according to a first embodiment of the invention with two upper and lower bars in spherical connection;

[0037] This is a schematic representation of the lower end of an upper bar according to the invention;

[0038] Laest is a schematic representation of a first step in a kinematic of interlocking the upper part with the lower part of the central part of a piece of furniture according to a first embodiment of the invention;

[0039] This is a schematic representation of a second stage 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 a first embodiment of the invention.

[0040] This 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.

[0041] Laest is a schematic cross-sectional representation of the central part according to a second embodiment of the invention in which the central part is in a pre-assembly position;

[0042] Laest is a schematic cross-sectional representation of the central part according to a second embodiment of the invention in which the central part is in the mounting position;

[0043] This is a schematic perspective representation of a superior ball joint according to the invention;

[0044] Laest is a schematic cross-sectional representation of a superior ball joint according to the invention;

[0045] This is a schematic perspective representation of a lower ball joint according to the invention;

[0046] This is a schematic cross-sectional representation of a lower ball joint of a piece of furniture according to the invention. Description of a method of implementation

[0047] The invention relates to a folding piece of furniture, such as a stool, bed, seat, chair, table, or hammock. The folding piece of furniture according to the invention is designed to be lightweight and compact so as to be easily transported and stored.

[0048] Lare 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.

[0049] The furniture 1 according to the invention is also foldable between a use position P1, visible in, in which the furniture 1 is unfolded to put substantially under tension the support surface 2 and a storage position P2, visible in, in which the furniture 1 is folded to relax the support surface.

[0050] The term "subjectively tensioned support surface" refers to a state of the support surface that allows a user to use the furniture for its intended function, i.e., as a seat for a chair, etc. Similarly, the term "subjectively relaxed support surface" refers to a state of the support surface that prevents a user from using the furniture for its intended function.

[0051] Without limitation, the transition from storage position P2 to usage position P1 will be made automatic by an elastic deployment system of furniture 1.

[0052] The furniture 1 according to the invention includes in particular a frame carrying the support surface, feet supporting the frame and a central part 3 connecting the frame and the feet in the position of use P1.

[0053] 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 2. In the example shown, 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 tubing.

[0054] The feet are formed here by at least two lower bars 5, each comprising an upper end 5a connected to the central part 3. In the example shown, there are three lower bars 5. The feet are designed to be placed on the ground.

[0055] The number of bars can be modified depending on the type of furniture desired. For a table, for example, four upper bars (4) and four lower bars (5) could be considered.

[0056] As shown in Figure 1, 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 to 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 fixed at one end inside the bar, and an elastic or non-elastic link 12b may connect the other end of the spring to the central part 3 so that the bars automatically deploy to position the furniture in the use position P1 by releasing the spring.

[0057] In one embodiment of the invention shown in, the link may also pass through the central part 3 to be connected to another spring arranged in another bar.

[0058] The furniture 1 also includes consolidation links 6 of 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 5b of at least one lower bar 5. The consolidation links 6 help maintain the geometric shape of the structure and contribute to the mechanical resistance when the furniture 1 is in the use position P1.

[0059] 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.

[0060] With this arrangement, the bars are mostly subjected to buckling, which allows the use of smaller bar sections than for mechanical dimensioning in bending while maintaining the same resistance.

[0061] It can 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.

[0062] 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 portion 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 portion in its operating position. By convex surface, it is understood that the central portion shall have either a fully convex surface, for example in the form of a sphere, or a partially convex surface, for example with portions of a convex surface. Whether the surface of the central portion is fully or partially convex, the convex surface must allow the formation of spherical connections with the concave surfaces of the lower and upper bars.

[0063] These spherical connections 7a allow the said at least one upper and lower bar to be articulated with the central part 3 in the manner of a ball joint.

[0064] Each spherical connection 7a may consist of a concave upper spherical surface arranged at the end of a bar, as shown in, and a convex lower spherical surface arranged on the central part 3, visible on the.

[0065] 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 for by a fixed connection 7b with the upper part 3a and the lower part 3b, respectively. This means that the upper bars 4 and the lower bars 5, connected by a fixed connection 7b, are not spherically connected with the upper part 3a and the lower part 3b, respectively. For example, one upper bar may be fixed and all other upper and lower bars spherically connected; one lower bar may be fixed and all other lower and upper bars spherically connected; or one upper and one lower bar may be fixed and all other upper and lower bars spherically connected.

[0066] It can 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 section 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 section 3 and to obtain the smallest possible cross-sections of highly resistant bars, always with the aim of minimizing weight. This concentration of 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.

[0067] 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.

[0068] More particularly, the elastic means 12 described above may be provided to elastically connect at least one of said upper bars 4 and at least one of said lower bars 5 with the central part 3 so that at least one upper bar 4 and at least one lower bar 5 can automatically move from a folded position PP in which their concave surface no longer forms the spherical connection with the convex surface of the central part 3 to an unfolded position PD in which their concave surface forms the spherical connection with the convex surface of the central part 3.

[0069] The furniture 1 according to the invention may also have upper ball joints 13, as shown in Figures 11 and 12, each designed to connect the upper end 4a of an upper bar 4 to the support surface 2. Each upper ball joint 13 may thus be formed of a female part 13a fixed to the support and a male part 13b fixed to an upper end of an upper bar 4. Without restricting the scope of the invention, the male parts 13b and female parts 13a may be clipped together. It can also be provided that the male part 13b has a geometric center O1, the male part 13b having a shape here globally spherical, and a passage 14 passing through the geometric center O1 so that each consolidation link 6 connecting the upper end of an upper bar 4a and the lower end of a lower bar 5b extends through the passage 14.This configuration allows the consolidation links 6 to exert a tensile force on the geometric center O1 when the furniture is in the operating position. The link 6 can be fixed by a right-angle drive in a cavity in the male part 13a of the upper ball joint 13, where the fixing point is represented by a node 6a that locks against a stop 4' inside the upper bar 4. Finally, the female part 13a of each upper ball joint 13 may have a groove 17a designed to receive a consolidation link 6 connected to or directly integrated into the support surface 2.

[0070] The furniture according to the invention may also include lower ball joints 15, as shown in Figures 13 and 14, each designed to connect the lower end of a lower bar 5 to at least one consolidation link 6 connecting a lower end of another lower bar 5. Each lower ball joint 15 may be formed of a female part 15a integral with said consolidation link 6 connecting a lower end of another lower bar 5 and a male part 15b integral with a lower end of a lower bar 5. In the same way as for the upper ball joints 13, the male parts 15b and female parts 15a of the lower ball joints 15 may be clipped together.The male portion 15b may also have a geometric center O2 and a through-passage 16 passing through the geometric center O2, such that each reinforcement link 6 connects an upper bar 4 with a lower bar 5 by extending through the passage 16. This configuration allows a tensile force to be exerted on the geometric center O2. The female portion 15a of each lower ball joint 15 may also have a groove 17b designed to receive a reinforcement link 6 connecting the lower ends 5b of two lower bars 5 by surrounding the female portion. To improve the stability of the furniture legs, the reinforcement links 6 connecting the lower end 5b of the same leg may, for example, be crossed as shown in Figures 13 and 14, and a fastening means may optionally be added to the crossing, for example, a seam.The tensile force of the consolidation link 6 connecting two lower bars 5 and the tensile force of the consolidation link 6 connecting one of these two lower bars 5 to an upper end 4a of an upper bar 4 both pass through point O2, thus limiting any unwanted bending on the lower bars 5, which consequently allows for the smallest possible bar dimensions. The female part 15a of the ball joint can also include an interchangeable pad 15a' that is clipped or screwed on, which ensures stable support on floors of varying hardness while protecting the female ball joint 15 from wear.

[0071] In an embodiment of the invention shown in Figure 1, 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 P1 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 11a of the supplementary bars 10 to an upper end 4a of an upper bar and extending perpendicularly to the backrest.

[0072] In a first particular embodiment according to the invention shown in figures 3, 4, 6 and 7, said upper part 3a and said lower part 3b cooperate with each other by means of a central joint 8 with free angular movement, when the furniture is in the use position P1.

[0073] 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 to receive the ball in a ball joint.

[0074] Thanks to the use of the central joint 8 coupled with the joints of the bars on the central section 3, and when a user sits on the support surface, deformations across the entire piece of furniture 1 do not alter the stress patterns on the structural elements. If the angles between the bars change by several degrees, the compressive forces on the bars continue to converge at 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 with utmost precision, resulting in a significant weight reduction compared to a structure that must withstand the bending forces generated by the geometric deformations of the structure.

[0075] It may also be possible to provide for the lower part 3b and upper part 3a 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 using the central joint in the storage position P2, while they will be articulated to each other using the central joint in the use position P1.

[0076] 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 which the central joint is engaged.

[0077] As an example, and as shown in the figure, the means for engaging 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 the figure, the female part 8b may be grooved to facilitate the engagement of the male part 8a in the female part 8b.

[0078] It can also be provided that the upper part 3a and the lower part 3b of the central part 3 each include a magnetic element 9, for example a magnet, so that they are 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.

[0079] In a second particular embodiment of the invention shown in Figure 10, the upper part 3a and the lower part 3b may be designed to cooperate mechanically between a pre-assembly position (P3) in which the elastic means 12 are in a first tension state, here a low or even zero tension, and an assembly position P4 in which the elastic means 12 are in a second tension state higher than said first tension state, here a high tension. This configuration simplifies the industrial assembly of the central part 3, for example, to allow the links 12b to be tensioned by the springs 12a.

[0080] More specifically, the upper part 3a and the lower part 3b of the central part may respectively be in the form of an upper hemisphere and a lower hemisphere, angularly indexed to each other by a notch 3a', 3b'.

[0081] A toothed ring 3x can also be positioned between the two upper parts 3a and lower parts 3b to facilitate angular indexing and rotation of the upper and lower parts relative to each other around axis A5. Figure 1 represents the central part with the upper and lower parts in the pre-assembly position (P3), while Figure 2 shows the upper and lower parts in the assembly position (P4).

[0082] Each link 12b can also be designed to abut 12c the spring it passes through in order to tension the spring against the central part 3. The central part can also have a cavity within which extends a support, here in two support parts S1 and S2 extending respectively into the upper part 3a and the lower part 3b, designed so that, when the lower part 3b rotates relative to the upper part 3a, the links 12b wrap around the support, thus tensioning the springs 12a. The support can be arranged so that the links concentrate the tensile force at the single central point PC.

[0083] A non-return notching, made here as an example by the notched ring 3x, allows the elastic means 12 to be kept under tension. An optional fixing means, for example in the form of a screw or a rivet, can be added between the upper and lower parts 3a and 3b in order to prevent their disassembly.

[0084] For the sake of clarification and without limiting the scope of the invention, the use position P1 and storage position P2 are associated with the furniture 1, the deployed position PD and folded position PP are associated with the bars 4 and 5, and finally the assembly position P4 and pre-assembly position P3 are associated with the central part 8.The elastic means 12 will therefore exhibit particular tension states depending on the position in which each of the aforementioned elements is located, namely: a first tension state, when the central part 8 is in the pre-assembly position P3 and the bars are in the deployed position PD, the furniture 1 not being in the storage position P2, a second tension state, greater than the first tension state, when the central part 8 is in the assembly position P4, when furniture 1 is in the use position P1 and when the bars 4 and 5 are in the deployed position PD, a third tension state, greater than the second tension state, when the central part 8 is in the assembly position P4, when the bars 4 and 5 are in the folded position PP, the furniture 1 not being in the use position P1.

Claims

Folding furniture (1) comprising a flexible support surface (2), said furniture being foldable between a use position (P1) 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. 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. Folding furniture according to any one of 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. Folding furniture according to any one of the preceding claims, characterized in that it comprises elastic means (12) elastically connecting at least one of said upper bars and at least one of said lower bars with the central part so that said at least one upper bar and at least one lower bar can automatically move from a folded position (PP) in which their concave surface no longer forms the spherical connection with the convex surface of the central part to an unfolded position (PD) in which their concave surface forms the spherical connection with the convex surface of the central part. Folding furniture according to any one of the preceding claims, characterized in that it comprises upper ball joint connections (13) each designed to connect the upper end of an upper bar to the support surface. Folding furniture according to claim 5, characterized in that each upper ball joint is formed of a female part (13a) attached to the support and a male part (13b) attached to an upper end of an upper bar. Folding furniture according to claim 6, characterized in that the male part has a geometric center (O1) and a through passage (14) passing through the geometric center and in that the consolidation links connecting the upper end of an upper bar and the lower end of a lower bar extend through the passage. Folding furniture according to any one of the preceding claims, characterized in that it comprises lower ball joint connections (15) each designed to connect the lower end of a lower bar to at least one consolidation link connecting a lower end of another lower bar. Folding furniture according to claim 8, characterized in that each lower ball joint is formed of a female part (15a) integral with said consolidation link connecting a lower end of another lower bar and a male part (15b) integral with a lower end of a lower bar. Folding furniture according to any one of claims 8 or 9, characterized in that the male part has a geometric center (O2) and a through passage (16) passing through the geometric center and in that each consolidation link connecting an upper bar with a lower bar extends through the passage. Folding furniture according to any one of claims 8 to 10, characterized in that the female part of each lower ball joint has a groove (17b) and in that each consolidation link connecting the lower ends of two lower bars extends through the groove to surround the female part. Folding furniture according to any one of the preceding claims, 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 central part. Folding furniture according to any one of the preceding claims, 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. Folding furniture according to any of the preceding claims designed to be used as a seat or table or hammock or bed or stool. Folding furniture according to any one of claims 3 to 14, characterized in that the upper and lower parts of the central part are designed to cooperate with each other when the furniture is in the position of use to form a central joint (8). Folding furniture according to claim 15, characterized in that the upper and lower parts of the central part are designed to be separated from each other when the furniture is in the storage position. Folding furniture according to claim 15 or 16, characterized in that the upper part and the lower part of the central part each comprise a magnetic element (9) so as to be attracted to each other by magnetic attraction. Folding furniture according to any one of claims 15 to 17, characterized in that the central joint is formed of 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. Folding furniture according to any one of claims 3 to 15, characterized in that the upper part and the lower part are designed to cooperate mechanically together between a pre-assembly position (P3) in which the elastic means are in a first state of tension, to an assembly position (P4) in which the elastic means are in a second state of tension superior to said first state of tension. Folding furniture according to claim 19, characterized in that the upper part and the lower part of the central part can respectively be in the form of an upper hemisphere and a lower hemisphere, angularly indexed to each other by a notch (3a', 3b'). Folding furniture according to claim 19 or 20, characterized in that the central part includes a toothed ring (3x) arranged between the two upper and lower parts so as to facilitate angular indexing and rotation around the axis (A5) of the upper and lower parts relative to each other between the assembly and pre-assembly position. Folding furniture according to any one of claims 19 to 21, characterized in that the central part comprises a cavity inside which extends a support having a first support part (S1) and a second support part (S2) extending respectively into the upper and lower parts, designed so that, during the mechanical cooperation between the lower and upper parts, the support means put the elastic means into tension.

Images