WO2024023400A1

WO2024023400A1 - Foldable chair with two connecting bars - jump seat

Info

Publication number: WO2024023400A1
Application number: PCT/FR2023/000137
Authority: WO
Inventors: Patrick Herbault
Original assignee: Patrick Herbault
Priority date: 2022-07-29
Filing date: 2023-07-23
Publication date: 2024-02-01

Abstract

The invention relates to a foldable chair with two connecting bars - a jump seat. The invention relates to the field of foldable chairs. The aim is to achieve a fold inscribed in a cuboid, which preserves the width and depth of the seat in the unfolded configuration, with a minimum height and a minimum number of components. The kinematic elements are made up of three connecting elements: the seat portion (A, LM) itself which connects the front pivot (L) to a pivot (M) positioned on the uprights (MD) of the backrest (D), a single connecting bar (B, LR) which connects the front pivot (L) to a pivot (R) positioned on a rear leg (PR) and a single connecting bar (B, KV) which connects the rear pivot (K) to a pivot (V) positioned on a front leg (PV). The chair is unfolded without the chair touching the ground, the backrest being in a vertical position specific to, inter alia, a jump seat.

Description

Title of the invention: Foldable chair with two connecting bars - Strapontin

[0001] FIELD OF INVENTION TO WHICH THE INVENTION RELATES

[0002] The invention relates to the field of foldable chairs.

PRIOR ART

[0003] Conventionally, most foldable chairs, whether occasional chairs, garden chairs or camping chairs, have a simple folding method consisting of folding down the seat and a pair of feet on the rigid assembly. consisting of the backrest and the feet in the extension of the backrest.

[0004] Although this folding is simple, it nevertheless leads to a folded chair which retains the height of the rigid assembly consisting of the backrest and the feet in the extension of the backrest, i.e. in order of magnitude between 80 centimeters and one meter.

[0005] This can be considered penalizing.

[0006] There are more sophisticated folding systems where both the seat folds onto the backrest and the feet fold under the seat.

[0007] Patent US20150115667 discloses such folding kinematics, but such folding kinematics as described applied to a chair results in a folded configuration in an increase in the depth of the chair as well as a significant height.

[0008] In fact it is a three-dimensional folding which combines a widthwise folding carried out by a central folding cross and a lateral folding on each side carried out by antiparallelograms.

[0009] At the time of combined folding, the central cross which in the unfolded position typically fits for a folding chair into a square of side 45 cm whose cross is formed of the two diagonals, has in the folded position the length of the diagonals i.e. 45 x 2 or 63.5 cm and therefore extends by approximately 18.5 cm.

[0010] Likewise, the antiparallelograms extend by approximately 18.5 cm between the folded position and the unfolded position to accompany the folding of the central foldable cross.

[0011] Note that if the seat is not described, it is also assumed to be foldable, inscribed in the unfolded position typically in a square of 45 cm side and substantially horizontal, typically in a plane parallel to the foldable cross. The purpose of the connecting bars of the antiparallelograms is the folding kinematics of the antiparallelograms and are not described as a component of the seat, which in any case would not be feasible due to their inclination imposed by the variation in depth of 18, 5 cm in this embodiment. [0012] The objective of the folding according to the invention is to obtain a folding inscribed in a volume which is a rectangular parallelepiped which practically retains the width and depth of the seat in the unfolded configuration with a minimum height and a minimum of components.

[0013] BRIEF DESCRIPTION OF THE INVENTION

[0014] The foldable chair according to the invention comprises a backrest frame integrated or not into the backrest with two right and left uprights, a seat frame integrated or not into the seat, a pair of front legs and a pair of feet back.

The backrest and the rear legs are articulated by a common rear pivot, the seat frame and the front legs are articulated by a common front pivot.

[0016] A first connecting element connects the front pivot to a pivot positioned on at least one of the uprights of the backrest frame, a second connecting element connects the front pivot to a pivot positioned on at least one of the rear legs, a third connecting element connects the rear pivot to a pivot positioned on at least one of the front legs.

The first connecting element connecting the backrest uprights to the front axle is in the form of a seat frame.

[0018] In the folded configuration, the ends of the rear legs come opposite the front part of the seat, the ends of the front legs come opposite the rear part of the seat and the upper part of the backrest (D) comes opposite the front part of the seat.

[0019] It is advantageous that the foldable chair is not foldable in width.

[0020] It is advantageous for the backrest frame to be rigid and non-foldable.

[0021] It is advantageous for the seat frame to be rigid and not foldable.

[0022] It is advantageous that the foldable chair is asymmetrical in the vertical plane, that is to say that the left part of the foldable chair is not symmetrical to the right part of the foldable chair so as to separately optimize the left part and the right part of the folding chair.

[0023] It is advantageous for the rear legs to be joined together and for the second connecting element connecting the rear legs to the front axle to be a single connecting bar.

[0024] It is advantageous that this single connecting bar, second connecting element, is a connecting bar positioned laterally and not in the middle of the foldable chair.

[0025] It is advantageous for the front legs to be joined together and the third connecting element connecting the front legs to the rear axle is a single connecting bar.

[0026] It is advantageous that this single connecting bar, third connecting element, is a connecting bar positioned laterally and not in the middle of the foldable chair.

[0027] It is advantageous that all of the pivots, pivot positioned on at least one of the uprights of the backrest frame, pivot positioned on at least one of the rear legs, pivot positioned on at least one of the front legs, are at a distance maximum pivots respective rear and front equal to at most 10 cm,

[0028] It is advantageous for the offset of the backrest uprights relative to the rear axis to be between two and five centimeters.

[0029] It is advantageous for the offset of the rear feet relative to the rear axis to be between two and five centimeters.

[0030] It is advantageous for the offset of the front feet relative to the front axis to be between two and five centimeters.

[0031] It is advantageous if the offset of the backrest uprights, the rear legs and the front legs relative to their respective pivots are identical.

[0032] It is advantageous for all of these pivots to be positioned in the unfolded position at a height difference along an axis conventionally called z, relative to the front and rear pivots equal to the offset.

[0033] It is advantageous that the architecture of the chair, the kinematics retained and the creation of an offset for all of the front legs, the rear legs and the backrest uprights, relative to their respective pivot, front pivots and rear leads to a way of reducing the depth of the chair by several centimeters in the folded configuration.

[0034] It is advantageous for the chair in the folded configuration to fit into a rectangular parallelepiped which virtually retains the width and depth of the chair in the unfolded configuration with a height at least divided by eight of the height of the chair in the unfolded configuration. .

[0035] For a classic height of 80 cm, this represents a height in folded configuration of less than 10 cm.

[0036] To further optimize compactness, it is possible for the seat to also be foldable along an axis at the location of at least one of the two front and rear pivots.

[0037] Advantageously, the right and left rear legs are in the same vertical plane respectively as the right and left uprights of the backrest frame.

[0038] It is preferred that the right and left uprights of the backrest, the rear legs and the front legs are made in the form of oval-shaped profiles.

[0039] It is advantageous for the connecting bars to be smaller than the front and rear legs.

[0040] It is advantageous for the connecting bars to be made of polycarbonate.

[0041] It is advantageous for the backrest and the rear legs to be articulated by a rear pivot with an angle limiting device.

[0042] It is advantageous for the backrest and the backrest uprights to be articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat.

[0043] It is advantageous for the rear legs to be articulated by a pivot with a device angle limitation with a maximum angle of at most 120° in relation to the seat. [0044] It is advantageous for the front legs to be articulated by a front pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat.

Whatever the folding method chosen, it is preferable that at least one additional locking device secures the unfolded position.

[0046] It is advantageous for the chair to include a gripping means at the top of the backrest.

[0047] It is advantageous to create a folding seat comprising the foldable chair according to the invention and a means of fixing or vertically positioning the back of the foldable chair against a vertical wall.

[0048] Advantageously, the folding seat includes a return means for raising the seat into a vertical position when the seat is not in use.

[0049] In terms of use, it is advantageous that the unfolding of the foldable chair is obtained in one movement without the foldable chair having to touch the ground, with the backrest in the vertical position.

Brief description of the drawings

[0050] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, for an understanding of which reference will be made to the appended drawings.

[0051] [Fig.1] shows in perspective view the foldable chair according to the invention in the unfolded position.

[0052] [Fig.2] shows in perspective view the foldable chair according to the invention in the folded position.

[0053] [Fig.3] shows the basic diagram of the kinematics according to the invention in the unfolded position and in the folded position according to an embodiment with rectilinear connecting bars.

[0054] [Fig.4] shows the basic diagram of the kinematics according to the invention in the unfolded position and in the folded position in a more integrated embodiment due to the presence of an offset for the connecting bars.

[0055] [Fig.5] shows the detail of the articulation between the backrest upright and the rear legs according to one embodiment.

[0056] [Fig.6] shows the detail of the articulation between the front foot and another element according to one embodiment.

[0057] [Fig.7] shows the detail of the articulation between the front foot and another element according to another embodiment.

[0058] [Fig.8] shows an embodiment of the foldable chair in the case of an angle limitation of 110° with a more aesthetic design. [0059] [Fig-9] shows an embodiment of a folding seat on the base of the foldable chair according to the invention in the unfolded position.

[0060] [Fig.10] shows an embodiment of a folding seat on the base of the foldable chair according to the invention in an intermediate position.

[0061] [Fig.11] shows an embodiment of a folding seat on the base of the foldable chair according to the invention in the folded position.

DETAILED DESCRIPTION OF THE INVENTION

The foldable chair (1) according to the invention comprises a backrest frame integrated or not into the backrest (D) with two uprights (MD) right and left, a seat frame integrated or not into the seat (A ), a pair of front feet (PV) and a pair of rear feet (PR).

[0063] The backrest and the rear legs are articulated by a common rear pivot, the seat frame and the front legs (PV) are articulated by a common front pivot (L).

[0064] A first connecting element (LM) connects the front pivot (L) to a pivot (M) positioned on at least one of the uprights (MD) of the backrest frame, a second connecting element (LR) connects the pivot front (L) to a pivot (R) positioned on at least one of the rear legs (PR), a third connecting element (KV) connects the rear pivot (K) to a pivot positioned (V) on at least one of the legs forward (PV).

The first connecting element (LM) connecting the backrest uprights (MD) to the front axle (L) is in the form of a seat frame (A, LM).

[0066] In the folded configuration, the ends of the rear legs (PR) come opposite the front part of the seat (A), the ends of the rear legs (PR) come opposite of the front part of the seat (A) and the upper part of the backrest (D) comes opposite the front part of the seat (A).

[0067] The foldable chair according to the invention has classic dimensions.

[0068] Its backrest and its seat can be made in multiple ways.

[0069] These may be solutions where the backrest and the seat, particularly in the field of camping, are made in the form of fabric stretched in a metal frame.

[0070] In the garden sector, it may involve a backrest and seat made for example from exotic woods where the backrest frame or the seat frame is integrated into the backrest or into the seat.

[0071] These can also be plastic supports, either bare or combined with fabric filling.

[0072] In order of size, the dimension of the seat is 40 cm by 40 cm and the backrest can also be of the same value or be limited to a simple upper backrest typically 15 cm by 40 cm.

[0073] The feet have a height of around 40 cm.

[0074] Classically, foldable and therefore transportable chairs have smaller dimensions. generous than a generally more comfortable apartment chair.

[0075] The object of the invention is, whatever the dimensions, not to increase the width or depth of the chair in the unfolded position while reducing the height of course.

[0076] It is advantageous that the foldable chair (1) is not foldable in width, folding in width most of the time resulting in an increase in depth of the folded chair in the folded position.

[0077] It is advantageous for the backrest frame to be rigid and non-foldable.

[0078] It is advantageous for the seat frame to be rigid and not foldable.

[0079] [Fig.l] and [Fig.2] illustrate the proposal according to the invention in folded configuration and in folded configuration in perspective view, [Fig.3] and [Fig.4] are more explicit in terms of architecture and kinematics used to fold and unfold the foldable chair (1) in a single movement.

[0080] In the case where as shown in the figures, the angles between the backrest upright (MD) and the seat (A), between the seat (A) and the rear legs (PV) and between the seat (A) and the front legs (PV) are identical then the connecting elements (LM, LR, KV) have identical geometric characteristics.

[0081] If the angles between the backrest upright (MD) and the seat (A), between the seat (A) and the rear feet (PV) and between the seat (A) and the front feet (PV ) are different so although it is an analogous solution, the connecting elements (LM, LR, KV) have different geometric characteristics.

[0082] [Fig.3] illustrates the kinematics in the case where the connecting elements are rectilinear.

[0083] [Fig.4] illustrates the kinematics in the case where the connecting elements have an offset relative to the pivots positioned on the different elements, the connecting elements being rotatably mounted at the other end on the front pivot (L) or the rear pivot (K).

[0084] It is advantageous as shown [Fig.4] that the connecting bars (B) are not necessarily rectilinear as shown in dotted lines but with an offset equal to the offset (x) of the other elements as shown in lines plus thick.

[0085] Then the connecting bars (B) are integrated not only into the volume of the foldable chair (1) in the folded position but also in the unfolded position.

[0086] In particular the connecting bar (B, LM) which connects the front pivot (L) to the pivot (M) of the backrest upright (MD) no longer risks interfering in the volume above the seat (HAS). On the contrary to the fact that it is now partly parallel to the line of the front (L) and rear (K) pivots unlike the rectilinear version which is oblique, the connecting bar (B, LM) which connects the front pivot ( L) to the pivot (M) of the backrest upright (MD) can even act directly as a seat support (A).

[0087] It is advantageous for the rear feet (PR) to be joined together and for the second connecting element (RL) connecting the rear legs (PR) to the front axle (L) i.e. a single connecting bar (B, RL).

[0088] It is advantageous for the front legs (PV) to be joined together and the third connecting element connecting the front legs (PV) to the rear axle (K) is a single connecting bar (B, KV).

[0089] According to other embodiments, the two rear legs (PR) are secured either by a physical axis connecting them or by a transverse bar (BT) connecting them.

[0090] According to other embodiments, the two front feet (PV) are joined either by a physical axis connecting them or by a transverse bar connecting them.

[0091] Note that if the front legs (PV) are connected by a transverse bar, it is advantageous for the front legs (PV) to be a few centimeters longer than the rear legs and for the transverse bar connecting them to be arranged at the ends of the front legs (PV) so as not to risk interfering with the rear legs (PR) and the transverse bar (BT) connecting them when it exists, when folding or unfolding the foldable chair (1).

[0092] The consequence of this difference in length between the front feet (PV) and the rear feet (PR), the front feet (PV) being longer, is an inclination of the seat (A) of a few degrees, typically between 5° and 10°, which is normal for a classic seat.

[0093] Preferably, when both a single connecting bar (B, RL) connecting the rear legs (PR) to the front axle (L) and a single connecting bar (B, KV) connecting the feet coexist. front (PV) to the rear axis (K), it is advantageous that they are on two different sides.

[0094] Note then that the foldable chair (1) even if it appears symmetrical is not strictly symmetrical due to the fact that the single connecting bar (B, RL) connecting the rear legs (PR) to the front axle (L) and the single connecting bar (B, KV) connecting the front legs (PV) to the rear axle (K) are different, not having the same function in the folding-unfolding kinematics.

[0095] When the two proposals are applied simultaneously, then the number of visually identifiable connecting bars (B) is limited to only two as illustrated in [Fig.l] and [Fig.2].

[0096] This represents a notable gain, particularly in terms of mass, which is always appreciable for a foldable and therefore portable object that the user must handle.

[0097] It is advantageous for all of the pivots, pivot (M) positioned on at least one of the uprights (MD) of the backrest frame, pivot (R) positioned on at least one of the rear legs (PR), pivot ( V) positioned on at least one of the front feet (PV), are at a maximum distance (d) from the respective rear (K) and front (L) pivots equal to at most 10 cm, [0098] While naturally to optimize the mechanical strength, it is preferable to separate the pivots positioned (M, R, V) on the different rotating elements, from the front (L) and rear (K) pivots, in terms of On the contrary, to optimize compactness, they must be brought closer together.

[0099] In fact, this distance increases the center distance between the front and rear axes, thereby widening the depth of the foldable chair (1) in the folded position as illustrated in [Fig.3] and [ Fig.4].

[0100] Consequently, it is advantageous to compensate for this increase in depth, even of a few centimeters, by a suitable geometry.

[0101] Consequently, it is also advantageous to compensate for the reduction in mechanical strength by supplementing the kinematics with a plurality of angle limitations integrated into the different pivots to relieve the three connecting elements (LM, LR, KV).

[0102] It is advantageous for the offset (x) of the backrest uprights (MD) relative to the rear axis (K) to be between two and five centimeters.

[0103] It is advantageous for the offset (x) of the rear feet relative to the rear axis (K) to be between two and five centimeters

[0104] It is advantageous for the offset (x) of the front feet relative to the front axis (K) to be between two and five centimeters

[0105] It is advantageous for the offset (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots to be identical.

[0106] In fact, the implementation of the kinematics as illustrated in [Fig.3] and [Fig.4] leads to increasing the center distance between the front (L) and rear (K) pivots of a approximate value of the value (z) which corresponds to the height difference along an axis conventionally called z and illustrated in [Fig.3] and [Fig.4], plus the offset (x).

[0107] [Fig.3] and [Fig.4] illustrate the principle diagram of the folding chair (1) both in the unfolded position and in the folded position in the same view.

[0108] According to the invention, in the unfolded position the center distance (e min) between the rear (K) and front (L) pivots is equal to the difference between the distance between the front (PV) and rear legs and twice the offset (x).

[0109] According to the invention, in the folded position the center distance (e max) between the rear (K) and front (L) pivots is equal to the sum of the offset (x) and the long side of the rectangle whose crossbar (B) is the hypotenuse.

[0110] In [Fig.3], we see that the center distance between the front (L) and rear (K) pivots in the unfolded configuration increases approximately by the value of this value (z) of difference in z plus the offset (x). The approximation is due to the fact that the connecting bars (B) are inclined obliquely at an angle of around 5° and that the value of the hypotenuse is very close to the value of the long side, less than 1% compared to cosine of 5°.

[0111] To comply with the compactness requirement according to the invention, the value of the height difference (z) along the z axis must be less than the gain provided by the offsets (x) or twice the value (x) offset.

[0112] It is actually advantageous for all of these pivots (M, R, V) to be positioned in the unfolded position at a distance in height (z) along an axis conventionally called z, relative to the front pivots (L) and rear (K) close to one or two centimeters close to the value of the offset (x).

[0113] Advantageously this difference in height (z) is less than 7 centimeters.

[0114] Advantageously not only the offset values (x) and the height differences

(z) along the z axis are close, but they are identical, typically of the order of 3 centimeters.

[0115] Advantageously, the distance between the pivots (M, R, V) positioned on the different elements and the respective front (L) and rear pivots is between 2.8 and 7 centimeters, typically 4.2 centimeters.

[0116] Then the center distance in the folded position has increased by twice the value of the offset (x) equal to typically 3 centimeters or typically 6 centimeters.

[0117] This increase in the center distance value typically of the order of 6 centimeters was compensated by the gain brought by the offset (x) on each side, i.e. twice the value of the offset (x), of the order typically twice 3 centimeters or 6 centimeters.

[0118] The size of the folding chair (1) along the x axis, that is to say in depth, is almost identical between the folded configuration and the unfolded configuration as illustrated [Fig.3] and [Fig.4 ],

[0119] The seat (A) and the connecting bars (B) are simply moved along the x axis by a few centimeters, typically 3 centimeters between the folded position and the unfolded position forwards or backwards as illustrated in [Fig.3] and [Fig.4].

[0120] It is advantageous that the architecture of the chair, the kinematics retained and the creation of an offset (x) for all of the front feet (PV), the rear feet (PR) and the backrest uprights ( MD), relative to their respective pivot, front (K) and rear (L) pivots lead to a means of reducing by several centimeters the depth of the chair (1) in the folded configuration.

[0121] It is advantageous for the chair (1) in the folded configuration to fit into a rectangular parallelepiped which almost retains the width and depth of the chair (1) in the unfolded configuration with a height at least divided by eight of the height of the chair (1) in the unfolded configuration.

[0122] For a classic height of 80 cm, this represents a height in folded configuration of less than 10 cm. [0123] The creation of an offset (x), a gap between the natural extension of the pivoting element comprising a substantially rectilinear part and the pivot axis makes it possible to optimize both the height of the chair (1) in configuration folded and making possible the parallelism of the constituents of the chair (1) and also to optimize the depth since at the time of pivoting the depth is reduced at each end by the value (x) of the offset, i.e. twice the value (x) of deportation.

[0124] This optimization consists of creating an offset value between two and five centimeters, typically three centimeters which gives a gain in depth, a gain between four and ten centimeters, typically six centimeters to be compared to dimensions of the order forty centimeters.

[0125] It should also be noted that the proposal according to the invention is compatible with any type of folder, whether it has a minimum height of 15 cm up to 40 cm, knowing that part of the folding kinematics exploits the fact that it This is a mini folder with a height of 15 centimeters.

[0126] Preferably, the right and left uprights (MD) of the back frame are placed furthest towards the inside of the chair (1).

[0127] Thus it is easier to connect the left and right backrest uprights (MD) by a backrest (D) without interference with the other elements.

[0128] The same applies to the rear legs (PR) insofar as this allows them to be connected by a transverse bar (BT) without interfering with the other elements.

[0129] Preferably, the right (PV) and left front feet are placed furthest towards the outside of the chair (1).

[0130] This has the advantage, on the one hand, of preventing the folding of the front legs (PV) from interfering with the folding of the rear legs at the time of folding and, on the other hand, of possibly allowing a wider seat at the 'front than at the rear more relevant in terms of ergonomics.

[0131] It is preferred that the right and left uprights (MD) of the backrest, the rear legs (PR) and the front legs (PV) are made in the form of oval-shaped profiles.

[0132] Indeed, the demand for effort is much greater in the longitudinal direction when, for example, a corpulent user is rocking on his chair (1) only on the two rear feet (PR) than in the transverse direction.

[0133] It is preferred that the chair (1) in the folded configuration fits into a rectangular parallelepiped which almost retains the width and depth of the chair (1) in the unfolded configuration with a height at least divided by eight of the height of the chair (1) in the unfolded configuration.

[0134] For a classic height of 80 cm, this represents a height in folded configuration of less than 10 cm.

[0135] Note that if the height of the feet is greater than the depth of the seat, then the legs may protrude slightly in the folded position but the rectangular parallelepiped in which the chair (1) fits in the folded configuration remains minimal.

[0136] To further optimize compactness, it is possible for the seat (A) to also be foldable along an axis at the location of at least one of the two pivots (K, L).

[0137] Indeed, to gain a few more centimeters in depth in the folded configuration, it is also possible for a seat that we would like to extend a few centimeters forward to make it foldable of course at the cost of additional complexity and the need to synchronize this folding with at least that of a pair of legs of the chair, for example through a transverse physical axis securing the rotation of this foldable part of the seat (A) to the two rotations of the two front legs ( PV).

[0138] Note that in terms of angle limitation devices, a single angle limitation between two elements is propagated to the other elements via the connecting bars (B) which in turn indirectly become devices angle limitation.

[0139] In this embodiment of the folding kinematics using connecting bars, it is advantageous for the connecting bars (B) to be smaller than the front (PV) and rear (PR) legs which are load-bearing elements.

[0140] The supporting elements are, by way of example, pivoting relative to physical axes embodying the axes of the front and rear pivots with a diameter of around 20 mm, while the axes of rotation (M, R, V) positioned at the other end of the connecting bars (B) have a diameter of around 5 millimeters.

[0141] These connecting bars (B) allow the folding kinematics to operate but are not directly the supporting elements such as the front (PV) and rear (PR) legs.

[0142] For example, the supporting elements could be solid profiles while the connecting bars (B) would be hollow profiles.

[0143] It is advantageous for the connecting bars (B) to be made of polycarbonate.

[0144] It is advantageous for the backrest (D) and the rear legs (PR) to be articulated by a rear pivot (K) with an angle limiting device.

[0145] It is advantageous for the backrest (D) and the backrest uprights (MD) to be articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat (A ).

[0146] It is advantageous for the rear legs (PR) to be articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat (A).

[0147] It is advantageous for the front legs (PV) to be articulated by a front pivot (L) with an angle limiting device with a maximum angle of at most 120° relative to on the seat (A).

[0148] There are multiple devices for limiting the rotation of the elements, for example flap compasses, foldable compasses or joints with stops.

[0149] [Fig.5] illustrates an appropriate embodiment of such a device in the form of a rotary joint (AR, ARR) composed of a male part (AM) which fits into a part female (AF).

[0150] The male part (AM) includes an elbow (AM, C) which makes it possible to achieve an offset (x) of 3 centimeters.

[0151] The female part includes a stop (AF, BU) also at 45° which prevents the angle from exceeding 180°.

[0152] In a variant where the stop is horizontal, then this makes it possible to prevent exceeding 180° plus 45° or 225°.

[0153] These two values make it possible to prevent an angle between the seat (A) and the backrest (D) from exceeding half the value, that is to say between 90° and 112.5°, i.e. i.e. relevant values in the context of chairs.

[0154] [Fig.6] illustrates an appropriate embodiment of such a device in the form of a rotary articulation (AR, ARV) between two elements.

[0155] The first element is integral with an axis (AX) or comprises a physical axis (AX) for example with a diameter of 20 mm on which a second element is rotatably mounted, for example one front foot (PV).

[0156] The second element comprises a key (CL) which passes through the cylindrical location intended to receive the physical axis (AX).

[0157] The physical axis (AX) is hollowed out to allow free rotation of the first element according to the authorized angles and the remaining material in the form of a sector (AX, S) acts as a stop for limiting the angle of rotation of the second element.

[0158] [Fig.7] illustrates another suitable embodiment of such a device in the form of a simple rotary joint (AS) composed of two cylindrical elements (AA, BB)

[0159] Advantageously, this simple rotary joint includes a removable axis.

[0160] Advantageously, the removable axle is a shouldered screw (VE).

[0161] Advantageously, the first element (AA) of the simple rotary articulation and the second element (BB) of the simple rotary articulation (AS) comprise sectors (SA, SB) representing several tens of degrees of angle, in this case as shown 60°.

[0162] Advantageously, the joint (AS) is hermaphroditic, that is to say that the two elements of the joint facing each other comprise both angular sectors (SA, SB) and hollow angular housings (CA) facing each other, that is to say that the first element (AA) comprises an angular sector (SA) which penetrates into the second element and that the second element (BB) comprises angular sectors (SB) which penetrate into the first element (AA).

[0163] The compactness is such that this simple rotary joint (AS) fits into the volume of a cylinder of a few centimeters in diameter.

[0164] Note that the angle limitation devices can be multiple and redundant or not, the angle limitation device being obtained elsewhere,

[0165] For example, there may be three angle limitation devices, the first being an angle limitation of 120° between the backrest (D) and the seat (A), the second being an angle limitation of 120° between the front legs (PV) and the seat (A), the third being an angle limitation of 240° between the backrest (D) and the rear legs (PR). The third limitation by a third device is redundant and in the absence of a third device, the limitation is still obtained by the device resulting from the combination of the first two devices.

[0166] Even if a single rotary articulation device with angle limitation can propagate to the entire folding chair (1) via the connecting bars (B), it remains preferable to limit the stress on the effort of these connecting bars (B) to redundantly maintain the physical presence of rotary joints to directly limit the angles between the seat (A), the backrest uprights (MD), the rear legs (PR) and the front legs (PV).

[0167] Note that in the case where the connecting element (LM) acts directly as a seat support (A), a rotary articulation with angle limitation can be directly implemented on the pivot (M) of the post of backrest (MD) to limit the angle between the backrest upright (MD) and the crossbar (B, LM) and thus be able to support the weight of a large person, including when balancing on the rear feet (PR ) of the folding chair (1).

[0168] Advantageously, the right and left rear legs (PR) are in the same vertical plane respectively as the right and left uprights (MD) of the backrest frame (D).

[0169] Indeed, in this implementation, this makes it possible to stiffen the assembly of the backrest upright (D) and the rear leg (PR) for example by the preceding rotary articulation (AR, ARR) which ensures guidance additional in the vertical plane.

[0170] Regardless of the folding method chosen, it is preferable that at least one additional locking device secures the unfolded position.

[0171] Regardless of the folding method chosen, it is preferable that at least one additional locking device secures the folded position for transport and storage.

[0172] It is advantageous that the chair (1) includes a gripping means at the top of the backrest (D).

[0173] It may be a simple location for the passage of fingers arranged in the top of the backrest (D).

[0174] It can also be a handle similar to that of a briefcase.

[0175] It is also advantageous for the foldable chair (1) to have attachment points for a shoulder strap so as to actually allow the foldable chair (1) to be carried over the shoulder.

[0176] According to a particular embodiment, it is advantageous to create a folding seat comprising the foldable chair according to the invention and a means (F) of fixing or vertically positioning the backrest (D) of the chair (1) against a vertical wall (P).

[0177] This means (F) of vertically fixing the backrest can be, as shown, a set of four screws positioned on the two backrest uprights (MD).

[0178] It can also be hooks installed on the wall (P) which allow the foldable chair (1) to be kept removable for other uses.

[0179] Advantageously, the means of fixing or vertically positioning the backrest (D) against a wall (P) comprises a return means to raise it by one or two centimeters in order to facilitate the installation of the feet rear rotating before a person sits on it.

[0180] Advantageously, the folding seat includes a return means for raising the seat (A) into the vertical position when the seat is not in use.

[0181] For this folding seat, it is advantageous for the angle limitation to be 90° to allow folding and unfolding for example against a wall as shown in [Fig.9] in the unfolded position, in [Fig. .10] in the intermediate position and on [Fig.l 1] in the folded position.

[0182] Compared to a conventional folding seat, this solution according to the invention makes it possible to deploy both front feet (PV) and rear feet (PR) which are load-bearing elements which ensure that the wall (P) does not is required in effort only to hang the folding chair (1) on the wall without having to support the weight of a person typically of 50 to 75 kilos, or even 120 kilos for a large person.

[0183] Thus such a folding seat can advantageously replace folding seats where they are already used such as cinemas and theaters.

[0184] Other applications become possible such as seats in a waiting room, a seat for a bus or metro public transport, a seat for a restaurant, a bathroom, a kitchen cramped.

[0185] The wall (P) can in this case be relatively light and pivotally mounted on a double-jointed arm, for example combined with a desk or kitchen unit.

[0186] In addition, this has the advantage when it is in the raised position of being able to easily maintain and clean the floors.

[0187] In terms of use, it is advantageous that the unfolding of the chair (1) is obtained in one movement without the chair (1) having to touch the floor (S), the backrest (D) in vertical position.

[0188] This is the case of the folding seat described above, the chair (1) only touching the ground (S) in the final situation.

[0189] According to another use case, the unfolding of the chair (1) is obtained under the effect of its own weight.

[0190] It is indeed possible to hold the foldable chair (1) by the top of the backrest (D) with one hand and to accompany the unfolding by holding the front end of the seat (A) with the other hand. ).

[0191] For folding, it is also possible without the chair (1) touching the ground, to hold the backrest (D) vertical with one hand and with the other to fold the seat (A) against the backrest (D).

Industrial application

[0192] In terms of industrial application, the invention applies to folding chairs.

[0193] The present invention is in no way limited to the embodiments described and represented but those skilled in the art will be able to make any variation consistent with their spirit for a range of products in different environments or different worlds of use.

Claims

[Claim 1] Foldable chair (1) characterized in that it comprises a backrest frame integrated or not into the backrest (D) with two uprights (MD) right and left, a seat frame integrated or not into the seat ( A), a pair of front legs (PV) and a pair of rear legs (PR), that the backrest (D) and the rear legs (PR) are articulated by a common rear pivot (K), that the frame seat and the front feet (PV) are articulated by a common front pivot (L), a first connecting element (LM) connects the front pivot (L) to a pivot (M) positioned on at least one of the uprights ( MD) of the backrest frame, that a second connecting element (LR) connects the front pivot (L) to a pivot (R) positioned on at least one of the rear legs (PR), that a third connecting element ( KV) connects the rear pivot (K) to a pivot positioned (V) on at least one of the front legs (PV), in that the first connecting element (LM) connecting the backrest uprights (MD) to the axis front (L) is in the form of a seat frame (A, LM) and that in the folded configuration the ends of the rear legs (PR) come opposite the front part of the seat ( A), the ends of the front legs (PV) came opposite the rear part of the seat (A) and the upper part of the backrest (D) came opposite the part front of the seat (A).

[Claim 2] Foldable chair (1) according to claim 1 characterized in that the foldable chair is asymmetrical in the vertical plane, that is to say that the left part of the foldable chair is not symmetrical to the part right of the folding chair

[Claim 3] Foldable chair (1) according to any one of claims 1 to 2 characterized in that the rear legs (PR) are secured and that the second connecting element (RL) connecting the rear legs (PR) at the front axle (L) is a single connecting bar (B, RL).

[Claim 4] Foldable chair (1) according to any one of claims 1 to 3 characterized in that the front legs (PR) are secured and the third connecting element connecting the front legs (PV) to the rear axle (K) is a single connecting bar (B, KV).

[Claim 5] Foldable chair (1) according to any one of claims 1 to 4 characterized in that all of the pivots, pivot (M) positioned on at least one of the uprights (MD) of the backrest frame, pivot (R) positioned on at least one of the rear feet (PR), pivot (V) positioned (V) on at least one of the front feet (PV), are at a maximum distance (d) of the respective rear (K) and front (L) pivots equal to at most 10 cm,

[Claim 6] Foldable chair (1) according to any one of claims 1 to 5 characterized in that the offset (x) of the backrest uprights (MD) relative to the rear axis (K) is between two and five centimeters

[Claim 7] Foldable chair (1) according to any one of claims 1 to 6 characterized in that the offset (x) of the rear legs relative to the rear axis (K) is between two and five centimeters

[Claim 8] Foldable chair (1) according to any one of claims 1 to 7 characterized in that the offset (x) of the front legs relative to the front axis (K) is between two and five centimeters

[Claim 9] Foldable chair (1) according to any one of claims 1 to 8 characterized in that the offset (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots are identical.

[Claim 10] Foldable chair (1) according to claim 9 characterized in that all of these pivots (M, R, V) are positioned in the unfolded position at a distance in height (z) along an axis conventionally called z, relative to the front (L) and rear (K) pivots equal to the offset (x).

[Claim 11] Foldable chair (1) according to claim 10 characterized in that the architecture of the chair, the kinematics retained and the creation of an offset (x) for all of the front feet (PV), of rear legs (PR) and backrest uprights (MD), relative to their respective pivot, front (K) and rear (L) pivots leads to a means of reducing the depth of the chair by several centimeters (1) in folded configuration.

[Claim 12] Foldable chair (1) according to claim 11 characterized in that the chair (1) in the folded configuration is part of a rectangular parallelepiped which almost retains the width and depth of the chair (1) in the unfolded configuration with a height at least divided by eight of the height of the chair (1) in the unfolded configuration.

[Claim 13] Foldable chair (1) according to any one of claims 1 to 12 characterized in that the backrest (D) and the rear legs (PR) are articulated by a rear pivot (K) with a limitation device corner.

[Claim 14] Foldable chair (1) according to any one of claims 1 to 13 characterized in that the backrest (D) and the backrest uprights (MD) are articulated by a pivot with an angle limiting device with a maximum angle of at most 120° in relation to the seat (A).

[Claim 15] Foldable chair (1) according to any one of claims 1 to 14 ca- characterized by the fact that the rear legs (PR) are articulated by a pivot with an angle limiting device with a maximum angle of at most 120° in relation to the seat (A).

[Claim 16] Foldable chair (1) according to any one of claims 1 to 14 characterized in that the front legs (PV) are articulated by a front pivot (L) with an angle limiting device with an angle maximum at most 120° in relation to the seat (A).

[Claim 17] Folding seat comprising the chair (1) according to any one of claims 16 and a means (F) for fixing or vertically positioning the backrest (D) of the chair (1) against a vertical wall (P) .

[Claim 18] Use of the foldable chair (1) according to any one of claims 1 to 17, characterized in that the unfolding of the foldable chair (1) is obtained in one movement without the foldable chair (1) must touch the ground (S), with the backrest in a vertical position.