Folding chair in a minimal rectangular parallelepiped
The folding chair design addresses the issue of bulkiness in conventional chairs by using pivot articulations and offsets to minimize depth in the folded state, ensuring compact storage and transport.
Patent Information
- Application Number
- FR2022007887
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-06-20
- Filing Date
- 2022-07-29
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2042-07-29
AI Technical Summary
Conventional folding chairs either maintain a significant height or increase in depth when folded, making them bulky and inconvenient for storage or transport.
A folding chair design that incorporates specific pivot articulations and offset mechanisms, allowing the backrest, rear legs, and front legs to fold in a way that minimizes depth while maintaining the width and depth of the unfolded configuration, fitting into a rectangular parallelepiped shape with reduced height.
The chair achieves a compact folded configuration with a height reduced by several centimeters, maintaining the width and depth of the unfolded state, facilitating easy storage and transport without increasing bulk.
Smart Images
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Abstract
Description
Title of the invention: Foldable chair in a minimal rectangular parallelepiped
[0001] FIELD OF THE INVENTION TO WHICH THE INVENTION RELATES
[0002] The invention relates to the field of folding chairs. PREVIOUS ART
[0003] Conventionally, most folding chairs, whether they are occasional chairs, garden chairs or camping chairs, have a simple folding process consisting of folding the seat and a pair of legs onto the rigid assembly consisting of the backrest and the legs 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 made up of the backrest and the legs in the extension of the backrest, i.e. in order of magnitude between 80 centimetres and one metre.
[0005] This can be considered as penalizing.
[0006] There are more sophisticated folding systems where both the seat folds onto the backrest and the legs fold under the seat.
[0007] Patent FR2990919 discloses such folding kinematics, but such folding kinematics as described applied to a chair results in the folded configuration in an increase in the depth of the chair as well as a significant height.
[0008] The objective of the folding according to the invention is to obtain a folding inscribed in a volume which is a rectangular parallelepiped which preserves the width and depth of the seat in the unfolded configuration with a minimum height.
[0009] BRIEF DESCRIPTION OF THE INVENTION
[0010] The folding 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 rear legs, that the backrest and the rear legs are articulated by a rear pivot, that the front legs are articulated by a front pivot and that the offsets of the backrest uprights, the rear legs and the front legs relative to their respective pivots are between two and five centimeters, that in the folded configuration the ends of the rear legs are opposite the front part of the seat, the ends of the front legs are opposite the rear part of the seat and the upper part of the backrest is opposite the front part of the seat.
[0011] Advantageously the backrest and the rear legs are articulated by a rear pivot with an angle limiting device.
[0012] Advantageously, the backrest and the backrest uprights are articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat.
[0013] Advantageously, the rear legs are articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat.
[0014] Advantageously, the front legs are articulated by a front pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat.
[0015] It is indeed advantageous that the architecture of the chair, the kinematics retained and the creation of an offset for all the front legs, the rear legs and the backrest uprights, relative to their respective pivot, front and rear pivots lead to a means of reducing the depth of the chair by several centimeters in the folded configuration.
[0016] Advantageously, the right and left rear legs are in the same vertical plane respectively as the right and left uprights of the backrest frame.
[0017] Preferably, the right and left uprights of the backrest frame are placed furthest towards the inside of the chair.
[0018] Preferably, the front right and left legs are placed furthest towards the outside of the chair.
[0019] 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.
[0020] It is preferred that the chair in the folded configuration fits into a rectangular parallelepiped which practically 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.
[0021] For a classic height of 80 cm, this represents a height in folded configuration of less than 10 cm.
[0022] 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.
[0023] The folding chair according to the invention can be folded manually by the user in three independent movements consisting of folding or unfolding the backrest uprights relative to the seat, folding or unfolding the front legs relative to the seat and folding or unfolding the rear legs relative to the seat.
[0024] On the other hand, it is advantageous according to another embodiment that the chair has a folding kinematics combining the three movements, in this case a kinematics relative to the seat (A)
[0025] On the other hand, it is advantageous according to another embodiment that the chair (1) has folding kinematics combining the three movements, in this case an antiparallelogram kinematic or similar comprising at least three lateral arms, a first lateral arm connecting the front pivot to a pivot positioned on the uprights of the backrest frame, a second lateral arm connecting the front pivot to a pivot positioned on the rear legs, a third lateral arm connecting the rear pivot to a pivot positioned on the front legs, all of these pivots being positioned at a maximum distance from the respective front and rear pivots equal to 2.5 times the value of the offset.
[0026] Preferably, all of these pivots are 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.
[0027] In this embodiment of the antiparallelogram folding kinematics, it is advantageous for the side bars to be smaller than the front and rear legs.
[0028] It is advantageous if the side bars are made of polycarbonate.
[0029] It is advantageous for the seat to be articulated on the front pivot and connected to the rear pivot by a sliding device.
[0030] In the embodiment of the antiparallelogram folding kinematics, it is advantageous for the seat to be articulated on at least one of the two pivots and that in the unfolded position it becomes a means of locking the chair by blocking the center distance between the two front and rear pivots or of adjusting the inclination of the backrest by allowing the center distance between the two front and rear pivots to be modulated.
[0031] According to other embodiments, the folding chair comprises a single side bar, connecting the backrest uprights to the front axis in the form of a seat frame.
[0032] According to other embodiments, when the rear legs are secured then the folding chair comprises a single side bar connecting the rear legs to the front axle.
[0033] According to other embodiments, when the front legs are secured then the folding chair comprises a single side bar connecting the front legs to the rear axle.
[0034] It is advantageous that at least one side bar, including when it is the seat frame when it acts as a side bar, has an offset relative to its pivot equal to that of the offsets of the backrest uprights, the rear legs and the front legs relative to their respective pivots.
[0035] Whatever the folding method chosen, it is preferable that at least one additional locking device secures the unfolded position.
[0036] It is advantageous for the chair (1) to have a gripping means at the top of the backrest (D).
[0037] In terms of use, it is advantageous that the unfolding of the chair (1) is obtained without the chair (1) touching the ground, the backrest in a vertical position under the effect of its own weight. Brief description of the drawings
[0038] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the attached drawings.
[0039] [Fig-1] shows in perspective view the folding chair according to the invention in the unfolded position.
[0040] [Fig.2] shows in perspective view the folding chair according to the invention in the folded position.
[0041] [Fig.3] shows in right-hand view the folding chair according to the invention in the unfolded position.
[0042] [Fig.4] shows in right-hand view the folding chair according to the invention in the folded position.
[0043] [Fig.5] shows in perspective view the folding chair according to the invention in position unfolded according to an embodiment with antiparallelogram kinematics.
[0044] [Fig.6] shows in perspective view the folding chair according to the invention in the unfolded position according to an embodiment with antiparallelogram kinematics.
[0045] [Fig.7] shows in right-hand view the folding chair according to the invention in the unfolded position according to an embodiment with antiparallelogram kinematics.
[0046] [Fig.8] shows in right-hand view the folding chair according to the invention in the unfolded position according to an embodiment with antiparallelogram kinematics.
[0047] [Fig.9] shows the detail of the articulation between the backrest upright and the rear legs according to one embodiment.
[0048] [Fig. 10] shows the detail of the articulation between the front foot and another element according to one embodiment.
[0049] [Fig. 11] 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 side bars.
[0050] [Fig. 12] 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 side bars.
[0051] [Fig. 13] shows according to one embodiment a folding chair according to the invention with only two side bars visually identifiable in the folded position.
[0052] [Fig. 14] shows according to one embodiment a folding chair according to the invention with only two visually identifiable side bars in the unfolded position. DETAILED DESCRIPTION OF THE INVENTION
[0053] The folding 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 legs (PV) and a pair of rear legs (PR), which the backrest (D) and the rear legs (PR) are articulated by a rear pivot (K), that the front legs (PV) are articulated by a front pivot (L) and that the offsets (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots are between two and five centimeters, that in the folded configuration the ends of the rear legs (PR) are opposite the front part of the seat (A), the ends of the front legs (PV) are opposite the rear part A of the seat (A) and the upper part of the backrest (D) is opposite the front part of the seat (A).
[0054] Advantageously, 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° relative to the seat (A).
[0055] Advantageously, the backrest (D) and the rear legs (PR) are articulated by a rear pivot (K) with an angle limiting device.
[0056] Advantageously, the rear legs (PR) are articulated by a rear pivot (K) with an angle limiting device with a maximum angle of at most 120° relative to the seat (A).
[0057] Advantageously, the front legs (PV) are articulated by a front pivot (L) with an angle limiting device with a maximum angle of at most 120° relative to the seat (A).
[0058] The folding chair according to the invention has conventional dimensions.
[0059] Its backrest and its seat can be made in many ways.
[0060] These may be solutions where the backrest and the seat, particularly in the camping sector, are made in the form of fabric stretched in a metal frame.
[0061] In the garden sector, this may involve a backrest and seat made, for example, from exotic wood, where the backrest frame or the seat frame is integrated into the backrest or the seat.
[0062] These can also be plastic supports either bare or combined with fabric padding.
[0063] In order of magnitude, the dimension of the seat is 40 cm by 40 cm and the backrest can also be the same value or be limited to a simple top of the backrest typically 15 cm by 40 cm.
[0064] The feet are about 40 cm high.
[0065] Traditionally, folding and therefore transportable chairs have less generous dimensions than an apartment chair, which is generally more comfortable.
[0066] The object of the invention is, whatever the dimensions, not to increase the width or depth of the chair in the unfolded position while of course reducing the height.
[0067] [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] in straight view more explicit in terms of architecture, retained kinematics and the interest of creating an offset (x).
[0068] It is indeed advantageous that the architecture of the chair, the kinematics retained and the creation of an offset (x) for all the front legs, the rear legs and the backrest uprights (MD), relative to their respective pivot, front pivot (K) and rear pivot (L) lead to a means of reducing by several centimeters the depth of the chair (1) in the folded configuration.
[0069] The creation of an offset (x), a gap between the natural extension of the pivoting element comprising a substantially rectilinear part and the pivoting axis makes it possible to optimize both the height of the chair (1) in the folded configuration and making it possible to keep the components of the chair (1) parallel 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 the offset.
[0070] This optimization consists of creating an offset value between two and five centimeters, typically three centimeters, which gives a gain in depth of between four and ten centimeters, typically six centimeters, compared to dimensions of the order of forty centimeters.
[0071] It should also be noted that the proposal according to the invention is compatible with any type of backrest, whether it has a minimum height of 15 cm or up to 40 cm, knowing that part of the folding kinematics exploits the fact that it is a mini backrest with a height of 15 centimeters.
[0072] There are many devices for limiting the rotation of elements, for example, flap stays, folding stays or stop joints.
[0073] [Fig.9] illustrates a suitable embodiment of such a device in the form of a rotary joint (AR, ARR) composed of a male part (AM) which fits into a female part (AF).
[0074] The male part (AM) includes an elbow (AM, C) which allows an offset (x) of 3 centimeters to be created.
[0075] The female part has a stop (AF, BU) also at 45° which prevents the angle from exceeding 180°.
[0076] In a variant where the stop is horizontal, then this makes it possible to prevent exceeding 180° plus 45° or 225°.
[0077] These two values make it possible to prevent an angle between the seat (A) and the backrest (D) from exceeding half the value, i.e. between 90° and 112.5°, i.e. relevant values in the context of chairs.
[0078] [Fig. 10] illustrates a suitable embodiment of such a device in the form of a rotary joint (AR, ARV) between two elements.
[0079] 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 a front foot (PV).
[0080] The second element comprises a key (CL) which passes through the cylindrical location intended to receive the physical axis (AX).
[0081] 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 limiting the angle of rotation of the second element.
[0082] Note that the angle limiting devices may be multiple and redundant or not, the angle limiting device being obtained elsewhere,
[0083] 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 rear legs (PR) 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.
[0084] Advantageously, the right and left rear feet (PR) are in the same vertical plane respectively as the right and left uprights (MD) of the backrest frame (D).
[0085] 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 previous rotary joint (AR, ARR) which provides additional guidance in the vertical plane.
[0086] Preferably, the right and left uprights (MD) of the backrest frame are placed furthest towards the inside of the chair (1).
[0087] Thus it is easier to connect the left and right backrest uprights by a backrest without interference with the other elements.
[0088] The same applies to the rear feet (PR) insofar as this allows them to be connected by a crossbar (BT) without interfering with the other elements.
[0089] Preferably, the right front (PV) and left front feet are placed furthest towards the outside of the chair (1).
[0090] This has the effect, on the one hand, of preventing the folding of the front legs (PV) from interfering with the folding of the rear legs when folding and, on the other hand, of possibly allowing a wider seat at the front than at the rear, which is more relevant in terms of ergonomics.
[0091] 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.
[0092] Indeed, the stress on efforts is much greater in the longitudinal direction when, for example, a corpulent user swings on his chair (1) only on the two rear feet (PR) than in the transverse direction.
[0093] It is preferred that the chair (1) in the folded configuration fits into a rectangular parallelepiped which practically 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.
[0094] For a classic height of 80 cm, this represents a height in folded configuration of less than 10 cm.
[0095] 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).
[0096] Indeed, to gain a few more centimetres in depth in the folded configuration, it is also possible for a seat that one would like to extend a few centimetres towards the front to make it foldable, of course at the cost of additional complexity and the need to synchronise this folding with at least that of a pair of legs of the chair, for example through a transverse physical axis securing their rotation.
[0097] The folding chair (1) according to the invention can be folded manually by the user in three independent movements consisting of folding or unfolding the backrest uprights (D) relative to the seat (A), folding or unfolding the front legs (PV) relative to the seat (A) and folding or unfolding the rear legs relative to the seat (A)
[0098] It is however advantageous according to another embodiment that the chair (1) has a folding kinematics combining the three movements, in this case an antiparallelogram kinematics or the like comprising at least three lateral arms (B), a first lateral arm (LM) connecting the front pivot (L) to a pivot (M) positioned on the uprights (MD) of the backrest frame, a second lateral arm (LR) connecting the front pivot (L) to a pivot (R) positioned on the rear legs (PR), a third lateral arm (KV) connecting the rear pivot (K) to a pivot positioned (V) on the front feet,all of these pivots being positioned at a maximum distance (d) from the respective front and rear pivots equal to 2.5 times the value of the offset (x).
[0099] Indeed, antiparallelograms, due to their geometric properties, make the rotations of the elements that form their small side symmetrical, regardless of their dimensions.
[0100] 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 antiparallelogram solution actually applies.
[0101] If 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 different then this is a solution similar to the antiparallelogram solution but effectively with different values.
[0102] Note that in terms of angle limiting devices, a single angle limiting device between the backrest (D) and the rear legs (PR) propagates to the other elements via the side bars (B) which in turn become angle limiting devices.
[0103] On the other hand, their implementation leads to increasing the center distance between the front (L) and rear (K) pivots by an approximate value of the value (z) which corresponds to the height difference along an axis conventionally called z and illustrated in [Fig.7] and [Fig.8], plus the offset (x).
[0104] In [Fig.8], we see that the center distance between the front (L) and rear (K) pivots in the unfolded configuration of [Fig.7] 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 side bars (B) are inclined obliquely at an angle of the order of 5° and that the value of the hypotenuse is very close to the value of the long side, less than 1% with respect to the cosine of 5°.
[0105] To meet 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), i.e. twice the value (x) of the offset.
[0106] In order of magnitude, this corresponds to a value of the distance between the pivots positioned on the elements and the two front (L) and rear (K) pivots at most of the order of 2.5 times.
[0107] In this embodiment of the antiparallelogram folding kinematics, it is advantageous for the side bars (B) to be smaller than the front (PV) and rear (PR) feet which are load-bearing elements.
[0108] The supporting elements are, for example, pivotable relative to physical axes embodying the axes of the front and rear pivots with a diameter of the order of 20 mm, whereas the positioned rotation axes of the side bars (B) have a diameter of the order of 5 mm.
[0109] These side bars (B) allow the folding kinematics to function but are not directly the load-bearing elements such as the front (PV) and rear (PR) feet.
[0110] For example, the load-bearing elements could be solid profiles while the side bars (B) would be hollow profiles.
[0111] It is advantageous if the side bars (B) are made of polycarbonate.
[0112] As for the seat (A), it must be maintained even though the center distance between the front (L) and rear (K) pivots changes value even if it is only by a few centimeters.
[0113] It is advantageous for the seat (A) to be articulated on the front pivot (L) and connected to the rear pivot by a sliding device.
[0114] [Fig.6] illustrates an example of implementation in which two rods (T) are fixed perpendicular to the rear axis which materializes the rear pivot (K) and on the other hand can move at the other end in housings fitted in the seat (A).
[0115] In the embodiment of the antiparallelogram folding kinematics, it is advantageous for the seat (A) to be articulated on at least one of the two pivots (K, L) and that in the unfolded position it becomes a means of locking the chair (1) by blocking the center distance between the two front (L) and rear (K) pivots or of adjusting the inclination of the backrest (D) by allowing the center distance between the two front (L) and rear (K) pivots to be modulated.
[0116] Indeed, if during folding the center distance between the two front (L) and rear (K) pivots increases, on the contrary during unfolding it decreases.
[0117] This value decreases until, for example, the rotating devices of the supporting elements come to a stop, for example at a limit of 120°, unless beforehand the seat prevents the two front (L) and rear (K) pivots from coming together, stopping the simultaneous rotation of the elements of the chair (1).
[0118] Thus the chair (1) can become an additional locking device if it is itself locked or a device for adjusting the angle between the backrest and the seat if its position is adjustable either continuously or by positioning notches.
[0119] It is advantageous for all of these pivots (M, R, V) to be positioned in the unfolded position at a height difference (z) along an axis conventionally called z, relative to the front (L) and rear (K) pivots close to within one or two centimeters of the value of the offset (x).
[0120] Advantageously, this height difference (z) is less than 7 centimeters.
[0121] Advantageously not only the offset values (x) and the height differences (z) along the z axis are close, but they are typically identical to the order of 3 centimeters.
[0122] 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.
[0123] [Fig. 11] illustrates the schematic diagram of the folding chair (1) in both the unfolded and folded positions in the same view.
[0124] 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 feet and twice the offset (x).
[0125] 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 transverse bar (B) is the hypotenuse.
[0126] It is indeed advantageous that all of these pivots (M, R, V) are positioned in the unfolded position at a height difference (z) along an axis conventionally called z, relative to the front (L) and rear (K) pivots close to within one or two centimeters of the value of the offset (x).
[0127] Advantageously, this height difference (z) is less than 7 centimeters.
[0128] In the case where the offset values (x) and the height differences (z) along the z axis are not only close, but identical then in the unfolded position this large side of the rectangle whose crossbar (B) is the hypotenuse has the value of the sum of the center distance (e min) in the folded position and the value of the offset (x).
[0129] 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.
[0130] This increase in the center distance value, typically of the order of 6 centimeters, was compensated by the gain provided by the offset (x) on each side, i.e. twice the value of the offset (x), typically of the order of twice 3 centimeters, i.e. 6 centimeters.
[0131] The size of the folding chair (1) along the x axis, i.e. in depth, is almost identical between the folded configuration and the unfolded configuration as illustrated [Fig.11].
[0132] Note indeed that if the height of the legs is greater than the depth of the seat, then the legs can protrude slightly but the rectangular parallelepiped in which the chair (1) fits in the folded configuration remains minimal. It is conventional for the heights of the front legs (PV) to be a few centimeters greater than the height of the rear legs to give an inclination of the seat of a few degrees.
[0133] Furthermore, the inclination of the side bars (B) typically of the order of 5° relative to the line of the front (L) and rear (K) pivots has not changed because the sine of the angle has remained unchanged between the folded position and the unfolded position.
[0134] The side bars (B) are simply moved along the x axis by a few centimeters, typically 3 centimeters between the folded position and the unfolded position forward or backward as illustrated [Fig. 11].
[0135] It is advantageous as shown [Fig. 12] that the side 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 thicker lines.
[0136] Then the side bars (B) fit not only into the volume of the chair in the folded position but also in the unfolded position.
[0137] In particular the side 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 (A). 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 side 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).
[0138] Even if a single rotary articulation device with angle limitation can be propagated to the entire folding chair (1) via the side bars (B), it remains preferable, in order to limit the stress on these side bars (B), to redundantly retain the physical presence of rotary articulations to directly limit the angles between the seat (A), the backrest uprights (MD), the rear legs (PR) and the front legs (PV).
[0139] Note that in the case where the crossbar (LM) acts directly as a seat support (A), a rotary joint (AR) with angle limitation can be directly implemented on the pivot (M) of the backrest upright (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 corpulent person even when balancing on the rear legs (PR) of the folding chair (1).
[0140] To increase the strength of the folding chair (1), it remains possible to connect the two rear legs (PR) by a crossbar (BT) and to connect the two left and right side bars (B, LR) by a cross which is equivalent in terms of kinematics but which reinforces the structure of the folding chair (1).
[0141] According to other embodiments, the two rear feet are secured either by a physical axis connecting them or by a crossbar connecting them.
[0142] According to other embodiments, the two front legs are secured either by a physical axis connecting them or by a transverse bar connecting them.
[0143] Note that if the front legs (PV) are connected by a crossbar, it is advantageous for the front legs (PV) to be a few centimeters longer than the rear legs and for the crossbar 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 crossbar (BT) connecting them when it exists, when folding or unfolding the folding chair (1).
[0144] The consequence of this difference in length between the front legs (PV) and the rear legs (PR), the front legs (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.
[0145] Then it is possible to simplify the embodiment with reference to that of [Fig.5] and [Fig.6] where six side bars (B) are present.
[0146] Indeed, already according to a previous paragraph, the seat frame can act as a side bar (B, LM) connecting the backrest uprights (MD) to the front axis (L) and vice versa, and then two side bars connecting the backrest uprights (MD) to the front axis (L) are no longer visually identifiable.
[0147] Preferably, then the folding chair (1) comprises a single side bar (B, LM), connecting the backrest uprights (MD) to the front axis (L) in the form of a seat frame (A).
[0148] Furthermore, when the rear legs (PR) are secured, then the pair of side bars (B, RL) connecting the rear legs (PR) to the front axis (L) become redundant with each other and only one of the two side bars (B, RL) connecting the rear legs (PR) to the front axis (L) is sufficient to accompany the folding-unfolding of the chair (1).
[0149] Preferably, when the rear legs (PR) are secured then the folding chair (1) comprises a single side bar (B, RL) connecting the rear legs (PR) to the front axis (L).
[0150] Similarly, when the front legs (PV) are secured, then the pair of side bars (B, KV) connecting the front legs (PV) to the rear axis (K) become redundant with each other and only one of the two side bars (B, KV) connecting the front legs (PV) to the rear axis (K) is sufficient to accompany the folding-unfolding of the chair (1).
[0151] Preferably, when the front legs (PR) are secured then the chair (1) comprises a single side bar (B, KV) connecting the front legs (PV) to the rear axis (K).
[0152] Preferably, when there coexist both a single side bar (B, RL) connecting the rear legs (PR) to the front axis (L) and a single side bar (B, KV) connecting the front legs (PV) to the rear axis (K), it is advantageous for them to be on two different sides.
[0153] As illustrated [Fig.12], it is advantageous for at least one side bar (B), including when it is the seat frame when it acts as a side bar, to have an offset (x) relative to its pivot equal to that of the offsets (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots.
[0154] When all three propositions are applied simultaneously, then the number of visually identifiable sidebars (B) decreases from six with reference to [Fig.5] and [Fig.6], to only two as illustrated in [Fig. 13] and [Fig. 14].
[0155] 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.
[0156] Whatever the folding method chosen, it is preferable that at least one additional locking device secures the unfolded position.
[0157] It is advantageous for the chair (1) to have a gripping means at the top of the backrest (D).
[0158] This may be a simple location for the passage of fingers provided in the top of the backrest (D).
[0159] It can also be a handle similar to that of a briefcase.
[0160] In terms of use, it is advantageous that the unfolding of the chair (1) is obtained without the chair (1) touching the ground, the backrest in a vertical position under the effect of its own weight.
[0161] It is possible to hold the folding chair (1) with one hand by the top of the backrest (D) and to accompany the unfolding by holding the front end of the seat (A) with the other hand.
[0162] For folding, it is also possible without the chair (1) touching the ground, to hold the backrest (D) vertically with one hand and with the other to fold the seat (A) against the backrest (D). Industrial application
[0163] In terms of industrial application, the invention applies to folding chairs.
[0164] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to provide any variation in accordance with its spirit for a range of products in different environments or different universes of use.
Claims
Claims
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 rear pivot (K), that the front legs (PV) are articulated by a front pivot (L) and that the offsets (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots are between two and five centimeters, that in the folded configuration the ends of the rear legs (PR) are placed opposite the front part of the seat (A),the ends of the front legs (PV) are placed opposite the rear part of the seat (A) and the upper part of the backrest (D) is placed opposite the front part of the seat (A) and also by the fact that it has a folding kinematics comprising at least three lateral arms (B), a first lateral arm (LM) connecting the front pivot (L) to a pivot (M) positioned on the uprights (MD) of the backrest frame, a second lateral arm (LR) connecting the front pivot (L) to a pivot (R) positioned on the rear legs (PR), a third lateral arm (KV) connecting the rear pivot (K) to a pivot positioned (V) on the front legs, all of these pivots being positioned at a maximum distance (d) from the respective front and rear pivots equal to 2.5 times the value of the offset (x).,
2. Folding chair (1) according to claim 1 characterized in that the backrest (D) and the rear legs (PR) are articulated by a rear pivot (K) with an angle limiting device.
3. Foldable chair (1) according to any one of claims 1 to 2 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° relative to the seat (A).
4. Foldable chair (1) according to any one of claims 1 to 3 characterized in that the rear legs (PR) are articulated by a pivot with an angle limiting device with a maximum angle of at most 120° relative to the seat (A).
5. Foldable chair (1) according to any one of claims 1 to 4 characterized in that the front legs (PV) are articulated by a front pivot (L) with an angle limiting device with an angle maximum of 120° relative to the seat (A).
6. Foldable chair (1) according to any one of claims 1 to 5 characterized in that the architecture of the chair, the retained kinematics and the creation of an offset (x) for all of the front legs (PV), the rear legs (PR) and the backrest uprights (MD), relative to their respective pivot, front pivot (K) and rear pivot (L) leads to a means of reducing the depth of the chair (1) in the folded configuration by twice the value of the offset (x) compared to a version without offset.
7. Foldable chair (1) according to any one of claims 1 to 6 characterized in that the chair (1) in the folded configuration fits into a rectangular parallelepiped which practically 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.
8. Foldable chair (1) according to any one of claims 1 to 7, characterized in that all of these pivots (M, R, V) are positioned in the unfolded position at a height difference (z) along an axis conventionally called z, relative to the front (L) and rear (K) pivots equal to the offset (x).
9. Folding chair (1) according to any one of claims 1 to 8 characterized in that the folding chair (1) comprises a single side bar (B, LM), connecting the backrest uprights (MD) to the front axis (L) in the form of a seat frame (A).
10. Folding chair (1) according to any one of claims 1 to 9, characterized in that the rear legs (PR) are secured and the folding chair (1) comprises a single side bar (B, LR) connecting the rear legs (PR) to the front axis (L).
11. Folding chair (1) according to any one of claims 1 to 10, characterized in that the front legs (PR) are secured and the folding chair (1) comprises a single side bar (B, KV) connecting the front legs (PV) to the rear axis (K).
12. Foldable chair (1) according to any one of claims 1 to 11 characterized in that at least one side bar (B) including when it is the seat frame when it acts as a side bar, has an offset (x) relative to its pivot equal to that of the offsets (x) of the backrest uprights (MD), the rear legs (PR) and the front legs (PV) relative to their respective pivots.
13. Use of the folding chair (1) according to any one of claims 1 to 12, characterized in that the unfolding of the chair (1) is obtained in one movement without the chair (1) touching the ground, the backrest in a vertical position under the effect of its own weight, due to kinematics combining the three movements consisting of folding or unfolding the backrest uprights (D) relative to the seat (A), folding or unfolding the front legs (PV) relative to the seat (A) and folding or unfolding the rear legs (PR) relative to the seat (A).