Chair with a tensioning system for support surface and / or upholstery control

Abstract

A chair (1 ) with a tensioning system for the support surface and / or upholstery control is provided, comprising a support surface (2) adapted to support a user seated on the chair (1) and including at least a membrane (20) woven in a knitted fabric, defining a first face (20a) intended to come into contact with the user, a second face (20b) opposite to the first face (20a), and being perimetrically delimited by an edging (21) extending along the contour of the membrane (20), a first filament (22) embedded at least partially within the membrane (20) between the faces (20a, 20b); a frame (3) configured to support the membrane (20) at least at part of the edging (21), thereby maintaining the support surface (2) in suspension with respect to the ground; wherein the first filament (22) develops along its own development trajectory (22a), mostly inside the membrane (20), woven into the membrane (20) adjacent to one of the faces (20a, 20b), and / or mostly outside the membrane (20), between opposite parts of the frame (3) or part of opposite edges of the edging (21 ), in such a way as to connect parts or edges, forming a support (5) respectively integrated with the first face (20b) or facing the membrane (20), on which the second face (20b) can rest when a user is leaning on the membrane (20); wherein the chair (1) further comprises tensioning means (4) integral to the frame (3) or to the membrane (20) and configured to directly or indirectly tension the first filament (22), so as to locally stiffen the membrane (20) and / or the support (5) in proportion to the applied tension.

Description

[0001] DESCRI PTION

[0002] CHAIR WITH A TENSIONING SYSTEM FOR SUPPORT SURFACE AND / OR UPHOLSTERY CONTROL

[0003] The present invention relates to a chair with a tensioning system for a support surface and / or upholstery control of the type specified in the preamble of the first claim.

[0004] In particular, the present invention relates to a chair whose support surface can be tensioned to determine greater or lesser yieldingness of the support surface upon contact by a user and which, if provided with padding, also allows control over the volume conferred to the padding, thereby managing the overall comfort of the seat. As is well known, in the current state of the art, many different types of chairs have been developed, such as armchairs, reclining chairs, slings, sofas, and others, depending on the target market for which the chairs are intended.

[0005] Historically, chairs derive from simpler benches. The latter are, in fact, provided with a simple support surface defining the seat, structurally constrained to at least two support pillars designed to allow an elevated seat above the floor.

[0006] Currently, chairs are typically designed to support at least one user, preferably a single user, on a surface called a seat. Most chairs also feature additional support elements, such as a backrest, and may include armrests and supports for resting the upper and lower limbs, respectively.

[0007] Among the most common types of chairs, it is possible to identify the so-called deck chair, consisting of a foldable frame whose backrest is reclinable at variable angles and on which the user can assume a seated or reclined position at will; the curule chair, also developed as a faldstool, with a substantially crossed or X-shaped structure, sometimes foldable to support the seat; the Tripolina chair, entirely foldable and historically used in battle camps; the monobloc chair, generally made of polymeric material and used for outdoor environments, primarily in the catering sector; the rocking chair, comprising two curved supports allowing the characteristic rocking movement of the chair in question; and the cantilever chair, commonly used and featuring only two bent uprights at the floor level and the seat level, connected horizontally by a continuous tube.

[0008] To the aforementioned examples, numerous other different types and structures of chairs have been added, designed to meet aesthetic requirements, such as market demand for a specific shape, or technical needs, arising, for example, from the necessity to optimize the production process while maintaining high product quality standards.

[0009] One of the most important aspects regarding chairs, in general, is the rigidity or yieldingness of the chair when in contact with the user and, more generally, the comfort that these characteristics can provide to the user.

[0010] To better control this aspect, especially recently, seating fabrics incorporating specific design solutions have been developed.

[0011] Specifically, the control of the yielding ness of the support surface has been achieved in recent years through the use of heat-shrinkable yams.

[0012] Heat-shrinkable yams are essentially composite yams capable of permanently shrinking when heated; this property is similar to that of materials commonly used for heat-shrink tubing.

[0013] In particular, unlike the tubing technique, where the tubular element undergoes constrictions, heat-shrinkable yarns are configured to reduce their length when exposed to a heat source.

[0014] The heat-shrinkable yam is particularly useful when introduced into the weave of a fabric, whether it is a woven fabric consisting of warp and weft or a knitted fabric. The ability of the yam to shrink allows localized tensioning of the fabric upon command, thereby enabling control over the mechanical properties of the fabric itself in the area where the yam is woven.

[0015] More specifically, the heat-shrinkable yam generally consists of a first filament, or core, and a second heat-shrinkable filament wrapped around the first filament. The entire composite may also be woven into the warp or in the direction of the weft.

[0016] This heat-shrinkable yam has recently been employed for the production of knitted fabrics, where the yam is uniformly woven into the knit to create seats or backrests of chairs that can be tensioned through the application of heat, for example, in an oven or with hot steam.

[0017] An example of an implementation of such a fabric is marketed under the name Camira knit™.

[0018] The known technique described has several significant drawbacks.

[0019] In particular, technical solutions involving the use of heat-shrinkable yams are useful for controlling the yieldingness of the support surface during the chair assembly phase but do not allow for tension control at later stages.

[0020] Above all, the tensioning control is exclusively achieved through the application of heat and therefore, for the uniform tensioning of the yarns, and generally of the fabric, it is always necessary to have access to adequate heat sources, which are certainly not always available.

[0021] Moreover, the use of fully woven yams in fabric or knit, especially when padding is present, can introduce unwanted deformations that may alter, for example, the functioning of the seat, reducing its overall comfort when tensioning of the support surface is desired.

[0022] Additionally, controlling the degree of padding is not feasible with currently known technologies.

[0023] Therefore, the efficient use of heat-shrinkable yarns is highly challenging, as it requires a correct balance between functionality and comfort in the chair.

[0024] In this context, the technical task underlying the present invention is to design a chair with a tensioning system for the support surface and / or upholstery control capable of substantially overcoming at least part of the aforementioned drawbacks. Within this technical task, an important object of the invention is to provide a chair with a tensioning system for the support surface and / or upholstery control that can be actuated even when the chair is fully assembled and without the need for specific measures, such as heat sources.

[0025] Another important object of the invention is to create a chair with a tensioning system for the support surface and / or upholstery control that allows maintaining control over the yieldingness of the surface without reducing the comfort of the chair.

[0026] Finally, an object of the invention is to develop a chair with a tensioning system for the support surface and / or upholstery control that enables effective control over the volume of the upholstery in the support surface.

[0027] The technical task and the specified objects are achieved by a chair with a tensioning system for the support surface and / or upholstery control as claimed in the appended claim 1 .

[0028] Preferred technical solutions are highlighted in the dependent claims.

[0029] The features and advantages of the invention are clarified below throughout the detailed description of preferred embodiments of the invention, with reference to the appended drawings, wherein: Fig. 1 shows a detail of a first embodiment of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the first filament is mostly woven into the membrane, and a second filament wrapped around the slider and the padding is also shown;

[0030] Fig. 2a illustrates a schematic cross-sectional view of the support surface of the chair of Fig. 1 ;

[0031] Fig. 2b is a schematic cross-sectional view of the support surface of Fig. 2a, wherein the second filament has undergone shrinkage due to heat application, and the padding is thicker and more compacted;

[0032] Fig. 3 represents an alternative embodiment of the embodiments shown in Figs. 1 -3, wherein both the first filament and the second filament protrude from the membrane moving away from the edging;

[0033] Fig. 4 shows a detail of a second embodiment, which may be an alternative to or coexist with the first, of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the first filament is mostly external to the membrane, passes alternately through the slots of the opposite edging flaps, and, together with them, forms the support on which the second face of the membrane can rest;

[0034] Fig. 5a illustrates a schematic cross-sectional view of the support surface and frame of the chair of Fig. 4 while the chair is unloaded;

[0035] Fig. 5b is a schematic cross-sectional view of the support surface and frame of Fig. 5a, wherein the membrane, particularly the second face, is pushed against the rigid support by a seated user;

[0036] Fig. 6a represents two schematic cross-sectional views of the support surface and frame of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the second filament is constrained to the first face, opposite the second face, and wherein the tensioning mechanism is highlighted starting from the first filament in a relaxed state (below) and then in a tensioned state (above), resulting in an outward protrusion of the padding toward the user’s seating area; and

[0037] Fig. 6b shows two schematic cross-sectional views of the support surface and frame of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the second filament is constrained, along with the first filament, to the second face, and wherein the tensioning mechanism is highlighted starting from the first filament in a relaxed state (below) and then in a tensioned state (above), primarily resulting in the stiffening of the second face behind the padding relative to the user’s seating area;

[0038] Fig. 7a illustrates a schematic cross-sectional view of a third embodiment of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the first filament is mostly inside the membrane and is connected to the tensioning means, alternately passing between hooks on opposite parts of the frame, and is in an unloaded state;

[0039] Fig. 7b is a schematic cross-sectional view of the support surface and frame of Fig. 7a, wherein the first filament is tensioned, and consequently, so is the membrane, particularly the second face;

[0040] Fig. 8 represents a schematic rear view, i.e. , from the perspective of the second face, of a third embodiment of a chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein the first filament is mostly inside the membrane and is connected to the tensioning means via a cable, alternately passing between hooks on opposite parts of the frame, and is indirectly tensioned by the tensioning means proportionally to the tension applied to the cable by the tensioning means;

[0041] Fig. 9a shows a schematic perspective view of an additional embodiment of the chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein there are two cables inserted into the slots on the respective sides of the membrane and connected to opposite ends of a plurality of first filaments and with the portion of the membrane at the edging wrapping around part of the frame;

[0042] Fig. 9b illustrates a schematic cross-sectional view of the support surface of Fig. 9a;

[0043] Fig. 10a is a schematic perspective view of another embodiment of the chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein there are two cables inserted into the slots on the respective sides of the membrane and connected to opposite ends of a plurality of first filaments and with the portion of the membrane at the edging not wrapping around part of the frame but instead being adjacent to the second face; Fig. 10b represents a schematic cross-sectional view of the support surface of Fig. 10a;

[0044] Fig. 11a shows a schematic perspective view of another embodiment of the chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein there are two cables inserted into the slots on the respective sides of the membrane and connected to opposite ends of a plurality of first filaments through respective bars;

[0045] Fig. 11 b illustrates a schematic cross-sectional view of the support surface of Fig. 11a;

[0046] Fig. 12a is a schematic cross-sectional view of another embodiment of the chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein there are first filaments emerging from the membrane in a central position, distal with respect to the edging, and wherein the first filaments are not tensioned;

[0047] Fig. 12b represents a schematic cross-sectional view of the chair of Fig. 12a, wherein the first filaments are tensioned; and

[0048] Fig. 12c represents a schematic cross-sectional view of another embodiment of the chair with a tensioning system for the support surface and / or upholstery control according to the invention, wherein there are two cables inserted into the slots on the respective sides of the membrane and connected to opposite ends of a plurality of first filaments emerging from the membrane in a central position, distal with respect to the edging.

[0049] In this document, the measurements, values, shapes, and geometric references (such as perpendicularity and parallelism), when associated with words like "about" or other similar terms such as "approximately" or "substantially”, should be understood as allowing for measurement errors or inaccuracies due to production and / or manufacturing errors and, especially, minor deviations from the value, size, shape, or geometric reference with which they are associated . For example, such terms, when associated with a value, preferably indicate a deviation not exceeding 10% of the value itself.

[0050] Moreover, terms such as "first", "second”, "upper”, "lower”, "main”, and "secondary" when used do not necessarily identify an order, priority of relation, or relative position but may simply be used to more clearly distinguish different components from one another.

[0051] Unless otherwise specified, as highlighted by the following discussions it is considered that terms such as "processing", "computing", "determination", "computation", or similar refer to actions and / or processes of a computer or similar electronic computation device that manipulates and / or transforms data represented as physical quantities, such as electronic magnitudes of records of a computing system and / or memories, into other data similarly represented as physical quantities within computer systems, records, or other information storage, transmission, or display devices.

[0052] Unless otherwise indicated, the measurements and data reported in this text are to be considered as performed in International Standard Atmosphere ICAO (ISO 2533: 1975).

[0053] With reference to the Figures, the chair with a tensioning system for the support surface and / or upholstery control according to the invention is globally denoted by the number 1.

[0054] The term "chair" preferably refers to a seat. However, the chair may be any device that allows a user to be seated and that, depending on the configuration, can also refer to devices other than a standard chair, such as an armchair or a loveseat.

[0055] For example, the chair may also be a vehicle seat, such as for an automobile, or for other means of transport, such as trains or aircraft.

[0056] Furthermore, the chair is not restricted to a specific use or design but can be adapted, depending on convenience, for various purposes, including home, office, or environments other than those mentioned, such as restaurants, hotels, conference rooms, study halls, or other settings.

[0057] In particular, the modular chair 1 preferably comprises at least one support surface 2

[0058] The support surface 2 is preferably designed to allow a user to rest upon it. Therefore, it is essentially the part of the chair 1 intended to accommodate at least a portion of the user's body. Accordingly, the support surface 2 is adapted to support a user seated on the chair 1 .

[0059] Preferably, the support surface 2 defines the backrest of the chair 1. More specifically, the support surface 2 preferably corresponds to the lumbar region of the backrest. In this regard, the support surface preferably comprises a membrane 20.

[0060] The membrane 20 is essentially a thin element that extends primarily along two main directions. Additionally, the membrane 20, by itself, is a yielding or otherwise deformable element.

[0061] Since it is an element that mainly extends along two dimensions, the membrane 20 preferably defines a first face 20a and a second face 20b.

[0062] The first face 20a is preferably designed to be in contact with the user. Therefore, the first face 20a is the portion of the membrane 20 that remains exposed towards the interior of the chair 1 , i.e., the side considered as facing the user in use. It is intended to accommodate and support the legs of a user if the membrane 20 defines the seat, or the back if the membrane 20 defines the backrest, or, naturally, both.

[0063] The second face 20b is opposite to the first face 20a. Thus, the second face 20b is the portion of the membrane 20 that remains exposed towards the exterior of the chair 1.

[0064] Additionally, the membrane 20 is perimetrically delimited by an edging 21. The edging 21 extends substantially along the contour of the membrane 20. Consequently, the edging 21 defines the edge regions, specifically the perimeter, of the membrane 20, i.e., the areas through which the membrane 20 preferably interacts with other parts of the chair 1 , as will be better explained later. In any case, preferably, the support surface 2 also includes a first filament 22.

[0065] The first filament 22 is at least partially embedded within the membrane 20, between the faces 20a, 20b. The term "embedded" means that the first filament 22 is generally positioned between the faces 20a, 20b and may, for this purpose, be woven into the membrane 20 or inserted into slots formed between the faces 20a, 20b.

[0066] Furthermore, the faces 20a, 20b extend throughout the entire area of the membrane 20, i.e., along its two main directions, and, therefore, they also form the opposite faces 20a, 20b of the edging 21 .

[0067] Thus, the first filament 22 may be embedded in the membrane 20 at any region, for example the central portion of the membrane 20 defining the support surface 2, or the edge region of the support surface 2, defined by the edging 21 of the membrane 20.

[0068] Preferably, the first filament 22 extends along its own development trajectory 22a. The development trajectory 22a essentially defines the orientation of the first filament 22.

[0069] Specifically, the first filament 22 extends along the development trajectory 22a in at least two possible ways, which may be alternative or coexisting.

[0070] Indeed, the first filament 22 may extend mostly within the membrane 20 or outside it. The term "mostly" means that the majority, preferably in length, i.e., along the development trajectory 22a, of the first filament 22 can be either inside or outside the membrane 20.

[0071] In detail, the first filament 22 may be primarily embedded within the membrane 20, being woven into it. In this case, preferably, the first filament 22 develops or extends adjacent to one of the faces 20a, 20b. Even more specifically, the first filament 22 preferably extends adjacent to the second face 20b, meaning that it is not positioned near the contact area with the user. In this case, the first filament 22 may then exit the membrane at a lateral portion of the membrane 20, even if spaced from the edging 21 , as in the embodiments shown in Figs. 1 -3, or alternatively, may exit the membrane 20 at a central position, i.e., distal with respect to the edging 21 , as in the embodiments of Figs. 12a-12c.

[0072] If the first filament 22 is embedded in the membrane 20 but extends mostly outside of it, the first filament 22 develops between part of opposite edges of the edging 21 . Consequently, the first filament 22 can connect opposite ends of the membrane 20. Additionally, in this case, the configuration of the first filament 22 is such that the first filament 22 connects the edges and forms a support 5.

[0073] The support 5 is essentially an element extending along a surface facing the membrane 20. The support 5 is therefore formed by at least part of the edgings 21 and the first filament 22, which connects the edges of the edgings 21 .

[0074] Thus, the support 5 is a structure on which one face 20a, 20b, preferably the second face 20b, of the membrane 20 can rest when a user is leaning on the membrane 20. This means that, for example, if the membrane 20 forms the backrest of the chair 1 , and the user leans its back against the membrane 20, the latter may deform until it touches the support 5. In this embodiment, the support 5 acts as a reinforcement for the membrane 20.

[0075] Naturally, the support surface 2 as a whole is held up by a support structure.

[0076] Thus, the chair 1 also comprises a frame 3. The frame 3 is essentially the supporting structure of the support surface 2. Preferably, the frame 3 is configured to support the membrane 20 at at least part of the edging 21 . In this way, the frame 3 keeps the support surface 2 suspended above a ground surface.

[0077] To ensure the connection between the frame 3 and the membrane 20, several configurations can be adopted.

[0078] For example, the membrane 20 may comprise at least one slider 23. The slider 23 is essentially an elongated-shape element. In this regard, it may be a kind of tubular element or another structure that creates a localized thickening of the membrane 20. In detail, preferably, the slider 23 is trapped between the faces 20b, 20a at the edging 21 . Therefore, the slider 23 preferably extends at least parallel to the contour of the membrane 20. Thus, the frame 3 may define at least one guide 30.

[0079] If present, the guide 30 is preferably hollow and it is preferably continuous. In general, the guide 30 is configured to trap at least part of the slider 23 to mutually bind the membrane 20 and the frame 3.

[0080] An example of a complete structure of a chair that includes a support surface 2 and a frame 3 with coupling systems as just described is found in patent application WO- A-2020115627, which is incorporated herein by reference, from page 6, line 21 to page 22, line 21 , and illustrated in Figures 1 -2, 6, 8, and 9a-9b.

[0081] The presence of the frame 3 also allows for the development of additional chair embodiments that facilitate the tensioning of the first filament 22 and, therefore, the stiffening of at least one face 20a, 20b of the membrane 20.

[0082] Indeed, as shown, for example, in Figures 7a-8, the frame 3 may include hooks 31. The hooks 31 are essentially portions of the frame 3 or elements integral with the frame, which define holes or slots through which filaments or cables can pass.

[0083] Moreover, in detail, preferably, the hooks 31 are distributed on opposite parts of the frame 3. Preferably, the hooks 31 are arranged on the frame 3 parallel to the guide 30. Thus, when the first filament 22 is mostly outside the membrane 20, it may be threaded through the hooks 31 , for example, alternately between hooks 31 , meaning between hooks 31 near distinct sides, such as opposite sides of the membrane 20, so that the support 5 is at least partially integrated into the second face 20b, as shown in Figures 7a-7b.

[0084] Additionally, the support 5 externally defines a corset-like structure. If, on the other hand, the first filament 22 is mostly within the membrane 20, in an embodiment such as the one shown in Figure 8, the chair 1 may comprise a plurality of such first filaments 22. Thus, the chair 1 may further include a cable 50.

[0085] If the cable 50 is present, it preferably connects adjacent ends of the first filaments 22. Additionally, the cable 50 may be placed between the hooks 31 and the first filaments 22, preferably passing alternately between the hooks 31 and the end groups, thereby forming, together with the first filament 22, the support 5. The support 5 thus formed is at least partially integrated into the second face 20b. Therefore, the cable 50 defines a corset-like structure such that the tensioning of the cable 50 can lead to the tensioning of the first filaments 22.

[0086] The chair 1 according to the invention further includes important features. Advantageously, the chair 1 comprises tensioning means 4.

[0087] The tensioning means 4 are preferably integral with the frame 3 or the membrane 20. Moreover, the tensioning means 4 are configured to apply tension along the development trajectory 22a of the first filament 22, either directly or indirectly, for example, by tensioning the cable 50, which, in turn, tensions the first filament 22. In this way, the tensioning means 4 are capable of locally stiffening the membrane 20, proportionally to the applied tension, preferably at the second face 20b, and / or the support 5, depending on the configuration of the first filament 22. Naturally, the stiffening occurs due to the tension applied by the tensioning means 4 to the first filament 22. Therefore, the tensioning means 4 and the first filament 22 together form the tensioning system for the support surface 2.

[0088] Naturally, if the cable 50 is present, it may be configured to connect the ends of the first filaments 22 to the tensioning means 4. Thus, the tensioning means 4 may not be directly connected to the first filaments 22, but instead may allow direct tensioning of the cable 50, which, in turn, transfers that tension to one or more first filaments 22, stretching them and thereby enabling the tensioning means 4 to indirectly tension the first filaments 22, as shown in Fig. 8.

[0089] In a preferred embodiment, the tensioning means 4 may include at least one tensioner 40.

[0090] The tensioner 40 is preferably a spool-type tensioner, similar to those found in some models of ski boots or running shoes. Thus, it defines a rotation axis around which the first filament 22 can be rotated on command and subsequently wound or unwound around the spool, thereby adjusting its tension along the trajectory 22a. In the embodiment where the first filament 22 is mostly embedded in the membrane

[0091] 20, the tensioner 40 is preferably integral with the frame 3. Conversely, in the embodiment where the first filament 22 is mostly external to the membrane 20, the tensioner 40 is preferably integral with the membrane 20, particularly at the edging

[0092] 21 . It follows that, since the membrane 20 and the frame 3 are coupled, the tensioner 40 is essentially integral with both.

[0093] More specifically, the first filament 22 may be anchored at a first end to a tensioner 40. The first filament 22 may then be anchored at a second end, opposite to the first end, to either another tensioner 40 or a fixed point on the frame 3 or the membrane 20. If configured in this manner, therefore the first filament 22 can be tensioned either between the tensioners 40 or between a tensioner 40 and a part of the frame 3 or the membrane 20, preferably distinct from the tensioner 40, when the first filament 22 is rotated around the rotation axis of a tensioner 40, or even of both.

[0094] As previously mentioned, in the embodiment shown in Fig. 8, the cable 50 can replace the configurations of the first filament 22 as just described in relation to the tensioner 40. Therefore, the first filament 22 may be connected to the cable 50 and become tensioned when the tensioner 40 or multiple tensioners 40 apply tension to the cable 50.

[0095] Among the various possible configurations, some are particularly significant.

[0096] For example, in addition to what has been described, the membrane 20 may comprise at least one padding 6.

[0097] If present, the padding 6 is positioned between the faces 20a, 20b of the membrane 20. Thus, the membrane 20 may be thickened by the padding 6. Naturally, the membrane 20 may include a plurality of paddings 6, which are mutually distinct and separate from one another.

[0098] Furthermore, the padding 6 may be an only elastically deformable padding or may also have additional characteristics. For instance, the padding 6 may comprise heat- shrinkable material. In this case, therefore the application of heat may allow for localized shrinkage of the padding 6, as illustrated in Figs. 2a-2b, which consequently affects the membrane 20 as a whole and may lead to swelling of the membrane 20 itself.

[0099] Regardless of whether the padding 6 is heat-shrinkable, it can still be controlled, at least in terms of swelling, through the tensioning system. Thus, in this situation, the tensioning system, i.e., the tensioning means 4 and the first filament 22, can contribute, by tensioning the first filament 22, to induce localized reductions in the dimensions of the membrane 20, which result in compression of the padding 6 and, consequently, its swelling.

[0100] More specifically, a reduction in the dimensions of one or both faces 20a, 20b along the development trajectory 22a may lead to an increase in the thickness of the padding, transversely to the development trajectory 22a, thereby increasing the distance between the faces 20a, 20b.

[0101] Thus, the tensioning system allows for control over the padding 6.

[0102] To enhance the tensioning effects or to achieve more precise control over the overall behavior of the membrane 20, various technical solutions can be implemented.

[0103] For example, in the embodiment where the first filament 22 is mostly inside the membrane 20, the first filament 22 may protrude from the membrane 20 transversely to one of the faces 20a, 20b, preferably from the second face 20b, away from the edging 21 when the first filament 22 is woven into said membrane 20. It may also exit away from the edging 21 , but in a lateral position relative to the membrane 20, or also away from the edging 21 but in a distal position, particularly at the center of the membrane 20.

[0104] This embodiment enables the stiffening of, for example, the second face 20b, while keeping the padding 6 free and avoiding dimensional reductions on the second face 20b along the development trajectory 22a that could alter the behavior or thickness of the padding 6. In this case, therefore the padding 6 remains essentially floating over the stiffening effect provided by the tensioning means, particularly the first filament 22.

[0105] Thus, the first filament 22 may be woven in such a way that it remains substantially free with respect to the membrane 20 or alternatively, the first filament 22 may be integrally bound to one of the faces 20a, 20b, inside the membrane 20, along the development trajectory 22a.

[0106] In particular, preferably, the first filament 22 in this case may be bound to the second face 20b, therefore to achieve this attachment, the first filament 22 is preferably hooked with a fisherman’s rib stich, or with a loop within the cavity, at the face 20a, 20b, or it may be wound with a loop around one or more filaments of the membrane 20, particularly those forming the knitted fabric structure. The first filament 22 can, of course, be made of any material. However, particularly when anchored to the second face 20b and if made of heat-shrinkable material, the first filament 22 may also induce dimensional reductions in the second face 20b when exposed to a heat source, leading to an increase in the overall thickness of the padding 6.

[0107] Furthermore, the tensioning means 4 can assist in regulating this thickness.

[0108] As an alternative or in coexistence with what has just been described, and as already mentioned, the first filament 22 may develop mostly outside the membrane 20 to form the support 5. Preferably, the support 5 is formed by a continuous first filament 22 that extends from one side to the other, for example, from left to right, across the membrane 20 in a continuous manner.

[0109] In this case, preferably, the first filament 22 enters and exits the membrane 20 transversely to the edging 21 . Additionally, the first filament 22 preferably enters and exits alternately between the edges of the edging 21 , so that the support 5 is defined by a corset-like structure. The corset-like structure is itself well known and is comparable to the lace-up fastening system of shoes, where laces enter and exit opposite lateral edges of the shoe to form the lacing system.

[0110] More specifically, in this embodiment, at least two opposite edges of the edging 21 include a plurality of slots 21a. The slots 21a may be formed essentially by holes defined between the faces 20a, 20b of the membrane 20. More preferably, the slots 21a may be formed as tunnels created by sleeves between the faces 20a, 20b at the edging 21 .

[0111] If a slider 23 is present, the slots 21a preferably develop parallel to the slider 23, positioned further outward on the membrane 20 with respect to the slider 23. In other words, the slots 21a may surround the slider 23. Thus, the second filament 22 is alternately threaded between the slots 21 a on the edges, thereby forming the support 5 with a corset-like structure. In this case, then the membrane 20 can be attached to the frame 3 via the slider 23, which is trapped in the guide 30, while simultaneously forming a support 5, positioned behind the membrane 20, which can be stiffened using the tensioning system.

[0112] The slots 21a may also be used in combination with the cable 50 to create other embodiments, as shown in Figs. 9a-11 b.

[0113] In this case, a cable 50 is preferably connected at adjacent ends of the first filaments 22. Additionally, the cable 50 is preferably threaded through a row of slots 21a positioned along the same side of the membrane 20. Preferably, in this case, the support 5 is formed by two cables 50, each positioned separately on opposite sides of the membrane 20, at the edges, and both connected to opposite ends of the same first filaments 22.

[0114] However, the first filaments 22 may exit the membrane 20 at a central position, i.e. , distal from the edging 21 , and as a result, the two cables 50 may develop in front of a central portion of the membrane 20, as illustrated in Figs. 12a-12c.

[0115] Then, the support 5 thus formed is at least partially integrated into the second face 20b. Furthermore, the cables 50 serve the purpose of tensioning the first filaments 22 when they themselves are tensioned.

[0116] Therefore, preferably, the cable 50 is operatively connected to the tensioning means 4, which allow for the direct tensioning of the cable 50 that, in turn, transfers the tension to one or more first filaments 22, stretching them and thereby allowing the tensioning means 4 to indirectly tension the first filaments 22, as shown in Figs. 11 a- 12c.

[0117] Additionally, the support 5 may also include one or more bars 51.

[0118] If present, one or more bars 51 extend transversely to the development trajectory 22a, preferably parallel to the edges 21. Thus, the bar 51 can be configured to connect a cable 50 to one end of one or more first filaments 22.

[0119] The support surface 2 may also include additional features.

[0120] For example, the support surface 2 may also comprise a second filament 24.

[0121] If present, the second filament 24 may be configured similarly to the first filament 22. For instance, the second filament 24 may be woven into the membrane 20.

[0122] Furthermore, in terms of material, the second filament 24 preferably includes at least a first yam.

[0123] The first yam includes elastic material.

[0124] Additionally, the second filament 24 preferably also includes a second yam.

[0125] The second yam is wrapped, for example, in a Z or S pattern around the first yam at a predetermined pitch.

[0126] The second yam is made of heat-shrinkable material, which, when exposed to a heat source capable of shrinking the second yam, defines a second maximum plastic linear expansion, preferably a contraction. More specifically, advantageously, the first yam is pre-tensioned, therefore preferably in traction, and defines a first elastic linear expansion, which is stably maintained at least until the second yam is exposed to the heat source and subsequently shrinks.

[0127] Additionally, preferably, the first elastic linear expansion corresponds to the maximum elastic linear expansion that can be applied to the first yam in the absence of the heat source.

[0128] Moreover, the second yam may be configured so that the second maximum plastic expansion imposes on the first yam a length variation equivalent to the first elastic linear expansion when the second filament 24 is subjected to said heat source.

[0129] These characteristics allow for the membrane 20 to exhibit a behaviour influenced also by the second filament 24.

[0130] In fact, the tension and expansion of the second filament 24 can be controlled simply by exposing the second filament 24, particularly the second yam, to a heat source capable of shrinking the second yam and, consequently, the second filament 24 itself. Naturally, the degree of expansion depends on the heat applied, and / or the duration of exposure, and the chemical composition of the second filament 24. However, preferably, the second filament 24 is activated at approximately 100°C, and the shrinkage reaction is fully executed to ensure uniform and permanent deformation. Therefore, the second maximum plastic linear expansion applied to the second yam may not necessarily reach its maximum extent, for example, if heat is applied for a short period. In any case, the first yam remains tensioned (at least until the second yam is deformed), and then prevents the second filament 24 from undergoing undesired deformation. Thus, once the second yam is heated and consequently shrinks, the second filament 24 forms wrinkles, causing both the second filament 24 and the membrane 20 to become undesirably deformed. However, by releasing the shrinkage and consequently removing the elastic deformation of the second yam, thereby allowing the first yam to return to its tensioned state, it is possible to restore the second filament 24 to a tensioned state such that the wrinkles are eliminated.

[0131] It should be noted that, especially in the absence of the second filament 24, the first filament 22 may be designed as just described, meaning that it could include the characteristics now described for the second filament 24 to allow even better control over the behaviour of the membrane 20.

[0132] If both the first filament 22 and the second filament 24 are both present, along with a slider 23, the second filament 24 is preferably wrapped around the slider 23 at the edging 21 . Thus, the second filament 24 may be integrally attached to one of the faces 20a, 20b along the development trajectory 22a. It may then be hooked with a fisherman’s rib stich or loop, at the face 20a, 20b, or wound with a loop around one or more filaments of the membrane 20.

[0133] Additionally, when padding 6 is present, the first and second filaments 22, 24 may be configured in specific ways to modify the behaviour of the membrane 20.

[0134] For example, as shown in Fig. 6a, the first filament 22 may be integrally attached to the second face 20b along the development trajectory 22a, while the second filament 24 may be attached, preferably hooked with a fisherman’s rib stich or loop so that it can move independently while still being connected, to the first face 20a, parallel to the development trajectory 22a.

[0135] In this case, when the first filament 22 is not tensioned, the membrane 20 may appear to be without padding 6 when the user rests on it, as the padding 6 remains essentially hidden behind the first face 20a and cannot emerge. However, when the first filament 22 is tensioned, the padding 6 is protruded outward relative to the frame 3, emerging toward the contact area of the support surface 2, allowing the user to perceive it. Naturally, the perception of the padding 6 is due to the fact that, in the second face 20b, the first filament 22 is tensioned along the trajectory 22a.

[0136] Alternatively, as shown in Fig. 6b, the first filament 22 may be attached, preferably hooked with a fisherman’s rib stich or loop so that it can move independently while still being connected, to the second face 20b along the development trajectory 22a, and the second filament 24 may be integrally attached to the first face 20a along the development trajectory 22a.

[0137] In this case, the tensioning of the first filament 22 results only in an overall stiffening of the membrane 20, but the padding 6 remains present and perceivable by the user, as it is positioned between the first face 20a and the second face 20b, with the second filament 24 acting as a support even when the first filament 22 is not tensioned.

[0138] In all these cases, as already explained, the first filament 22 preferably exits through the face 20a or 20b, preferably moving away from the edging 21 , and therefore away from the slider 23. However, preferably, the first filament 22 is configured to exit the membrane 20 near the frame 3, or even at a central position relative to the membrane 20.

[0139] Then, in this embodiment, the second filament 24 may allow for control over the yieldingness of the membrane 20, or, more preferably, the thickness of the padding 6, if the latter is present. Therefore, the first filament 22, together with the tensioning means 4, which form the tensioning system, enables control over the localized stiffness of the support surface 2, acting either directly on the membrane 20 in which it is woven or on the support 5 integrated within it, or as a resting surface for the membrane 20, serving as support 5.

[0140] Naturally, in this context, the support surface 2 may include a plurality of first filaments 22, for example, distributed parallel to one another within the membrane 20, if mostly embedded within it, or interwoven if they are mostly external to the membrane 20. In this case, multiple tensioners 40 may be used, each dedicated to a respective first filament 22, or all first filaments 22 may be connected to the same tensioner 40. Naturally, a greater number of tensioners 40 allows for more localized control over the stiffness of the support surface 2.

[0141] Similarly, the support surface 2 may include a plurality of second filaments 24.

[0142] The operation of the chair 1 with a tensioning system for the support surface and / or upholstery control, previously described in structural terms, is as follows.

[0143] The chair 1 substantially allows for on-demand stiffening of the support surface 2, depending on the rotation applied to the tensioners 40. The stiffening may directly affect the membrane 20, particularly the second face 20b, and the first filament 22 is mostly embedded in the membrane 20. Alternatively, the stiffening may occur on a support 5, formed by the first filament 22, which passes between the opposite edges of the edging 21 and the edges themselves, creating a rigid support for the membrane 20, allowing the second face 20b to rest on the support 5 when a user is seated.

[0144] The chair 1 with a tensioning system for the support surface and / or upholstery control according to the invention achieves significant advantages.

[0145] In fact, the chair 1 with a tensioning system for the support surface and / or upholstery control includes a tensioning system that can be activated at any time, even when the chair is fully assembled, and without requiring specific measures, such as heat sources.

[0146] Furthermore, the chair 1 with a tensioning system for the support surface and / or upholstery control allows for continuous control over the yieldingness of the surface, without reducing the comfort of the chair. In conclusion, the chair 1 with a tensioning system for the support surface and / or upholstery control enables effective control over the volume of the padding within the support surface, particularly allowing for control over the protrusion of the padding beyond the fabric of the backrest or seat.

[0147] The invention is susceptible to variations within the scope of the inventive concept defined by the claims.

[0148] Within this scope, all details may be replaced by equivalent elements, and the materials, shapes, and dimensions may be any.

Claims

C LAI M S1. Chair (1 ) with a tensioning system for a support surface and / or upholstery control comprising:- a support surface (2) suitable for supporting a user sitting on said chair (1 ) and comprising at least:- a membrane (20) woven in a knitted fabric defining a first face (20a) suitable for contacting said user, a second face (20b) opposite said first face (20a), and delimited perimetrically by an edging (21 ) extending along a contour of said membrane (20),- a first filament (22) embedded at least in part in said membrane (20) between said faces (20a, 20b);- a frame (3) configured to support said membrane (20) at least at a part of said edging (21 ) so as to keep said support surface (2) in suspension with respect to a ground;- said first filament (22) developing along its own development trajectory (22a):- mostly within said membrane (20) textured inside said membrane (20) adjacent a said face (20a, 20b), or- mostly outside said membrane (20) between opposite parts of said frame (3) or part of opposite edges of said edging (21 ) so as to connect said parts or said edges by forming a support (5) respectively integrated with said first face (20b) or facing said membrane (20) on which said second face (20b) can rest when a user is leaning on said membrane (20); and said chair (1 ) being characterised by further comprising- tensioning means (4) integral to said frame (3) or to said membrane (20) and configured to directly or indirectly tension said first filament (22) along said development trajectory (22a) so as to locally stiffen, in proportion to said tensioning, said membrane (20) and / or said support (5).

2. Chair (1 ) according to claim 1 , wherein said first filament (22) protrudes from said membrane (20) transversely to a said one face (20a, 20b), when said first filament (22) is wefted within said membrane (20), away from said edging (21 ) in a lateral position with respect to said membrane (20), or away from said edging (21 ) in a distal position, in particular central, with respect to said membrane (20).

3. Chair (1 ) according to the preceding claim, wherein within said membrane(20) said first filament (22) is integrally constrained with said one face (20a, 20b) along said development trajectory (22a) hooked with a fisherman’s rib stich at said face (20a, 20b) or wound with a loop to one or more filaments of said membrane (20).

4. Chair (1 ) according to any preceding claim, wherein said first filament (22) enters and exits said membrane (20) transversely to said edging (21 ) in an alternating manner between said edges of said edging (21 ) when said first filament(22) is arranged mostly outside said membrane (20) so that said support (5) is defined by a corset-like structure.

5. Chair (1 ) according to any preceding claim, wherein said membrane (20) comprises at least one slider (23) defining an elongated-shape element trapped between said faces (20b, 20a) at said edging (21 ) and said frame (3) defines at least one hollow and continuous guide (30) configured to trap at least part of said slider(23) to mutually bind said membrane (20) and said frame (3).

6. Chair (1 ) according to at least claims 4-5, wherein at least two opposing edges of said edging (21 ) comprise a plurality of slots (21 a) developing parallel to said slider (23) at a position outermost of said membrane (20) with respect to said slider (23) and said first filament (22) is alternately threaded between said slots (21a) of said edges.

7. Chair (1 ) according to at least claim 5, wherein said frame (3) comprises a plurality of hooks (31 ) distributed on said opposite sides of said frame (3) parallel to said guide (30) and said first filament (22) is arranged mostly outside of said membrane (20) and is threaded alternately between said hooks (31 ) so that said support (5) is at least partially integrated into said second face (20b) and defines at least externally a corset-like structure.

8. Chair (1 ) according to at least claim 5, wherein said frame (3) comprises a plurality of hooks (31 ) distributed on said opposite sides of said frame (3), said first filament (22) is arranged mostly within said membrane (20) and said chair (1 ) comprises a plurality of said first filaments (22) and further a cable (50) connecting a group of adjacent ends of said first filaments (22) to said tensioning means (4) passing alternately between said hooks (31 ) so as to form with said first filament (22) said support (5) at least partially integrated in said second face (20b) and to define a corset structure such that the tensioning of said cable (50) by means ofsaid tensioning means (4) results in the tensioning of said first filaments (22).

9. Chair (1 ) according to at least claim 6, wherein said first filament (22) is arranged mostly within said membrane (20) and said chair (1 ) comprises a plurality of said first filaments (22) and further a cable (50) connecting groups of adjacent ends of said first filaments (22) to said tensioning means (4) and threaded within a row of slots (21a) arranged at one and the same side of said membrane (20) so as to form with said first filament (22) at least said support (5) and to define a corsetlike structure such that the tensioning of said cable (50) by means of said tensioning means (4) results in the tensioning of said first filaments (22).

10. Chair (1 ) according to any of the previous claims, wherein said support surface (2) further comprises a second filament (24) woven into said membrane (20) including a first yarn comprising elastic material and a second yarn wrapped around said first yarn with a predetermined pitch and including shrinkable material defining, when subjected to a heat source, a second maximum plastic linear expansion; wherein said first yarn is pre-tensioned and defines a first elastic linear expansion stably maintained at least until said second yarn is subjected to said heat source and then retracted.

11. Chair (1 ) according to any preceding claim, wherein said first linear elastic expansion is equal to the maximum linear elastic expansion chargeable on said first yarn in the absence of said heat source.

12. Chair (1 ) according to any preceding claim, wherein said membrane (20) comprises at least one padding (6) arranged between said faces (20a, 20b).

13. Chair (1 ) according to at least claim 10, wherein said first filament (23) is integrally bound to said second face (20b) along said development trajectory (22a) and said second filament (24) is integrally constrained with said first face (20a) parallel to said development trajectory (22a) or to said second face (20a) along said development trajectory (22a).

14. Chair (1 ) according to any preceding claim, wherein said tensioning means (4) comprise at least one spool tensioner (40) defining a rotation axis around which said first filament (22) can be rotated on command to bring it into tension along said trajectory (22a).

15. Chair (1 ) according to any preceding claim, wherein said first filament (22) is constrained at a first end thereof to a said tensioner (40) and at a second endthereof, opposite said first end, to one at a choice of another said tensioner (40) and a fixed point of said frame (3) or of said membrane (20) in such a way as to be stretched between said tensioners (40) or one of said tensioner (40) and said frame (3) or said membrane (20) when said first filament (22) is rotated about said axis of rotation of said tensioner (40).

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