WO2022233713A1

WO2022233713A1 - Backrest of an item of seating furniture, and item of seating furniture

Info

Publication number: WO2022233713A1
Application number: PCT/EP2022/061387
Authority: WO
Inventors: Armin Sander; Martin Potrykus
Original assignee: Armin Sander
Priority date: 2021-05-06
Filing date: 2022-04-28
Publication date: 2022-11-10
Also published as: DE202021102458U1; DE112022001383A5

Abstract

The invention relates to a backrest (22) of an item of seating furniture (2), more particularly office chair, having a backrest frame (24) that is provided with a covering (34), an arched flexible crossmember (32) being connected to the ends (24) of the frame. The crossmember (32) is spaced apart from the covering (34). The invention also relates to an item of seating furniture (2).

Description

description

BACKREST OF A SEAT AND SEAT

The invention relates to a backrest of a piece of seating furniture and a piece of seating furniture.

The seating furniture is preferably an office chair.

A piece of seating furniture is generally understood to mean a piece of furniture on which at least one user can sit. Basically, this includes chairs, office chairs (both in a version as a swivel chair and as a conference chair) and armchairs (also known as lounge furniture). Such seating furniture usually has a seat and a back rest set at an angle to it, against which the user can lean.

For example, the backrest is completely rigid so that robustness is increased. To increase comfort, however, a rigid support structure on the backrest is covered with foam, which is why the user is not injured when leaning against it. So that there is sufficient support for the user, there is usually a mechanism or at least defined contact points of a mechanism on the user's back, such as a lumbar support. This is used to provide selective support for the spine and/or back muscles. This means that the chair can also be used over a longer period of time without getting tired.

To further increase comfort, the mechanism is designed in such a way that increased support of the user's back is provided when the load is greater. For this purpose, the mechanism has, for example, several joints. However, such mechanisms are comparatively heavy, so that the weight of the seat furniture is enlarged. As a result, it is difficult to reposition the seating furniture.

The invention is based on the object of specifying a particularly suitable backrest of a piece of seating furniture and a particularly suitable piece of seating furniture, wherein comfort is advantageously increased and/or weight is reduced.

With regard to the backrest, this object is achieved by the features of claim 1 and with regard to the chair by the features of claim 10 according to the invention. Advantageous developments and refinements are the subject of the respective dependent claims.

The backrest is part of a piece of seating furniture. In other words, the backrest is particularly suitable, expediently provided and set up to be part of a piece of seating furniture. Here, the backrest is used in particular to stabilize and / or to lean a back of a user who uses the chair and sits furniture, for example, on a seat of the seat. The backrest is particularly suitable for this purpose, preferably provided and configured.

The backrest has a backrest frame which is seen ver with a fabric. The covering is thus held by means of the backrest frame, and the shape of the backrest frame, in particular the external dimensions, preferably define the dimensions of the covering. The covering is suitably stabilized by means of the backrest frame. In particular, the covering is designed to be at least partially flat. Because of the backrest frame, it is therefore not necessary to design the covering to be self-supporting and/or rigid, which is why the weight of the backrest is comparatively low.

The covering serves in particular to support the user's back and is particularly suitable, provided and/or set up for this purpose. In other words, in the intended state, the user leans with his back against the covering. The covering is expediently located in the appropriate state at a rear end of any seat of the chair and / or runs at least substantially vertically and is therefore inclined to the vertical only by a small angle, for example less than 20 °, 10 °, or 5 °.

Furthermore, the backrest includes a cross brace that is designed in an arc shape. In other words, the cross brace has an arc shape. For example, the curvature of the cross brace, ie the course of the arc shape, is constant or different. In other words, the cross brace is, for example, in the shape of a circular arc or at least partially elliptical. In an alternative to this, the cross brace has, for example, one or more angles. Particularly preferably, however, the change in the course of the cross brace is continuous.

In addition, the cross brace is designed to be flexible. When a force is applied to the cross brace, it is elastically deformed so that the bending of the cross brace, i.e. the arc shape, changes. In other words, the cross brace is not designed to be rigid/stiff. The cross brace is particularly preferably in one piece, so that robustness is increased.

The cross brace is connected to the backrest frame at its ends, that is to say at the ends of the arc shape. For example, in this case the cross brace is fastened to the backrest frame, for example by means of an additional fastening medium, such as screws or clips. As an alternative to this, the cross strut is glued to the backrest frame or, for example, is formed onto it and is therefore in particular in one piece with it. In a further alternative, the cross brace is plugged into the backrest frame and/or held there in a non-positive manner. Appropriately, the cross member is thickened at the end and held in a corresponding measure on the backrest frame, which is preferably designed like a socket joint. In particular, the cross brace is located on the side of the covering facing away from any seat surface, so that the cross brace does not rest against the back of the user. In particular, the cross brace is arranged horizontally. In other words, the cross strut is in a horizontal plane when the backrest is installed on other components of the chair when used as intended. At least, however, the two ends of the transverse strut, which are connected to the backrest frame, are at the same height and thus in particular have the same vertical distance to any seat surface of the chair.

The cross brace is spaced from the covering. At least in the unloaded state of the backrest, ie when the user is not leaning against it, the cross brace is spaced apart from the covering and expediently also when the user is supporting himself on the covering. Due to the spacing of the cross brace from the covering, the user's leaning against the backrest is not disturbed by the cross brace, so that there is no mechanical contact between the cross brace and the back, possibly via the covering. As a result, comfort for the user is increased.

When the covering is loaded, the force is suitably introduced at least partially into the backrest frame and as a result the cross brace is elastically bent and in particular more strongly curved, so that a force is exerted by means of this on the backrest frame, which forces the backrest frame open. As a result, the fabric is tightened and therefore creates a force that opposes the depressing force of the fabric. In other words, when the skin buckles, a force is generated that is directed in such a way that the skin is moved to the original position. In this case, the two forces are essentially proportional to one another. Due to the arched shape of the cross strut, the extent to which the cross strut is deformed in a bending-elastic manner when the force is applied to the covering is already predetermined, so that uncontrolled deformation of the cross strut is avoided. Appropriately, the covering is not or only slightly stretchable. As a result, the functionality is improved. The backrest frame is preferably designed in such a way that when the force is exerted, it is essentially not bent in the direction of the force. In summary, the backrest frame is stabilized by means of the cross brace when a force acts on the covering, ie in particular the user is leaning against the covering. It is therefore not necessary to make the backrest frame comparatively robust and therefore to have a comparatively high weight, which is why the weight of the backrest is reduced. The backrest of the user is also stabilized by means of the backrest, so that comfort is increased.

The seating furniture is, for example, an armchair or a sofa. However, the piece of seating furniture is particularly preferably an office chair. The office chair has, for example, a frame that has, in particular, a rotatable and height-adjustable chair column. The chair column is attached to a star base, which has a star-shaped arrangement of cantilever arms, at the ends of which a roller is held. The office chair can thus be slid/repositioned along a subsurface. For example, the office chair includes two armrests that are attached to the frame, the backrest and/or the seat. The office chair expediently includes a mechanism, which is in particular part of the frame and by means of which the backrest can be inclined with respect to the seat surface.

For example, the curved shape of the cross brace is open on the side facing away from the covering, so that the curved shape points in the direction of the covering. As a result, a space requirement is comparatively small. However, it is particularly preferred that the arched shape of the cross brace is open on the side facing the covering, so that the arched shape points away from the covering. As a result, when the covering is loaded, the crossbar is moved further away from the covering, so that contact between the user's back and the crossbar is avoided at all times.

For example, the cross brace is made of plastic, which simplifies manufacture. In particular, the cross brace is created in an injection molding process. The cross brace is particularly preferably made of a fiber-reinforced plastic, so that robustness is increased. For example, here- used with glass fibers or alternatively carbon fibers, so that the cross brace is made of GRP or CFRP. It is thus possible to design the cross brace in a comparatively filigree manner, while still being robust. It is also possible to adapt the flexural elasticity of the cross brace to the respective requirements by means of the fibers.

The backrest preferably comprises a plurality of such transverse struts, so that the transverse struts can be designed in a comparatively filigree manner, with the backrest frame still being adequately stabilized. It is also possible in this way to specifically support the user's back when it leans against the back, namely in the area of the respective cross brace. It is thus possible to support the user's back in the area of the lordosis and/or the shoulders. For this purpose, a respective cross brace is expediently positioned in the area of the backrest frame which is at the same height as the body part to be supported.

The backrest particularly preferably has between three and eight such crossbars, and for example exactly five such crossbars. In this way, targeted stabilization of the user's back is made possible, with the complexity and weight of the backrest not being excessively increased. Alternatively, I have eight cross braces. Preferably, the cross braces are structurally identical to one another, with their respective lengths being adapted to the shape of the backrest frame, for example. Thus, production is simplified.

The backrest frame is particularly preferably U-shaped and thus has two side parts which are fastened to one another by means of a holding element. The Hal teelement is located in particular at one of the ends of the side parts, which are arranged parallel to each other in particular. For example, the side parts are arranged essentially vertically, with the holding element being arranged horizontally or at most essentially horizontally. The holding element is located in particular at the lower end of the side parts in the vertical direction and forms, for example, the lower end of the backrest. In particular, serves the retaining element the connection of the backrest to other components of the chair, such as the seat or the frame of the chair. In particular, the holding element partially forms a joint/bearing by means of which the backrest can be pivoted/inclined with respect to the seat surface.

The side parts and/or the holding element are expediently designed to be rigid/stiff and are therefore only comparatively slightly elastically deformable. However, at least one elasticity is reduced compared to the elasticity of the cross brace and consequently the stiffness is increased. In this case, however, it is possible for the two side parts to be pivoted slightly relative to one another with respect to the holding element when the covering is loaded, with the transition between the side parts and the holding elements being deformed, for example. When pivoting, the cross strut is deformed in a flexible manner, and thus the side parts are at least partially stabilized relative to one another by means of the cross strut. In other words, the side parts are pushed apart by means of the cross brace if a force acts perpendicularly to the covering and the latter is thus pressed in. Since the side parts are at least partially pushed apart by means of the cross brace, the loading is in turn tightened. Due to the U-shape of the backrest frame, the force used to tighten the upholstery can be adjusted in a targeted manner, namely via the cross brace. For example, the cross brace is also prestressed in the unloaded state, so that stabilization of the user's back is improved. Suitably, the cross strut is offset from the holding element in the direction of the free ends of the side parts, so that even with a comparatively filigree cross strut, there is sufficient tightening.

The side parts are preferably designed in such a way that when the force is exerted on the covering, the side parts are only bent toward one another, but not in the direction of the force. For this purpose, in particular, the cross section of the side parts has an increased extension in the direction of the force, ie in particular perpendicular to the course of the covering in the unloaded state. The horizontal cross section of the side parts is expediently essentially rectangular for this purpose. For example, the side parts are identical to each other or mirror images of each other. These are particularly preferably at least partially S-shaped, with a suitable curvature of the covering being realized on the basis of the S-shape, so that comfort is increased. The backrest frame is particularly preferably in one piece, so that it can be manufactured. For example, the backrest frame is made of glass fiber reinforced plastic, which is why the weight is comparatively low. Here, in particular, the glass fibers are arranged in such a way that rigidity is increased in comparison to the rigidity of the cross brace.

The side parts are particularly preferably connected at the free end, ie on the side opposite the retaining element, by means of a retaining strut. Excessive bending of the side parts due to the comparatively large lever arm is thus prevented by means of the retaining strut, which is why robustness is increased. For example, the retaining strut forms the upper end of the backrest in the vertical direction. In one variant, the retaining strut is made from the same material as the side parts. Particularly preferably, however, the retaining strut is designed to be flexible and is preferably made of the same material as the cross strut. A movement of the side parts is thus also possible here, with the side parts being moved again into the original position by means of the retaining strut if the covering is subjected to excessive stress. Therefore, there is also targeted support for the user's back.

The retaining strut is preferably also at least partially arcuate, so that when the side parts are pivoted relative to one another, in particular due to the loading of the covering, the type of deformation of the retaining strut is already predetermined. The curved shape of the retaining strut is suitably at least partially open at the bottom, so that it is easier for one hand to grip it there when moving the seating furniture item.

For example, the covering is made of a limp fabric or at least includes this. As a result, when force is applied to the fabric, especially in a buckling, when the user leans against the upholstery, the movement of the backrest frame is not prevented by the upholstery itself. As a result, the deformation of the cross brace is not impeded, which is why it is always safe to function. When the covering is loaded, a tensile force is only applied to the backrest frame and the cross braces are thus at least partially bent. In other words, the force that acts on the covering is introduced into the cross brace essentially unchanged, so that the counteracting force, which tightens the covering again, is essentially the same size.

For example, the fabric is provided with a cover, such as a leather, a fabric or a plastic. In this way, robustness is increased. In particular, there is padding between the cover and the fabric, so that comfort is further increased. However, the covering, and thus the fabric, is particularly preferably a limp mesh. Thus, on the one hand, there is ventilation, which is why comfort is increased. On the other hand, a weight of the backrest is reduced.

For example, a tie is attached to the cross strut, by means of which an excessive bending of the cross struts in the unloaded state is avoided. In other words, a minimum bending of the cross strut is specified by means of the tie and consequently also a maximum distance between the two ends of the cross strut to one another. For this purpose, the drawstring is expediently fastened in the region of the ends of the cross brace, in particular at the ends. Appropriately, the cross brace is already pretensioned, even if no load is acting on the covering. An excessive application of force to the backrest frame in the unloaded state is thus avoided by means of the tension strap. In a preferred further development, the drawstring is designed to be limp and only tightened if no further force is acting on the covering, ie in the unloaded state. As a result, a force acting on the covering via the side parts is limited, so that the service life of the covering is increased. In particular, a lending or plastic deformation avoided. If there are several cross braces, each is expediently assigned a corresponding drawstring.

The drawstring is made from a flexible material, for example, which is expediently not stretchable. A fabric such as a polyamide belt is preferably used for this purpose. As an alternative to this, the drawstring is at least partially made of a steel cable. Particularly preferably, the backrest has one or more retaining clamps, by means of which the tension strap is held on the cross brace. The retaining clip at least partially prevents the tension band from being spaced apart from the transverse strut when the transverse strut is deformed as a result of the force acting on it. Conveniently, the clamp is at least partially annular or rectangular with the train band and the cross brace are passed through this. Alternatively or in combination with this, the drawstring and the cross brace are arranged in a common stocking-like cover. The cover is made of a fabric, for example. In this way, pinching of the user's extremities is avoided between the drawstring and the retaining strut. Consequently, security is increased. The piece of seating furniture has a seat that is suitable, in particular provided and set up, so that a user can sit on it. Furthermore, the chair has a backrest that includes a backrest frame that is provided with a covering and to which an arcuate, flexible cross brace is connected at the ends. The cross brace is spaced from the covering.

For example, the backrest is rigidly attached to the seat or particularly preferably pivotally mounted with respect to this. The piece of seating furniture preferably includes a frame, by means of which the seat surface and the backrest are stabilized relative to one another. The frame includes, for example, one or more legs that serve to make contact with a floor/underground. As an alternative to this, the chair has a base on which several castors are mounted, so that the chair can be moved in a suitable manner. Suitably, the frame designed to be adjustable in height, so that the distance between the seat and the floor/underground can be changed. In particular, the piece of seating furniture is designed as an office chair. The piece of seating furniture, expediently the office chair, preferably comprises two armrests, which are used to rest elbows when the user is sitting on the piece of seating furniture.

The advantages and further developments described in connection with the backrest can also be transferred to the seating furniture and vice versa.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. Show in it:

1, 2 in perspective a piece of seating furniture in the form of an office chair with a backrest, FIG. 3 a rear view of a detail of the seating furniture, FIG. 4 a plan view of the seating furniture with no load on the backrest,

5 shows the backrest according to FIG. 4 in a horizontal sectional view, FIG. 6 shows the seating furniture according to FIG. 4 when the backrest is loaded, FIG. 7 shows the backrest according to FIG.

Fig. 8 is a perspective view of a variant of the chair, Fig. 9 is a fragmentary perspective sectional view of the backrest of a further variant of the chair with no loading loads on the backrest, and

Fig. 10 according to FIG. 9, the backrest under load.

Corresponding parts are provided with the same reference symbols in all figures.

FIG. 1 and FIG. 2 show a piece of seating furniture 2 from different perspectives. The seating 2 is an office chair and has a seat 4, which is attached to egg nem frame 6 is connected. The seat surface 4 is oriented essentially horizontally and has a foam material (not shown) that is inserted into a seat shell 8 that is covered with a seat cover 10 . The seat cover 10 is a fabric.

At the bottom of the seat shell 8, the frame 6 is connected, which has a bearing, not shown, by means of which the seat shell 8 can be rotated about a verti cal axis. In addition, the frame 6 has a chair column 12, which includes a gas pressure spring, not shown in detail, so that the length of the chair column 12, ie its extension in the vertical direction, can be changed.

A base 14 is fastened to the lower end of the chair column 12 in the vertical direction and comprises a total of five cantilever arms 16 arranged in a star shape. A roller 18 is held at each end of each cantilever arm 16 so that the chair 2 can be moved. On the frame 6, two armrests 20 are also connected, which engage the seat 4 on opposite sides. Furthermore, a backrest 22 is tiltably mounted on the frame 6 so that the inclination of the backrest 22 with respect to the seat surface 4 can be changed. The backrest 22 has a rigid backrest frame 24 . The backrest frame 24 is U-shaped and has two essentially vertical (perpendicular) side parts 26, the lower ends of which in the vertical direction (perpendicular direction) are connected by means of a holding element 28, which is shown in Figure 3, in which a section in a rear view of the chair 2 is shown.

The holding element 28 partially forms a bearing that rests for fastening the back 22 to the frame 6 . The holding elements 28 and the side parts 26 are designed to be rigid and stiff, namely from a glass fiber reinforced plastic. The side parts 26 are designed to be mirror images of one another and have an S-shape. The free ends of the side parts 26 opposite the holding elements 28 are connected to one another by means of a flexible holding strut 30 connected, whose rigidity is reduced compared to that of the side parts 26. The support strut 30 is arranged substantially horizontally and is slightly arcuate, the arcuate shape being opened downward in the vertical direction.

In addition, the backrest 22 has a total of five transverse struts 32, which are each configured in an arc shape and are spaced equidistantly from one another in the vertical direction. The cross braces 32 are between the side parts 26 is arranged and attached to them. The transverse struts 32 are made from the same material as the retaining strut 30 and are therefore also flexible. In summary, the five arcuate, flexible transverse strips 32 are connected at their ends to the backrest frame 24, namely the side parts 26.

The backrest frame 24 is provided with a covering 34 which is glued to the backrest frame 24 in an embodiment shown in more detail. In this variant, the covering 34 is inserted into a groove 35 (FIG. 5) of the backrest frame 22 and fixed there by means of an adhesive. In both embodiments, the covering 34 is only fastened to the side parts 26 and stretched tautly between them, and thus has a basic tension. Also, the fabric 34 mimics the S-shape of the side panels 26.

The covering 34 is a flexible net and is intended for a user to lean against it with his back. The covering 34 is located on the side of the cross braces 32 facing the seat surface 4, which are located completely on only one of the two sides of the covering 34. The Querstre ben 32 are arranged such that the arched shape of each cross strut 32 is open on the side facing the covering 34 . In other words, the curvature of the transverse struts 32 and thus the arc shape points away from the covering 34 . The cross struts 32 are also spaced apart from the covering 34 so that the covering 34 is not directly stabilized by means of the cross struts 32 or rests against them. If no one is sitting on the item of seating furniture 2 or at least no additional force is acting on the covering 34, which is in particular perpendicular to its course, the covering is stretched tautly between the side parts 26, as also shown in Figure 4, in which the item of seating furniture 2 is in is shown in a plan view. In Figure 5, the backrest 22 is shown in egg ner horizontal sectional view. The covering voltage 34 runs in a straight line between the two side parts 26 and is arranged there in the respective groove 36 . The cross strut 32 shown here, like the remaining cross struts 32, is held in a socket-like receptacle at the end, for which purpose the cross strut 32 is designed to be spherically thickened at each end.

If the user leans against the covering 34, a force 40 acts on it perpendicularly to its course, and is thus directed at least partially in the direction of the cross braces 32. Due to the force 40, the covering 34 is at least partially bulged and moved in the direction of the cross braces 32, as shown in FIG. 6 and FIG. 7 according to the representation of FIG. 4 and FIG. 5, respectively. As a result, the course of the covering 34 between the side parts 26 is no longer completely straight, but slightly curved.

The covering 34 is designed to be essentially inextensible, so that the two side parts 26 are moved towards one another at least partially due to the force 40 acting on it. Since these are fastened to one another by means of the folding element 28, the ends there are held and not moved. Consequently, the side parts 26 are moved towards one another at the end facing the folding strut 30 and are consequently inclined towards one another. As a result, both the folding strut 30 and the transverse struts 32 are elastically deformed, with the curvature increasing in each case, that is to say the folding strut 30 and the transverse struts 32 are bent, the ends of which are each moved towards one another. In this case, the ends of the cross struts 32 held movably in the receptacles 38 are at least partially rotated, so that no tensioning of the cross strut 32 occurs in this area. The cross section of the side parts 26 in the horizontal is such that when the force 40 is exerted, it is essentially not, or are at least only slightly bent in the direction of the force 40, son countries perpendicular to this towards each other, so that a mode of action is improved.

Because of the arc shape, there is a controlled bending of the retaining strut 30 and the cross struts 32. In addition, due to their arrangement, the retaining strut 30 and the cross struts 32 are bent away from the covering 34, so that there is no mechanical contact between them. Thus, the back of the user of the chair 2 does not hit one of the cross braces 32 either. Due to the bending/deforming of the retaining brace 30 and the cross braces 32, a force is exerted on the side parts 26 by means of these, so that they are pushed apart. In other words, the backrest frame 24 is stretched as a result. The force is proportional to the force 40 acting on the fabric 34, and when these are in equilibrium, no further buckling of the fabric 34 occurs. As a result, the back of the user through which the force 40 is exerted is stabilized. so that comfort for the user is increased.

Another variant of the chair 2 is shown in FIG. In this case, the two armrests 20 are not present, but they can also be present in an embodiment that is not shown in detail. The retaining strut 30 is also not present, so that the two side parts 26 are not connected at the free ends. Otherwise, this variant of the chair 2 corresponds to the previous embodiment and also the mode of operation, but when the force 40 is exerted, the free ends of the side parts 26 are increasingly moved towards one another. To avoid this, the transverse struts 32 have increased rigidity in a variant that is not shown in detail.

FIG. 9 shows a further variant of the chair 2 in a perspective sectional view through the backrest 22 . There are in turn present at the side parts 26, each having the groove in each case within de rer the covering 34 is held. The receptacles 38 are also present, within which the cross strut 32 shown, as well as the other cross struts 32 not shown, rest at the end and are thus attached to the backrest frame 24. is bound. However, in this variant, the receptacles 38 are extended in the form of a cylinder and the cross brace 32 is widened.

Also attached to opposite ends of the cross member 32 is a drawstring 42 made from a flexible, non-stretchable fabric such as a polyamide belt. In an alternative embodiment, the drawstring 42 is formed by means of a steel cable. In addition, there are two retaining clamps 44, each of which is provided by means of a rectangular bent wire. The drawstring 42 and the cross brace 32 are guided through each of the retaining clamps 44 . The Hal teschellen 44 are attached to the cross member 32 and arranged symmetrically. As an alternative to this, the retaining clamps 44 can be moved with respect to the cross brace 32 .

If, as shown in Figure 9, the force 40 is not acting, the tension strap 42 is taut between the ends of the cross brace 32 and the retaining clamps 44, so that the force applied to the side parts 26 by means of the cross brace 32 causes the side parts 26 to presses on the outside, only up to a certain distance from each other. In other words, the tie rod 42 is used to set the side parts 26 from one another, from which point a force is exerted on them by means of the cross brace 32 . Consequently, a minimum bending of the cross brace 32 is specified by means of the drawstring 42 . As a result, the stress on the skin 34 is reduced when the force 40 is not acting, thereby avoiding lending or over-stretching of the skin 34 or removing it from the grooves 36 .

However, if the force 40 acts on the covering 34, as shown in FIG. 10, the transverse strut 32 will continue to bend, but the tension band 42 will no longer assume any function and will essentially be pliable. Due to the clamps 44 there is no uncontrolled spacing of the train bands 42 from the cross member 32, which is why snagging of the drawstring 42 is avoided on other components of the chair 2. When the force 40 subsides, the two side parts 26 are again pushed apart by the cross brace 32 up to the distance that is predetermined by the tension strap 42 . In a variant that is not shown in detail, there is only one such retaining clip 44 or several such retaining clips 44, or the cross brace 32 is arranged with the drawstring 42 in a common stocking-like sleeve, by means of which excessive removal of the drawstring 42 from the cross brace is also avoided 32 is avoided when it is bent.

The invention is not limited to the embodiment described above. On the contrary, other variants of the invention can also be derived from this by a person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

Reference List

2 seating furniture

4 seat 6 frame

8 seat shell

10 seat cover

12 chair column

14 star base 16 extension arms

18 roll

20 armrest

22 backrest

24 backrest frame 26 side panel

28 holding element

30 retaining strut

32 crossbar

34 covering 36 groove

38 recording

40 power

42 drawstring

44 retaining clip

Claims

Expectations

1. Backrest (22) of a piece of seating furniture (2), in particular an office chair, with a backrest frame (24) which is provided with a covering (34) and to which a curved, flexible cross brace (32) is connected at its ends (24). , wherein the cross brace (32) is spaced from the covering (34).

2. Backrest (22) according to claim 1, characterized in that the arched shape of the cross brace (32) on the side facing the covering (34) is open.

3. backrest (22) according to claim 1 or 2, characterized in that the cross brace (32) is made of a fiber-reinforced plastic.

4. backrest (22) according to any one of claims 1 to 3, characterized by between three and eight such cross braces (32).

5. Backrest (22) according to one of claims 1 to 4, characterized in that the backrest frame (24) is U-shaped and has two rigid side parts (26) which are fastened to one another by means of a rigid holding element (28).

6. backrest (22) according to claim 5, characterized in that the side parts (26) are connected at the free end by means of a flexible holding strut (30).

7. backrest (22) according to any one of claims 1 to 6, characterized in that the covering (34) is a flexible network.

8. backrest (22) according to any one of claims 1 to 7, characterized in that on the cross strut (32) a flexible drawstring (42) is attached, by means of which a minimum bending of the cross strut (32) is predetermined.

9. backrest (22) according to claim 8, characterized by a retaining clip (44) through which the drawstring (42) and the cross brace (32) are guided.

10. Seating furniture (2), in particular an office chair, with a seat (4) and a backrest (22) according to one of claims 1 to 9.