WO2018210910A1

WO2018210910A1 - Seat apparatus for supporting an upright seating position

Info

Publication number: WO2018210910A1
Application number: PCT/EP2018/062674
Authority: WO
Inventors: Mariam VOLLMAR
Original assignee: Vollmar Mariam
Priority date: 2017-05-18
Filing date: 2018-05-16
Publication date: 2018-11-22
Also published as: DE102017110834A1; EP3576574B1; EP3576574A1; DE102017110834B4

Abstract

The invention relates to a seat apparatus (1) for supporting an upright seating position having at least one seat base (2) and a backrest (3) comprising an elastic back support (4), a backrest vertical axis (LAH), and a backrest horizontal axis (LAQ). The backrest (3) has a predefined height (hL) and a backrest plane (EL), the backrest vertical axis (LAH) and the backrest horizontal axis (LAQ) being contained within the backrest plane (EL), and at least one support portion (4.1) of the back support (4) that points in the direction of the seat base (2) having a double convex shape. The seat apparatus (1) is particularly characterised in that at least the support portion (4.1) has a first convex principal curvature (KR1) along the direction of the backrest vertical axis (LAH) and protruding from the backrest plane (EL) in the direction of the seat base (2), and a second convex principal curvature (KR2) along the direction of the backrest horizontal axis (LAQ) and protruding from the backrest plane (EL) in the direction of the seat base (2), and in that, in vertical cross-section, an apex (S) of the first convex principal curvature (KR1) of the support portion (4.1) of the back support (4) has a distance (dS) from the seat base (2) which is at least 50% of the height (hL) of the backrest (3). Figure 1a

Description

Seat device for supporting an upright seating position

Technical area

The invention relates to a seat device for supporting an upright sitting position.

State of the art

Seating devices with adjustable backrests in the region of the backrest are well known. Also separate backrests for subsequent attachment to backrests of chairs are available on the market.

Such seat devices with back supports, which support the spine in a predefined, defined manner, are designed, for example, as office chairs or vehicle seats in order to enable the user to achieve the most healthy possible sitting position. The back supports are particularly often designed so that they certain areas of the spine of a person sitting on the seat device

support. Supporting the lumbar spine can, for example, counteract lordosis and support in the area of the thoracic spine helps to prevent a so-called hunchback or kyphosis.

For example, WO 2009/021245 A2 describes a chair with adjustable back support, wherein the back support consists of several individual curved

There are elements that can be moved individually and fixed after positioning, whereby the backrest can be adapted to the back of a person. According to an alternative embodiment of WO 2009/021245 A2, the back support may also be integrally formed as a separate body with a convex shape, which is attachable to the back of a chair. The structure of the chair according to WO 2009/021245 A2 and the adjustment of the associated back support is complex. Also, the separate back support does not allow specific support of the thoracic spine area of a seated person. Thus, despite the solutions known from the prior art, there is a need for simple seating devices to support an upright seating position, conducive to healthy, relaxed and ergonomic sitting.

Presentation of the invention

Object of the present invention is therefore to provide a seat device is available, which overcomes the disadvantages of the prior art and the

especially simple in construction and contributes to a reduction in seat fatigue and to prevent discomfort even with prolonged sitting. This object is achieved according to the invention by the seat device

independent claim 1 solved. A back support for attachment to a back of a chair or seat is further subject matter of claim 9. Further advantageous aspects, details and embodiments of the invention will become apparent from the dependent claims, the description and the drawings.

The invention provides a seating device for supporting an upright

Seating available, wherein the seat device at least one seat and a backrest comprising an elastic back support with a

Lehnenhochachse and a backrest transverse axis and wherein the backrest has a predetermined height and a backrest plane in which the backrest vertical axis and the backrest transverse axis are added. At least one in the direction of the seat facing support portion of the back support has a two-fold convex curved shape. The seat device is characterized in particular by the fact that the support section has a first convex main curvature protruding from the backrest plane in the direction of the seat surface in the direction of the backrest vertical axis and a second convex main curvature protruding in the direction of the seat surface from the backrest plane in the direction of the backrest transverse axis and that in the vertical section a vertex of the first convex main curvature of the support portion of the back support has a distance from the seat surface that is at least 50% of the height of the back rest.

The support portion of the elastic back support thus has a double convex curvature, in such a way that the support portion at least in one

Horizontal section along a direction perpendicular to the backrest plane horizontal cutting plane and at the same time in a vertical section along a plane perpendicular to the backrest plane vertical cutting plane each having a cross section in shape a circle segment or an elliptical section has. The seat surface oriented towards the surface of the support portion thus forms a double-curved elevation or a double curvature, for example, a dome-like curvature. The seat device according to the invention can be described for better understanding with reference to a three-dimensional coordinate system as indicated in the present figures la and lb, in the event that the backrest and the seat surface are oriented approximately perpendicular to each other. The seat extends substantially in a horizontal xy plane, which is spanned by the x-axis and the y-axis. The vertically oriented backrest level of the

Backrest is spanned by the z-axis and the x-axis and can thus be understood as xz plane. The curvature of the support section expands in the y direction, starting from the backrest plane to the seat surface. The seat surface facing the support portion therefore defines a curved surface with at least two curvatures.

The seat device according to the invention thus very particularly advantageously has a backrest with a backrest, which is convexly curved by its doubly convexly curved shape both in a substantially vertical direction and in a substantially horizontal direction. As a result, in the case of the backrest, there is a specific point or a section that protrudes maximally from the backrest in the direction of the seat surface, in the region of the apex of the first main curvature. This maximum protruding point or section or area represents the contact surface for the back of a person sitting on the seat device. According to the vertex of the first main curvature and thus the contact surface for the back at a distance of at least 50% of the vertical longitudinal extent of the backrest to Seat spaced. The apex is thus arranged in the upper half of the backrest and has a predetermined distance from the seat, wherein the apex is arranged so that the back support attaches to the level of the lower costal arch of a seated person and thus supports the thoracic spine.

Very special advantages result from the double convex curvature of the back support, since the thoracic spine is supported by a narrow portion, which can also be understood as a strip or ridge or as a support strip or Stützgrat, is supported such that, for example, the shoulder area remains free. The back is extended both in length and laterally stretched by the shoulders can be placed around the two-fold convex curvature and the Back thus undergoes a vertical and lateral extension. This results in a bulge of the breast and a lateral extension of the costal arch. As a result, for example, the ventilation of the lungs and airways can be significantly promoted.

With the seat device according to the invention, the upright seat can be maintained and used in a particularly advantageous manner in relaxation and complete muscle relaxation, since, in spite of an upright, straight and relaxing extended sitting position, leaning is possible. Tension and relaxation phases can thus complement each other optimally as needed and, even when used for long periods, reduce seatedness and prevent discomfort.

The seat device according to the invention allows ergonomic sitting and can be designed, for example, as a chair, in particular office chair or office swivel chair, as a chair or as a vehicle seat and a respectively necessary for this

Include substructure or a respective subframe. The base frame can be designed, for example, as a simple foot or as a turnstile, in particular as a turnstile with rollers or the like, and can basically be designed in the form of a swinging structure or as a simple base.

According to a preferred embodiment of the invention, the distance of the apex of the first main curve from the seat surface is 55%, preferably 60% of the height of the backrest. Likewise preferably, the backrest level closes with the

Seating an angle in a range of 85 ° to 95 ° and is most preferably oriented substantially perpendicular to the seat. An upright

Sitting position can be supported in this way particularly advantageous by the back support, in particular the support portion of the back support meets the back of a seated person in the region of the thoracic spine and supports it. Preferably, the backrest is adjustable, so that the angle between the backrest plane and seat can be adjusted as needed.

Alternatively or additionally, the seat can be adjusted, in particular tiltable formed over a predetermined range.

Preferably, a main axis of the backrest is oriented parallel to the backrest vertical axis and a transverse axis of the backrest is aligned perpendicular to the backrest plane. Based on the three-dimensional coordinate system, the main axis of the back support extends in the z-direction and the transverse axis in the y-direction.

For example, the transverse axis passes through the apex of the first Major curve. In preferred embodiments, the apex of the first main curvature coincides with a vertex of the second main curvature defined in the horizontal section, so that, for example, the transverse axis of the second main curvature coincides

Support section passes through the two vertices. Of course, the coincidence of the two peaks of the main curves represents only a preferred special case, and the vertex of the first main curve and the vertex of the second main curve may be arranged separately from each other.

Particular advantages result from the fact that the seat surface has a raised portion in a region adjoining the backrest, with the raised portion rising toward the backrest. By a seat with a raised portion in the rear, namely adjoining the backrest area an upright seating position is additionally supported. The slope of the

Heightening section acts lifting in the area of the coccyx and the

Lumbar spine and leads to improved posture.

Particularly preferably, the seat can also be designed in the form of a saddle seat. As a result, for example, the back and hip of a seated person are brought into an open angle, whereby the spine additionally relieved and the sitting position is improved. An upright dynamic sitting can be promoted in particular.

Advantageously, the backrest may additionally comprise a head / neck support, wherein the head / neck support is subsequently arranged on the back support and, in turn, on an upper end of the back support facing away from the seat surface. In this way, the backrest leads with the backrest for example in

ascending line to the end of the thoracic spine and runs from the

Thoracic spine straight to the base of the skull, with a small upward curvature can be formed at the level of the transition from the thoracic spine to the cervical spine. As a result, the spine is relieved, and in particular the area that carries the bulk of the head weight. By relieving this area, which is responsible for frequent general complaints like

Neck tension, migraine, Halsmuskelverkürzungen etc., can be particularly advantageous to prevent the occurrence of the aforementioned complaints.

At least the support portion of the back support according to a preferred embodiment of the invention at least partially describes the shape of an elongated ellipsoid of revolution. In this embodiment, the backrest takes For example, the shape of a rugby ball or a halved length rugby ball. In this preferred form, the back support in the area of the thoracic spine supports and lifts and thus facilitates sitting in an upright sitting position. In this preferred embodiment, in which the

Back support at least partially takes the form of an elongated ellipsoid of revolution, coincide the apex of the two main curvatures and the transverse axis passes through this coinciding vertex. Alternatively, the shape of the back support may also describe an oval or a longitudinal half of an oval.

The back support may be in the form of a body made of a resilient solid material. As an elastic material is suitable, for example

Polyurethane material, e.g. an elastomeric foam, preferably an elastomeric rigid polyurethane foam.

The invention also includes an elastic back support for attachment to a back of a chair or seat for assisting an upright sitting position. The back support has at least one attachment portion for attachment of the back support to the backrest of the chair or seat and an elastic

Supporting portion, wherein the support portion in the connected state in the direction of a seat surface of the chair or seat and wherein at least the support portion has a double convexly curved shape, such that the support portion oriented in the direction of a major axis of the back support first main curvature and perpendicular to the first Has major curvature and oriented in the direction of a transverse axis of the back support second major curvature. The attachment portion of the lumbar support is configured to allow attachment of the lumbar support to the back of the chair or seat such that a vertex of the first major curve of the support portion of the lumbar support is disposed in an upper region, particularly an upper half of the back of the chair or seat is.

The back support can be attached to the back, for example, a

Hanging device or a belt device, wherein under a suspension device in the present case also a plug-in or plug-on device is to be understood and a belt device may also include various variants of belt, Tragriemen- or Anschnallkonstruktionen. One as

Suspension device trained mounting portion is particularly suitable for attachment of the back support to the back of a conventional chair and trained as a belt attachment portion is particularly suitable for attaching the backrest to the back of a seat, such as a vehicle seat.

Particularly preferably, the attachment portion is adjustable, so that the back support can be adapted to the back of various models of chairs or seats. Thereby, the back support can be mounted in the desired and predetermined manner on the chair or seat, so that the apex of the first main curvature of the support portion of the seat has a distance which is at least 50% of the vertical longitudinal extent of the back of the chair or seat.

The back support is preferably in the form of an inflatable cushion or in the form of an inflatable body and comprises an airbag made of elastic material with an air inlet, in particular a valve. Particularly preferably, such an airbag has a combination of a plurality of preformed air chambers, wherein the desired shape of the backrest can be achieved via the arrangement and shape of the individual air chambers. Particularly advantageously, the back support in such an inflatable variant can be stored and transported in a practical and space-saving manner and made available only when needed or in use by inflation or inflation.

In particular, for an application with vehicle seats, this proves to be particularly advantageous.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures. In this case, all described and / or illustrated features alone or in any combination, in principle, the subject of the invention, regardless of their summary in the claims or their

Dependency.

Brief description of the drawings

The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. Show it Fig. La is a frontal view of an embodiment of the seat device according to the present invention;

Fig. Lb is a schematic representation of an ellipsoid of revolution;

FIG. 2 is a side view of an embodiment of the seat apparatus according to the present invention; FIG.

3a shows a side view of a further embodiment of the seat device according to the present invention;

3b in a very simplified schematic representation of a side view of a section of a seat device with a direction indicated in the seat position torso.

4 is a side view of a still further embodiment of the seat apparatus according to the present invention;

Fig. 5a is a side view of an embodiment of a back support according to the present invention and

Fig. 5b is a side view of another embodiment of a back support according to the present invention. Ways to carry out the invention

In Figure la, an embodiment of the seat device 1 according to the invention is shown in a front view. The seat device 1 is designed in the form of a chair, in particular an office swivel chair, and comprises, in addition to a seat surface 2 and a backrest 3, a base frame 8 with foot on which the seat surface 2 is mounted. The backrest 3 has a backrest plane E _L , which in the illustrated example essentially encloses a right angle with a plane receiving the seat surface 2, so that the seat device 1 can be described according to the example with reference to the three-dimensional coordinate system indicated at the edge in FIG.

The seat 2 extends substantially in a horizontal xy plane spanned by the x-axis and the y-axis. The vertically oriented Lehnene level E _{L of} the backrest 3 is spanned by the z-axis and the x-axis and can thus be understood as xz plane. One in the

Lehnenebene E _L recorded backrest axis LA _H runs in the z-direction and a also taken in the backrest level E _L Lehnenquerachse LA _Q runs in the x direction.

The backrest 3 has a predetermined height h _L and comprises an elastic back support 4, the support section 4.1 points in the direction of the seat 2 and is available for the plant of the back of a person sitting on the chair. The back support 4 made of an elastic material has a two fold convexly curved shape and has a protruding from the rest plane E _L in the direction of the seat surface 2 first convex main curvature KR1 in the direction of the backrest vertical axis LA _H and from the rest plane E _L in the direction of the seat surface 2 protruding second convex main curvature KR2 in the direction of

Rear transverse axis LA _Q on. In the present case, the back support 4 takes the form of an elongated ellipsoid of revolution. Such an extended one

The ellipsoid of revolution is shown schematically in FIG. 1b. The two

Principal curvatures KR1, KR2 are also indicated for better illustration in the schematic ellipsoid of revolution in FIG. 1b.

The support portion 4.1 thus forms a curvature, which stands out from the backrest level E _L. The curvature of the support section 4.1 expands in the y-direction, starting from the backrest plane E _L to the seat surface 2. The surface of the support section 4.1 facing the seat surface 2 therefore defines a curved surface with at least two curvatures.

The back support 4 is arranged such that a vertex S of the first

Main curvature KR1 has a distance d _s to the seat 2, which is at least 50% of the height h _{L of} the backrest 3.

Figure 2 shows a side view of an embodiment of the seat device 1 according to the present invention, which in turn is in the form of an office swivel chair and has a base frame 8 with a simple base foot. In the example of Figure 2, the backrest 3 is tilted slightly to the seat back 2, so that the rest plane _L E forms with the seat surface 2 an acute angle. The

Back support 4 has a main axis HA, which in the illustrated example runs slightly inclined to the backrest plane E _L. A transverse axis QA of

Back support 4 is oriented perpendicular to the main axis HA of the back support 4 and extends approximately in the y direction. In the example of Figure 2, the back support 4 again takes the form of an elongated ellipsoid of revolution.

The back support 4 is arranged such that its main axis HA with the seat 2 forms an angle α of about 80 ° and that in vertical section the apex S of the first main curvature KR1 lies in the upper half of the backrest 3, namely that the apex S a Distance d _s to the seat 2, which is at least 50%, in the illustrated example of Figure 2 about 60% of the height h _{L of} the backrest 3. The apex S is in the illustrated example in the region of the transverse axis QA of the support element 4. The apex S is at an optimal height to attack at about the level of the lower costal arch of a sitting on the seat device 1 person and the back of the person in the Support area of the thoracic spine. Due to the double convex curvature of the back support 4 is the

Thoracic spine of the seated person supported by only a narrow portion of the back support such that, for example, the shoulder area remains free and the shoulders can almost lay around twice the convex curvature and the back thus undergoes a vertical and lateral extension.

The backrest 3 further comprises a head / neck support 5, which on one of

Seat 2 facing away from the upper end of the backrest 4 connects to this. The head / neck support 5 is arranged at a height which is an area of the transition from the thoracic spine to the cervical spine one on the

Seating device 1 corresponds to a seated person, so that the head / neck support 5 can support this transition region from the thoracic spine to the cervical spine in a seated person to this center of gravity, which is the main part of

Head weight contributes to relieve. As a result, for example, general, common complaints such as neck tension, migraine, Halsmuskelverkürzungen or the like can be prevented.

For additional improvement of an upright, healthy sitting position, the seat surface 2 in a subsequent to the backrest 3 area, namely in a rear area on an elevation section 2.1, which rises to the backrest 3 out with a certain, predetermined slope. FIG. 3 a shows a side view of an alternative embodiment of the invention

Seating device 1 according to the present invention, which is also in the form of an office swivel chair. The embodiment of Figure 3 differs from that of Figure 2 mainly by the design of the backrest 3, in particular the back support 4. The back support 4 takes in the example of Figure 3a substantially the shape of a portion of an elongated ellipsoid of revolution, which along the major axis HA is cut or halved. The main axis HA of the back support 4 is taken in the example of Figure 3a in the back plane E _L and extends substantially perpendicular to the seat surface 2. The main axis HA of the back support 4 is parallel to the backrest axis LA _H , but this is not visible in the figure 3a , The distance d _{s of} the apex S from the seat surface 2 in the illustrated example of FIG. 3 is approximately 62% of the height h _{L of} the backrest 3. The base frame 8 deviates from a simple base foot in the example of FIG Vibration structure designed. In the figure 3b is shown in a very simplified schematic representation of a side view of a section of a seat device 1 with a torso, the torso is intended to indicate a person in sitting position. FIG. 3b shows that the back support 4 supports a person sitting on the seat apparatus 1 mainly in the area of the thoracic spine, namely between the shoulder blades.

FIG. 4 shows a side view of a further alternative embodiment of the seat device 1 according to the present invention, which differs from the one shown in FIG

Embodiment of Figure 2 essentially differs in that the seat surface 2 is formed in the form of a saddle seat.

In the figures 5a and 5b, an embodiment of a back support 40 for attachment to a backrest of a chair or seat is shown in lateral view in each case. The back support 40 has a mounting portion 40.2 for attachment to the back of the chair or seat and an elastic support portion 40.1, wherein the support portion 40.1 in the connected state with the back in the direction of a seat surface of the chair or seat and a bearing or support surface for a sitting on the chair or seat person forms to lean on and supporting the back.

In each of the illustrated examples, the support portion 40. 1 has a doubly convex curved shape and is in a first main curvature KRl oriented in the direction of a major axis HA of the back support 40 and in a direction perpendicular to the first main curvature KR1 and in the direction of a transverse axis QA

Back support 40 oriented second major curvature KR2 curved. Of the

Attachment portion 40.2 of the back support 40 is in each case designed such that an attachment of the back support 40 on the back of the chair or seat is possible such that a vertex S of the first main curvature KRL of the support portion 40.1 of the back support 40 in an upper region of the back of the chair or Seat is arranged when the backrest is fastened to the backrest. The back support 40 according to the example of Figure 5a essentially describes the shape of an elongated ellipsoid of revolution and is made of an elastic material. The attachment portion 40.2 of the illustrated backrest 40 is designed as a suspension device 6 and is particularly suitable for connecting the backrest 40 with the backrest of a standard chair. The suspension device 6 is adjustable and can thereby be adapted to different models of chairs. It is also ensured that the apex S of the first main curvature KR1 of the support portion 40.1 in the connected state at a distance from the seat of at least 50% of the vertical longitudinal extent of the back of the chair, so that the apex S in the region

Thoracic spine of a seated person and can support the thoracic spine.

In the back support 40 shown in FIG. 5b, the support section 40.1 describes a part of an elongated ellipsoid of revolution, the shape of which can be compared with a lengthwise halved rugby ball. The attachment portion 40.2 of the illustrated example is designed as a belt device 7, so that the back support 40 according to FIG. 4b is particularly suitable for attachment to the backrest of a seat, for example a vehicle seat. The belt device 7 is also adjustable, again such that the apex S of the first

Main curvature KRl of the support portion 40.1 in the connected state at a distance from the seat of at least 50% of the vertical longitudinal extent of the back of the seat, so that the apex S in the region of

Thoracic spine of a seated person and supporting the thoracic spine can. Subsequent to an upper end of the support portion 40.1 of the back support 40, a head / neck support 5 is arranged, which supports a seated person in the region of the cervical spine. The back support 40 shown in Figure 5b is formed as an inflatable body and comprises a flexible air bag with a plurality of air chambers, the

Back support 40 in the inflated state give their predetermined shape, especially the doubly convex curved shape.

LIST OF REFERENCE NUMBERS

1 seat device

2 seats

2.1 elevation section

3 backrest

4 back support

4.1 support section

5 head / neck support

6 suspension device

7 belt device

8 underframe

40 back support

40.1 support section

40.2 fixing section d _s distance of the vertex from the seat E _L backrest plane

h _L Height of the backrest

HA main axis

KR1 first major curvature

KR2 second major curvature

LA _H backrest axle

LA _Q backrest transverse axis

QA transverse axis

S vertex α angle

Claims

claims

Seat device (1) for supporting an upright seating position comprising at least one seat surface (2) and a backrest (3) comprising an elastic back support (4) with a backrest vertical axis (LA _H ) and a backrest transverse axis (LA _Q ), wherein the backrest (3) a predetermined height (h _L ) and a backrest plane (E _L ), wherein the backrest vertical axis (LA _H ) and the backrest transverse axis (LA _Q ) are received in the backrest plane (E _L ) and wherein at least one in the direction of the seat surface (2) pointing support section (4.1) of the back support (4) has a doubly convex curved shape, characterized in that at least the support portion (4.1) one of the

Lehnenebene (E _L ) in the direction of the seat (2) protruding first convex main curvature (KRL) in the direction of the Lehnenhochachse (LA _H ) and from the backrest level (EL) in the direction of the seat (2) protruding second convex main curvature (KR2) in Has the direction of the Lehnenquerachse (LA _Q ) and that in vertical section a vertex (S) of the first convex main curvature (KRL) of the support portion (4.1) of the back support (4) has a distance (d _s ) from the seat surface (2) at least 50% of the height (h _L ) of the backrest (3).

Seat device (1) according to claim 1, characterized in that the distance (d _s ) of the apex (S) of the first main curvature (KRl) of the seat surface

(2) 55%, preferably 60% of the height (h _L ) of the backrest (3) is.

3. Seat device (1) according to claim 1 or 2, characterized in that a main axis (HA) of the back support (4) is oriented parallel to the backrest vertical axis (LA _H ) and a transverse axis (QA) of the back support

(4) is aligned perpendicular to the backrest plane (E _L ).

Seat device (1) according to any one of the preceding claims, characterized in that the seat surface (2) in an adjoining the backrest (3) region has an elevation portion (2.1), wherein d increasing portion (2.1) to the backrest (3) increases.

5. Seat device (1) according to one of the preceding claims, characterized

in that the seat surface (2) is designed in the form of a saddle seat.

6. Seat device (1) according to any one of the preceding claims, characterized in that the backrest (3) additionally comprises a head / neck support (5), wherein the head / neck support (5) is arranged adjacent to the back support (4) and then to one of the seat surface (2) facing away from the upper end of the back support (4).

7. Seat device (1) according to one of the preceding claims, characterized

in that at least the support section (4.1) of the back support (4) at least partially describes the shape of an elongated ellipsoid of revolution.

8. Seat device (1) according to one of the preceding claims, characterized

characterized in that the back support (4) is in the form of a body made of a resilient solid material.

An elastic back support (40) for attachment to a back of a chair or seat for supporting an upright sitting position, comprising at least one attachment portion (40.2) for attaching the back support (40) to the back of the chair or seat and an elastic support portion (40.1). wherein the support portion (40.1) in the connected state points in the direction of a seat surface of the chair or seat and wherein at least the support portion

(40.1) has a doubly convex curved shape, such that the support portion (40.1) has a first convex main curvature (KR1) in the direction of a major axis (HA) of the back support (40) and a second convex

Main curvature (KR2) in the direction of a perpendicular to the main axis (HA) extending and transverse axis (QA) of the back support (40), wherein the

Fixing portion (40.2) of the back support (40) is adapted to allow attachment of the back support (40) to the back of the chair or seat such that a vertex (S) of the first main curvature (KR1) of the support portion (40.1) of Back support (40) is arranged in an upper region of the backrest of the chair or seat.

10. Back support (40) according to claim 9, characterized in that the

Back support (40) is designed in the form of an inflatable cushion.

11. Back support (40) according to claim 9 or 10, characterized in that the fastening portion (40.2) by a suspension device (6) is formed.

12. Back support (40) according to claim 9 or 10, characterized in that the fastening portion (40.2) by a belt device (7) is formed.

13. Back support (40) according to any one of claims 9 to 12, characterized in that in addition a head / neck support (5) is provided.