EP1931232B1 - Chair - Google Patents

Abstract

The chair has a sub frame (1) set on the floor, a mechanism (2) set on the sub frame, a seat (3) set on the mechanism (2) and a backrest (7) attached to the mechanism (2). The backrest (7) exhibits a backrest frame (5), which supports an elastically deformable backrest part (6) with a back panel (62). The back panel (62) has a back part (60), to which a head restraint (61) is attached. The backrest (7) is capable of pivoting about a first pivot shaft (D1) from an essentially upright, neutral position to a reclined position displaced towards the rear. The movements of the seat (3) and the backrest (7) are synchronized with one another. In the event of the elastic deformation of the back part (60) into a free space for the backrest frame (5), by the application of a force in the direction of the reclined position having an essentially concave tendency to the back of the user, means (53,67,D4;55,610,D5) are provided for an opposing raising of the shoulder area, as a transitional zone of the back part (60) for the head restraint (61), and of the head restraint (61).

Description

Field of application of the invention

The present invention relates to a chair of the type with a floor-mounted underframe, a patch on the base mechanism, a seated on the mechanics seat and attached to the backrest mechanism. The backrest has a back frame, which carries an elastically deformable backrest part with a back plate, wherein the back plate has a back part, with which a head extension is connected. The backrest is pivotable about a first axis of rotation from a basically upright zero position to a rearwardly directed tilt position. The movements of the seat and backrest are synchronized with each other.

State of the art

A chair of the type mentioned is, for example, in the EP 1 039 816 B1 disclosed.

The US 6,257,665 B1 relates to a chair with a base resting on the base, a placed on the base mechanism, a seated on the mechanics seat and attached to the mechanics backrest. The backrest has a back frame, which carries an elastically deformable backrest part with a back plate, wherein the back plate has a back part, with which a head extension is connected. The backrest is pivotable about a first axis of rotation from a basically upright zero position to a rearwardly inclined position of inclination, wherein the movements of the seat and backrest are synchronized with each other. With elastic deformation of the back part in a free space to the back frame - this by the action of a force in the direction of the inclination position with concave tendency in principle to the user's back - are means for an opposite erection of the shoulder area as a transitional zone of the back to the head and head approach intended.

Object of the invention

Based on the so far known prior art, the invention has for its object to propose a chair of the type defined above with perfected ergonomic function. In particular, when the backrest is in the rearwardly inclined inclination position, the support of shoulder area and head of the user should be improved.

Overview of the invention

The chair has a base placed on the floor, a mechanism attached to the base, a seat mounted on the mechanism and a backrest attached to the mechanism. The backrest has a backrest frame, which carries an elastically deformable backrest part with a back plate. The back plate has a back part to which a head attachment is connected. The backrest is about a first axis of rotation from a basically upright zero position to a rearwardly inclined tilt position pivotable. The movements of the seat and backrest are synchronized with each other. With elastic deformation of the back part in a free space to the backrest frame, by the action of a force in the direction of inclination with in principle to the back of the user konkaver tendency, means for an opposite erection of the shoulder area as a transition zone of the back to the head and head attachment are provided.

The following features relate to specific embodiments of the invention: The back part and the head attachment of the back plate merge into one another in one piece. The head attachment is divided into a lower first head section, which attaches to the back part, and an upper second head section, wherein the first head section together with a neighboring portion of the second head section forms a neck region. In the neck area, a fourth docking part is provided. The back part is divided into an upper first back section, which adjoins the neck region, and a lower second back section, wherein the second back section together with a neighboring portion of the first back section forms a lumbar region. In the lumbar area, a second docking part is provided.

Through the back frame first extends a fourth axis of rotation, which lies at the height level of the lumbar region and on which a first molded part is articulated with a first docking, wherein the first docking part is connected to the second docking part. Further, extending through the back frame a fifth axis of rotation, which lies at the height level of the neck region and on which a second mold part is articulated with a third docking part, wherein the third docking part is connected to the fourth docking part. The backrest frame is rigid and consists of two side struts, each with an extension at the lower ends and connections between the side struts together. The first connection is a cross member arranged near the extensions. The second connection is a central transverse strut, through which the fourth axis of rotation with the first molded part hinged thereto extends. The third connection is an upper transverse strut, through which the fifth axis of rotation extends with the second molded part hinged thereto.

The cross member consists of one of each of the associated side strut extending nozzle and a bridge piece, which is in two mutually facing sockets. The middle transverse strut consists of one of the associated side strut extending spigot and an axle rod, which is in two mutually facing sockets and carries the first molded part. The upper transverse strut consists of a respective extension extending from the associated side strut and an axle rod which is inserted in both mutually directed extensions and carries the second shaped part. The first docking part is releasably connected to the second docking part and the third docking part with the fourth docking part by means of locking members. The first docking part and the third docking part are designed as plug-in elements. The second docking part and the fourth docking part are designed as sleeve pieces that extend from the back of the back plate. In the lower part of the back plate a vertically displaceable lumbar support is arranged on its front side. On the back of the back plate reinforcing ribs and a cell for receiving a control lever for the adjustment of the lumbar support are provided. Vertical grooves for guiding the lumbar support are provided on the front side of the back plate, the vertical grooves following the course of the reinforcing ribs and extending over the lumbar region.

The mechanism consists of a fixed base, which is placed on the base frame, and a seat support connected to the base. The connection between the base and seat support is first realized on the first fixed axis of rotation and on a second movable axis of rotation, which faces the seat trailing edge. Finally, base and seat support are connected in a third movable axis of rotation, which faces the seat leading edge. In each case an extension of the back frame is attached to a respective frame connection, which is articulated on the one hand on the first axis of rotation and on the other hand on the second axis of rotation. In mechanics generates a spring assembly a bias that tends to keep the backrest in the upright null position.

The back plate is made of plastic. The lumbar region of the backplate has outer flanks with in principle the hip region of the user comprehensive tendency. The head extension has a curvature in the vertical cross-section with a tendency in principle to the user convex tendency. The fifth axis of rotation lies in the direction of the front edge of the seat in front of the upper edge of the head attachment and in front of the fourth axis of rotation. The back plate is surrounded by an envelope, preferably by a plastic foam surround. The cover is covered by a cover, wherein the cover for the head attachment is preferably present as a separately exchangeable part.

Brief description of the attached drawings

Figur 1A -

einen erfindungsgemässen Stuhl in Form eines Bürodrehstuhls mit Armlehnen, in aufrechter Nullposition, in perspektivischer Frontansicht;

Figur 1B -

die Wesensbestandteile des Stuhls gemäss Figur 1A, in perspektivischer Explosivansicht;

Figur 1C -

den Stuhl gemäss Figur 1A, ohne Armlehnen, in Nullposition, in Seitenansicht;

Figur 1D -

die Darstellung gemäss Figur 1C, mit Stellungsangaben zum Sitz, Lehnenrahmen und Lehnenteil;

Figur 1E -

den Stuhl gemäss Figur 1A, ohne Armlehnen, in maximaler Neigungsposition, in Seitenansicht;

Figur 1F -

die Darstellung gemäss Figur 1E, mit Stellungsangaben zum Sitz, Lehnenrahmen und Lehnenteil;

Figur 2A -

die Mechanik aus Figur 1B, mit einseitig eingesetzter Armlehne, in perspektivischer Frontansicht von oben;

Figur 2B -

die Mechanik aus Figur 1B, mit einseitig aufgesetzter Abdeckkappe, in perspektivischer Rückansicht von unten;

Figur 2C -

eine Prinzipdarstellung mit dem schwenkbaren Sitzträger der Mechanik gemäss Figur 1B, mit einer angenäherten Seitenstrebe des Lehnenrahmens, in perspektivischer Rückansicht von unten;

Figur 2D -

die Prinzipdarstellung gemäss Figur 2C, im vertikalen Teilschnitt;

Figur 2E -

die Prinzipdarstellung gemäss Figur 2D, mit der kompletten Mechanik und darin vollständig eingehängter Seitenstrebe, im vertikalen Teilschnitt;

Figur 3A -

eine Rückenlehne aus Figur 1B, ohne Umhüllung, in perspektivischer Frontansicht;

Figur 3B -

die Rückenlehne gemäss Figur 3A, in Seitenansicht; Figur 3C - die Rückenlehne gemäss Figur 3A, mit angedeuteter Umhüllung des Lehnenteils, in perspektivischer Explosivansicht;

Figur 3D -

den Lehnenrahmen aus Figur 3C, zusammengebaut, in perspektivischer Frontansicht;

Figur 3E -

den Lehnenrahmen gemäss Figur 3D, mit angenähertem Lehnenteil und separater Lumbalstütze, in perspektivischer Rückansicht;

Figur 3F -

die Rückenplatte aus Figur 3E, mit Abschnittsunterteilung, in perspektivischer Rückansicht;

Figur 3G -

die Rückenplatte gemäss Figur 3F, mit Abschnittsunterteilung, in Seitenansicht;

Figur 3H -

das vergrösserte Lehnenteil aus Figur 1C, mit Abschnittsunterteilung, in aufrechter Nullposition;

Figur 3J -

das vergrösserte Lehnenteil aus Figur 1E, mit Abschnittsunterteilung, in maximaler Neigungsposition;

Figur 3K -

das vergrösserte Detail X1 aus Figur 3B; und

Figur 3L -

das vergrösserte Detail X2 aus Figur 3B.

Show it:

Figure 1A -

a chair according to the invention in the form of an office swivel chair with armrests, in an upright zero position, in a perspective front view;

FIG. 1B -

according to the essential parts of the chair Figure 1A in perspective exploded view;

FIG. 1C

according to the chair Figure 1A , without armrests, in zero position, in side view;

FIG. 1D -

the representation according to Figure 1C , with position information on the seat, backrest frame and backrest part;

FIG. 1E -

according to the chair Figure 1A , without armrests, in maximum inclination position, in side view;

FIG. 1F -

the representation according to Figure 1E , with position information on the seat, backrest frame and backrest part;

Figure 2A -

the mechanics out FIG. 1B , with one-sided inserted armrest, in perspective front view from above;

FIG. 2B -

the mechanics out FIG. 1B , with cap attached on one side, in perspective rear view from below;

FIG. 2C -

a schematic diagram with the swivel seat support of the mechanics according to FIG. 1B , with an approximate side strut of the backrest frame, in a perspective rear view from below;

FIG. 2D -

the schematic representation according to Figure 2C , in vertical section;

FIG. 2E -

the schematic representation according to FIG. 2D , with the complete mechanism and fully suspended side strut, in vertical section;

FIG. 3A -

a backrest off FIG. 1B , without wrapping, in perspective front view;

FIG. 3B -

the backrest according to FIG. 3A , in side view; FIG. 3C - the backrest according to FIG. 3A , with indicated wrapping of the backrest part, in perspective exploded view;

Figure 3D -

the backrest frame FIG. 3C assembled, in perspective front view;

FIG. 3E -

according to the backrest frame Figure 3D , with approximate backrest part and separate lumbar support, in perspective rear view;

FIG. 3F -

the back plate off FIG. 3E , with section division, in perspective rear view;

Figure 3G -

the back plate according to FIG. 3F , with section division, in side view;

FIG. 3H

the enlarged backrest part Figure 1C , with section division, in upright zero position;

FIG. 3J

the enlarged backrest part Figure 1E , with section division, in maximum inclination position;

Figure 3K -

enlarged detail X1 FIG. 3B ; and

FIG. 3L -

enlarged detail X2 FIG. 3B ,

embodiment

With reference to the accompanying drawings, the detailed description of an embodiment of the inventive chair follows.

The following definition applies to the entire further description. Are in a figure for the purpose of graphical uniqueness reference numerals included, but in the is not explained directly in the accompanying text, reference is made to their mention in the preceding description of the figures. For the sake of clarity, the repeated designation of components in subsequent figures is usually dispensed with, as far as the drawing clearly shows that they are "recurring" components.

Figures 1A to 1D

A comfortable office swivel chair basically consists of the resting on the floor base 1, resting on it mechanism 2, on which the seat 3 is mounted, a backrest 7 and preferably adjustable armrests 4. The base 1 typically has a first foot 10 - eg a 5th -Sternfuss - resting on floor elements 12, preferably rollers. To adjust the level of the seat 3 and simultaneous suspension a Höhengasfeder 13 is inserted vertically in a standpipe 11 centrally in the foot 10 , which carries the mechanism 2 , which consists of a fixed base 20 and the pivotable seat support 21 . The backrest 7 is divided into a backrest frame 5 and a backrest part 6, which is structured in the back part 60 and the head attachment 61 adjoining above. On the backrest part 6, the front side 607 and the back 608 are defined. The swivel chair can be pivoted about the vertical axis of rotation V generally by 360 ° and remains in the unloaded state in the upright zero position, which is enforced by the bias of the spring assembly 211 in the mechanism 2 and limited by a stop in the forward inclination.

• Sitz 3: Stellung S₀, d.h. die Oberfläche des Sitzes 3 ist zumindest im Prinzip horizontal;
• Lehnenrahmen 5: Stellung R₀, d.h. die Seitenstreben 51 des Lehenrahmens 5 stehen mit ihren wesentlichen Abschnitten im Prinzip vertikal; und
• Lehnenteil 6: Stellung B₀ , d.h. das Lehnenteil 6 mit Rückenpartie 60 und Kopfansatz 61 stehen im Prinzip vertikal und damit komplementär zur aufrechten Sitzhaltung eines Benutzers.

The upright zero position is defined by the following positions:

• Seat 3: position S ₀ , ie the surface of the seat 3 is at least in principle horizontal;
• Back frame 5: position R ₀ , ie the side struts 51 of the flock frame 5 are in principle vertical with their essential sections; and
• Backrest part 6: position B ₀ , ie the backrest part 6 with back portion 60 and head rest 61 are in principle vertical and thus complementary to the upright posture of a user.

The backrest frame 5 consists of two bow-shaped, multi-curved side struts 51, which are fastened at the bottom in each case on an angular piece formed as a frame connection 22 of the mechanism 2 . The frame connections 22 are articulated on the one hand on a first axis of rotation D1, which is located on the fixed base 20 , and on the other hand on a second axis of rotation D2, on the rear area of the pivotable seat carrier 21 . Above the first axis of rotation D1 and closer to the front edge 30 of the seat 3 is located in the base 20, a fixed third axis of rotation D3, are hinged to the two tabs 23 , on the other hand run in a slotted guide 212 . Each side of the seat support 21 , a receiving socket 25 is provided to attach the desired equipment of the chair with armrests 4, such. In a recess in the seat support 21 , a spring assembly 211 for generating the restoring force for the mechanism 2 is arranged. On the seat support 21 , the front part 218 and the rear part 219 are defined, which lie adjacent to the seat front edge 30 and seat trailing edge 31 .

Adjacent to the frame terminals 22 , both side struts 51 are interconnected by a composite cross member 52 . At the lower end of each side strut 51 is provided with an extension 50 formed in principle as an angle. Each extension 50 has a first holding contour 501 and a second holding contour 502. Above the seat 3 is hinged between the two side struts 51 in a fourth axis of rotation D4, a first docking part 53 which is connected to a second docking part 67 , which opens into a cell 66 which lies on the back 608 of the back plate 62 of the backrest part 6 . In the cell 66 , a lever 64 is used, by means of which a arranged on the front side 607 of the back plate 62 plate-shaped lumbar support 65 limited in height can be moved. Through the upper ends of both side struts 51 , the fifth axis of rotation D5 extends with the third docking part 55 hinged therein , which is connected to a fourth docking part 610 extending from the back 608 of the lower portion of the head 61 of the back plate 62 . Below the fifth axis of rotation, D5 has the back plate 62 fasteners 620 to fix it to a removable cover 69 ' for the head extension 61 .

Internally, the backrest part 6 has the elastic back plate 62, which is surrounded by a cover 68 , which preferably consists of a foam of plastic. Outside is the backrest part 6 of a cover 69 - eg knitted fabric, leather or similar. - Surround so that the inner sheath 68 is not visible. In order to maintain the displaceability of the lumbar support 65 after foaming, this is previously covered with a release film 63 . The seat 3 includes a seat plate 32 fastened to the seat support 21 , which has a padding 38 on top, which is provided with a cover 39 at least from the front edge 30 to the rear edge 31 . An armrest 4 is composed of an angle bent support arm 40, a vertical branch of the support arm 40 enveloping sleeve piece 41 and the armrest 42 together. To adjust the height of the armrest 42 , the sleeve piece 41 can be moved telescopically on the vertical branch and lock, for example, in stages. The free end of the Horizontalasts of the support arm 40 is provided as a slider 400 with a slot, so that after loosening the clamping screws 49 a width adjustment between the two armrests 4 on the chair is possible.

FIGS. 1E and 1F

Relocates a user sitting on the chair body weight of the pre-bent writing posture or upright posture backwards and thereby exerts an area, sufficient compressive force F on the backrest part 6 , the pressure load is introduced into the back frame 5 and against the force of the spring assembly 211 in the Mechanics 2 the entire backrest 7 moves to the maximum tilt position. The backrest sinking down back frame 5, which is articulated in the first axis of rotation D1 draws on the moving frame terminals 22 which are articulated in the second axis of rotation D2 , the rear portion 219 of the pivotal seat support 21 to the rear downwards. At the same time pivoted in the third axis of rotation D3 tabs 23 are pivoted, on the other hand run in the slide guides 212 of the seat support 21 in the direction of the front end 218 . The connections of first and second docking 53.67 and from the third and fourth docking 55,610 pivot about the respective associated fourth axis of rotation D4 and fifth axis of rotation D5 by the denting deformation of the backrest part 6 with the internally arranged back plate 62 - due to the applied compressive force F - to each other. This creates supported space for the shoulder area of the user and on the head restraint 61 for obliquely lowering the backrest 7 an opposite upright positioning of the head rest 61.

• Sitz 3: Stellung S₁, d.h. die Oberfläche des Sitzes 3 hat sich aus der Ausgangsstellung S₀ in den Sitzwinkel β mit angehobener Vorderkante 30 und abgesenkter Hinterkante 31 bewegt;
• Lehnenrahmen 5: Stellung R₁ , d.h. die Seitenstreben 51 des Lehnenrahmens 5 haben sich aus der Ausgangsstellung R₀ mit ihren wesentlichen Abschnitten in den Lehnenwinkel α bewegt; und
• Lehnenteil 6: Stellung B₁ , d.h. das gesamte Lehnenteil 6 hat sich nach hinten schräg abgesenkt, der unterste Abschnitt der Rückenpartie 60 hat sich dabei der abgesenkten Hinterkante 31 des Sitzes 3 angenähert, der zwischen den Drehachsen D4,D5 gelegene Abschnitt der Rückenpartie 60 hat sich eingedellt den Seitenstreben 51 angenähert und der Kopfansatz 61 dadurch aufgerichtet.

The maximum tilt position is defined by the following positions:

• Seat 3: position S ₁ , ie the surface of the seat 3 has moved from the starting position S ₀ into the seat angle β with the front edge 30 raised and the rear edge 31 lowered;
• Back frame 5: position R ₁ , ie the side struts 51 of the back frame 5 have moved from the initial position R ₀ with their essential sections in the backrest angle α; and
• Backrest part 6: position B ₁ , that is, the entire backrest part 6 has been inclined downwards, the lowermost portion of the back portion 60 has thereby approximated the lowered trailing edge 31 of the seat 3 , which has located between the axes of rotation D4, D5 portion of the back section 60 eingedellt the side struts 51 approximated and erected the headset 61 thereby.

FIGS. 2A and 2B

On the mechanism 2 , a recess 28 for the forward inclination of the seat 3 is provided below the second axis of rotation D2 in the seat carrier 21 . The adjusting lever 14 is used to actuate the Höhengasfeder 13, with the actuator 242 can be the bias of the spring assembly 211 set and the actuator 27 is actuated for the seat depth adjustment. The receiving socket 25 have a first and a second segment 250,251 for gripping the sliding piece 400 to be inserted , which represents the end of the Horizontalasts 403 of the support arm 40 . For width adjustment, a slot 401 is present in the slider 400 . The threaded shank of the clamping screw 49 engages in an internally threaded bore 253 in the second segment 251 , which has a grid 252 for better locking of the inserted slider 400 at the bottom. About the vertical branch 405 of the support arm 40 , the shaft 410 of the sleeve piece 41 of the armrest 4 is mounted. If you do not want to attach armrests 4 , the receiving socket 25 is closed with a cap 259 for aesthetic reasons. For placing on the high-pressure gas spring 13 , an opening 200 is present in the base 20 . In order to dock the extensions 50 on the backrest frame 5 to the frame connections 22 , a storage recess 210 is inserted in each case in the region of the second rotation axis D2 in the seat support 21 .

FIGS. 2C to 2E

The side struts 51 have near the extensions 50 each have an inwardly facing stub 520 and on the fourth and fifth axis of rotation D4, D5 each have a further neck 540.560. When mounting the back frame 5 in the mechanism 2 brings in the angled state, the first hook-shaped holding contours 501 of the extensions 50 to the second axis of rotation D2 and pivots the back frame 5, so that the second holding contours 502 reach the first axis of rotation D1 , where a screw connection ,

FIGS. 3A to 3L

Both side struts 51 are joined to the back frame 5 on the cross member 52 of the middle cross member 54 and on the upper cross member 56 , wherein the projections 50 come to lie at the lower ends of the side struts 51 . The back plate 62 is detachably docked on the back frame 5 . On the front side 607 two vertically extending grooves 606 are present in the lumbar region 603 , in which the plate-shaped lumbar support 65 is guided vertically displaceable. The side flanks 604 have a bending tendency for embracing the hip area of the user. The back plate 62 is structured in the back part 60 and the head extension 61 adjoining above , in which the fourth docking part 610 is connected, which is connected to the third docking part 55 . Below this, two fasteners 620 extend from the front side 607 for releasably attaching the cover 69 ' for the head extension 61.

The lower sockets 520 are connected to each other by means of a bridge piece 521 inserted therein and secured by screws 529 . The central transverse strut 54, through which the fourth axis of rotation D4 extends, is composed of the connecting piece 540, an axle rod 541, the molded part 543 pushed onto it and the bearing shells 542 . Screws 549 serve for cohesion of the transverse strut 54. From the rotatably mounted first molded part 543 , the first docking part 53, which has locking members 531 extends. The upper transverse strut 56, through which the fifth axis of rotation D5 extends, is composed of the connecting piece 560, an axle rod 561, the second molded part 563 pushed thereon and the bearing shells 562 . Screws 569 serve to hold the transverse strut 56 together. From the rotatably mounted second molded part 563 extends the third docking part 55, which has latching elements 551, 552 .

In the assembled state, the third docking part 55 is in the fourth docking part 610 and is secured by the locking members 551,552 . On the back 608 of the back plate 62 , a cell 66 for receiving a control lever 64 is disposed in the lumbar region 603 , which engages with its driver 640 in a driver 650 of the lumbar support 65 and serves to their displacement. Of the cell 66 to a second docking part 67 rises with located therein detent member 671 for receiving the first docking part 53 with its catch members 531. Also, from the back side 608 610. rises from the neck 613, the fourth docking both sides of the cell 66 and the fourth docking part 610 extend on the back 608 reinforcing ribs 609 in which the vertical grooves 606 run. The second docking part 67 and the fourth docking part 610 open as openings 605, 610 on the front side 607. The back plate 62 is surrounded by a covering 68 , which preferably consists of foam-coated plastic. Before the foaming, the inserted lumbar support 65 is covered by a separating film 63 in order to obtain the displaceability of the lumbar support 65 . About the enclosure 68 , a cover 69 is pulled, which is formed for example of knitted or leather.

The back panel 62 is divided into the back part 60 and the adjoining top head restraint 61. Below the fourth docking part 610 is a first portion 611 and above a second portion 612, wherein the first portion 611 with an adjoining portion of the second portion 612 of the neck 613 forms. Below the second docking portion 67 is a second portion 602 and above the first portion 601, wherein the second portion 602 forms with an adjacent portion of the first portion 601, the lumbar region 603 .

If a user pushes his body weight, in particular above the lumbar region 603, against the backrest 7, this moves up to the maximum inclination position B ₁ with elastic deformation of the back part 60, mainly above the lumbar region 603 into the free gap to the back frame 5 , with, in principle to the back of the user concave tendency. Depending on the intensity of the pressure against the back section 60 , an opposite raising of the shoulder region as a transition zone of the back section 60 to the head attachment 61 and the head attachment 61 is effected. Here, the connections of the first and second docking part 53,67 move around the fourth axis of rotation D4 upwards and from the third and fourth docking part 55.610 around the fifth rotation axis D5 downward.

Claims (9)

1. A Chair with:

   a) a sub frame (1) set on the floor;

   b) mechanism (2) set on the sub frame (1);

   c) seat (3) set on the mechanism (2); and

   d) backrest (7) attached to the mechanism (2), which:

   da) exhibits a backrest frame (5) which supports an elastically deformable backrest part (6) with a back panel (62), which back panel (62) has a back part (60) to which a head restraint (61) is attached; and

   db) is capable of pivoting about a first pivot shaft (D1) from an essentially upright, neutral position (B₀ ) to a reclined position (B₁ ) displaced towards the rear, wherein the movements of the seat (3) and the backrest (7) are synchronized with one another, so that:

   e) in the event of the elastic deformation of the back part (60) into a free space for the backrest frame (5), by the application of a force (F) in the direction of the reclined position (B₁ ) having in principle a concave tendency to the back of the user, means (53,67,D4;55,610,D5) are provided for an opposing raising of the shoulder area, as a transitional zone of the back part (60) towards the head restraint (61), and of the head restraint (61); and

   f) the backrest frame (5) is rigid and consists of two lateral braces (51), characterized in that

   g) as connections between the lateral braces (51) are provided:

   ga) a central transverse brace (54), through which the fourth pivot shaft (D4) extends with the first preformed part (543) articulated with it; and

   gb) an upper transverse strut (56), through which the fifth pivot shaft (D5) extends with the second preformed part (563) articulated with it.
2. The chair as claimed in claim 1, characterized in that

   a) as a further connection a transverse strut (52) is arranged between the lateral braces (51);

   b) the transverse strut (52) in each case consists of a connecting piece (520) extending from the associated lateral brace (51) and a bridging piece (521) which engages into both of the mutually aligned connecting pieces (520);

   c) the central transverse brace (54) in each case consists of a connecting piece (540) extending from the associated lateral brace (51) and an axle rod (541) which engages into both of the mutually aligned connecting pieces (540) and carries the first preformed part (543); and

   d) the upper transverse brace (56) in each case consists of a prolongation (560) extending from the associated lateral brace (51) and an axle rod (561) which engages into both of the mutually aligned prolongations (560) and carries the second preformed part (563).
3. The chair as claimed in at least one of claims 1 and 2, characterized in that

   a) a fourth pivot shaft (D4), which lies on a level with the lumbar area (603) in the vertical sense, and on which a first preformed part (543) is articulated with a first docking part (53), which first docking part (53) is attached to the second docking part (67); and

   b) a fifth pivot shaft (D5), which lies on a level with the neck area (613) in the vertical sense and on which a second preformed part (563) is articulated with a third docking part (55), which third docking part (55) is attached to the fourth docking part (610).
4. The chair as claimed in at least one of claims 1 to 3, characterized in that

   a) the first docking part (53) and the second docking part (67), and the third docking part (55) and the fourth docking part (610), are detachably attached to one another by means of locking means (531,671;551,552);

   b) the first docking part (53) and the third docking part (55) are embodied as push-in elements; and

   c) the second docking part (67) and the fourth docking part (610) are embodied as sleeves which extend from the rear side (608) of the back panel (62).
5. The chair as claimed in at least one of claims 1 to 4, characterized in that

   a) the back part (60) and the head restraint (61) of the back panel (62) blend uniformly into one another;

   b) the head restraint (61) is divided into a lower, first head section (611), which fits onto the back part (60), and an upper, second head section (612), which first head section (611) forms a neck area (613) together with a neighbouring part of the second head section (612);

   c) a fourth docking part (610) is provided in the neck area (613);

   d) the back part (60) is divided into an upper, first back section (601), which fits onto the neck area (613), and a lower, second back section (602), wherein the second back section (602) forms a lumbar area (603) together with a neighbouring part of the first back section (601); and

   e) a second docking part (67) is provided in the lumbar area (603).
6. The chair as claimed in at least one of claims 1 to 5, characterized in that

   a) a lumbar support (65) that is capable of vertical displacement is arranged in the lower area of the back panel (62) on its front side (607);

   b) strengthening ribs (609) and a cell (66) intended to accept an adjusting lever (64) for the adjustment of the lumbar support (65) are provided on the rear side (608) of the back panel (62); and

   c) vertical slots (606) for guiding the lumbar support (65) are present on the front side (607) of the back panel (62), which vertical slots (606) follow the course of the strengthening ribs (609) and extend over the lumbar area (603).
7. The chair as claimed in at least one of claims 1 to 6, characterized in that

   a) the mechanism (2) consists of a fixed base (20) set on the sub frame (1) and a seat carrier (21) attached to the base (20);

   b) the seat carrier (21) is attached to the base (20), on:

   ba) the first fixed pivot shaft (D1);

   bb) a second moving pivot shaft (D2), which faces towards the rear edge (31) of the seat;

   bc) a third moving pivot shaft (D3), which faces towards the front edge (30) of the seat;

   c) the two lateral braces (51) having on their lower ends close to the transverse strut (52), in each case a prolongation (50);

   d) a prolongation (50) of the backrest frame (5) in each case is attached to a frame connection (22) in each case, which is articulated with the first pivot shaft (D1) on the one hand and with the second pivot shaft (D2) on the other hand; and

   e) in the mechanism (2), a spring subassembly (211) generates a pretension, which endeavours to retain the backrest (7) in the upright, neutral position (B₀ ).
8. The chair as claimed in at least one of claims 1 to 7, characterized in that

   a) the back panel (62) consists of plastic;

   b) the lumbar area (603) of the back panel (62) possesses outer flanks (604) with a tendency to engage in principle around the user;

   c) the head restraint (61) exhibits a curvature in its vertical cross section with a tendency to present an essentially convex surface to the user; and

   d) the fifth pivot shaft (D5) lies in the direction of the front edge (30) of the seat ahead of the upper edge of the head restraint (61) and ahead of the fourth pivot shaft (D4).
9. The chair as claimed in at least one of claims 1 to 8, characterized in that

   a) the back panel (62) is surrounded by a covering (68), preferably a plastic foam material; and

   b) the covering (68) is covered by a cover (69,69'); wherein

   c) the cover (69') for the head restraint (61) preferably takes the form of a separate, replaceable part.

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