EP0593881A1 - A seat-support for sitting furniture - Google Patents

Abstract

The invention relates to a seat-support for sitting furniture, having a base body which is connected to a leg extension of the piece of sitting furniture and supports the essential elements for ensuring displacement or adjustment of individual elements of the piece of sitting furniture in accordance with the requirements of the individual user, such as for example the link of the back and/or of the seat, the link (6) of the back (2) cooperating via a linkage with a damping member, in particular a gas spring (16). A locking device in the form of a complete constructional unit to be installed in the base body (8) of the seat-support and intended for the mobility of the link (6) and hence of the back (2) is provided, the locking device closing the gas spring (16) for a fixed link (6) and opening the gas spring (16) for a movable link (6), and the two settings of the link (6) being able to be set by the user via the locking device by means of an actuating part, in particular a handle (37), which is to be operated. <IMAGE>

Description

The present invention relates to a seat support for seating furniture according to the preamble of claim 1 and a seating furniture using the seat support according to the invention.

The object of the present invention is to provide a seat support for seating furniture which enables a simple construction which is favorable in terms of production technology and which is highly user-friendly and reliable.

This task is solved in the generic seat carrier by the combination of the features of the characterizing part. In contrast to known constructions of the prior art, such as the slat construction according to DE-PS 30 30 009, the invention has only one damping member for backrest adjustment, in particular a gas spring, which interacts with a locking device provided as a complete structural unit. The gas spring usually has a valve which can be actuated by the locking device, the locking device being adjustable by the user via an actuating part, in particular via a handle. As a result, the necessary parts of the generic seat carrier can be significantly reduced compared to previously known solutions.

According to claim 2 it is provided that the action of the gas spring is carried out via a longitudinally displaceable pin of the locking device, which creates the possibility to easily control the locking device, namely so that only a longitudinal displacement of the pin necessary is. The embodiment of claims 3 and 4 have the advantage that the control of the pen is carried out only by pressurization at its free end, the locking - as in a ballpoint pen - changes with each pressurization of the pen. The design means that the user only ever has to operate the handle in the same way to unlock or lock the backrest.

The object of claim 5 has the advantage that all parts connected to the handle and transmitting the rotary movement are not visible from the outside, since they run in the cross member. In addition, these parts are effectively protected against contamination. Finally, the risk of injury is reduced by avoiding parts protruding from the underside of the seat.

The base body is preferably designed like a housing, the gas spring and its locking means being arranged within the base body.

According to claim 6, the base body is connected with the interposition of a rocker with the seat, which has the advantage that different rockers can be mounted, so that for example when synchronizing the movement of the backrest and the movement of the rocker of the seat different synchronization angles can be achieved depending on customer requirements .

In order to maintain a comfortable sitting position when pivoting the backrest to the rear, it is provided according to the invention that the inclination of the rocker changes with the inclination of the rocker for the backrest, in such a way that the rear region of the seat, which directly adjoins the backrest pivoted slightly downwards. This maintains an ergonomically favorable positioning of the backrest and seat.

It is structurally advantageous if the housing of the gas spring is arranged to be longitudinally movable in the base body. Here, the plunger of the gas spring can act as a fixed part, for example on the locking device, which serves as an abutment. In the latter embodiment, a synchronization of the movement of the backrest to the rocker of the seat can also be achieved in that the rocker engages on a fastening part of the housing of the gas spring via at least one inclined or curved cam part. The cam surface is designed such that when the rocker arm of the backrest is pivoted backwards, due to the movement of the housing of the gas spring or its fastening part, the rocker arm swings downward on the side facing the backrest.

If - according to a further embodiment of the seat support according to the invention according to claim 10 - the rocker is equipped with an adjustment device, in particular a spindle for any adjustment of the seat inclination, the pivoting range of the backrest can be changed by adjusting the adjustment device or spindle, i.e. be made smaller. The force exerted by the spindle is transmitted to the fastening part of the gas spring via the cam surface of the rocker and causes something to be displaced longitudinally from its rest, which reduces the stroke of the gas spring.

The object of claim 11 is particularly simple from a design point of view, since the cross bolt as a fastening part of the housing of the gas spring firstly ensures the guidance of the gas spring within the base body and secondly forms the receptacle for the cam surface of the rocker for the seat.

A common movement from the swing arm to the backrest Swing arm of the seat can also be achieved in that the rocker arm of the seat is connected to one another via a synchronization linkage which is rotatably mounted on both sides with the cross bar and a lever arm fixedly arranged thereon. The synchronization linkage thus transmits the rotary movement of the crossbar and thus the swing arm of the backrest to the swing arm of the seat.

A further embodiment of the invention, in particular intended for a standard seat support model, is characterized in that the rocker arm is connected to the base body so that it does not move, so that there is no movement even when the backrest is moved.

According to the invention, an additional damping element is provided for damping the movement of the backrest, to ensure effective damping even for people with a high body weight.

The damping element is expediently designed so that when the rocker arm of the backrest is pivoted back, the damping element is compressed.

The subject matter of claim 16 describes a structurally very simple configuration of the attenuator, which can be assembled in a simple manner and, moreover, consists of a few parts.

The damping effect of the attenuator is also adjustable depending on the weight of the user.

The subject matter of claim 18 offers a very simple possibility of constructively realizing the attenuator. In addition, assembly is particularly easy.

The subclaims 20-24 relate to expedient configurations of the seat height adjustment, which also applies in this way it is provided that all transmission parts starting from the handle on the outside of the crossbar run inside the crossbar and are therefore not visible from the outside. The Bowden cable intended for power transmission is changed in its longitudinal extent via inclined planes on the handle side, which are rotated relative to one another. The use of two inclined planes which can be rotated relative to one another has the advantage that these parts can also be accommodated within the cross member.

The subject matter of claim 23 offers a particularly simple possibility of ensuring a restoring force of the seat height adjustment mechanism.

The base body is expediently designed like a housing, the gas spring, locking device, damping element and seat height adjustment mechanism being arranged for the most part within the base body and therefore not accessible or not visible from the outside. Only the transmitting parts starting from the handles arranged on both sides of the crossbars are located within the crossbars in question, which creates a very compact design. The basic body is designed as a module as a unitary part, so that there is the possibility of using the seat support for different chair types. Only minor modifications or adjustments are necessary.

Appropriately, the base body for accommodating the individual parts can have a plurality of chambers running transversely to the two cross bars. This results in advantages in terms of assembly, for example the lateral guidance of the fastening element of the gas spring.

In order to be able to carry out a simple connection of the backrest to the swing arm, which is also to be carried out by the customer, the connection between the swing arm and the backrest is form-fitting on the rocker slide-on holding part is provided, which is attached to the backrest. Since the swing arm of the backrest tapers towards the top, the holding part can be pushed downward onto the swing arm if the holding part is designed analogously.

A device for quick locking is expediently provided for connecting the parts.

The invention also relates to seating furniture with a seat, a backrest, a foot extension and a foot frame using the seat support according to the invention according to at least one of claims 1-27.

Fig. 1

einen Bürodrehstuhl unter Verwendung des erfindungsgemäßen Sitzträgers in Vorderansicht;

Fig. 2

eine Teilschnittdarstellung des Grundkörpers entlang der Schnittlinie I - I in Fig. 1 in Blickrichtung A;

Fig. 3

eine Teilschnittdarstellung des Grundkörpers entlang der Schnittlinie II - II in Fig. 1 in Blickrichtung B;

Fig. 4

das Prinzip der Sitzhöhenverstellung in der Ausgangsstellung (a) sowie in der Stellung während der die Höhenverstellung erfolgt (b);

Fig. 5

eine Draufsicht auf den Innenteil des Grundkörpers;

Fig. 6

eine Rückansicht des Bürodrehstuhls gemäß Fig. 1 in stark vereinfachter Darstellungsweise;

Fig. 7

je eine Teildarstellung der Schwinge für den Sitz sowie des Querholms der Rückenlehne einschließlich des Betätigungsarms in Ausgangsstellung (a) sowie in verschwenkter Stellung (b), wobei die Schwinge für den Sitz hierbei starr ausgebildet ist;

Fig. 8

zeigt eine Möglichkeit der synchronisierten Bewegung der Schwinge der Rückenlehne und der Schwinge für den Sitz in Ausgangsstellung (a) sowie verschwenkter Stellung (b) und

Fig. 9

eine Ausgestaltung zur synchronen Bewegung der beiden Schwingen zueinander unter Verwendung einer zusätzlichen Einstelleinrichtung in verschiedenen Stellungen (a - c).

Various configurations of the present invention are explained in more detail below with reference to the drawings. Show it:

Fig. 1

an office swivel chair using the seat support according to the invention in front view;

Fig. 2

a partial sectional view of the base body along the section line I - I in Figure 1 in viewing direction A;

Fig. 3

a partial sectional view of the base body along the section line II - II in Figure 1 in viewing direction B;

Fig. 4

the principle of the seat height adjustment in the starting position (a) and in the position during which the height adjustment takes place (b);

Fig. 5

a plan view of the inner part of the base body;

Fig. 6

a rear view of the office swivel chair according to Figure 1 in a greatly simplified representation.

Fig. 7

a partial representation of the rocker for the seat and the crossbar of the backrest including the actuating arm in the starting position (a) and in the pivoted position (b), the rocker for the seat being rigid;

Fig. 8

shows a possibility of synchronized movement of the rocker of the backrest and the rocker for the seat in the starting position (a) and pivoted position (b) and

Fig. 9

an embodiment for the synchronous movement of the two rockers to each other using an additional setting device in different positions (a - c).

Reference number 1 denotes an office swivel chair using the seat body according to the invention. The office swivel chair comprises a backrest 2, a seat 3 and a housing-like base body 8 which merges into a foot extension 4 which is preferably telescopic. There is a base 5 on the underside of the foot extension 4.

Two cross bars 30, 31 open into the respective side area of the base body 8 and are pivotably mounted in the latter. The two cross bars 30, 31 form part of the rocker arm 6, which supports the backrest 2. There is a handle 36, 37 on each end of the two crossbars 30, 31, which - as will be explained in detail later - each for the adjustment of the backrest mobility and for the height adjustment the seat is provided.

On the underside of the base body 8 there is a spindle 15 or 53 for setting the damping of the backrest 2 desired by the user and the pivoting position and pivoting movement of the seat 3. This will also be explained in more detail below.

From Fig. 2, the control and adjustment of the backrest is clear. As can already be seen from FIG. 1, the rocker 6 of the backrest is connected to the respective cross member 31, of which the cross member 30 is shown in FIG. 2. Both cross bars 30, 31 are rotatably mounted in the interior of the base body 8.

The cross member 31 is connected in a rotationally fixed manner to two lever arms, the lever arms being arranged on both sides of the housing 20 of a locking device. For the sake of clarity, only the rear lever arm 12 is shown in FIG. 2. The two lever arms are provided in order to transmit the pivoting movement of the backrest 6 to a gas spring 16 in the interior of the base body 8. For this purpose, two actuating arms are provided, which on the one hand with the respective lever arm e.g. 12 are pivotally connected and act on a transverse pin 26 at their opposite end. For the sake of clarity, only the rear actuating arm 19 is shown in FIG. 2.

The cross pin 26 extends transversely through a head region of the housing 24 of the gas spring 16 and through the two actuating arms and is guided in two longitudinal holes 38, 39 on the housing of the base body 8 (cf. also FIG. 4).

The housing 20 of the locking device is connected to the base body 8 in a manner fixed against movement. The locking device forms a complete component, as it were. The housing 20 of the locking device serves as an abutment for the stamp 21 the gas spring 16.

The construction causes that when pivoting the backrest 6, i.e. Swiveling the crossbar 30 over the lever arms e.g. 12, the operating arms e.g. 19 the housing 24 of the gas spring 16 is moved in the longitudinal direction when the plunger 21 is stationary, which enables the backrest to be pivoted gently backwards when the valve (not shown) of the gas spring 16 is open. When the backrest is pivoted backwards, the gas present in the gas spring 16 is compressed, so that the backrest automatically returns to its starting position when the load is released. The inclination range of the backrest 2 is normally between approximately 95 ° and 111 °.

To actuate the valve of the gas spring 16, a longitudinally displaceable and cross-rotatable pin 47 is provided which passes through the housing 20 of the locking device and the stamp 21. Depending on the longitudinal position of the pin 47, the open or closed position of the gas spring 16 is set via the valve.

To actuate the pin 47, a rotatably mounted lever arm 34 is provided, which is controlled by a cam 33 connected to a shaft 32 guided in the interior of the cross member 30. The handle for actuating the shaft 32 and thus the pin 47 is, as shown in FIG. 1, at the end of the associated cross member.

The respective axial position of the pin 47 is determined by a control part 29 which has recesses 23 of different depths; 28, into which a projection 46 of a ring 48 connected to the housing 20 engages. The two different depths of the recesses provided in the control part ensure two different axial longitudinal positions of the pin 47.

So that each time the pin 47 is actuated via the lever arm 34, thus each time the handle 37 is rotated, a different axial position is locked in comparison to the previous one, on the rear of the control part, likewise in fixed connection with the housing 20 of the locking device Wreath 62 provided, the inclined planes 22, for example Serrations interact with the inclined planes 27 of the control part in such a way that when the pin 47 and thus the control part 29 are axially displaced, the latter is rotated slightly, so that the projection 46 of the ring 48 when springing back, i. when the pin 47 is relieved via the lever arm 34 into the next recess e.g. 23 engages.

The restoring force on the pin 47 is ensured by a spring or the like which is not shown in FIG. 2 for the sake of clarity.

Fig. 3 shows an embodiment of the seat support according to the invention, in which there is a synchronization between the movement of the backrest and the seat inclination.

To fasten the seat 3, the seat support has a one-piece rocker arm 9, each of which is pivotably connected to the base body 8, in particular screwed, via two support arms, of which only the support arm 62 is shown in FIG. 3.

This rocker is connected via a synchronization linkage 11 in the form of a double-articulated connecting rod to a lever arm 12 on the cross member 30. If, for example, the backrest is pivoted backwards, then the rocker arm 9 swivels slightly via the synchronization linkage 11, thereby maintaining an ergonomically favorable arrangement between the seat 3 and the backrest 2 even when the backrest 2 is pivoted backwards can be.

From Fig. 3 there is also an attenuator 13 in the form of a block of elastic material e.g. elastic polyurethane foam recognizable. The block 27 rests on its underside on a lever arm 34 which is connected to the cross bar 30. On the upper side there is a spring plate 14 which is fastened in the region of the base body 8 facing the cross member 31, comprises the block and is held at the opposite point by means of a spindle 15 arranged on the underside of the base body 8.

When the rocker 6 swings back, the lever arm 34 is pressed upward, as a result of which the damping member 13 is compressed and the back movement of the backrest 2 or its rocker 6 is thereby damped.

To set the damping effect for people of different weights, it is only necessary to actuate the spindle 15 located on the underside of the base body 8. By tightening the spindle 15, the damping effect can be increased by compressing the block 27 and correspondingly reduced when the spindle is loosened.

4 is also adjusted via a gas spring (not shown) provided in the foot extension 4, which is also controlled via a pin 50 running in the foot extension 4. For this purpose, a pivotably mounted lever arm 40 in the form of an angle is provided within the base body 8, the angle section of which is connected to a Bowden cable 42.

The Bowden cable 42 is actuated via two inclined planes 51, 52 accommodated in the cross member 30, which lie against one another in the normal state (passive position) (FIG. 4 a)), when pivoting the inclined plane 52 with respect to the inclined plane 51 by the handle 36, however, experience a displacement such that the part of the inclined plane 52 in question, which is connected to the Bowden cable 42, is pressed outwards, as a result of which the lever arm 40 is actuated and the pin 15 moves axially. The valve is then open, so the seat height can be adjusted.

On the top of the foot extension 4, preferably between the lever arm 40 and pin 50, a layer of elastic polyurethane foam is provided, which provides the necessary restoring force.

Fig. 5 shows the arrangement of the individual components within the base body 8. The base body 8 is constructed like a housing and has three chambers 43, 44 and 45, which run transversely to the two spars 30, 31 and through two central struts 27; 35 are formed.

The gas spring 16 and the locking device are located in the chamber 43 arranged on the left in FIG. 5.

The damper 13 and the synchronization rod 11 connected to the rocker 9, not shown, are located in the chamber 45 arranged on the right.

In the middle chamber 44, which is partially open towards the bottom, the lever arm 40 of the seat height adjustment mechanism is arranged, which via a disk-shaped part 41 made of elastic material, e.g. elastic polyurethane foam acts on the pin to open or close the gas spring housed in the foot extension.

To connect the backrest 2 to the rocker 6, a holding part 54 is screwed to the backrest 2 according to FIG. 6. The holding part 54 comprises two laterally arranged Projections 55, which partially enclose the rocker 6. For the sake of clarity, only one side of the holding part 54 is provided with the reference number 55. The backrest 2 is pushed together with the holding part 54 onto the rocker arm 6, which tapers upwards and is secured via a snap connection 56.

Fig. 7 shows two positions of an embodiment of the seat support, in which the rocker 9 of the seat is rigid. When the backrest is moved, the actuating arm 19 is consequently pulled forward, this movement being transmitted to the housing of the gas spring 16 via the cross bolt 26. The guidance takes place via the transverse bolt 26, which is arranged to be longitudinally displaceable within the two elongated holes 38, 39. The backrest and the seat are not synchronized in this embodiment.

8 shows the configuration of the seat support using the synchronization linkage 11. If the backrest is pivoted backwards from its basic position according to FIG. 8 a), the synchronization linkage 11 causes the rocker 9 for the seat 2 to pivot slightly (FIG. 8 b). ) in a range from -1 ° to 6 ° based on the horizontal. At the same time, the synchronization also means that when the seat is loaded, i.e. the swing arm 9 a slight pivoting caused by this is transmitted to the swing arm 6 and thus to the backrest 2.

FIG. 9 shows a further embodiment of the seat support according to the invention, in which the seat inclination can additionally be adjusted by hand using a spindle 53. The synchronization of the movement of the rocker 9 of the seat with the movement of the rocker 6 of the backrest 2 takes place via two inclined cam surfaces of the rocker 9, which rest on the top of the cross pin 26. For the sake of clarity, only the cam surface 25 is shown in Fig. 9.

On the one hand, the cam surfaces alone synchronize the movement from the backrest to the seat. This is because the backrest is pivoted backwards, the housing of the gas spring being pulled forward via the two actuating arms and the transverse bolt, so that the rocker arm swings slightly for the seat.

9, a holding part 61 is provided on the underside of the rocker 9, which serves as an abutment for a spindle 53 provided on the underside of the base body 8. The spindle is held in the holding part via a cross pin 60, which is positioned within a longitudinal hole 59.

If the spindle 53 is tightened out of the starting position according to FIG. 9 a), which increases the inclination of the seat and the rocker 9 for the seat, the inclination of the backrest changes due to the cam surfaces which act on the transverse bolt 26 ( see Fig. 9 b)). The movement of the seat to the backrest takes place in a ratio of approximately 1: 1.1.

A limited mobility of the backrest can then take place in this setting (FIG. 9c).

REFERENCE SIGN LIST

1

Seating

2nd

backrest

3rd

Seat

4th

Process of the foot

5

Wreath

6

Swing arm for backrest

7

Crossbar

8th

Basic body

9

Swing arm for seat

10th

Lever arm

11

Synchronization linkage

12th

Lever arm

13

Attenuator

14

Counter bearing (spring plate)

15

spindle

16

Gas spring

17th

Guide bushing

18th

Spring rod

19th

Operating arm

20th

Housing of the locking device

21

stamp

22

sloping surface

23

Exemption

24th

Gas spring housing

25th

Cam surface

26

Cross bolt

27

Middle strut

28

Recess

29

Control section

30th

Querholm

31

Querholm

32

wave

33

Cam

34

Lever arm

35

Middle strut

36

Handle

37

Handle

38

Longitudinal hole

39

Longitudinal hole

40

Lever arm

41

disc-shaped part

42

Bowden cable

43

chamber

44

chamber

45

chamber

46

head Start

47

pen

48

wreath

49

Mating ring

50

Pin in the process of the foot

51

inclined plane

52

inclined plane

53

spindle

54

Holding part

55

head Start

56

Snap connection

57

Lever arm

58

Support arm

59

Longitudinal hole

60

Cross pin

61

Holding part

62

Support arm

Claims (28)

Seat support for seating furniture with a base body, which is connected to a foot extension of the seating furniture and the essential elements for ensuring an adjustment or adjustment of individual elements of the seating furniture such as, for example, the requirements of the respective user. B. carries the swing arm of the backrest and / or the seat,
marked by
following features: a) the rocker (6) of the backrest (2) interacts with a damping member, in particular a gas spring (16) via a linkage; b) there is a locking device in the form of a complete structural unit to be installed in the base body (8) of the seat support for the mobility of the rocker (6) and thus of the backrest (2), the gas spring (16) for a fixed rocker (6) closes and the gas spring (16) opens for a movable rocker (6); c) the two settings of the rocker (6) can be adjusted by the user via the locking device by means of an operating part to be operated, in particular a handle (37). Seat support according to claim 1,
characterized,
that the locking device one with the gas spring (16) connected, longitudinally displaceable pin (47) which can be locked in two axial positions in the longitudinal direction and the two positions determine the respective settings of the gas spring (16). Seat support according to claim 2,
characterized,
that the pin (47) runs in a housing (20) of the locking device, on the outside of the pin an annular control part (29) is provided which, to ensure the longitudinal position of the pin (47) to be locked, recesses (23; 28) of different depths which is engaged by at least one projection (46) of a ring (48) fixed to the housing (20) of the locking device or vice versa. Seat support according to claim 3,
characterized,
that a restoring force acts on the pin (47) and the same is pivoted each time the pin (47) is actuated due to the interaction of inclined planes. Seat support according to at least one of the preceding claims,
characterized,
that the locking device is arranged on the outside of the one cross member (31) of the rocker (6) Handle (37) can be actuated, the rotary movement of the handle (31) via a shaft (32) extending inside the cross member (31), a cam (33) fixedly connected to the shaft (32) and a lever arm moved by the cam ( 34) is transferred to the pin (47). Seat support according to at least one of the preceding claims,
characterized,
that a rocker (9) for the seat (3) is mounted on the base body (8). Seat support according to claim 6,
characterized,
that the inclination of the rocker (9) changes with the inclination of the rocker (6) for the backrest (2). Seat support according to claim 6 or 7,
characterized,
that the housing (24) of the gas spring (16) in the base body (8) is arranged to be longitudinally movable. . Seat support according to claim 8,
characterized,
that the rocker (9) on at least one inclined or curved cam surface (25) on one Fastening part of the housing (24) of the gas spring (16) engages. Seat support according to claim 9,
characterized,
that the rocker (9) is equipped with an adjusting device, in particular a spindle (53), for any adjustment of the seat inclination. Seat support according to at least one of claims 8-10,
characterized,
that the fastening part is a cross bolt (26) which is connected to the head (24) of the gas spring (16) and is guided so as to be longitudinally displaceable within two longitudinal holes (38, 39) in the base body (8). Seat support according to at least one of claims 6 - 11,
characterized,
that the rocker (6) with a lever arm (for example 30) on the cross arm (31) are connected to one another via a synchronously rotatably mounted synchronous linkage (11). Seat support according to claim 7,
characterized,
that the rocker (9) is fixedly connected to the base body (8) and rests on the obliquely formed section of the actuating arm (19). Seat support in particular according to at least one of claims 1-13,
characterized,
that an additional damping member (13) is provided to dampen the movement of the backrest (2). Seat support according to claim 14,
characterized,
that the damping member (13) is designed so that when the rocker (6) is pivoted back, the damping member is compressed. Seat support according to claim 14 or 15,
characterized,
that a lever arm (12), which is firmly connected to the rocker (6), engages on the underside of the damping member (13) and a holding part (14) arranged on the top of the damping member is provided as an abutment. Seat support according to claim 15 or 16,
characterized,
that the damping effect of the attenuator (13) is adjustable. Seat support according to claim 17,
characterized,
that the holding part (14) is pivotally connected on one side to the base body (8), in the central region of which a recess (28) is provided which partially surrounds the damping member and the holding part (14) at the other end with a spindle (15) is connected, which ensures a certain compression of the attenuator depending on the spindle position. Seat support according to at least one of claims 15-18,
characterized,
that the attenuator (13) consists of a block of elastic polyurethane foam. Seat support, in particular according to at least one of claims 1-19,
characterized,
that the seat height is adjusted via a gas spring (35) provided in the foot extension (4), which can be closed or opened via a longitudinally displaceable pin (50), the control being effected via a handle (36) arranged on the outside of the cross member (31) which moves a lever arm (40) via an actuating part, which acts on the pin (50) for longitudinal movement thereof. Seat support according to claim 17,
characterized,
that the handle (36) and the lever arm (40) are connected via a Bowden cable (42) which is longitudinally movable by the handle (36). Seat support according to claim 20 or 21,
characterized,
that the longitudinal movement of the actuating part, in particular Bowden cable (42) takes place over two inclined planes (51, 52) which can be rotated relative to one another within the cross member (31). Seat support according to at least one of claims 20-22,
characterized,
that the restoring force of the seat height adjustment takes place via a preferably disc-shaped part (41) made of elastic material which is acted upon by the lever arm (40). Seat support according to claim 23,
characterized,
that the disc-shaped part (41) consists of elastic polyurethane foam. Seat support according to at least one of the preceding claims,
characterized,
that the base body (4) is constructed as a basic module and has several elongate chambers (43 - 45) running transversely to the two cross bars (30, 31), which the locking device for the backrest (2) including the gas spring (16) for the Backrest movement, the damping element (13) and the lever arm (40) for the seat height adjustment include. Seat support according to at least one of the preceding claims,
characterized,
that the connection of rocker (6) and backrest (2) via a form-fitting on the rocker (6) slide-on holding part (54). Seat support according to claim 26,
characterized,
that the holding part (53) is equipped with quick locking means for locking with the rocker which is attached to the backrest. Office chair with a backrest, a seat, a foot in the shape of a star base and a foot extension,
marked by
a seat support according to at least one of claims 1-27.

Images