EP0303996B1 - Working-chair with a tiltable seat - Google Patents

Abstract

A work or office chair having a seat shell which is pivotably arranged on a height-adjustable seat carrier, characterized by the seat shell being spring loaded to oppose tilting of the seat shell from a raised position towards a tilted, lower position. The chair includes a fixing arrangement for fixing the chair in specific tilted positions. One improvement is a spring arrangement for supporting the chair and a toggle arrangement coacting with the spring arrangement for opposing tilting of the chair with the springs of the toggle arrangement and the supporting spring coacting to require a substantial force to cause initial tilting then followed by a gradual force to cause tilting.

Description

The invention relates to a work chair with a seat shell which is pivotable in its inclination on a height-adjustable seat support, which is spring-loaded against the seat load by means of a force element arrangement arranged in the seat support and can be fixed in different swivel positions by means of a blocking element arrangement, the seat shell being next to it Front edge is connected to the seat support via a pivot axis

So-called tilt mechanisms for chairs and in particular for work chairs of the type mentioned at the outset are known, which, in order to meet ergonomic requirements, are equipped with very complex chair mechanisms, the adjustment of the backrest and seat being carried out separately or synchronously. The mechanics are mainly designed so that an adjustment can only be made with a loaded seat, which then takes place more or less suddenly according to the mass on the seat.

With the knowledge of these features of known embodiments, which are perceived as disadvantageous and justified in the chair mechanism itself, the present invention was based on the object of creating a chair mechanism which on the one hand enables the use of relatively simple elements, and on the other hand an inclination adjustment with a transition from an inclination position that is as fluid as possible to equip to another, to which there was still a need for a concealed mechanism and a completely new look for a chair equipped in this way.

According to this task, the present invention provides that the force element arrangement of the chair mechanism consists of a spring element supporting the seat shell to support the seat shell supporting the base shell at the transition area of the seat surface from a first spaced apart from the front pivot axis of the seat shell on the knee joint arrangement to the back surface of the seat shell supporting spring element, one toggle lever of the toggle arrangement with one end pivotable on a bearing pin on the seat support and the other a locking pin for interaction with a blocking device having toggle lever via a hinge pin on the other free end of the first-mentioned toggle lever, the first spring element articulated at one end to the first-mentioned toggle lever and fixed at the other end to the seat support in its orientation in the seat support for the pivoting movement of the toggle lever arrangement a pr aggressive spring characteristic and the second spring element receiving the basic load has a linear spring characteristic in its orientation to the load on it, and both spring elements are designed for a mutual superimposition of the two spring movements for the purpose of soft seat shell cushioning and adjustment.

With this basic embodiment according to the present invention, it is basically achieved that the special arrangement of the spring elements overlaps two spring movements in connection with an as The knee lever arrangement, which is a characteristic feature, leads to a particularly soft adjustment of the seat shell.

In the further development of this basic design, and in the endeavor to accommodate a mechanism that is as completely concealed in the seat support, it is therefore provided that the lever of the toggle lever arrangement which is articulated on the pivotable part of the first or below the seat support is articulated by means of a pin via a spring receptacle in the form of a Tension spring is formed, which is arranged longitudinally in the seat support and anchored at the outer end of the same, and that by corresponding fixing or positioning of the pin on the lower toggle lever, the first spring element is given the linear spring characteristic of the other, second spring element overlapping non-linear spring characteristic.

In the special embodiment of the second spring element, which supports the seat shell at the transition area to the backrest part directly vertically, it is provided that the spring is mounted in a visually concealed manner in a two-part spring guide, and the lower spring guide part can be pivoted on the bottom side by means of a bearing bolt on a support fork fixedly arranged on the seat support superimposed, the spring element on the head side has a longitudinally axially guided fork flange by means of a guide pin, the fork of which is penetrated by an axis with freely rotating rollers thereon, on which the seat shell rolls on a circular path formed as a recess, and the fork flange furthermore a doe pivoting movement of the spring element for Change of the spring engagement point by hand via a flexible shaft causing spindle drive with a spindle nut pivoted in the fork and has a spindle drive in engagement therewith.

In this way it is achieved by means of a spindle drive that the spring element supporting the base load is pivoted out of the vertical by hand via a flexible shaft and the suspension axis for the deflection path of the toggle lever arrangement acted upon by the first spring element can be changed almost continuously to adapt to the mass seated on the seat shell .

It is also essential for the soft inclination adjustment that the latching element is arranged in the form of a latching pin at the lower free end of the upper toggle lever which is pivotably supported on the lower toggle lever and which engages through a guide slot of a blocking lever pivotably mounted in the seat support and can be latched into the latching recesses provided in the guide slot is, whereby when the seat pan is tilted, the spring force of the first spring element articulated on the lower toggle lever continuously counteracts the seated load, and the function causing disengagement and engagement is carried out solely by the pivoting movement of the blocking lever by means of the locking lever attached to it by hand via an actuating shaft with a button becomes.

Further features and advantages, as well as the interaction of the individual elements, will become apparent from the following detailed explanations of the present invention, which makes reference to the accompanying drawings.

Figur 1

eine Seitenansicht der Stuhlmechanik gemäß der Erfindung entlang der Schnittlinie I-I der Figur 2;

Figur 2

eine Draufsicht auf die Stuhlmechanik der Figur 1;

Figur 3a und 3b

eine Detaildarstellung der Blockiervorrichtung im entrasteten bzw. eingerasteten Zustand,

Figur 4

eine Detaildarstellung der Rastausnehungen im Führungsschlitz des Blockierhebels;

Figur 5

die Stützkraftkennlinie des am Kniehebel ansetzenden Federelements;

Figur 6

die Stützkraftkennlinie des die Grundlast abstützenden Federelements;

Figur 7

die Stützkraftkennlienie im Zusammenwirken beider Federn;

Figur 8

eine Stirnansicht der Stuhlmechanik in Blickrichtung des Pfeiles VIII der Figur 1;

Figur 9

die konzentrisch aus dem Stahlrohrelement austretende und zum Spindelantrieb führende biegsame Welle;

Figur 10

eine Seitenansicht (Silhouette) eines mit der erfindungsgemäßen Stuhlmechanik ausgerüsteten Arbeitsstuhls;

Figur 11

eine Seitenansicht ähnlich der der Figur 1, jedoch mit der Sitzschale in der unteren Position und dem Federelement (Grundlastfeder) nicht ausgeschwenkt.

In the drawings -

Figure 1

a side view of the chair mechanism according to the invention along the section line II of Figure 2;

Figure 2

a plan view of the chair mechanism of Figure 1;

Figure 3a and 3b

a detailed representation of the blocking device in the unlocked or locked state,

Figure 4

a detailed view of the locking recesses in the guide slot of the locking lever;

Figure 5

the supporting force characteristic of the spring element attached to the toggle lever;

Figure 6

the supporting force characteristic of the spring element supporting the base load;

Figure 7

the supporting force characteristics in the interaction of both springs;

Figure 8

an end view of the chair mechanism in the direction of arrow VIII of Figure 1;

Figure 9

the flexible shaft emerging concentrically from the tubular steel element and leading to the spindle drive;

Figure 10

a side view (silhouette) of a work chair equipped with the chair mechanism according to the invention;

Figure 11

a side view similar to that of Figure 1, but with the seat shell in the lower position and the spring element (base load spring) not swung out.

1 shows the side view of the chair mechanism according to the invention in the preferred embodiment. On a foot frame (not shown in detail) with a lift unit known per se 17, a preferably diagonally projecting support in the form of a seat support 1 is fixed on the head side of the vertical lift column by means of a conical receptacle 18.

The outer end of the seat support 1 forms the pivot point of the seat shell 2 resting thereon, the front edge of which is pivotally connected to the seat support 1 on the pivot axis 8. The rear or backrest transition area is supported by a spring element 4 which is vertically aligned in the starting position and is supported on a fork 44 which is fastened to the conical receptacle 18 with respect to the seat support 1. The seat shell 2 is supported in the central region by a toggle lever arrangement 5, 6, which in the illustrated embodiment of the chair mechanism is acted upon in the supporting sense by a spring element 3 arranged longitudinally in the seat support.

Figure 1 shows the chair mechanism according to the invention in the starting position, i.e. with the seat shell 2 in the upper locking position. The toggle lever arrangement is pivotably mounted with the lower lever 6 on a bearing pin 10 of the seat support 1, and in this starting position lies with a molded stop cam next to a stop element 59 on the seat support side.

The spring element 3 in the form of a pressure point spring is arranged between the lower lever 6 of the toggle lever arrangement and the outer end of the seat support 1. A pin 68, on which the spring is suspended by means of a spring receptacle 38, serves as the articulation point on the lever 6. The other end of the spring 3 is at the end of the seat support 1 anchored to a stop plate by means of a stop bolt 36 with nut 37, as can be seen in particular from FIG. 2.

At the upper end of the lower lever 6, the upper toggle lever 5 of the toggle lever arrangement is pivotally mounted via a hinge pin. The toggle lever 5 is penetrated approximately in the central region by the hinge pin, and thus forms two swivel arms. The upper arm of the toggle lever 5 is connected in a supporting manner to the seat shell 2 via a bearing pin 9, while the lower arm of the toggle lever 5 carries a locking pin 15 which is firmly anchored and which engages with the blocking lever 14.

The blocking device initially consists of a shaft 27, which is shown in more detail in FIGS. 2 and 3. This shaft is rotatably mounted in a tubular steel element 30 and is connected in a rotationally fixed manner at the outside end to a blocking button 29. The other end projecting into the seat support 1 has a recess 28, with the free front end of the locking lever 24 resting against the spring around the outer circumference of this shaft 27. FIG. 3b shows the blocking device in the locked position. The free end of the locking lever 24 lies in the recess 28 of the shaft 27, and the locking pin 15 of the toggle lever 5 is fixed in a locking recess 16.

When the blocking button 29 is actuated, the shaft 27 is rotated, the free end of the locking lever 24 emerges from the recess 28, and the entire blocking device assumes the position shown in FIG. 3a. The locking lever 24, which is designed according to FIG. 2 with a ribbed plastic part Approach 26 is connected and carries a driving pin 25 which engages in an associated bore 34 on the blocking lever 14, is thereby pivoted, and with the pivoting of the locking lever 24, the blocking lever 14 is pivoted about the pivot point 23 at the same time. This position of the locking lever and the blocking lever is shown in FIG. 3a. Compared to the illustration in FIG. 3b, the toggle lever arrangement 5,6 is now unlocked, and in this non-locked position, the locking pin 15 can be moved in a straight line in the arrow directions 69 (FIG. 4) in the guide slot 39 of the blocking lever 14 when the seat shell 2 is pivoted .

With a counter-movement of the blocking button 29, the blocking lever 14 is pivoted back into the starting position via the locking lever 24, the locking pin 15 then comes back into the region of a locking recess 16, whereby the position of the seat shell 2 is blocked in both directions, namely in pivoting positions, as they are predetermined by the distance between the recesses 16.

In Figure 1, for example, a locking pin 15 'is shown in dashed lines, which has been moved into the rear end position of the guide slot 39, in which it is not locked.

The seat support 1 itself has, in a manner known per se, a lift assembly 17 which engages in the cone receptacle 18 via a corresponding gas spring. The valve of the gas spring is via an actuating cam 54 with a U-shaped pivot lever 53 which, as can be seen from FIG. 2, is pivotably mounted on the seat support 1 and at the opposite end of the lever via a screw 52 formed coupling element is connected to an actuating shaft 51. The actuating shaft 51 is rotatably mounted in a tubular steel element 30 and has an actuating button 50 connected to the shaft 51 in a rotationally fixed manner on the outside.

When the button 50 is actuated, the actuating shaft 51 and the screw 52 connected to it in a rotationally fixed manner are pivoted, as a result of which the pivot lever 53 actuates the valve for the height adjustment spring via the actuating cam 54.

The rear cushioning of the seat shell 2 is carried out by the spring element 4, which is mounted on the support fork 44 by means of a bearing pin 11 arranged on the lower part 45 of the spring guide so as to be pivotable out of the vertical. The lower spring guide includes an inner guide sleeve 56, onto which a helical compression spring as spring element 4 is pushed. An upper spring guide 46 is telescopically displaceable in the lower spring guide 45.

The helical compression spring 4 rests with its upper end against a flange forming the upper end of the upper spring guide. The upper spring guide 46 also includes an inner guide pin 55 which is freely displaceable in a central, central bore 57 of the lower spring guide 45. Through an opening provided in the bottom of the lower spring guide 45 and adapted to the cross section of the guide pin, the guide pin 55 can emerge from the floor, thus ensuring the required long-stroke travel.

The entire base load spring element 4 with upper and lower Spring guide 46, 45 is, as already explained and can be seen from the drawing figures, pivotally mounted on the bearing pin 11 on the seat support fork 44, and the entire spring arrangement 4 rolls up on the seat shell 2. In a preferred embodiment, the flange closing the upper spring guide 46 after the top is designed as a fork flange 49, the upwardly projecting forks being penetrated by a roller axis 48 on which two rollers 42 are rotatably arranged on the outside of the forks. These rolls 42 roll on a circular path 12 in the form of a recess 43 in the seat shell 2. The entire arrangement of the swing-out spring element 4 with support of the seat shell 2 via a roller arrangement enables the spring engagement point of the spring element 4 on the seat shell 2 to be adjusted and, in connection therewith, the very simple adaptation to different user weights.

An actuation chain is provided for adjustment from the position of the other operating elements, which includes a flexible shaft 33. For this purpose, a spindle nut 40 is arranged in the area of the roller axis 48 and is in engagement with a spindle 7. The spindle 7 is fixedly connected to the flexible shaft 33 via a counter bearing 70, the flexible shaft 33, as shown in dashed lines in FIG. 2 and shown in detail in FIG. 9, from the counter bearing 70 in a curved shape to the end of the actuating shaft 27 on the seat support side rotatably mounted tube element 30 and through a center bore of the shaft 27 to the outside end of the element 30, on which a weight adjustment button 32 is arranged and connected to the shaft 33 in a rotationally fixed manner. The weight adjustment button In the embodiment shown (FIG. 8), 32 is rotatably mounted in the blocking button 29.

By turning the flexible shaft 33 by means of the weight adjustment knob 32, the spindle 7 is rotated, the spindle nut 40 thereby moves in the direction of the arrow 41 (FIG. 1), for example to the rear, and assumes the position 40 '. This simultaneously rolls the roller assembly 42 in the region of the curve 12 in the recess 43 of the seat shell 2 and relocates the point of application of the spring element 4 to the seat shell 2, whereby the effective lever arm in the area L₁ / L₂ and the bias of this base load spring 4 in the area S₁ / S₂ is changed. Figure 1 illustrates the meaning of this measure in the dash-dotted representation.

It is consequently achieved with the arrangement according to the invention that the lever arm L₁ to L₂ can now be changed by actuating the spindle arrangement. It is also essential that when pivoting the seat pan 2, the spring force of the Federele element 4 is increased, namely by simultaneously biasing the spring more when adjusting this spring 4 via the spindle 7. This is caused by the fact that the roller arrangement 42 can roll in the region of the cam track 12, it being important that this cam track 12 is eccentric in the direction with respect to the lower bearing point 11, so that the rollers 42 in the direction of the arrow when the upper bearing point is adjusted 41 pivoted backwards and thus come to a curve area that pushes the spring 4 together more, namely by the displacement 47, as can be seen from the difference S₁ to S₂ (Figure 1).

The main advantage is thus achieved that the spring force can be adjusted simultaneously with the spindle adjustment. I.e. for a relatively small adjustment range, which is predetermined by the spindle length, the supporting force of the spring element 4 is changed disproportionately. In other words, on the one hand the entire spring arrangement is supported in a region of the seat shell 2 which is moved to the rear, and on the other hand the spring 4 is increasingly biased, which results in a double effect.

With regard to the drawing figures 5, 6 and 7 it should be explained that the arrangement, design and design of the spring elements 3, 4 together with the toggle lever arrangement 5, 6 led to the result, as shown by the curves of these figures, in particular the Superimposition of two spring movements leads to a particularly soft adjustment.

FIG. 5 shows the spring characteristic of spring 3, while FIG. 6 shows the spring characteristic of spring 4.

According to FIG. 6, the spring characteristic of spring 4 is linear, as represented by curve 60. The spring 4 is preloaded so that the spring tension starts at point 61. If the envisaged spring 3 were now missing, then a simple spring characteristic would result on the linear curve up to point 62, which would, however, have the disadvantage that this results in much too rapid downward pivoting when the bed is loaded on the body of the user. The user would swivel the seat shell immediately, even with a slight shift of weight to the rear, as is known, but is not desired.

In order to avoid this undesirable state, the linear curve 60 is assigned a non-linear curve 63 according to the spring characteristic of the spring 3, which is shown in FIG. 5.

As already described, the spring 3 is articulated on the lower toggle lever 6 of the toggle lever arrangement 5, 6, which means that this spring 3, and thus the entire seat shell 2, gives a progressive characteristic, as can be seen from curve 63 can be seen in Figure 5. First, the curve 63 has a curve section 64, which rises very steeply in relation to the spring travel and then merges flat into a relatively straight curve section 65. If the spring characteristic of the spring 3 (FIG. 5) is used to superimpose the spring characteristic of the spring 4 (FIG. 6) by means of other elements, as is done with the described mechanics of the present invention, a curve is produced as shown in FIG. 7 is shown. This curve, labeled 66, has a curve section 64 with a relatively steep rise, but then changes into a curve section 67 with a soft progression to the end position, which means that the user first of all exerts a relatively large force to pull out the seat pan to pivot their rest position, but then, after overcoming the steep curve section 64, which requires only a small or short swivel path, a soft curve section 67 is reached, with which a gentle swinging of the seat shell begins.

This particular spring characteristic or vibration characteristic of the seat shell is therefore achieved with a relatively inexpensive mechanism, as can also be seen in detail from the drawing figures.

The drawing figure 1 shows the position of the pivotable elements in the opposite end position in dash-dotted lines. The inclination positions of the seat shell 2 that can be adjusted by the predetermined latching recesses 16 are also shown. FIG. 11 also illustrates the position of the toggle lever arrangement 5, 6 and the spring element 3 articulated thereon in the lower pivoting position of the seat shell 2, the spring element 4 being able to allow the extreme inclination of the seat shell 2 when not pivoted out.

Finally, FIG. 10 shows, in a side view, how a chair, and here in particular a work chair, optically wins with this compact chair mechanism according to the invention if only a few compact elements are visible. With this chair mechanism according to the invention, it is no longer necessary to cover the entire area underneath the seat shell far down. As can be seen from FIG. 10, only an upper upward strut 72 is now visible, in which the entire mechanism according to FIG. 1 is accommodated. Only the upper part of the toggle lever 5 protrudes from this strut 72, while only the spring guide 45, 46 can be seen at the rear. The attractive thing about this illustration is that there is now an area 73 and an area 74 in which a clear view under the seat shell is possible, which leads to a completely new look.

Although a one-piece seat shell is generally assumed in this invention, it is of course also possible to mount the seat in the same way on the pivot axis 8 and to support it on the seat backrest, and the backrest is separated from the seat on one To store the pivot axis in or on the seat support, with a slight modification then using a point synchronous mechanism for transmitting the pivoting movement to the backrest part or other suitable transmission elements.

Drawing legend

1

Seat support

2nd

Seat shell

3rd

Spring element pressure point spring

4th

Spring element base load spring

5

Toggle lever, upper

6

Toggle lever, lower

7

Spindle drive

8th

Swivel axis

9

Swivel axis, bearing

10th

Bearing bolt

11

warehouse

12

Circular path

13

warehouse

14

Locking lever

15

Locking pin

16

Notches

17th

Lift column / lift unit

18th

conical mount

23

Bearing bolt

24th

Locking lever

25th

Driver pin

26

approach

27

Actuating shaft

28

Assumption

29

Blocking button

30th

Tubular steel element

31

Center hole

32

Weight adjustment knob

33

flexible shaft

34

drilling

35

Hinge pin, bearing point

36

Stop pin

37

mother

38

Feather mount

39

Guide slot

40

Spindle nut

41

Arrow direction

42

role

43

Recess in 2nd

44

Support fork

45

Lead, lower

46

Lead, upper

47

Displacement

48

Roller axis

49

Mounting flange / fork flange

50

button

51

Actuating shaft

52

screw

53

U-shaped swivel lever

54

Actuating cam

55

Guide pin

56

57

drilling

58

Stop cam

59

impact-absorbing element

60

Curve

61

Point

62

Point

63

Curve

64

Curve piece

65

Curve piece

66

Curve

67

Curve piece

68

Pin (spring linkage)

69

Arrow direction

70

Counter bearing

71

Area

72

strut

73

strut

74

Area

Claims (11)

1. A work chair with a seat shell (2) arranged so as to be orientable on a vertically adjustable seat carrier (1), which seat shell (2) is acted upon elastically against the sitting load by means of a force element arrangement arranged in the seat carrier, and is able to be secured in different positions of orientation by means of a locking element arrangement, in which the seat shell (2) nearest to its front edge is articulatedly connected with the seat carrier via a swivel axis (8),
   characterised in that
   the force element arrangement consists of a first spring element (3) acting on the seat shell (2) in a supporting manner via a knee-joint arrangement (5,6) at a distance from the swivel axis (8) on the front side, and of a second spring element(4) supporting on the seat carrier (1) the base load at the transition region of the seat surface to the support surface of the seat shell (2), one bent lever (6) of the bent lever arrangement is mounted so as to be orientable with one end on a bearing pin (10) on the seat carrier (1) and the other bent lever (5), having a detent pin (15) for cooperating with a locking device (14,24), is mounted via a joint pin (35) at the other free end of the lever (6), in which the spring element (3), which is articulated by one end on the bent lever (6) and is secured by the other end on the seat carrier (1), has a progressive spring characteristic in its alignment in the seat carrier (1) to the swivelling movement of the knee joint arrangement, and the second spring element (4), receiving the base load, has a linear spring characteristic in its alignment to the resting load, and both spring elements (3,4) are designed for a reciprocal overlapping of the two spring movements for the purpose of a gentle springing and adjustment of the seat shell.
2. A work chair according to Claim 1,
   characterised in that
   the spring element (3), which is articulated on the orientable part of the lever (6) by means of a pin (68) via a spring mounting (38), is constructed in the form of a tension spring which, arranged longitudinally in the seat carrier (1), is anchored at the outer end thereof, and that through the corresponding securing of the articulation position (pin 68) on the lever (6) of the bent lever arrangement, the spring element (3) is given the non-linear spring characteristic (curve 63) overlapping the linear spring characteristic (curve 60) of the spring element (4).
3. A work chair according to Claim 1 and 2,
   characterised in that
   the spring element (4) is mounted in a two-part spring guide (45,46), which rests orientably on the base side by means of a bearing pin (11) on a supporting branch (44) fixedly arranged on the seat carrier (1), the spring element(4) has on the head side a fork flange (49) guided on the longitudinal axis by means of a guide lug (55), the fork of which flange is penetrated by an axis (48) with rollers (42) turning freely thereon, on which rollers the seat shell (2) rolls in a supported manner on a circular path (12), moulded as recess (43), and the fork flange (49) in addition has a spindle drive bringing about the swivel movement of the spring element(4) to alter the spring application point manually via a flexible shaft (33), with a spindle nut (40) mounted orientably in the fork and with a worm drive (7) in engagement therewith.
4. A work chair according to Claim 1 to 3,
   characterised in that
   to fix the inclined positions of the seat shell (2), the associated locking device includes a locking lever (14), which is articulated on the seat carrier (1) via a bearing pin (23) and is penetrated by the pin (15), arranged at the free end of the bent lever (5), in a guide slot (39), which has moulded therein detent recesses (16) or the like, corresponding to the respectively inclined positions of the seat shell (2), for the arrested engagement of the pin (15).
5. A work chair according to Claim 4,
   characterised in that
   an arresting lever (24) is arranged in front of the locking lever (14) in the direction of actuation and is orientably arranged with two arms on the bearing pin (23), the arresting lever (24) has at one end a follower pin (25) which, to transfer the swivel movement, penetrates a bore (34) moulded in the locking lever (14) at a distance from the swivel bearing (bearing pin (23), and at the other end is in engagement with an actuating shaft (27) bringing about the swivel movement of the locking device and with the recess (28) formed thereon.
6. A work chair according to one of Claims 1 to 5,
   characterised in that
   one bent lever (5) at the end supporting the seat shell (2) is articulated via a bearing pin (9) in a position provided approximately between the swivel axis (8) of the swivel mounting of the seat shell (2) arranged nearest to the front edge on the seat carrier (1) and the supporting region of the seat shell (2) on the spring element (4), the other lever (6) of the bent lever arrangement is articulated with its end resting on the seat carrier (1) via a bearing pin (10), and the bearing pin (10) on the outer side additionally supports a U-shaped rocking lever (53), one shank of which has at the end a cam (54) to actuate the lifting unit (17), and the other shank of which is in engagement with an actuating shaft (51).
7. A work chair according to one of Claims 1 to 6,
   characterised in that
   at right-angles to, and on the outer side of the seat carrier (1), steel tube elements (30) are applied on both sides, on and in which actuating- and transferring elements are arranged for the spindle drive (7,40), bringing about the swivel movement of the spring element (4), in the form of the flexible shaft (33) penetrating a tube element (30) in a central bore (31), with a weight adjustment button (32) applied to the outer end, for the locking device (14,15,24) bringing about the inclination adjustment and -fixing of the seat shell (2), in the form of the actuating shaft (27), penetrating a tube element (30) with a locking key (29) applied to the outer end, and for the rocking lever (53) acting on the control element of the lifting unit (17) in the form of an actuating shaft (51) penetrating the other tube element (30), with a rocking lever coupling element (52) and an actuating key (50) on the outer side.
8. A work chair according to Claim 7,
   characterised in that
   the steel tube elements (30), applied laterally to the seat carrier (1), at the same time form the swivel bearing (8), on the front side, of the seat shell (2) on the seat carrier (1).
9. A work chair according to Claim 7,
   characterised in that
   the steel tube elements (30), applied laterally to the seat carrier (1), are combined with the swivel axis (8), supporting the seat shell (2), i.e. are constructed so as to engage into each other concentrically.
10. A work chair according to one of Claims 1 to 9,
    characterised in that
    the lever (6) has stop cams (58) formed on the bent lever arrangement, which cams, in the respective end positions of the lever, come to rest against impact-damping elements (59) on the seat carrier side, such as, for example, felt-or rubber elements.
11. A work chair according to one of Claims 1 to 10,
    characterised in that
    instead of a seat shell (2) in one piece, the seat carrier (1) is equipped, by means of a point synchronous mechanism, with a separate support part, articulated on the seat carrier (1), and is orientable in synchronism with the seat part.

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