EP2953508B1 - Mechanism for an office chair - Google Patents

Description

The invention relates to a mechanism for an office chair, in which the pivoting resistance of the backrest support can be changed. As a rule, a setting between "hard" and "soft" can be selected, depending on whether the user of the office chair is a heavy or light person.

Out EP 2244605 A1 a mechanism for an office chair is known, with a spring mechanism having at least one spring element, which is operatively connected to a backrest support of the office chair and determines the pivoting resistance of the backrest support when pivoting from a starting position to a pivoting position, with a movably connected to the spring mechanism Functional element, and with an operatively connected to the functional element movable actuating element whose position changes during pivoting of the backrest support.

In EP 1 258 212 A2 is an office chair with adjustable backrest preload described in which by means of a lever, the pivoting resistance of the backrest of "soft" to "hard" and back is adjustable, for this purpose, the distance between two pivot axes or articulation points and thus an effective lever arm is changed.

An object of the present invention is to provide a mechanism for an office chair in which a small displacement sufficient to realize a large adjustment of the swing resistance of the backrest.

This object is achieved by a mechanism according to claim 1. Advantageous embodiments of the invention are specified in the subclaims.

Thereafter, it is envisaged to design the mechanism such that the actuating element has a support and / or guide track for the functional element whose position on the support and / or guide track changes during a change in position of the actuating element during a pivoting of the backrest support. In addition, a movable link element for coupling the functional element is provided with a further structural element of the mechanism, wherein the link element determines the type of change in position of the functional element on the support and / or guideway during pivoting of the backrest support. According to the invention, the link element is movably connected to the further construction element of the mechanism, wherein the link element can be supported at different locations of the further construction element and / or can connect to the construction element at these locations.

A key idea of the invention is, in other words, that the actuating element itself provides the support and / or guideway for the functional element, which functional element causes a change in the spring tension during pivoting. Since the actuator always moves in a pivoting of the backrest support, at the same time also performs the support and / or guideway a corresponding movement and therefore influences the change in position of the functional element, without the need for further design measures are required. At the same time, the position and the movement of the functional element on the supporting and / or guideway during pivoting is forced by a link element, which link element is arranged between the functional element and a further structural element of the mechanism.

Such an arrangement makes it possible, with the help of an easily realizable spatially variable connection of the link element with the further structural element of the mechanism, a large adjustment of the

Pivoting resistance of the backrest to realize at a small adjustment. Therefore, the mechanism of the invention requires very little space for the spring force adjustment.

A structurally particularly simple structural embodiment of the invention is possible if the actuating element is firmly connected to the backrest support. It then performs the pivoting movement of the backrest support 1: 1 with.

As a particularly advantageous, an embodiment of the invention has been found, in which the functional element is a variable-position mounted and directly acted upon by the actuating element rolling or sliding body, preferably in the form of a cylindrical bolt. In such an embodiment, when pivoting the backrest support the invention distinguishing, dynamic automatic positioning of the functional element under the action of the actuating element and simultaneous guidance of the link element can be particularly easily realized.

The functional element preferably comprises a bearing, which is a roller bearing, in particular in the form of a ball or needle bearing. Of course, however, other storage devices, such as plain bearings, are used.

The link element is based in one embodiment of the invention on the further structural element of the mechanism only from without being connected to the other structural element stationary. In the simplest case, the link element is in itself rigid component between the functional element and the further construction element of Mechanics, while keeping his position automatically. For this purpose, the link element is articulated in one embodiment of the invention with its one end to the functional element and jammed with its opposite end against a receptacle in the further construction element. In another case, the position of which is supported on the further construction element link element held by the fact that a cooperating with the link element, preferably provided directly on the link element additional connecting element is provided, which forms a releasable, the support arresting connection with the further construction element.

Is the handlebar element based only on the other construction element, then it is possible in a particularly simple manner, the connection of link element to the other construction element spatially variable, as defined in claim 1, execute. A portable connection of the link element to the further construction element is, as defined in claim 1, but also possible if the link element is connected in a different manner with the further construction element.

That the link element is spatially connected to the other construction element means at a position immutable, ie stationary further construction element, that the position of the connection location is variable in that the link element can be connected to different points of the construction element. In other words, the link element can be supported at different locations of the further construction element and / or connect to the construction element at these locations.

A change in the connection location causes according to the invention in all cases a changed change in position of the functional element on the support and / or guideway during pivoting of the backrest support and thus a change in the swing resistance of the backrest from "soft" to "hard" or vice versa.

In one embodiment, the further construction element has a number of mutually adjacent receptacles into which the end of the link element associated with the further construction element can be successively moved. As a result, an adjusting device for non-continuous, discrete change of the pivoting resistance is created. As an adjusting element is used in one embodiment of the invention with a that end of the link element, which is assigned to the further construction element, connected traction means, preferably in the form of a Bowden cable.

In one embodiment of the invention, the receptacles provided on the further construction element are arranged such that the link element can be pivoted on a circular path about its articulation point on the functional element, without the connection between the link element and the further construction element is released. During the change in position of the link element by means of the adjusting device, the coupling between the functional element and the further construction element therefore always remains maintained. In addition, the spring force applied by the spring mechanism to the movable functional element operatively connected to the spring mechanism preferably acts perpendicular to the support and / or support provided by the actuator Guideway. As a result, the location of the connection of the link element with the further structural element of the mechanism can be changed, without causing a significant change in the position of the functional element on the support and / or guideway. Therefore, when adjusting the spring force in the untwisted state of the backrest must not be worked or only to a very small extent against the force of the at least one spring element of the spring mechanism. It is therefore possible a particularly smooth spring force adjustment.

In an alternative embodiment of the invention, an adjusting device for non-continuous, discrete change of the pivoting resistance is created by the fact that the link element, is supported on the further structural element of the mechanism, releasably connected to the further construction element via an additional connecting element. The further construction element has, in addition to a preferably straight bearing surface on which the handlebar element is supported, a number of locking elements, in which an additional connecting element for forming a lock can engage in succession, said connecting element is connected to that end of the link element adjoins supported the further construction element. Such a connection of the link element to the further construction element is preferably carried out in such a way that the link element, together with its articulation point on the functional element, is moved linearly with a change of the pivoting resistance occurring with the aid of the adjusting device. Preferably, the functional element is supported during the entire change in position of the link element on the further construction element. In this embodiment of the invention results from a change in the connection location of the link element with the further construction element, a simultaneous change in the position of the functional element on the support and / or guideway. As a result, the distance between the functional element and the main pivot axis of the mechanism changes. This is preferably done in such a way that this distance increases with a change from a "soft" to a "hard" setting of the pivoting resistance. This extends during the adjustment of the pivoting resistance of "soft" to "hard" for the subsequent pivoting movement of the backrest support decisive effective lever arm, which is determined by the distance between the axis of the functional element and the main pivot axis of the mechanism. As a result, this causes a higher initial resistance to be overcome by a user of the chair at the time of pivoting at a pivoting of the backrest. In other words, the size of the initial resistance of the backrest pivoting movement is adapted to the size of the pivoting resistance by the structural design of this embodiment of the invention. A "hard" setting of the swivel resistor is assigned a suitable higher initial resistance. As a result, heavy people in particular find a constructive support in leaning against the backrest. Too easy start of the pivoting movement and thus a "falling through" is prevented. Again, the position of the functional element on the support and / or guideway preferably changes in such a way that when adjusting the spring force in the untwisted state of the backrest not or only to a very limited extent against the force of the at least one spring element of the Spring mechanism to be worked. It is therefore possible in this case, a particularly smooth spring force adjustment.

A structurally particularly simple structural embodiment of the invention is possible if the further construction element of the mechanism is a part of the base support.

Due to the change in position of the actuating element during a pivoting of the backrest and the resulting change in position of the functional element, the voltage of the at least one spring element is changed according to the invention. In the spring mechanism, any types of spring members may be used for the purposes of the present invention. Be particularly advantageous because of their simplicity and robustness coil springs, especially proven in the form of helical compression springs. If a helical compression spring is used, the functional element is preferably a component acting directly or indirectly on one end of the spring, preferably on a spring plate.

The support and / or guide track can in the simplest case have the shape of a circular arc section. Variations in the concavity of the bearing surface, for example, initially flat, later steeper etc., are possible and have a different dynamic spring behavior result.

The spring mechanism operatively connected to the backrest support of the office chair can be connected to the backrest support both directly or indirectly. In an indirect connection, the spring mechanism is preferably via the seat support as a coupling element with the Backrest support connected. The concrete design is dependent on the structure of the office chair and the type of mechanics (synchronous mechanism, asynchronous mechanism).

Fig. 1

eine Schnittdarstellung einer ersten Mechanik mit "weicher" Einstellung des Schwenkwiderstandes in einer Ausgangsposition,

Fig. 2

eine Schnittdarstellung der Mechanik aus Fig. 1 mit "weicher" Einstellung des Schwenkwiderstandes in einer Schwenkposition,

Fig. 3

eine Schnittdarstellung der Mechanik aus Fig. 1 mit "harter" Einstellung des Schwenkwiderstandes in einer Ausgangsposition,

Fig. 4

eine Schnittdarstellung der Mechanik aus Fig. 1 mit "harter" Einstellung des Schwenkwiderstandes in einer Schwenkposition,

Fig. 5

eine perspektivische Darstellung der Mechanik aus Fig. 1 mit "harter" Einstellung des Schwenkwiderstandes,

Fig. 6

eine Schnittdarstellung einer zweiten Mechanik mit "weicher" Einstellung des Schwenkwiderstandes in einer Ausgangsposition,

Fig. 7

eine Schnittdarstellung einer zweiten Mechanik mit "harter" Einstellung des Schwenkwiderstandes in einer Ausgangsposition.

Two embodiments of the invention will be explained in more detail with reference to the drawings. Hereby show:

Fig. 1

a sectional view of a first mechanism with "soft" setting of the pivoting resistance in a starting position,

Fig. 2

a sectional view of the mechanics Fig. 1 with "soft" adjustment of the pivoting resistance in a pivoting position,

Fig. 3

a sectional view of the mechanics Fig. 1 with "hard" setting of the pivoting resistance in a starting position,

Fig. 4

a sectional view of the mechanics Fig. 1 with "hard" adjustment of the pivoting resistance in a pivoting position,

Fig. 5

a perspective view of the mechanics Fig. 1 with "hard" setting of the swivel resistance,

Fig. 6

a sectional view of a second mechanism with "soft" setting of the pivoting resistance in a starting position,

Fig. 7

a sectional view of a second mechanism with "hard" adjustment of the pivotal resistance in a starting position.

All figures show the invention only schematically and with its essential components. The same reference numerals correspond to elements of the same or comparable function.

The figures show parts of a pivot mechanism 1 for an office chair, with only the structural elements required for the understanding of the present invention are shown.

The swivel mechanism 1 comprises a base support 2 with a cone seat 3 for the upper end of a chair column, a seat support 4 and a backrest support 5. The cheeks of the backrest support 5, which is forked in plan view, are arranged on both sides of the base support 2.

The front end 6 of the base support 2 is connected to the front end 7 of the substantially horizontally arranged seat support 4 via a not shown in detail rotary / sliding joint 8. The rear end 12 of the seat support 4 is also pivotally connected at bearing points 13 with the backrest support 5, more specifically with an upper cheek part of the backrest support 5. Just as the seat support 4 can be provided with a seat, so the backrest support 5 can be provided with a backrest, wherein neither the type of seat, nor the type of backrest for the invention plays a role. The backrest support 5 is also articulated with its front end 14 on the base support 2, whereby the transverse to the chair longitudinal direction 11 extending main pivot axis 9 of the mechanism 1 is formed. The bearing points 13 are seen in chair longitudinal direction 11 behind the main pivot axis. 9

The backrest support 5, when leaning a user against the backrest of his in the FIGS. 1 and 3 shown starting position are transferred to a pivot position, as exemplified in the Figures 2 and 4 is shown. To set the restoring force of the backrest support 5, a spring mechanism 15 is provided, whose operation will be explained in detail below.

The spring mechanism 15 comprises a centrally arranged in the mechanism 1 helical compression spring 16. In the figures, this compression spring 16 is shown only partially for the sake of clarity. In the compression spring 16 a trained as a hollow cylinder guide means 17 is used with a guided therein guide rod 18 in parallel, which prevents kink protection, that the compression spring 16 kinks during compression. The guide device 17 forms a spring plate 19 at the fixed end 21 of the compression spring 16. This spring plate 19 is articulated to the front end 6 of the base support 2. The guide rod 18 is connected to a spring plate 20 at the movable end 23 of the compression spring 16. This spring plate 20 is connected to a variable-position functional element 22 in the form of a pin-shaped rolling and / or sliding body. The axis 24 of this rolling and / or sliding body 22 extends parallel to the main pivot axis 9 of the mechanism 1. In the starting position of the backrest is the axis 24 of the functional element 22 seen in chair longitudinal direction 11 in front of the main pivot axis 9 of the mechanism 1. The functional element 22nd has two needle bearings 27 for rotatably supporting the functional element 22 on a supporting and / or guideway 25, which is formed by a seen in chair longitudinal direction 11 forward opening, concave bearing surface of a pivot lever 28. Serving as an actuating element pivot lever 28 is designed as part of the backrest support 5 and rotatably connected to the front end 14 of the backrest support 5 below the main pivot axis 9 of the mechanism 1. The main pivot axis 9 of the mechanism 1 is at the same time the axis of rotation of the pivot lever 28.

With the functional element 22, a lower, fixed end 29 of a serving as a link element coupling 31 is pivotally connected. For this purpose, a provided at the end 29 of the coupling 31 tab 32 which surrounds the functional element 22.

The following will be in the Fig. 1 to 5 illustrated embodiment described in more detail.

At the upper, movable end 33 of the coupling 31, a cylindrical clamping bolt 34 is mounted, whose central longitudinal axis 35 extends parallel to the main pivot axis 9 of the mechanism 1. The clamping bolt 34 is supported in a correspondingly shaped receptacle 37 on the underside 38 of the base support 2, so that the coupling 31 between functional element 22 and base support 2 jammed.

The receptacle 37 is part of a receiving plate 39, which together with a serving as an adjusting element, only in the Fig. 1 and 2 partially illustrated Bowden cable 41 a Adjusting device 42 for the coupling 31 forms. The receiving plate 39 has for this purpose a number of adjacent receptacles 37, in which the free end 33 of the coupling 31 can be moved in succession. The Bowden cable 41, which is designed so that it can move the coupling 31 from a receptacle 37 in the next receptacle 37 and back, is connected to the free end 33 of the coupling 31 and is supported at suitable points of the base support 2 from.

The receptacles 37 are arranged on the receiving plate 39 such that the coupling 31 can be pivoted on a circular path about its pivot point 44 on the functional element 22, without the connection between the coupling 31 and the bottom 38 of the base support 2 is lost. The pivot point 44, the in Fig. 1 and 5 is indicated, is determined by the connection of the tab 32 with the functional element 22. The compression spring 16 is in the untwisted state of the backrest perpendicular or substantially perpendicular to the support and / or guideway 25. In a movement of the clamping bolt 34 of a receptacle 37 in the next, therefore, essentially only the force must be applied, which is required to overcome the dividers, which separate the individual trough-shaped receptacles 37 from each other.

When pivoting the backrest support 5 in the pivoting direction 46 backwards down pivoted to the backrest support 5 pivot lever 28 also pivots in the same manner, whereby the held by the coupling 31 at a defined distance from the base support 2 functional element 22 on the support and / or guideway 25 is moved. This results in a defined movement the functional element 22 as a function of the pivoting movement of the backrest support 5.

In the in Fig. 1 and 2 shown example, the free end 33 of the coupling 31 in the chair longitudinal direction 11 seen the rearmost receptacle 37 of the receiving plate 39, whereby the "softest" setting of the spring force adjustment is defined. In the starting position of the backrest, the central longitudinal axis 35 of the clamping bolt 34 is viewed in the chair longitudinal direction 11 behind the main pivot axis 9 of the mechanism 1. When pivoting the backrest support 5, the functional element 22 moves upward in the direction of the main pivot axis 9 and at the same time forward in the direction of the front end 6 of the base support 2. This reduces the distance between the spring plates 19, 20, the compression spring 16 is compressed.

With the help of the Bowden cable 41, the free end 33 of the coupling 31 is moved from the rearmost receptacle 37 seen in the chair longitudinal direction 11 into the foremost receptacle 37 ', as in FIG Fig. 3 and 4 shown, this is the "hardest" setting made. The support and / or guide track 25 remains unchanged, in particular, the slope of the web 25 does not change. In the initial position of the backrest is then the central longitudinal axis 35 of the clamping bolt 34 viewed in the chair longitudinal direction 11 in front of the main pivot axis 9 of the mechanism 1 and just behind the axis 24 of the functional element 22. By operating the adjusting device 42, the position of the coupling 31 changes relative to the Position of the compression spring 16, more precisely relative to the spring longitudinal direction 47, but not the length of the coupling 31. Therefore, results in a pivoting of the backrest support 5, a changed ratio of acting forces, which is reflected in an altered movement of the functional element 22.

Upon pivoting of the backrest support 5, the functional element 22 moves downwardly away from the main pivot axis 9 and at the same time towards the front end 6 of the base support 2. This reduces the distance between the spring seats 19, 20 significantly stronger and the compression spring 16 is more compressed than in the "soft" setting described above. At the same time for the pivoting movement of the backrest support 5 crucial effective lever arm (not shown) is increased, which is determined by the distance between the axis 24 of the functional element 22 and the main pivot axis 9 of the mechanism 1. At the same time increases due to the changed position of compression spring 16, coupling 31 and pivot lever 28 to each other on the pivot lever 28 effectively acting sum of forces. Overall, this has a significantly increased swing resistance result.

Overall, despite the small adjustment path between the rearmost receptacle 37 and the foremost receptacle 37 'of the adjusting device 42 results in a large adjustment range of the spring force adjustment. In other words, by a comparatively small change in the position of the free end 33 of the coupling 31, a spring force adjustment from a very soft to a very hard setting and vice versa done.

The following will be in the Fig. 6 and 7 illustrated embodiment described in more detail. This embodiment differs from the embodiment described above primarily by the Way, as the upper end 33 of the coupling 31 'is connected to the base support 2. Instead of a self-locking design, a lock which can be produced by means of an additional connecting element 48 is provided. This results in addition to a modified adjustment 42 'in particular a change in position of the functional element 22 on the support and / or guide track 25 during pivoting of the backrest support 5. All other essential features, in particular the resulting functional advantages of the mechanism 1, however, remain the same or arise in a corresponding manner.

At the upper, movable end 33 of the coupling 31 ', the additional connecting element 48 is articulated. The connecting element 48 comprises a pawl 49. The pivotable about a parallel to the main pivot axis 9 of the mechanism 1 Arretierungsschwenkachse 50 connecting element 48 is supported with its one, the base support 2 side facing 51 on a flat support surface 52. This support surface 52 is provided on the underside 38 of the base support 2, rigidly connected to the base support 2 and defines a linear guide track for the upper end 33 of the coupling 31 'at an adjustment of the pivoting resistance.

The position of the coupling 31 'between the functional element 22 and base support 2 is held by the fact that on the opposite, so the support surface 52 facing away from 53 of the connecting element 48 provided pawl 49 engages in locking elements in the form of locking teeth 54 and thus to form a locking the Connecting element 48 and thus the coupling 31 'locked to the base support 2.

The ratchet teeth 54 are arranged in the form of a rectilinear, parallel to the support surface 52 extending rack and together with the support surface 52, with which they are firmly connected, the further construction element in the context of the invention. At each pivoting of the backrest support 5 in the pivoting direction 46, the coupling 31 'is acted upon in the direction of the support surface 52. As a result, the coupling 31 ', more precisely the upper side 51 of the connecting element 48 of the coupling 31', is supported on the bearing surface 52. A displacement of the connecting element 48 on the flat bearing surface 52 in the direction of a "softer" setting, in the figures to the top right, but is prevented by the pawl 49 locked in the ratchet teeth 54.

In the in Fig. 6 As shown, the connecting element 48 is supported on the rearmost in chair longitudinal direction 11 contact point of the support surface 52 and the pawl 49 is located next to the chair in the longitudinal direction 11 rearmost ratchet 54 in the rack, whereby the "softest" setting the spring force setting is defined. In the starting position of the backrest is the Arretierungsschwenkachse 50 of the connecting element 48 viewed in the chair longitudinal direction 11 behind the main pivot axis 9 of the mechanism first

To change the pivoting resistance of "soft" to "hard" is provided as an adjusting element (in the figures for reasons of clarity, only symbolically and away from its actual position indicated) first Bowden cable 56 which acts on a first point of application 57 of the connecting element 48 and is supported at suitable points of the base support 2. This first engagement point 57 is provided on the connecting element 48 such that the connecting line between the first point of application 57 and the Arretierungsschwenkachse 50 of the connecting element 48 extends parallel to the support surface 52. In a train in the thus defined first pulling direction 58, the pawl 49 is unlocked and caused by the pawl 49 locking overcome. The locking mechanism formed from pawl 49 and ratchet teeth 54 acts in this case as a kind Grenzkraftgesperre in which the blocking forces can be overcome by a train in the first direction of pull 58. An increase in the pivoting resistance, ie a change in the position of the coupling 31 'in a respective "harder" position is possible in each case by a renewed actuation of the first Bowden cable 56.

If, on the other hand, the pivoting resistance is to be reduced, ie the coupling 31 'is moved into a "softer" position, this is not possible with the aid of the first Bowden cable 56. Because of the pawl 49 and locking teeth 54 formed locking mechanism acts because of the supporting surface 52 on the support member 49 with simultaneous engagement of the pawl 49 in the ratchet teeth 54 as a kind Richtgesperre that does not allow movement of the connecting element 48 against the first direction of pull 58. To change the pivoting resistance of "hard" to "soft" is therefore as adjusting a (in the figures for reasons of clarity, only symbolically and away from its actual position indicated) second Bowden cable 59 is provided, which is at a different from the first point 57 second Attack point 60 of the connecting element 48 engages and is supported at suitable points of the base support 2. This second one Engagement point 60 is provided on the connecting member 48 so that it is not on the connecting line between the first point of application 57 and the Arretierungsschwenkachse 50 of the connecting element 48. Instead, the second point of application 60 is arranged on a force acting on the pawl 49 lever arm 61 of the connecting element 48 so that at a train in the different direction of the first pulling direction 58 second pulling direction 62, a torque acts on the pawl 49 such that it is unlocked , In other words, the pawl 49 designed as part of the connecting element 48 is raised and swung out of the locking teeth 54 so that the entire connecting element 48 pivots about its locking pivot axis 50 on the coupling 31 '. A reduction of the pivoting resistance, ie a change in the position of the coupling 31 'in a "softer" position, is then possible in each case by a renewed actuation of the second Bowden cable 59.

With the aid of the first Bowden cable 56, the upper end 33 of the coupling 31 'was moved from the rearmost point of contact of the bearing surface 52 seen in the chair longitudinal direction 11 to the foremost contact point, as in FIG Fig. 7 shown, this is the "hardest" setting made. In the initial position of the backrest is then the Arretierungsschwenkachse 50 of the connecting element 48 viewed in chair longitudinal direction 11 again in front of the main pivot axis 9 of the mechanism 1 and just behind the axis 24 of the functional element 22nd

During the adjustment of the pivoting resistance is always a change in the position of the coupling 31 'such that the upper end 33 of the coupling 31' is linearly moved according to the guide surface defined by the support surface 52. The position of the functional element 22 connected to the fixed end 29 of the coupling 31 'on the support and / or guide track 25 likewise changes. In other words, moves both the upper end 33 on the support surface 52 and the fixed end 29 of the coupling 31 'on the support and / or guide rail 25 with an increase in the pivoting resistance in the chair longitudinal direction 11 forward and a reduction of the swing resistance in the chair longitudinal direction 11 to the rear. Thus, the coupling 31 'is always moved in total with a change in the pivoting resistance.

The functional element 22 moves during the adjustment of the pivoting resistance in a defined, constant relationship to the movement of the upper end 33 of the coupling 31 '. While the upper end 33 of the coupling 31 'moves in the first pulling direction 58 or opposite to the first pulling direction 58, the fixed end 29 of the coupling 31' moves with the functional element 22 on a circular path around the fixed point 21 of the helical compression spring 16 Due to this movement path, the helical compression spring 16 is not or only slightly compressed when adjusting the pivoting resistance. The swivel resistance is therefore particularly easy to adjust.

LIST OF REFERENCE NUMBERS

1

swivel mechanism

2

base support

3

cone holder

4

seat support

5

Backrest support

6

front end of the basic carrier

7

front end of the seat carrier

8th

Rotary / sliding joint

9

Main pivot axis

10

(free)

11

Chair longitudinally

12

rear end of the seat support

13

bearing point

14

front end of the backrest support

15

spring mechanism

16

Helical compression spring

17

guide means

18

guide rod

19

spring plate

20

spring plate

21

solid end of the spring

22

Functional element, rolling and / or sliding body

23

movable end of the spring

24

Axis of the functional element

25

Support and / or guideway

26

(free)

27

needle roller bearings

28

pivoting lever

29

tight end of the paddock

30

(free)

31

paddock

32

flap

33

moving end / free end of the paddock

34

clamping bolts

35

central longitudinal axis

36

flap

37

admission

38

Bottom of the base carrier

39

mounting plate

40

(free)

41

Bowden

42

adjustment

43

(free)

44

articulation

45

(free)

46

pan direction

47

Spring longitudinally

48

connecting element

49

pawl

50

Arretierungsschwenkachse

51

Top of the connecting element

52

bearing surface

53

Bottom of the connecting element

54

ratchet

55

(free)

56

first Bowden cable

57

first point of attack

58

first train direction

59

second Bowden cable

60

second point of attack

61

lever arm

62

second pulling direction

Claims (9)

1. Mechanism (1) for an office chair,
   having a spring mechanism (15) that has at least one spring element (16), said spring mechanism being operatively connected to a backrest support (5) of the office chair and determining the pivoting resistance of the backrest support (5) during pivoting from a starting position into a pivoted position,
   having a movable functional element (22) that is operatively connected to the spring mechanism (15),
   having a movable actuating element (28) that is operatively connected to the functional element (22), the position of said actuating element (28) being altered during pivoting of the backrest support (5), wherein the actuating element (28) has a supporting and/or guide track (25) for the functional element (22), the position of which on the supporting and/or guide track (25) is altered during a change in position of the actuating element (28) during pivoting of the backrest support (5), and
   having a movable control arm (31, 31') for the coupling connection of the functional element (22) to a further structural element (39; 52, 54) of the mechanism (1), wherein the control arm (31, 31') determines the type of change in position of the functional element (22) on the supporting and/or guide track (25) during pivoting of the backrest support (5),
   characterized in that the control arm (31, 31') is connected to the further, non-variable-position structural element (39; 52, 54) of the mechanism (1) at various locations on the structural element (39; 52, 54) in a variable location, wherein the control arm (31, 31') can be supported at various locations on the further structural element (39; 52, 54) and/or be connected to the structural element (39; 52, 54) at these locations.
2. Mechanism (1) according to claim 1, characterized in that the actuating element (28) is firmly connected to the backrest support (5).
3. Mechanism (1) according to claim 1 or 2, characterized in that the functional element (22) is a rolling or sliding body, preferably in the form of a cylindrical pin, that is mounted in a variable position and is acted upon directly by the actuating element (28) .
4. Mechanism (1) according to claim 3, characterized in that the functional element (22) has at least one bearing, wherein the latter is preferably a roller bearing (27).
5. Mechanism (1) according to one of claims 1 to 4, characterized in that the control arm (31, 31') is supported on the further structural element (39; 52, 54) of the mechanism (1).
6. Mechanism (1) according to one of claims 1 to 5, characterized in that the location of the connection of the control arm (31) to the further structural element (39) of the mechanism (1) is variable while the position of the functional element (22) on the supporting and/or guide track (25) remains substantially unaltered.
7. Mechanism (1) according to one of claims 1 to 5, characterized in that the location of the connection of the control arm (31') to the further structural element (52, 54) of the mechanism (1) is variable, wherein such a variation is associated with a simultaneous change in the position of the functional element (22) on the supporting and/or guide track (25).
8. Mechanism (1) according to one of claims 1 to 7, characterized in that a change in the connecting location brings about an altered change in position of the functional element (22) on the supporting and/or guide track (25) during pivoting of the backrest support (5).
9. Mechanism (1) according to one of claims 1 to 8, characterized in that the further structural element (39; 52, 54) of the mechanism (1) is a part of the base support (2).

Images