EP3120732B1 - Mechanism for an office chair - Google Patents

Description

The invention relates to a mechanism for an office chair with a base support that can be placed on a chair column, with a seat support arranged on the base support, movable relative to the base support, and with a backrest coupled to the seat support, wherein pivoting of the backrest causes movement of the seat support relative to the Base carrier causes.

With such a mechanism, as it is used as an assembly in the seat substructure of an office chair, a kinematics is provided which brings about a certain relative movement of the seat and backrest to one another, so that a correlated seat-backrest movement results. The seat and backrest are pivoted back and down together.

Numerous solutions for changing the movement characteristics of such a mechanism are known from the prior art, in particular for changing the swivel resistance of the backrest. A setting between "hard" and "soft" is usually selected with the aid of an actuating element, for example a rotary crank or the like, depending on whether the user of the office chair is heavy or light.

In addition, an adjustability of the inclination of the seat is increasingly required to further improve the ergonomics of office chairs. In the loaded state, the seat should be able to assume a position that deviates from the horizontal position and is slightly inclined forwards.

The resistance to inclination against which the seat carrier inclines when the office chair is held cannot be changed in many of the solutions known from the prior art. Light and heavy people therefore always experience one and the same inclination resistance.

In other solutions, the resistance to inclination of the seat support is adjustable. However, this is often solved in a constructively complex manner. Additional components increase the manufacturing and assembly costs and require a corresponding installation space.

Out CH 702 970 A2 and JP H02 31530 Mechanics for an office chair are known in which the seat support can be tilted relative to the base support against the spring force by a spring arrangement and the spring arrangement at the same time defines the tilt resistance of the seat support. At CH 702 970 A2 the seat support cannot assume a position inclined slightly forward in the loaded state, which would be desirable from the user's point of view, due to the design, while in the off JP H02 31530 U known construction such a lowering of the front end of the seat support is possible.

It is an object of the present invention to provide an alternative solution for adjusting the inclination resistance of the seat support of an office chair. This object is achieved by a mechanism according to claim 1. Advantageous embodiments of the invention are specified in the subclaims.

A basic idea of the invention is to provide a seat support that can be tilted forward from the horizontal against the spring force of a spring arrangement acting on the seat support, the same spring arrangement also acting on the backrest support. For setting the swivel resistance of the In other words, the spring arrangement used for the backrest support is used to adjust the inclination resistance of the seat support. By choosing the points of application of the spring arrangement on the seat support and the backrest support, as well as by choosing suitable structural designs, the swivel characteristics of the seat can be adjusted in a simple manner and adapted to the swivel characteristics of the backrest.

By changing the spring force presetting of the spring arrangement, the inclination resistance of the Seat support set stronger or weaker and thus adapted to different body weights of the user.

The seat support is, according to the invention, using a suitable movable coupling element between the base support and the seat support, lowered in its front area against the spring force of the spring arrangement when the chair is held and accordingly automatically returned to its starting position with the aid of the spring force when the seat is relieved erect. In other words, when the chair is held and, in particular, when the body weight is shifted on the seat support, the seat support is rocked or rocked into the seat tilt position and out of the seat tilt position. For the user of the chair, this results in a comparatively "dynamic" sitting feeling.

According to the invention, this compression and rebound into the seat tilt position or out of the seat tilt position is not effected with a spring specifically responsible for this; Instead, the main spring of the mechanism, which is primarily responsible for pivoting the backrest, is used. The invention therefore not only provides a particularly dynamic seat tilt functionality. This functionality is also achieved with a minimum of design effort, in particular without additional spring elements. This reduces manufacturing and assembly costs.

It is particularly advantageous that a presetting of the spring force of the spring arrangement with regard to the weight of the user has a direct effect on the functionality of the side tilt. For heavy users who need a higher backrest swivel resistance, the spring action for the seat inclination is also harder, so that there is automatically a stronger spring effect for lowering into the seat tilt position. The stronger the swivel resistance of the backrest is set, the stronger the tilt resistance of the seat will be. Thus, the rocking or rocking of the seat into the seat tilt position is made possible for all user weights equally and felt equally by all users, regardless of their weight, provided the mechanism, in particular the spring arrangement of the mechanism, is suitably adjusted to the user.

It is irrelevant in which way the adjustment of the spring arrangement takes place, for example manually and / or self-adjusting depending on the weight of the user.

The basic idea of the invention is independent of the specific movement carried out by the seat support relative to the base support. As a rule, however, the movement of the seat support is a movement in the longitudinal direction of the seat, which is superimposed by a tilting, swiveling and / or tilting movement of the seat support.

Fig. 1

eine Seitenansicht der Mechanik im unbelasteten Zustand,

Fig. 2

eine Seitenansicht der Mechanik aus Fig. 1 mit einem belastetem Sitz,

Fig. 3

eine Seitenansicht der Mechanik aus Fig. 1 mit einem belastetem Sitz und einer Belastung der Rückenlehne,

Fig. 4

eine Seitenansicht einer weiteren Mechanik im unbelasteten Zustand.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Here show:

Fig. 1

a side view of the mechanics in the unloaded state,

Fig. 2

a side view of the mechanics Fig. 1 with a loaded seat,

Fig. 3

a side view of the mechanics Fig. 1 with a loaded seat and a load on the backrest,

Fig. 4

a side view of another mechanism in the unloaded state.

All of the figures show the invention not to scale, only schematically and only with its essential components. The same reference symbols correspond to elements with the same or comparable function.

In a preferred embodiment of the invention, the mechanism 1 for an office chair comprises a means of an in Fig. 1 indicated cone receptacle 2 on the upper end of a chair column (not shown), preferably fixed base support 3.

It further comprises a seat support 4 connected to the base support 3 and movable relative to the base support 3, the seat support 4 being neither directly nor directly connected to the base support 3. The seat (not shown) of the office chair, which is generally provided with an upholstered seat, is mounted on the seat support 4.

The mechanism 1 further comprises a backrest support 5 which is connected both to the base support 3 and to the seat support 4 and is movable relative to the base support 3, the pivoting of which causes the seat support 4 to move relative to the base support 3. The cheeks 6 of the backrest support 5, which is forked in plan view, are arranged on both sides of the base support 3.

The mechanism 1 is constructed mirror-symmetrically with respect to the central longitudinal plane, as far as the actual kinematics are concerned. In this respect, the following description is always from both sides construction elements of the mechanics 1 that are present in pairs.

"Front" or "front" means that a component is arranged at the front in the longitudinal direction 7 of the seat or refers to a component extending or pointing in the direction of the front seat edge 8, while "rear" or "rear" means , that a component is arranged at the rear in the longitudinal direction 7 of the seat or refers to a component that extends or points in this direction in the direction of the backrest or the backrest support 5 or the rear seat edge 9. The information "above" and "below" refer to the intended use of the office chair or the office chair mechanism 1.

According to the invention, the backrest support 5 is used to form a first connection between the seat support 4 and the base support 3 both at a rear end 11 of the seat support 4, namely with the free ends of its cheeks 6 in the vicinity of the conical receptacle 2, forming a transverse to the seat longitudinal direction 7 first seat support pivot axis 12, as well as on the base support 3, namely on an area of its cheeks 6 spaced apart from the free ends, forming a first base support pivot axis 13 running transversely to the seat longitudinal direction 7, whereby a pivoting of the backrest support 5 in the pivoting direction 14 causes a movement of the seat support 4 relative to the base support 3 towards the rear and bottom, ie from an upright starting position to a rear pivoting position. The manner in which the pivotable backrest support 5 is coupled to the seat support 4 only plays a subordinate role for the present invention. As in the In the present case, it is a direct or indirect coupling.

The mechanism 1 also comprises coupling elements 15 arranged on both sides of the base support 3, here as an extension of the cheeks 6 of the backrest support 5, which extend from the base support 3 forwards in the direction of the front edge 8 of the seat support 4. Each coupling element 15 is to form a second connection of the seat support 4 to the base support 3 both on a front end 16 of the seat support 4, namely with the formation of a second seat support pivot axis 17 running transversely to the seat longitudinal direction 7, and on the base support 3, namely with the formation of a second base support pivot axis 18 running transversely to the longitudinal direction 7 of the seat, pivotably articulated. The front ends of the coupling elements 15 terminate in two arms 19 ending on both sides of the seat support 4. There the coupling elements 15 are connected, for example, to structural elements arranged inside the seat support 4, the mobility of the coupling elements 15 relative to the seat support 4 in the longitudinal direction 7 of the seat being ensured by openings 21 in the manner of elongated holes. In other cases, the coupling elements 15 are connected to the seat support 4, for example, with the formation of rotary / sliding joints.

So that the backrest can perform a defined pivoting movement, spring elements that interact directly or indirectly with the backrest or the backrest support 5 must be provided. These spring elements determine the swivel resistance of the backrest when swiveling from an initial position into a swivel position and the corresponding restoring force of the backrest. Accordingly, the mechanism 1 comprises a spring arrangement 22 acting between the backrest support 5 and the seat support 4. The type of spring arrangement 22 and the type of possible adjustment of the spring arrangement 22 are not decisive for the present invention. The spring arrangement 22 is therefore only indicated symbolically in the figures, see Fig. 1 . For example, in a simple case, the spring arrangement 22 can be a number of coil springs. It is preferably one or more helical tension springs, the spring ends of which are attached to the seat support pivot axes 12, 17. However, other spring elements or spring assemblies with several spring elements can also be used.

The points of application of the spring elements of the spring arrangement 22 are determined by their connections to the backrest support 5 or the seat support 4. In a simple case, the ends of the spring elements are suspended in the seat support pivot axes 12, 17. All pivot axes 12, 13, 17, 18, but preferably at least the seat support pivot axes 12, 17, are designed as physical axes.

When the seat carrier 4 is loaded by a user, the seat support 4 can be inclined relative to the base support 3 against the spring force of the spring arrangement 22 with respect to the horizontal 23. In other words, the seat support 4 acts on a first end 24 of the spring arrangement 22 during the tilting. The inclination thus acts on the spring arrangement 22 in that the first end 24 of the spring arrangement 22 is moved away from the opposite second end 25 of the spring arrangement 22.

The backrest support 5 can be pivoted relative to the base support 3 against the spring force of the spring arrangement 22. Different In other words, the backrest support 5 acts on the second end 25 of the spring arrangement 22 during the pivoting of the backrest support 5. The spring arrangement 22, the spring force of which determines the swivel resistance of the backrest support 5, determines, together with the weight of the user, the degree of inclination of the seat support 4. If a user sits down on the chair, the seat support 4 inclines against the spring force of the spring arrangement 22. The The restoring force of the spring arrangement 22 also causes a partial or complete movement of the seat support 4 from the seat tilt position to its starting position when the user partially or completely relieves the seat support, i.e. either moves on the seat or stands up from the seat.

In the seat tilt position, the user's weight is shifted forward in the longitudinal direction of the seat. Due to the shift in weight, you cannot lean against the backrest at the same time. If the user wants to lean against the backrest, he will first shift his weight backwards in the longitudinal direction of the seat. The seat support 4 is then shifted again in its starting position. In other words, the seat support 4 springs back into its starting position before the backrest can pivot. In other words, the seat support 4 is then in an essentially horizontal position, despite the fact that a user is sitting on the chair. This coordination of the pivoting movements of the seat support 4 and the backrest support 5 with one another and the introduction of a neutral state of equilibrium, in which neither the seat support 4 nor the backrest support 5 are pivoted out of their starting positions, is ensured by the user a simultaneous Pivoting of seat support 4 and backrest support 5 is excluded.

In a preferred embodiment of the invention, the spring force of the spring arrangement 22 is adjustable. Preferably in the unloaded condition, i.e. Manual presetting of the spring arrangement 22 can take place without a user sitting in the chair. Changing the spring force presetting of the spring arrangement 22 is important with a view to a subsequent inclination of the seat support 4. By setting the presetting, not only the swivel resistance of the backrest support 5, but also the seat inclination resistance can be set to a specific user, more precisely his / her weight. At the same time it is possible in this way to set the chair mechanism 1 to a specific user group, for example by means of a corresponding setting ex works. However, the spring force setting can also be changed several times while the office chair is in use.

The device for changing the pretension is preferably an adjusting device with a track element, as described in the patent application DE 10 2014 104 870.9 is described.

By simply setting the bias of the spring arrangement 22, in conjunction with a suitable geometric arrangement of the individual components of the mechanism 1 to one another, in particular the arrangement of the articulation points and pivot axes 12, 13, 17, 18, in particular their spacing from one another, in a particularly simple manner the entire synchronous movement of the office chair mechanism 1 is set and the desired neutral A state of equilibrium between a seat inclination and a pivoting of the backrest can be achieved.

According to the invention, the spring arrangement 22 acts between the seat support pivot axes 12, 17. In other words, the ends 24, 25 of the spring elements used act on the seat support pivot axes 12, 17. In a preferred embodiment of the invention, the position of the second seat support pivot axis 17, and thus the position of the articulation point of the coupling element 15 on the seat support 4, can be changed in the longitudinal direction 7 of the seat, namely when the seat support 4 is tilted and / or when the backrest support is pivoted 5 in pivoting direction 14.

In a preferred embodiment of the invention, the mechanism 1 is designed in such a way that loading the seat support 4 by a user sitting down while pivoting the coupling element 15, namely lowering the front, movable arm 19 of the coupling element 15, lowering the front edge 8 or the front part 16 of the seat support 4, as well as a displacement of the articulation point 17 of the coupling element 15 on the seat support 4 in the longitudinal direction 7 of the seat forwards, see Fig. 2 .

The swivel resistance of the backrest support 5 and the seat inclination resistance resulting therefrom result from the distance L (0) of the points of application of the spring arrangement 22, in this case the seat support swivel axes 12, 17, in the unloaded state.

The spring elements of the spring arrangement 22 are acted upon when the seat support 4 is tilted and therefore the seat support 4 moves relative to the base support 3. The mainspring will curious; excited. The spring travel ΔL = L (1) -L (0) covered here is dependent on the preset preload of the spring arrangement 22 and on the weight of the user.

During this first movement, the seat support 4 does not move in the longitudinal direction 7 of the seat. The seat support 4 merely inclines. From an initial position in which the seat support 4, more precisely its upper side 26 and thus the seat mounted on it (not shown), is in the horizontal 23, the seat support 4 moves by an angle of inclination 27 of, for example, 5 ° relative to the horizontal 23 inclined forward. If the seat support 4 is in such an inclined position, then the front edge 8 of the seat support 4 is lower than the rear edge 9 of the seat support 4, see FIG Fig. 2 .

Before the backrest support 5 is pivoted, the seat support 4 is in its non-inclined starting position, into which it is brought back by the spring arrangement 22 when the user stands up or leans backwards to lean against the backrest.

In a preferred embodiment of the invention, the mechanism 1 is designed in such a way that a load on the backrest support 5 by the user leaning against the backrest with simultaneous pivoting of the backrest support 5, a lowering of the rear edge 9 or the rear part 11 of the seat support 4 and a displacement of the articulation point 17 of the coupling element 15 on the seat support 15 in the seat longitudinal direction 7 forwards, see Fig. 3 . The articulation point 17 of the coupling element 15 on the seat support 4 is shifted further forward in the seat longitudinal direction 7 than in the seat tilt position.

Here, the seat support 4 simultaneously performs a movement in the longitudinal direction 7 of the seat to the rear. In other words, the seat support 4 is moved back and down, more precisely pulled from the backrest support 5. The seat support 4 is pivoted in such a way that the seat support 4, more precisely its upper side 26 and thus the seat mounted thereon (not shown), is inclined backwards and has an angle of inclination 28 of, for example, 5 ° with respect to the horizontal 23. In the state of the backrest support 5 pivoted to the maximum rearward, the rear edge 9 of the seat support 4 is therefore lower than the front edge 8 of the seat support 4.

The spring elements of the spring arrangement 22 are acted upon again when the backrest support 5 is pivoted and therefore the seat support 4 moves relative to the base support 3. The distance L (2) of the points of application 12, 17 of the spring arrangement 22 increases compared to the distance L (0) of the unswiveled position of the backrest support 5 and is also greater than the distance L (1) of the points of application 12, 17 in the seat tilt position. The covered spring travel ΔL = L (2) - L (0) depends on the swivel angle of the backrest.

In a preferred embodiment of the invention, the two base support pivot axes 13, 18 run coaxially. In other words, the articulation point 13 of the backrest support 5 on the base support 3 corresponds to the articulation point 18 of the coupling element 15 on the base support 3, see Figs. 1 to 3 .

If the center distance 29 is equal to zero, that is to say if there is only a single common axis of rotation 13, 18 on the base support 3, the result is a mechanically particularly simple construction. In another alternative preferred embodiment of the invention, the two base support pivot axes 13, 18 are spaced apart from one another in the longitudinal direction 7 of the seat. In other words, the articulation point 13 of the backrest support 5 on the base support 3 is offset in the seat longitudinal direction 7 to the articulation point 18 of the coupling element 15 on the base support 3. The pivot axes 13, 18 are spaced from one another.

With an existing center distance 29, the ratio of the swivel resistance, namely the swivel resistance of the backrest support 5 and the seat inclination resistance of the seat support 4, can be changed by a suitable choice of the center distance 29. In other words, a more or less large center distance 29 enables the proportionality of the pivoting resistances to be matched to a specific mechanical design. The mechanism 1 can thus be preset particularly easily for specific target groups.

List of reference symbols

1

mechanics

2

Cone mount

3

Base carrier

4th

Seat support

5

Backrest support

6th

cheek

7th

Longitudinal direction of the seat

8th

Front seat edge

9

Rear seat edge

10

(free)

11

rear end of the seat support

12th

first seat support pivot axis

13

first base support swivel axis

14th

Swivel direction

15th

Coupling element

16

front end of the seat support

17th

second seat support pivot axis

18th

second base support pivot axis

19th

front end of the coupling element

20th

(free)

21st

opening

22nd

Spring arrangement

23

Horizontal

24

first end of the spring arrangement, first point of application

25th

second end of the spring assembly, second point of application

26th

Top of the seat support

27

first angle of inclination

28

second angle of inclination

29

Center distance

Claims (7)

1. A mechanism (1) for an office chair,

   - having a base support (3) which is placeable on a chair column,

   - having a seat support (4) which is connected to the base support (3) and is movable relative to the base support (3),

   - having a backrest support (5) which is connected to both the base support (3) and the seat support (4) and is movable relative to the base support (3), the pivoting of said backrest support causing the seat support (4) to move relative to the base support (3),

   - having a spring arrangement (22) which acts between the backrest support (5) and the seat support (4) for determining the pivoting resistance of the backrest support (5), wherein the backrest support (5) is pivotable relative to the base support (3) against the spring force of the spring arrangement (22), wherein the seat support (4) is tiltable relative to the base support (3) against the spring force of the spring arrangement (22) and the spring arrangement also determines the tilting resistance of the seat support (4), and

   - having a coupling element (15) which is able to movable connect base support (3) and seat support (4), wherein the backrest support (5) is pivotably hinged

   both on a rear end (11) of the seat support (4), thereby realizing a first seat support pivot axis (12) which extends transversely with respect to the seat longitudinal direction (7),

   and on the base support (3), thereby realizing a first base support pivot axis (13) which extends transversely with respect to the seat longitudinal direction (7),

   wherein pivoting the backrest support (5) causes the seat support (4) to move relative to the base support (3),
   and wherein the coupling element (15) is pivotally hinged

   on a front end (16) of the seat support (4), realizing a second seat support pivot axis (17) which extends transversely with respect to the seat longitudinal direction (7),

   and on the base support (3), realizing a second base support pivot axis (18) which extends transversely with respect to the seat longitudinal direction (7),

   characterized in that the spring arrangement (22) acts between the seat support pivot axes (12, 17), wherein the ends (24, 25) of the used spring elements cooperate with the seat support pivot axes (12, 17).
2. The mechanism (1) as claim in claim 1, wherein the spring force of the spring arrangement (22) is adjustable, as a result of which both the pivoting resistance of the backrest support (5) and the tilting resistance of the seat support (4) are modifiable.
3. The mechanism (1) as claimed in claim 1 or 2, wherein the position of the second seat support pivot axis (17) is modifiable when the seat support (4) is tilted and/or when the backrest support (5) is pivoted in the seat longitudinal direction (7).
4. The mechanism (1) as claimed in claim 3, where loading the seat support (4) results in lowering the front edge (8) of the seat support (4) as well as in displacing the hinge point (17) of the coupling element (15) on the seat support (4) forward in the seat longitudinal direction (7).
5. The mechanism (1) as claimed in claim 3 or 4, where loading the backrest support (5) results in lowering the rear edge (9) of the seat support (4) as well as in displacing the hinge point (17) of the coupling element (15) on the seat support (4) forward in the seat longitudinal direction (7).
6. The mechanism (1) as claimed in one of claims 1 to 5, wherein the two base support pivot axes (13, 18) extend in a coaxial manner.
7. The mechanism (1) as claimed in one of claims 1 to 6, wherein the two base support pivot axes (13, 18) are spaced apart from one another in the seat longitudinal direction (7).

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