CN101160076A - Device for seat inclination adjustment of a chair - Google Patents

Abstract

The invention relates to a device for adjustment of the seat angle of a chair, in particular an office chair. According to the invention, a seat angle adjustment permitting a particularly secure and reliable adjustment of the seat angle may be achieved, by means of a device comprising a base support (2), a seat support (3), connected to the base support (2), by means of a joint (13) and an adjustment mechanism (18), such that a forwards pivot movement of the seat support (3) may be selected beyond an essentially horizontal base position.

Description

Device for seat inclination adjustment of a chair

technical field

The invention relates to a device for inclination adjustment (seat angle adjustment) of a seat of a chair, especially an office chair.

Background technique

High-quality office chairs are often equipped with so-called synchromechanisms, by which the seat and the backrest of the chair rotate back and down together in response to the user's reclining in the associated motion. Furthermore, various possible adjustments are known for improving the ergonomics of office chairs, such as, for example, height adjustment of the seat, backrest and armrests, adjustability of the armrests in longitudinal and transverse position, and longitudinal adjustment of the chair.

In addition, an enhanced degree of adjustability of the chair's reference angle is required in order to further improve the ergonomics of the office chair. Thereby, at least the seat can be adjusted between a horizontal position and a slightly forwardly inclined position. In response to actuation of the synchronization mechanism, the chair thus initiates a rearward and downward pivotal movement from this position caused by the synchronization mechanism.

Contents of the invention

The object of the present invention is to provide a seat inclination adjustment device for a chair which allows a particularly safe and reliable adjustment of the seat inclination.

This object is solved by a device as claimed in claim 1 .

As required by the present invention, the apparatus includes a base frame, a seat frame connected to the base frame by a joint and an adjustment mechanism that permits selective forward pivotal movement of the seat frame beyond a substantially horizontal reference position .

The basic idea of the invention is to pivot the seat frame itself beyond its reference position in order to adjust the seat inclination of the chair. The adjustment of the seat inclination can be selectively turned on or off as required by the present invention. This enables a particularly flexible operation, depending on the application and the requirements of the user. Furthermore, the device as claimed in the present invention can be selectively mounted on different conventional synchronization mechanisms. In other words, retrofitting is an option.

The dependent claims describe advantageous embodiments of the invention. They are explained in more detail in the following description of exemplary embodiments by means of the accompanying figures.

Description of drawings

Figure 1 shows a perspective view of the synchronization mechanism in a horizontal reference position,

Figure 2 shows a side view of the synchronization mechanism in Figure 1,

Figure 3 shows a side view of the synchronization mechanism in Figure 1 in a tilted position,

Figure 4 shows an exploded view of the adjustment mechanism,

Figure 5 shows a top view of the adjustment mechanism set to a tilted position,

Figure 6 shows a top view of the adjustment mechanism set as a reference position,

FIG. 7 shows a cross-sectional view along line AA in FIG. 6 .

Detailed ways

Figure 1 shows an exemplary synchronization mechanism 1, ie a part on the chassis of an office chair which ensures interlinked movement which causes some relative movement of the seat and backrest to each other. For this purpose, the base frame 2 is placed on a chair post (not shown) on which the base frame 2 is mounted, on the one hand the seat frame 3 is pivotable about a transverse axis and is connected in an articulated manner To the base frame 2 , on the other hand, the backrest frame 4 is also pivotable about a transverse axis and is connected to the base frame 2 in an articulated manner.

Typically, the seat of an office chair provided with a padded seat is mounted on a seat frame 3 (not shown here for reasons of clarity). For this purpose, a plurality of latches 7 are provided on the side frame elements 5 of the substantially frame-shaped seat support 3 , which are arranged following one another in the longitudinal direction 6 of the chair, said latches 7 For the purpose of positioning and securing the seat to the seat frame 3 in an inherent manner, which will not be explained in detail.

The backrest bracket 4 supports the backrest (not shown) of the office chair by means of an arm which moves upwards, which backrest bracket extends rearwardly from the actual synchronization mechanism 1 in a set manner. The flanges 8 , 9 of the back support 4 are arranged on both sides of the base support 2 , the back support 4 being practically bifurcated in plan view.

The seat frame 3 and the back frame 4 are articulatedly coupled for a rearward pivoting movement of the backrest, which may be caused by the user leaning on the backrest, for example - causing a lowering movement of the rear edge of the seat. This associated seat-back movement brings considerable comfort benefits and is suitable for orthopedic reasons. On both sides of the base frame 2 are prepared operating levers 10, 11 for triggering the height adjustment of the chair leg and for the purpose of operating the pivot mechanism, respectively.

The further assembly of the synchronizing mechanism 1, in particular the connection of the seat frame 3 and the base frame 2, by means of rail structures or the like, in order to provide the associated seat/backrest movement, will not be considered further below.

However, for a better understanding it is pointed out that the seat frame 3 is connected to the base frame 2 in its front end region 12 via two swivel-slide joints 13. See Figure 7, where one of the swivel-slide joints 13 is illustrated in section. On the one hand, each swivel-sliding joint 13 consists of a sliding element 14 connected to the seat frame 3 and, on the other hand, is enclosed in a sliding guide rail formed by two mutually spaced sliding flanges 15 , 16 formed, the sliding flange is fixedly connected to the base bracket 2. In the illustrated horizontal reference position, the upper sliding flange 15 rests on stop elements 17 on the seat frame 3, which will be explained in more detail below. By this arrangement it is avoided that the seat frame 3 completes a forward pivoting movement which extends beyond the substantially horizontal reference position. Both sliding flanges 15, 16 surround a raised rail surface which allows the sliding element 14 and thus also the seat frame 3 connected to the sliding element 14 to follow this pivoting movement backwards and downwards. In other words, the sliding element 14 of the base frame 3, which is designed according to the rail type, moves with its upper side and its lower side along the guide rail surfaces of the upper and lower sliding flanges 15, 16, wherein the sliding element 14 The various pivoting states between the upper and lower sliding flanges 15, 16 are guided in a particularly secure manner. Other types of connectors can also be used.

An adjustment mechanism 18 as required by the invention is assigned to the seat frame 3 . As will be explained in more detail below, the adjustment mechanism 18 enables a safe and reliable adjustment of the seat tilt. An actuating lever 19 is provided for actuating the adjusting mechanism 18 , which is arranged transversely on the synchronization mechanism 1 in the same manner as the remaining actuating levers 10 , 11 and which can each be moved in the actuating direction 20 by Remove and insert to operate.

In an exemplary embodiment, the seat frame 3 can be tilted forward by an angle α of about 3 degrees by adjusting the seat tilt. Due to the seat/backrest connection, this corresponds here to an angle β of approximately 8 degrees of inclination of the backrest, see FIG. 3 . This angle notation is exemplary only and serves the purpose of clarifying the function. In particular, they depend on the length and the available displacement path of the stop element 17 in the adjustment mechanism 18 and on the specific design of the synchronization mechanism 1 , respectively.

Based on the "retracted" position of the adjustment mechanism 18 shown in FIG. 5, which corresponds to the tilted position of the seat frame 3 (shown in FIG. 3), its function is explained below. In the position of the adjustment mechanism 18 shown here, the seat frame 3 can be tilted forward beyond its horizontal reference position.

The adjustment mechanism 18 is essentially composed of a base plate 21 and a cover plate 22 on which the actual components of the structure are mounted. In the final installed state, the base plate 21 of the adjustment mechanism 18 is covered by a cover plate 22 which is fastened to the base plate 21 by means of screws 23 .

The adjustment mechanism 18 comprises two prismatically shaped stop elements 17, 17' On the lower side 59 of the stop element 17, 17', a positioning opening (not shown) is provided, and when in the "retracted" state, the positioning opening cooperates with the positioning button 60, which is arranged in the guide groove 24 middle. In this state, the position of the stop element 17, 17' is additionally fixed through the positioning opening.

A double T-shaped cushioning element 25 is inserted into the stop element 17, 17', which consists of a softer plastic material, such as rubber, and which consists of plastic. The front side 26 of the locking element 17 is completely covered by the damping element 25 . On its rear side 27 , the stop element 17 comprises inclined contact surfaces 28 oriented towards each other and in the direction to the center of the adjustment mechanism 18 . In the “retracted” position shown here, the two inclined wedge elements 29 , 30 comprise wedge surfaces 31 mounted on their outer ends, which face away from each other and bear against the contact surface 28 of the stop element 17 . The wedge-shaped elements 29, 30 are in turn located in a guide channel 33 of the adjustment mechanism 18, said guide channel 33 extending substantially in a transverse direction 32 extending perpendicularly to the longitudinal direction 6, and are mutually coupled by means of a coupling mechanism 34, which will be described below. described in more detail.

One 29 of the wedge-shaped elements contains a recess 35 which is provided with inclined side walls and which serves as a support for one end 42 of a generally L-shaped steel spring 36 . This bent end 42 of the steel spring 36 is thus inserted into the opening of the wedge element 29 and mounted therein so as to be rotatable.

The steel spring 36 is connected to the operating rod 19 . The operating lever 19 is designed to be composed of two parts and essentially consists of an operating arm 37 which is bent so as to be slightly S-shaped and has an operating button 38 mounted on its end, and an operating slide 39 is fixed by means of a screw 23. Fixed on the control arm, the other end 40 of the steel spring 36 is fixed therein. For this purpose, like the wedge element 29 , the operating slide comprises an opening 41 into which the other bent end 40 of the steel spring 36 is inserted. The steel spring 36 is enclosed in a diverging guide element 43 on the operating slide 39 and at the same time serves as an anti-twist device. The actuating slide 39 is guided in a transverse direction 58 in the base plate 21 of the adjustment mechanism 18 .

The actuating slide 39 includes a central opening 44 in which a catch element 45 is arranged. The catch element 45 can be used for the purpose of locking the adjustment means of the seat angle in the horizontal reference position and the reclined position respectively, and is designed in such a way that it interacts with two correspondingly arranged catch notches 46, 47 For locking, the catch recess is arranged in the base plate 21 of the adjustment mechanism 18 , see FIG. 4 . When locked in place, the catch element 45 can be disengaged in each case with a simple operation of the operating element 19 .

In response to actuation of the operating element 19 in the operating direction 20 towards the seat support 3 , a movement of the steel spring 36 , which carries a wedge element 29 , takes place in the operating direction 20 . The wedge element 29 comprises, on its end face facing a stop element 17, a wedge surface 31 which acts as a push wedge for a wedge gear and moves a stop in an operating direction 20 perpendicular to the longitudinal direction 6. Element 17, which now assumes the function of a driven element. In other words, the stop element 17 is moved in its guide groove 24 by means of the wedge element 29 which is arranged vertically there. Preferably, the wedge angle is 45 degrees. The displacement of the stop element 17 shortens the displacement path of the seat support 3 by a certain amount, which is still valid, and the displacement of the stop element corresponds to the width 48 of the outer ends of the wedge elements 29 , 30 . FIG. 6 illustrates the corresponding position of the adjustment mechanism 18 . In other words, the stop element 17 rests on the upper flange 15 of the swivel-slide joint 13 as soon as the horizontal reference position is reached. A further displacement beyond this reference position and thus no further lowering of the seat support 3 is then possible. As shown in FIG. 2, the seat frame 3 is in its horizontal reference position.

For the particular safety function of the adjustment mechanism 18, provision is made to use two stop elements 17, 17' in order to produce a stop for the two swivel-slide joints 13 of the seat support 3 against the corresponding slide rail 15. For this purpose, the wedge element 17 is coupled with a second wedge element 30, which is directly actuated by a steel spring 36, which in the same way actuates the opposite stop element 17'. For this purpose, a movement of the opposing wedge element 30 opposite to the original operating direction 20 is required. For this purpose, the movement is deflected by means of a guide element 49 which is situated on the base plate 21 of the adjustment mechanism 18 so as to be rotatable and which serves as a kind of bridge. For this purpose, the guide element 49 contains in its center a bearing opening 61 for receiving a pivot pin 62 mounted on the base plate 21 of the adjustment mechanism 18 . On their ends opposite the wedge face 31 , the two wedge elements 29 , 30 contain a journal 50 which extends perpendicularly to the operating direction 20 and which protrudes into a deep hole 51 of the guide element 49 and realizes the mechanical connect. In other words, the coupling of the two wedge elements 29, 30 is achieved with an indirect crank mechanism. In order to achieve a particularly secure guidance of the wedge elements 29 , 30 , they contain a spring 52 on their underside, which is enclosed in a corresponding recess 53 in the base plate 21 of the adjustment mechanism 18 , see FIG. 7 .

If the stop element 17, 17' is in the "extended" position, which corresponds to the horizontal reference position of the seat frame 3, the rear side 27 of the stop element 17, 17' then rests against the front side of the wedge element 29, 30 54, see Figure 6. If pressure is exerted on the seat support 3 , for example because the user sits on the chair and exerts pressure on the seat in the direction of the front end region 12 without supporting himself on the backrest, the force acts in the longitudinal direction 6 at the end. On the actuating unit 17, 17', it causes the wedge-shaped element 29, 30 between the rear side 27 of the stop element 17, 17' on the one hand and the opposite shoulder 55 of the guide groove 33 on the other hand. . In this position, if the operating element 19 is operated, that is, the steel spring 36 is retracted to its starting position, as shown in Figure 5, the L-journal 56 of the steel spring 36 fixed to the operating slide 39 is already in the 5, while the other L-journal 57 and its journal end 42 are still in the position shown in FIG. 6 . In this position, the two L-journals 56 , 57 form an obtuse angle with one another. The steel spring 36 is prestressed.

Once the seat frame 3 is decompressed, for example, when the user stands up or leans on the backrest, the second L-journal 57 suddenly follows the first L-journal 56 and causes the wedge-shaped elements 29, 30 to move as shown in FIG. In the position shown, the stop elements 17, 17' can thus be retracted. This safety feature ensures that no sudden changes in the angle adjustment are possible. The transition from one position to another always requires a "pressure relief" of the seat support 3 .

This also applies in the reverse case. If the seat support 3 is in the reclined position ( FIG. 5 ) and if pressure is exerted on the chair, the operating lever 19 can still be operated. In this case, the resulting force causes the rear side of the stop unit 17, 17' to clamp directly on the opposite side 55 of the channel 33. The first L journal 56 of the steel spring 36 is then already in the position shown in FIG. 6 , while the second L journal 57 is still in the position shown in FIG. 5 . In other words, the L-journals 56, 57 form an acute angle. The steel spring 36 is prestressed.

In response to the release of the seat pressure, there is then a sudden displacement of the wedge elements 29, 30 by means of the steel spring 36, which results in an extension of the stop elements 17, 17'. As a result of these safety features, the operating element 19 is always slightly movable. Also, the adjustment only takes place when the seat is depressurized, ie never automatically.

List of reference signs

1 Synchronization mechanism

2 Base brackets

3 seat brackets

4 backrest support

5 frame elements

6 portrait orientation

7 latches

8 flange

9 flange

10 joystick

11 joystick

12 front seat end

13 Rotary-sliding joint

14 sliding elements

15 sliding flange

16 sliding flange

17 stop element

18 Adjustment mechanism

19 joystick

20 Direction of operation

21 Bottom plate

22 cover

23 screws

24 longitudinal guide groove

25 buffer elements

26 front side

27 rear side

28 contact surface

29 Wedge elements

30 wedge elements

31 wedge-shaped surface

32 Landscape orientation

33 Lateral guide groove

34 Connection mechanism

35 notches

36 steel spring

37 control arm

38 Operation button

39 Operating the slide

40 spring end

41 opening

42 spring end

43 guide element

44 opening

45 catch element

46 catch notch

47 catch notch

48 Changes in the displacement path

49 guide element

50 journal

51 deep holes

52 springs

53 Groove

54 front side

55 side

56 L-Journal

57 L-Journal

58 Lateral rails

59 lower side

60 positioning button

61 Support opening

62 pivot pin

Claims (10)

1. A device for adjusting the inclination of the seat of a chair, especially an office chair, - including base brackets (2), - comprising a seat support (3), which is connected to said base support (2) by joints (13), and - comprising an adjustment mechanism (18) allowing selective forward pivotal movement of said seat frame (3) beyond a substantially horizontal reference position. 2. Device according to claim 1, wherein said joint (13) is a rotary-slip joint. 3. Device according to claim 2, wherein said joint (13) comprises a sliding element (14) connected to said seat frame (3) and a sliding rail connected to said base frame (2) (15, 16), said sliding element (14) is placed in said sliding guide rail (15, 16). 4. Device according to one of claims 1 to 3, wherein the adjustment mechanism (18) is designed in such a way that its operation causes a displacement of the seat support (3) on the joint (13) Change of path (48). 5. Device according to one of claims 1 to 4, wherein the adjustment mechanism (18) is part of the seat support (3). 6. Device according to one of claims 1 to 5, wherein the adjustment mechanism (18) comprises at least one adjustable stop element (17, 17'). 7. Device according to claim 6, wherein at least one stop element (17, 17') is designed for resting on the base support (2), in particular against the base support (2) ) on the sliding guide rails (15, 16). 8. Device according to claim 6 or 7, wherein the adjustment mechanism (18) comprises a wedge-shaped friction wheel for operating at least one stop element (17, 17'). 9. Device according to claim 8, wherein the adjustment mechanism (18) comprises a spring element (36) operable by an operating element (19) for moving the drive wedge ( 29, 30). 10. Device according to claim 9, wherein the spring element (36) can be operated without causing at least one stop element (17, 17') as long as pressure is exerted on the seat support (3) ) adjustment.

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