DE102007059986A1 - office chair - Google Patents

Abstract

In an office chair with tiltable backrest (20) and a synchronously with the backrest forcibly tiltable seat (10), wherein the synchronizing mechanism comprises a seat disposed under the housing (30) on which the seat via a rear seat handlebar (50) a first housing-fixed and a second seat-fixed bearing is mounted, it is provided according to the invention that the backrest is mounted on the housing in a third housing fixed bearing and that the forced coupling between the seat and the backrest in the housing via at least one connecting rod between the backrest and the rear Seat link and is translated so that the seat moves backwards towards the backrest with the inclination of the backrest. Due to the displacement of the seat relative to the backrest, the distance between the hip point on the one hand and the iliac crest or the lumbar point on the other hand can be kept substantially constant in all inclinations, so that it can not lead to a iliac crest or lordosis loss. In addition, due to the constant distances, a friction effect between the backrest and the back of the user is avoided, so that even the described "shirt pull-out effect" can not occur.

Description

TECHNICAL AREA

The The present invention relates to an office chair with a tiltable Backrest and one via a synchronous mechanism with the backrest forcibly tilted seat, wherein the synchronizing mechanism a housing arranged under the seat includes, at which the seat with a rear seat handlebar with a first fixed to the housing and a second seat firmly Warehouse is stored.

STATE OF THE ART

Such an office chair is for example off DE 199 21 153 A1 known, wherein the seat is also mounted at its front end via a seat link in the housing. A pivotal movement of the backrest to the rear - as can be caused for example by leaning of the chair user to the backrest - induces a lowering movement of the rear part of the seat, which is superimposed on a displacement of the seat to the rear. By the backrest is stored, inter alia, in the seat-fixed bearing of the rear seat arm, the distance between the seat and backrest, however, remains unchanged.

Out DE 100 48 783 A1 a chair is known with synchronous mechanism, wherein the distance of the seat from the backrest can be changed in order to change the seat inclination between two positions.

task the synchronous mechanism is to allow a dynamic sitting where the user is seated between a front, in essentially upright and a rear, slightly reclined sitting posture can change. The synchronous mechanism should be the user support as best as possible. From constructive, need practical as well as ergonomic reasons in the realization of synchronous mechanisms, however, always compromises be made so that a certain construction is not all ergonomic Can fulfill requirements at once optimally. typical Weaknesses of known constructions including the aforementioned are a more or less pronounced iliac crest and / or Loss of lordosis and the so-called "shirt extraction effect".

to metrological and numerical recording of these effects Three reference points can be set as follows: A hip point on the user's hip joint axis, this point being assumed to be fixed relative to the seat; a iliac crest point at the front of the backrest at height of Iliac crest bone of the user; and a lordosis point as well at the front of the backrest but at height the lumbar spine of the user.

One Pelvic crest loss occurs when starting from the front Sitting posture in which the user by appropriate choice of his sitting position and thus the hip joint point on the seat touch contact with the iliac crest point, the distance between the hip point and the iliac crest when reclining enlarged and the user thereby loses this contact. The same applies to the loss of lordosis. To the "shirt extraction effect" comes it, when the backrest when pivoting under friction shifts parallel to the user's back.

One Another problem known synchronization mechanisms is the so-called "Whips". This is a deflection followed by Knocking back the backrest, which thereby is triggered, that the user "with momentum" on drop the seat.

PRESENTATION OF THE INVENTION

The Invention, the task is an office chair of specify the type mentioned above, in which the iliac crest and Lordosis loss as well as the "shirt extraction effect" opposite known constructions on a for the user at least no longer relevant measure are reduced. In addition, the "whipping" be avoided.

These The object is achieved according to the invention by a Office chair with the features of claim 1. The According to the invention office chair is characterized characterized in that the backrest on the housing is stored in a third housing fixed bearing and that the forced coupling between the seat and the backrest in the housing via at least one connecting rod between the backrest and the rear seat handlebar and translated as translated is that the seat at the Backrest tilt shifts towards the back.

By the displacement of the seat relative to the backrest can the distance between the hip point on the one hand and the iliac crest or the lordosis point on the other hand in all inclinations essentially be kept constant, so it does not become noticeable Pelvic crest / or loss of lordosis may occur. Is avoided Due to the constant distances also a friction effect between the back and the back of the user, so that even the described "shirt extraction effect" does not occur can.

The Inventive storage of the seat on the rear seat handlebar on the first, fixed housing finally allows in a simple way, the avoidance of "whipping", provided the lever arm between the first and the second bearing of the rear seat steering in the position with the lowest Inclination of the seat and the backrest substantially is oriented vertically, as claimed in claim 2 is.

Further preferred embodiments are in the dependent claims 2-7 marked.

SHORT EXPLANATION THE FIGURES

The Invention will be described below with reference to an embodiment explained in more detail in connection with the drawing become. Show it:

1 an office chair according to the invention with the seat and the backrest in their lowest inclination position;

2 the office chair of 1 with the seat and the backrest in their position with maximum inclination;

3 the synchronous mechanism of the office chair of 1 in its lowest inclination position, with the front housing shell omitted to reveal the view of the interior of the housing and the parts disposed therein;

4 the synchronous technique of 3 in addition, the backrest has been omitted;

5 in a representation according to 3 the synchronous mechanism in its position with maximum inclination;

6 in a representation according to 4 the synchronous mechanism in its position with maximum inclination; and

7 the synchronous mechanism under a) in perspective and b) in an exploded view.

WAYS TO EXECUTE THE INVENTION

At the office chair of 1 and 2 describe 10 the seat and 20 the backrest, each one under the seat 10 arranged housing 30 are pivotally mounted. The housing 30 is from a pedestal 40 worn and is part or includes parts of a synchronous mechanism for positive coupling of the seat 10 with the backrest 20 , Due to the forced coupling can seat 10 and backrest 20 only move together. The seat 10 has a lower seat plate 11 and on it a seat upholstery 12 on. The backrest 20 includes a backrest support 21 as well as one with a padding 23 provided backrest plate 22 , The backrest carrier 21 is fork-shaped and surrounds the housing 30 with two arms from both sides, being in the 1 . 2 only the front arm can be seen.

1 shows the seat 10 and the backrest 20 their basic position with the lowest inclination, the backrest plate 22 the backrest 20 is approximately vertical. 2 shows the seat 10 and the backrest 20 in its position with maximum inclination, showing the seat 10 at an angle of 9.5 ° and the backrest 20 are pivoted at an angle of 28.5 ° to the home position, so that the tilt ratio is about 3: 1. In addition, the seat is 10 in the position of 2 towards the basic position of 1 horizontal 36 mm back against the backrest 20 postponed. The distances between the hip joint point PH and the iliac crest point PB and between the hip joint point PH and the lordosis point PL are thus approximately the same in both illustrated positions. The changes in the distance between the two positions are less than 10%. This results in the office chair shown no noticeable iliac crest and lordosis and also the mentioned "shirt extraction effect" does not occur.

Like this in 7 It can be seen, is the case 30 divided in two along a central vertical plane and has two mirror-image housing shells 31 on. Incidentally, as far as that is of importance for the present invention, the synchronous mechanism is also constructed in mirror image to this vertical plane. As already described, this also applies to the backrest 21 , The further description is therefore limited to the structure of only one of the two game-pictorial halves.

In the back area is the seat 10 via a rear seat handlebar 50 with a housing-fixed, behind the pedestal 40 arranged bearings 51 and a seat-fixed bearing 52 stored. In the in 4 The basic position shown is the rear seat handlebar 50 Almost vertically aligned.

In the area of its front edge is the seat 10 via a front seat handlebar 60 with a housing-fixed bearing 61 and a seat-fixed bearing 62 stored. The backrest carrier 21 is like this in 3 can be seen, in a housing-fixed, in front of the pedestal 40 arranged bearings 24 stored.

The forced coupling between the seat 10 and the backrest 20 is over a connecting rod 70 made, which at the rear seat handlebars 50 in a warehouse 53 below its housing-fixed bearing 51 is articulated. The rear seat handlebar 50 is to about the camp 51 extended with a handlebar down and thus forms a two-armed lever. On the backrest 21 is the connecting rod 70 in a warehouse 25 below their housing-fixed bearing 24 hinged. The distance or lever arm between the bearings 51 and 53 at the rear seat handlebar 50 is shorter and only about half as long as the distance or lever arm between the bearings 24 and 25 on the backrest 21 ,

With a tilt of the backrest 20 pans the backrest 21 and with him the camp 24 to which the connecting rod 70 hinged, clockwise around the housing fixed bearing 24 , The connecting rod 70 In doing so, put a pull on the lower bearing 53 of the rear seat steering 50 out and twisted this around his housing-fixed camp 51 also clockwise. Because of the different length of lever arms between the bearings 24 and 25 on the one hand and the camps 51 and 53 On the other hand, the rear seat handlebar turns 50 at a greater angle than the backrest 20 , By comparing the 3 or 4 with the 5 or 6 , which each show the position with the maximum inclination of the backrest, this is clearly visible. Due to the different angle of rotation is the seat 10 as by comparing the 3 or 4 with the 5 or 6 can also be seen, back against the backrest 10 postponed. This shift follows the front seat handlebars 60 while being around his housing-fixed warehouse 61 swings.

Between the camp 25 on the backrest support and an adjustable point of attack on the front seat link 60 is a spring 80 clamped when tilting the backrest 20 is compressed and the backrest 20 loaded with a restoring force in its basic position. When returning the backrest 20 from an inclined position, the connecting rod acts 70 as a push rod and turns the rear seat handlebars 50 back counterclockwise.

By the storage of the seat 10 over the substantially vertically oriented rear seat handlebars 50 on the housing fixed bearing 51 It may be under load of the seat 10 without leaning against the backrest 20 not come to a tilt adjustment. For a tilt adjustment, it comes only by pushing back the backrest 20 against the action of the spring 80 , A whip of the backrest 20 with a shock-like load on the seat 10 , as occurs with other synchronous mechanisms, is thereby avoided.

10

Seat

11

lower seat plate

12

seat upholstery

20

backrest

21

backrest support

23

upholstery

22

back panel

24

fixed to the housing Camp of the backrest

25

camp the connecting rod on the backrest support

30

casing

31

housing shells

40

pedestal

50

rear seat link

51

fixed to the housing Bearing of the rear seat arm

52

sitting tight Bearing of the rear seat arm

53

camp the connecting rod on the rear seat handlebar

60

front seat link

61

fixed to the housing Bearing of the front seat arm

62

sitting tight Bearing of the front seat arm

70

connecting rod

80

feather

PH

hip point

PB

Iliac crest point

PL

Lordosenpunkt

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19921153 A1 [0002]
• DE 10048783 A1 [0003]

Claims (7)

Office chair with tilting backrest ( 20 ) and a forcibly coupled via a synchronous mechanism with the backrest tiltable seat ( 10 ), wherein the synchronizing mechanism a housing disposed under the seat ( 30 ), on which the seat via a rear seat handlebar ( 50 ) with a first housing-fixed ( 51 ) and a second seated camp ( 52 ) is mounted, characterized in that the backrest on the housing in a third housing fixed bearing ( 24 ) and that the forced coupling between the seat and the backrest in the housing via at least one connecting rod ( 70 ) is made between the backrest and the rear seat handlebar and translated so that the seat shifts toward the rear of the backrest with the inclination of the backrest. An office chair according to claim 1, characterized in that the seat and the backrest by a spring arrangement ( 80 ) are biased against a position with the lowest inclination and that the rear seat link ( 50 ) is oriented substantially vertically in this position. Office chair according to one of claims 1 or 2, characterized in that the first stationary bearing ( 51 ) for the rear seat handlebar ( 50 ) in the housing ( 30 ) behind the third fixed bearing ( 24 ) for the backrest ( 20 ) is arranged. Office chair according to one of claims 1-3, characterized in that the at least one connecting rod ( 70 ) on the rear seat handlebar ( 50 ) in a fourth warehouse ( 53 ) below its first bearing ( 51 ) is articulated, that the at least one connecting rod ( 70 ) on the backrest ( 20 ) in a fifth warehouse ( 25 ) below the third camp ( 24 ) and that the lever arm between the first ( 51 ) and the fourth bearing ( 53 ) shorter than the lever arm between the third ( 24 ) and the fifth camp ( 25 ). Office chair according to one of claims 1-4, characterized in that the seat ( 19 ) at its front edge via a front seat handlebar ( 60 ) in the housing ( 30 ) is stored. Seating furniture according to one of claims 1-5, characterized in that the inclination ratio between the backrest ( 20 ) and the seat ( 10 ) is between 2.8: 1 and 3.2: 1 and that the seat is horizontally displaced by 26-30 ° by a distance of 30-40 mm when the backrest inclines. Seating furniture according to one of claims 1-6, characterized in that the seat in the inclination of the backrest ( 20 ) as far as the backrest is moved, that the distances between the hip point (PH) and the lordosis point (PL) and between the hip point (PH) and the pelvic point (PB) change by a maximum of 10%.