Adjusting mechanism for setting a restoring force which acts on a backrest of a chair, and office chair having an adjusting mechanism of this type

Patent metadata

Field	Value
Publication number	US-9265348-B2
Application number	US-201214236805-A
Country	US
Kind code	B2
Filing date	Aug 2, 2012
Priority date	Aug 3, 2011
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

The adjusting mechanism serves for the weight-dependent setting of a restoring force which acts on a backrest ( 4 ) of an office chair which is configured with a synchronous mechanism. The synchronous mechanism comprises a support ( 12 ), a seat support ( 10 ) and a backrest support ( 8 ) which are connected to one another via joint pins (A 1 -A 4 ), the restoring force being exerted via a spring element ( 18 ). In order to achieve as flat a design as possible, the restoring force is transmitted with the aid of a pivotable lever ( 16 ) via a front bearing pin (L 1 ) to a first front joint pin (A 1 ), an active lever length (h) which can be varied with the aid of an adjusting element ( 20 ) being defined by the spacing between the bearing pin (L 1 ) and the second front joint pin (A 2 ). A weight setting is made possible by the variation of the active lever length (h).

First claim

The invention claimed is:

1. An adjusting mechanism for a weight-dependent setting of a restoring force which acts on a backrest ( 4 ) of a chair which is configured with a synchronous mechanism, comprising a support ( 12 ), a seat support ( 10 ) and a backrest support ( 8 ) which are connected to one another via joint pins (A 1 -A 4 ) so as to form the synchronous mechanism, and having a spring element ( 18 ) for generating the restoring force, which spring element ( 18 ) extends along a longitudinal direction (a) between a front bearing pin (L 1 ) and a rear bearing pin (L 2 ), wherein the restoring force is transmitted with the aid of a lever ( 16 ) via the front bearing pin (L 1 ) to a front joint pin (A 2 ), a lever direction (d) being defined by a connecting line between the front joint pin (A 2 ) and the front bearing pin (L 1 ), and an active lever length (h) which can be varied with the aid of an adjusting element ( 20 ) being defined by the spacing between the bearing pin (L 1 ) and the front joint pin (A 2 ), the lever ( 16 ) connects the support ( 12 ) and the seat support ( 10 ) to one another via two front joint pins (A 1 , A 2 ).

2. Adjusting mechanism according to claim 1 , characterized in that, as viewed in a viewing direction towards the backrest ( 4 ), the front bearing pin (L 1 ) is arranged in front of a connecting line (c) between the front joint pins (A 1 , A 2 ).

3. Adjusting mechanism according to claim 1 , characterized in that the lever ( 16 ) has a first lever arm ( 16 A) which connects the front joint pins (A 1 , A 2 ) to one another, and a second lever arm ( 16 B) which receives the front bearing pin (L 1 ) and is mounted, in particular rotatably, on a bearing (D) on the first lever arm ( 16 A).

4. Adjusting mechanism according to claim 3 , characterized in that the second lever arm ( 16 B) is of bent-over and, in particular, approximately L-shaped configuration.

5. Adjusting mechanism according to claim 4 , characterized in that a direction of extent (b) which extends approximately parallel to the longitudinal direction (a) of the spring element ( 18 ) is defined by a connecting line between the front bearing pin (L 1 ) and the bearing (D).

6. Adjusting mechanism according to claim 3 , characterized in that, as viewed in a viewing direction towards the backrest ( 4 ), the bearing (D) is arranged behind a connecting line (c) between the front joint pins (A 1 , A 2 ).

7. Adjusting mechanism according to claim 3 , characterized in that, in order to vary the active lever length (h), the adjusting element ( 20 ) is fastened to the two lever arms ( 16 A, 16 B) in order to adjust their relative position.

8. Adjusting mechanism according to claim 1 , characterized in that the longitudinal direction (a) of the spring element ( 18 ) is oriented at an angle of action (β) with respect to the lever direction (d), which angle of action (β) lies in the range from 50° to 130°.

9. Adjusting mechanism according to claim 1 , characterized in that the longitudinal direction (a) of the spring element ( 18 ) is oriented at an angle of action (β) with respect to the lever direction (d), the angle of action (β) changing in the direction of a right angle in the case of an increasing inclination of the backrest support ( 8 ), and preferably assuming approximately 90° in the case of a completely inclined backrest support ( 8 ).

10. Adjusting mechanism according to claim 2 , characterized in that the adjusting element ( 20 ) is a spindle which is, in particular, self-locking.

Assignees

• Potrykus Martin
• Haworth Inc

Inventors

• Potrykus Martin

Classifications

• A47C1/03272 Primary

  with coil springs · CPC title

• A47C1/03266 Primary

  with adjustable elasticity · CPC title