Chair

Abstract

The invention relates to a chair with a seat, a base support and a backrest, wherein the seat is pivotably mounted on the base support and the backrest is pivotably mounted on the seat, and a first spring system is provided between the base support and the seat and a second spring system is provided between the seat and the backrest. Furthermore, means are provided for adjusting the spring behaviour of the two spring systems so that the pivotability of the seat in relation to the base support and the pivotability of the backrest in relation to the seat can be adapted to different requirements, especially to users of different weights.

1 . A chair with a seat, a base support and a backrest, wherein the seat is pivotably mounted on the base support and the backrest is pivotably mounted on the seat, and a first spring system is provided between the base support and the seat and a second spring system is provided between the seat and the backrest,
 wherein the pivoting movement of the backrest in relation to the seat is not mechanically coupled to the pivoting movement of the seat in relation to the base support and wherein means are provided for adjusting the spring behaviour of the two spring systems so that the pivotability of the seat in relation to the base support and the pivotability of the backrest in relation to the seat can be adapted to different requirements, especially to users of different weights.   
   
   
       2 . A chair according to  claim 1 , characterized in that the first spring system has at least one first spring member and the second spring system has at least one second spring member. 
   
   
       3 . A chair according to  claim 1 , characterized in that the first spring system has at least one first spring member and a first spring mechanism co-operating with the first spring member, and the second spring system has at least one second spring member and a second spring mechanism co-operating with the second spring member. 
   
   
       4 . A chair according to  claim 2 , characterized in that the means for adjusting the spring behaviour of the two spring systems are formed by means for adjusting the spring properties of the first and/or second spring member and/or by means for adjusting the first and/or second spring mechanism. 
   
   
       5 . A chair according to  claim 3 , characterized in that the means for adjusting the spring behaviour of the two spring systems are formed by means for adjusting the spring rate and/or the prestress of the first and/or second spring system, wherein the spring member and/or the spring mechanism of the respective spring system are optionally adjustable. 
   
   
       6 . A chair according to  claim 1 , characterized in that the means for adjusting the spring behaviour of the first spring system and the means for adjusting the spring behaviour of the second spring system are coupled together in such a way that the adjustment of the spring behaviour of the one spring system automatically effects adjustment of the spring behaviour of the other spring system. 
   
   
       7 . A chair according to  claim 1 , characterized in that the two spring systems and the means for adjusting the spring behaviour of the two spring systems are adapted to one another so that, even for users of different weights, substantially the same synchronous relationship between the inclination of the seat and the inclination of the backrest is rendered possible. 
   
   
       8 . A chair according to  claim 1 , characterized in that the seat is pivotable about a first articulation axis in the region of the front end of the seat and the backrest is pivotable about a second articulation axis in the region of the rear end of the seat. 
   
   
       9 . A chair according to  claim 1 , characterized in that means are provided for blocking the first and/or second spring system. 
   
   
       10 . A chair according to  claim 1 , characterized in that the first spring system has a first spring member and a first spring mechanism co-operating with the spring member, and furthermore the means for adjusting the spring behaviour of the spring system are formed by means for adjusting different spring characteristics of the spring system, wherein the spring system is formed so that the spring member is unloaded in the normal position of the chair, also for users of different weights, and in this unloaded starting position of the spring member all the adjustable spring characteristics of the spring system have a common origin. 
   
   
       11 . A chair according to  claim 1 , in that, in the normal position of the chair, the direction in which the spring mechanism is loaded by the user lies at right angles to the direction in which the spring mechanism acts on the spring member. 
   
   
       12 . A chair according to  claim 1 , characterized in that the seat is pivotable about a first articulation axis and the backrest is pivotable about a second articulation axis, wherein the two articulation axes are arranged so as to be displaceable relative to one another.