Abstract: A chair, particularly a work chair, includes a mounting plate for fastening a seat and back member. The mounting plate is supported so as to be pivotable with its front end about a horizontally extending axis on a support member which is, in turn, supported by a vertically extending, essentially vertically adjustable support tube and projects laterally relative to the support tube. The mounting plate is supported on its side facing away from the pivoting axis and near the seat and back member by a gas pressure spring. The gas pressure spring has at one end thereof a valve tarppet for operating a valve which is integrated in the gas pressure spring, so that the effective length of the gas pressure spring is adjustable. The end of the gas pressure spring with the valve tappet is supported on the support member. A two-armed lever which acts on the valve tappet is pivotally mounted on a bearing block of the support member which bearing block supports the gas pressure spring.

Abstract: At a seat carrier 4 of a chair, a backrest 5 is pivotally connected. A seat which rests on the seat carrier 4 and the backrest can be interdependently adjusted in their inclination. For return into the resting position and to fix in any desired position, a gas pressure spring 10 and, if necessary, additional springs 11 are provided. The one end of the gas pressure spring 10 engages at the free end of a thrust lever 15 which is pivotally held at the backrest 5, wherein this pivot axis 7 is arranged at a distance from the pivot axis 6 between the backrest 5 and the seat carrier 4. A lever arm 16 which is pivotally attached at the seat carrier 4 also engages at this thrust lever 15 at a distance from its pivot axis 7. The thrust lever 15 can perform a relative motion with respect to the backrest 5 by means of the arrangement of the lever arm 16. Therefore a relatively small movement of the backrest 5 results in a correspondingly larger movement of the gas pressure spring 10.