| 摘要 |
An arrangement for stepless vertical adjustment of a chair seat (1), which is carried by a chair base, comprising a pillar (3) with at least two members which are vertically movable relative to one another. An externally adjustable valve (35) is located in a fluid channel (45) between two concentric cylindrical spaces (20, 21) and is arranged to be switched between an open position, in which fluid may flow in the fluid channel between two spaces in one direction of flow or the other depending on the balance of forces on two pistons, one in each cylindrical space, and a closed position, in which communication is broken between the two spaces. A spring element (42) acts on the one piston to move it in its one direction and the second piston is anchored by means of a piston rod in said second one of the two members of the base which aremovable relative to one another. Means are arranged in the fluid channel (45) to maintain the rate of flow in the one direction of flow reduced relative to the rate in the opposite direction. |
