Abstract: A device for adjusting a seat depth of a chair has a seat carrier, an adjusting part which is arranged pullable out on a front edge of the seat carrier, a spindle rotatably supported in the adjusting part, two nuts arranged on the spindle so that during a rotation of the spindle they move on the spindle in opposite directions, and two braces hingedly supported on the seat carrier and connected with the nuts.

Abstract: A chair has a seat shell, a cushion having a front edge which extends outwardly beyond a front edge of the seat shell, a shaft arranged under a seat surface, an actuating element connected with the shaft and also connected with the front edge of the cushion, at least one first toothed disc arranged on the shaft, an endless element guided on the toothed disc and connected with the seat shell, a second toothed disc which together with the first toothed disc is displaceable parallel to the seat shell, so that by raising or lowering of the actuating element the front edge of the cushion is displaceable forwardly or rearwardly.

Abstract: A chair has a seat surface having a front region which is turned downwardly and is pullable rearwardly under the seat surface for reducing a seat depth.