Chair, in particular office chair

Claim 1

Load-bearing frame for a chair which can be adjusted in terms of its height and inclination, comprising: a standing column, a load-bearing and pivoting device arranged on said standing column, a seat carrier and a backrest carrier, the seat carrier and the backrest carrier being mounted on the load-bearing and pivoting device by means of two lateral struts arranged on a knee side of a spindle body, said carriers being pivotable about a horizontal axis of the load-bearing and pivoting device against the restoring force of at least one first, spring element, said carriers being lockable in any position and being releasable again by a second spring element, the load-bearing frame further comprising a retaining device, which is arranged at the upper end of the standing column and through which the spindle body passes, and said first spring element including two helical springs which are oriented in the longitudinal direction of said horizontal axis, said springs being arranged between the lateral struts and the retaining device, said springs being mounted on the spindle body and, in order to adjust spring restoring force each being held at a respective one end by a respective spring end piece on a bracing element mounted on the retaining device and, at a respective other end on a bearing element which is operatively connected to the backrest carrier, a knee side of the seat carrier being slidably and pivotably mounted on the struts arranged on the knee side of the spindle body by means of respective second bearing devices, each provided with a bearing pin, which is displaceably guided in a respective said strut, in order to maintain the knee side of the seat carrier at substantially a given height when a user pivots the chair about said horizontal axis.