The invention relates to an adjustment armature comprising a fixed component (11) which is associated with part the seat and an adjustable component (12) which is connected to the backrest. The components of the armatures (11, 12) are joined to each other by means of an actuating member (13). An adjusting and locking device, having the form of a gear, is provided in order to adjust the relative positions of the two armature components (11,12). The adjusting member (13) comprises an eccentric segment (14), whereby one of the armature components (12) is mounted thereon. The other armature component (11) acts as a bearing for the eccentric segment (14). The eccentric segment (14) is comprised of wedge segments (27), which rest against each other and partially overlap a catch (20). Said eccentric segment is also provided with a catch segment (29) between the narrow sides thereof and an energy accumulator which moves the wide ends of, the wedge segments (27) apart. The actuating member (13) optionally comprises a central receiving section for a rotationally fixed connection to the transmission rod. The catch (20) is made up of a bushing (21), and a ring (26), which is rotationally fixed to said bushing and consists of a catch segment (29), whereby no free movement can be felt when the armature (10) is initially displaced for adjustment purposes. The catch ring (26) is mounted on the armature component (11) and acts as a bearing for the wedges (27) in a peripheral region of said ring, which does not contain said catch segment (29).