The self-locking revolute joint which can be step by step adjustable to an angle by means of pumping movements of an activation lever is particularly suitable for adjustment of seat height or backrest inclination of vehicle seats. It has a mount in which a bearing shaft is journalled. Further, it has a locking disk with notches arranged at equal angular intervals and with a torsion-proof connection with the bearing shaft; further a locking element which is preferably journalled with turning capability at the mount, also having a locking tooth confunctioning with the notches and being elastically prestressed in the engagement direction of this locking tooth and having a total of two control profiles, each one of which has a release profile and an unblocking indentation, the distance between which corresponds to the angular intervals between the notches, and confunctioning with carriers, which can be adjusted by means of the activating lever. Thereby, a return spring is assigned to the activation lever, prestressing the latter into the central position.The activation lever has a rigid connection with an activation plate, which is journalled to turn freely with the bearing shaft. On the activation plate, around a linkage axle, a release segment is linked so that it can be freely turned, having two carriers arranged symmetrically to the line connecting the linkage axle and the axis of the bearing shaft, being prestressed by means of a return spring into a neutral position, in which both carriers are disengaged from the notches and these carriers are arranged so that after a turning away from the neutral position, one of the carriers engages in one notch, while the other impacts on the adjacent release profile of the locking element and unlocks it.