Abstract: The hinge mounting for an adjustment apparatus of a motor vehicle seat has a first outer wheel with an inner toothed surface and a second outer wheel with an inner toothed surface. At least two planet wheels mesh with both the first inner toothed surface and the second inner toothed surface. A driving toothed sun wheel meshes with the planet wheels. The sun wheel has a first gear wheel and a second gear wheel that are disposed axially behind each other; either gear wheel meshes with the planet wheels. The two gear wheels have coinciding toothed surfaces. The first gear wheel has a first out-of-round that has at least one first flank. The second gear wheel has a second out-of-round that has at least one second flank. In a state in which the toothed surfaces of the two gear wheels are aligned, the flanks are not aligned. An elastic element rests against the flanks and exerts an elastic bias between the first flank and the diametrically opposed second flank.

Abstract: An adjustment device for a rotational adjustment of two centrically mounted adapter pieces especially for a seat, preferably for a seat of a motor vehicle, includes a planetary gear with a sun wheel and planetary wheels. The planetary gear has a first housing part and a second housing part each with an internal toothing. The housing parts can be rotated relative to one another and are captively held on one another. Both housing parts have an edge flange. A separate retaining ring, which overlaps the edge flanges, holds the housing parts together. This allows to assemble the adjustment device in a simple manner and at low cost and ensures that the adjustment device functions even when subjected to high stress.