Seat depth adjustment device for a vehicle seat

A vehicle seat depth adjustment device 1 with a seat structure 3 having a support plate 6 moveable relative to the seat structure with the aid of a linear guide (7, figure 2), the seat structure receives an upholstery cover pre tensioned with the aid of a cover return 22, which is connected to the support plate and positionable infinitely variably, i.e. the cover return is gridless. Advantageously the cover return is thus free from noise of meshing and/or pinion engaging. Preferably the linear guide is formed in a basic support 5 of the seat structure and a two-part retaining element 23 connects the upholstery cover and the seat structure. Preferably the first part 25 of the retaining element is elastic (e.g. a spiral spring) for pretensioning of the upholstery cover and the second part 26 in inelastic for guidance of the retaining element 23. Preferably the cover return has a connecting element 27 for the releasable connection to a transverse stitched-down seam of the upholstery cover.