Translation movement guidance mechanism with positional locking, for adjustable elements of an automobile vehicle seat

A translation movement guidance mechanism with positional locking for adjustable elements of an automobile vehicle seat including a stem and at least one bush sliding in relation to the stem, the at least one bush being attached to a support plate extending parallel to the stem, and locking means, in fixed position in relation to the stem, including a locking component which has two substantially parallel bearing elements arranged so that, in a locking position of the locking component, the bearing elements exert a gripping force on two diametrically opposite sides of the stem, and the at least one bush being arranged so that the stem can be installed on the support plate in an assembly direction perpendicular to said support plate and the locking component further including, between the two bearing elements, a recess allowing the insertion of the stem into said recess simultaneously with the installation of the stem on the support plate in the assembly direction.