Position holding device in which the rod section (31) is guided on the rail floor (42) at a constant height (33) with the cams (36) aligned with the rail groove (44). A strip (32) in the rail interior (41) runs along the groove. The strip is arranged at a height (19) between the rod section (31) and the slider (50) such that it can be adjusted in height (61) but is not movable in the longitudinal direction. The strip is pressed against the rod section by a spring force (39).
