Abstract: This invention relates to linear positioning means and more particularly to a movable carriage and rod assembly for positioning switch elements such as limit switches relative to their actuating means. The primary purpose of this invention is to provide a switch positioning means which can be adjusted to a resolution commensurate with the need and precision of the switching device itself and to provide a positive locking device for the switch carrier which is immune to environmental difficulties such as vibrations and the like and will withstand the deleterious effects of repeated use.