US Patent 8096727 Retractable post system

A temporary barricade in the form of a retractable post system. In one configuration, the post is lowered into the ground, such that the top of the post is flush with the ground surface, leaving an unobtrusive configuration that one can walk over, drive over, and so forth. In another configuration, however, the post can be pulled up from the ground, and with a moderate rotational twisting motion, locked into vertical position, thereby providing a strong barrier to traffic and other situations.