US Patent 7340854 Breakaway sign post with magnetically coupled sections

An improved sign post assembly (10) for roadway use is provided wherein a sign post (12) includes a lower section (16) adapted for anchoring to the earth, a mating upper section (20) and a magnetic coupling assembly (24) for maintaining the sections during normal use while permitting breakaway of the upper section (20) when the host (10) is struck by a vehicle. Preferably, the coupling assembly (24) includes a magnetic body (26) and a corresponding component (28) which is magnetically attracted to the body (26). In order to cause breakaway in a predetermined direction, the coupling assembly (24) has mating surfaces for the body (26) and component (28) which are in a stairstep configuration.