Patent ID: 8638209

Claim:
Traffic control board apparatus comprising: an enclosure housing a liftable rotation assembly and a traffic control board, the traffic control board comprising visual signal forming devices mounted on the liftable rotation assembly, wherein the liftable rotation assembly includes: a vertical lift mechanism that raises and lowers the liftable rotation assembly upwardly and downwardly in the enclosure to move the traffic control board vertically out of and into the enclosure; a rotation mechanism that rotates the traffic control board about a vertical axis to selectable angular orientations with respect to the housing only when the liftable rotation assembly has lifted the traffic control board entirely out of the housing; and a high limit signal device that produces a high limit signal when the liftable rotation assembly is raised to an upper limit, a center position signal device that produces a center position signal when the traffic control board is in a center rotation position in which it can be lowered into the enclosure, and a low limit signal device that produces a low limit signal when the liftable rotation assembly is lowered to a docked storage position in the enclosure; and wherein the traffic control board apparatus also includes an electronic controller programmed to receive and process the high limit signals, the center position signals, and the low limit signals to determine, respectively, whether the traffic control board is out of the enclosure, whether the traffic control board is in the center rotation position, and whether the liftable rotation assembly is in the docked storage position.