US Patent 11867191 Aerodynamic anti-rotation device

An anti-rotation device configured to prevent a plurality of blades of the industrial fan from rotating. The anti-rotation device includes a movable member and a non-movable member, wherein the movable member is slidable relative to the blades between two positions, an unlocked position that substantially permits the plurality of blades to rotate and a locked position that substantially prevents the plurality of blades from rotating. The movable member is movable in a direction substantially perpendicular to a direction of rotation of the blades. In one embodiment, the anti-rotation device includes a substantially L-shaped lever having a long side and a short side, a pulley operatively connected to the L-shaped lever at a point where the long side and the short side meet, and a substantially flat plate attached to one end of the short side of the L-shaped lever.