US Patent 7779578 Rolling door retainer

A retainer for aircraft hangar doors in which vertical movement of doors is adjustably limited to allow sufficient movement to permit door removal from their supporting tracks or to prevent such undesirable displacement during high wind conditions as experienced during hurricanes and tornadoes or violent earth motions during earthquakes. The retainer in its retaining position does not obstruct normal opening and closing of the doors and is economical to manufacture and install.