Patent attributes
A ceiling fan may include a column; a hub case coupled to the column and rotatable with respect to the column; and a plurality of blades disposed at the hub case, and arranged radially around the column. Each blade may include a lower blade having a first side coupled to the hub case and a second side, opposite to the first side, directed radially outwardly; an upper blade spaced apart from the lower blade, and having a first side coupled to the hub case and a second side, opposite to the first side, directed radially outwardly; and an air gap disposed between the lower blade and the upper blade. The blade may be formed as a tandem blade, thereby generating a greater lift force than a blade having one positive pressure surface and one negative pressure surface, such that an air volume may increase at a same power output.
