Patent attributes
A fan comprises a hub, fan blades, and inserts. The hub comprises outwardly extending mounting tabs that lie along a common horizontal plane. The fan blades are hollow, such that each mounting tab is inserted in the hollow interior of a corresponding fan blade. Each insert is positioned in the hollow interior of each fan blade, between each mounting tab of the hub and the interior surface of the corresponding fan blade. Each insert is configured to position and maintain the chord line of each corresponding fan blade at an oblique angle relative to the horizontal plane of the hub. A kit may include several insert sets to choose from to provide adjustable angle of attack. A fan control system includes a dimmer switch and a control module, which allows the dimmer switch to be used to infinitely adjust the speed of a fan motor within a range.
