Patent ID: 8066480

Claim:
A high volume low speed fan comprising: a plurality of radially oriented fan blades each having a tip end, a base end and a body formed along a longitudinal axis; a rotatable shaft attached to said base end and aligned with said longitudinal axis; said rotatable shaft terminated by an offset crank arm; said offset crank arm having a crank pin; said fan blade being rotatable around said rotatable shaft by movement of said crank pin around said longitudinal axis thereby setting a fan blade pitch angle; a grooved disk having an external annular groove, said crank pins captured within said annular groove; an axial shaft axially attached to said grooved disk, said axial shaft being axially movable; a rotatable tubular shaft radially surrounding said axial shaft; a hub assembly attached to said tubular shaft, said hub assembly configured to engage said rotatable shafts in a radially symmetrical pattern while permitting rotation of said rotatable shafts; a drive motor rotatably coupled via a drive assembly to said tubular shaft wherein operation of said drive motor causes rotation of said tubular shaft and said hub assembly, thereby causing radial rotation of said fan blades; and, a position control motor coupled to said axial shaft, wherein operation of said position control motor causes axial translation of said axial shaft and said grooved disk, thereby causing uniform and simultaneous movement of said crank pins, and thereby causing uniform and simultaneous angular rotation of said fan blades to set said fan blade pitch angle.