Patent Number: 6,250,886

Title: Axial flow fan and fan blade

Abstract: The present invention provides an axial flow fan and fan blade. A true tapered, twisted airfoil section is constructed by cutting a flat piece of light alloy to a unique shape to obtain a flat pattern representative of a selected airfoil design, forming the airfoil section by making three simple bends in the pattern and joining the trailing edge with rivets. A transition piece is provided to connect the airfoil section to the fan hub. The transition piece has first and second airfoil bearing surfaces, substantially all of which are in contact with the interior surface of the airfoil section and which possess a twist complementary to the twist of the airfoil section. The transition is substantially flat and is preferably of a two piece design comprising juxtaposed first and second pieces joined along a peripheral flange. The transition piece allows for the use of a generally U-shaped rivet pattern for the mechanical connection between the airfoil section and the transition.

Inventors: Immell; William F. (Tulsa, OK), Scott; Sean D. (Broken Arrow, OK), Van Atta; John W. (Tulsa, OK)

Assignee: Chittom International, Inc.

International Classification: F04D 29/38 (20060101); F04D 029/34 ()

Expiration Date: 06/26/2018