Patent ID: 6447251
Filing Date: 2002-09-10
Classification: F04D,Y10S

Abstract:
A blade for use in a fan assembly to be coupled to the shaft of a motor for rotation about an axis, said blade comprising:a front side, a rear side, an inner attachment portion, a curved outer edge, a curved leading edge, and a curved trailing edge, said blade having a convex front side and a concave rear side, said outer edge defining an arc extending between a forward position and a rearward position, said leading edge extends outward and intersects the arc of said outer edge at said forward position, said trailing edge extends outward to said rearward position, said blade comprises an angle &agr;L formed by a straight line having a length equal to RL extending from a given axis coinciding with the axis of the fan assembly to said forward position and a straight line extending from said given axis to a first position on said leading edge and having a length equal to about 0.5RL wherein said angle &agr;L is equal to at least 35 degrees.