Patent ID: 7665967
Filing Date: 2010-02-23
Classification: F04D

Abstract:
1. A high efficiency traditional appearing ceiling fan comprising: a hub with a motor; and a plurality of solid plastic molded base blades attached to the ceiling fan motor, each blade having a flat and planar lower surfaces that visually appear to be flat and planar when viewed underneath the fan, and flat and planar upper surfaces, each of the base blades being having a substantially uniform thickness between a flat root end and a tip end that is wider than the flat root end, the base blades being contiguous except for the root end having a plurality of mounting holes therethrough for attaching to a blade arm, the base blades having a leading edge and a blunt tipped trailing edge; and separate attachable aerodynamic attachment members, each being formed from solid molded plastic, having a lower surface that is flat and planar and has a root end identical in width to the root end of the base blades, and a tip end identical in width to the tip end of the base blades, the lower surface of the aerodynamic attachment members being attached to the flat and planar upper surfaces of the base blades, the aerodynamic attachment members having upper surfaces with a single upwardly curving slope from a leading edge to a point of maximum thickness that is closer to the leading edge than to a trailing edge, the aerodynamic upper surfaces having a single downwardly curving slope from the maximum thickness point to the trailing edge, each of the aerodynamic attachment members having a mid-thickness along a longitudinal axis of the aerodynamic attachment members being thicker than both thicknesses along the leading edge and the trailing edge of the aerodynamic attachment members, the aerodynamic attachment members having an overhanging rounded leading edge for fitting and wrapping about a leading edge on each base blade, the overhanging leading edge having a lower flat surface which is even with the lower flat surface of the base blade, so that both the lower flat surface of the base blade and the lower flat surface of the overhanging leading edge of the aerodynamic attachment members appear to be flat and contiguous with one another when viewed from below the ceiling fan, the aerodynamic attachment members having a trailing edge that extends no farther than the blunt tipped trailing edge of the base blades so that the blunt tipped trailing edge of the base blades remains visible thereon, wherein the aerodynamic upper surfaces of the attachment members when used with the base blades provide increased airflow over blades having both upper and lower flat and planar surfaces.