Patent ID: 7806661
Filing Date: 2010-10-05
Classification: B63H,Y10S

Abstract:
1. A propeller for a motor of a boat, the motor having a rotating output shaft extending along a propeller axis, the propeller comprising: a hub connectable to the rotating output shaft; and a plurality of blades, each blade including: a concave blade base connected to the hub; and a blade body portion connected to the blade base, the blade body portion having a leading edge and a trailing edge each extending from the blade base and intersecting at a blade tip, the leading edge being sized and configured in the shape of a logarithmic spiral, the trailing edge being linear and extending along an axis offset from intersection with the propeller axis; wherein a leading edge angle of the leading edge increases logarithmically from the concave blade base to the tip of the blade, the leading edge angle being defined by a tangent line to the leading edge and a radial line from a center of the propeller to the intersection of the tangent line to the leading edge.