Patent attributes
Propeller for an airplane or boat includes a rotatable hub attachable to a power axle, a ring structure including an inner ring spaced apart from and connected to the hub, and shovel blades fixed to the inner ring. Each shovel blade is connected at an inner lateral edge to an outer surface of the inner ring and is angled rearward. The shovel blades are spaced apart from one another such that a leading edge of each shovel blade does not overlie a trailing edge of an immediately adjacent shovel blade and the trailing edge of each shovel blade does not underlie the leading edge of an immediately adjacent shovel blade. There may be an outer ring around the shovel blades, or separated blade guides on an opposite side of the shovel blades from the inner ring with each blade guide being associated with a respective shovel blade.