Propeller

A propeller, comprising:

• a hub coaxially surrounding a longitudinal axis;
• a ring shroud coaxially surrounding the longitudinal axis and spaced radially from the hub;
• and
• a plurality of motive blades extending radially across at least a portion of the distance between the hub and the ring shroud, each motive blade having a blade root directly attached to a chosen one of the hub and the ring shroud, for rotation about the longitudinal axis due to the attachment to the chosen one of the hub and the ring shroud, and a blade tip extending toward the other one of the hub and the ring shroud, at least one selected motive blade of the plurality of motive blades being angled in a first twist direction, and at least one other motive blade of the plurality of motive blades being angled in a second twist direction which is substantially opposite the first twist direction;
• wherein at least one selected blade tip is directly attached to the other one of the hub and the ring shroud;
• and
• wherein at least one other blade tip is cantilevered from the blade root and is radially spaced apart from the other one of the hub and the ring shroud.

An aircraft comprising:

• a body;
• at least one fixed wing and at least one propeller mount extending from the body;
• at least one drive shaft positioned within a corresponding one of the at least one propeller mount and drivable by a motor or gear/clutch system;
• and
• at least one propeller operationally attached to the at least one drive shaft to obtain motive power therefrom, the propeller comprising
• a hub coaxially surrounding a longitudinal axis,
• a ring shroud coaxially surrounding the longitudinal axis and spaced radially from the hub, and
• a plurality of motive blades extending radially across at least a portion of the distance between the hub and the ring shroud, each motive blade having a blade root directly attached to a chosen one of the hub and the ring shroud, for rotation about the longitudinal axis, under motive power from the drive shaft, due to the attachment to the chosen one of the hub and the ring shroud, and a blade tip extending toward the other one of the hub and the ring shroud, at least one selected motive blade of the plurality of motive blades being angled in a first twist direction, and at least one other motive blade of the plurality of motive blades being angled in a second twist direction which is substantially opposite the first twist direction,
• wherein at least one selected blade tip is directly attached to the other one of the hub and the ring shroud, and
• wherein at least one other blade tip is cantilevered from the blade root and is radially spaced apart from the other one of the hub and the ring shroud.