Device for air and fluid acceleration and method of making same

Claim 1

A rotational device adapted to act in a fluid medium to provide a reaction therewith including a plurality of wing-like blades, said blades being generally disposed in a plane perpendicular to the axis of revolution of the device, said blades being curved to form a generally cup-shaped structure opening in a direction toward the flow of fluid through said device and further each including outer radial portions generally disposed in a direction parallel to said axis of revolution whereby said fluid medium will move in a direction parallel to said axis of revolution and movement of any of said fluid medium in a radial direction generally perpendicular to said axis is resisted by said outer radial portion, said outer radial portions of said blades being in an overlapping relationship with respect to one another whereby escape of said fluid medium in said radial direction is minimal, said outer radial portion of each of said blades in the area of said trailing edge being displaced radially inwardly a substantial amount with respect to the outer radial portion of the blade which is overlapped, and said trailing edge of each of said blades overlapping the next blade by a least one fifth of the circumferential extent of said next blade, and said blades have a generally straight line leading edge and a spirally curved trailing edge.