Patent ID: 7467923

Claim:
An impeller device operationally connected to drive a load, the device comprising: a vertical shaft; an upper horizontal surface and a lower horizontal surface fixed to the shaft; a plurality of panels, each panel being mounted upon a hinge pin connected between the upper horizontal surface and the lower horizontal surface, each panel being comprised of a vertical exterior planar surface and a vertical interior planar surface which are mounted on the respective hinge pins for rotational movement relative to the upper and lower horizontal surfaces; wherein each panel has a first stop associated therewith in a selected one of the upper and lower horizontal surfaces to limit the travel of its vertical exterior planar surface about its respective hinge pin to a most open position; wherein each panel has a second stop associated therewith in a selected one of the upper and lower horizontal surfaces to limit the travel of its vertical interior planar surface about its respective hinge pin to a most open position; wherein each panel has a third stop associated therewith in a selected one of the upper and lower horizontal surfaces to limit the travel of its respective vertical exterior planar surface about its respective hinge pin to a most closed position; wherein each panel has a fourth stop associated therewith in a respective one of the upper and lower horizontal surfaces to limit the travel of its respective vertical interior planar surface about its respective hinge pin to a most closed position; and a connection between the vertical shaft and the load to be driven.