Patents Represented by Attorney W. G. Kane, Jr. D. H. Fasse
  • Patent number: 4863351
    Abstract: An airscrew for propelling an aircraft has a hub, a jacket and a plurality of propeller blades secured by blade necks to the hub. These blade necks are secured to the hub with symmetric or equal angular spacings around the hub between neighboring radial blade neck axes. Each propeller blade has a longitudinal axis. At least certain of these longitudinal blade axes extend at different sweep angles relative to the respective radial blade neck axis. When the sweep angle is positive the respective sweep of the blade is a positive sweepback with a trailing sweep of the respective blade relative to a rotational direction of the airscrew. When the sweep angle is negative the respective sweep of the blade is a negative sweep forward with a leading sweep of the respective blade relative to a rotational direction of the airscrew. These differing sweep angles achieve a substantial noise reduction compared to conventional airscrews having a completely symmetrical construction.
    Type: Grant
    Filed: January 19, 1989
    Date of Patent: September 5, 1989
    Assignee: Rhein-Flugzeug GmbH
    Inventors: Hans-Otto Fischer, Karl H. Gronau