Patents by Inventor Arnold C. V. Holmberg

Arnold C. V. Holmberg has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Propellors for watercraft
    Patent number: 4921404
    Abstract: A propellor (10) for watercraft has a hub (11) with a pair of blades (12) with a leading portion (13) central portion (14) and trailing portion (15). The leading portion (13) of the blades are forwardly inclined relative to the hub (11) and the blades progress through the generally radial central portion (14) to the rearwardly inclined trailing portion (15), the radial height of the blades decreasing from the central portion (14) to the trailing portion (15). Both the peripheral pitch of the blades (12), and the pitch of the line of junction (16) of the blades (12) to the hub (11) increase along the propellor (10), at least from the central portion (14) to the trailing portion (15).
    Type: Grant
    Filed: June 12, 1986
    Date of Patent: May 1, 1990
    Inventor: Arnold C. V. Holmberg