Patents by Inventor Allan Ohman

Allan Ohman 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).

  • Hollow hub marine propeller with anticavitation groove
    Patent number: 3947151
    Abstract: This invention relates to hollow hub marine propellers provided with an external groove girdling the hub disposed between the propeller blades and the rear hub opening. The walls of the groove or annular cavity do not extend outwardly of the hub and thereby offer minimal water resistance. The groove serves to minimize forward migration of exhaust gas issuing from the rear end of the hub, thus to minimize blade cavitation.
    Type: Grant
    Filed: December 6, 1974
    Date of Patent: March 30, 1976
    Inventors: Karl Gustav Herman Stillerud, Allan Ohman