Patents by Inventor Douglas Otto Keller

Douglas Otto Keller 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).

  • Double Slotted Flap for Small Airplane
    Publication number: 20120280089
    Abstract: A short take-off and landing airplane includes double slotted flaps attached to a wing, and a manual control for mechanically deploying the double slotted flaps without hydraulic or electric assistance.
    Type: Application
    Filed: May 1, 2012
    Publication date: November 8, 2012
    Inventor: Douglas Otto Keller