Patents by Inventor David E. Ziegler

David E. Ziegler 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).

  • Patent number: 5020741
    Abstract: A multiple blade aircraft propeller hub has a bulkhead supporting concentric slip rings connected by slide blocks to the aircraft electrical system. Electrical conducting flexible leads connect the slip rings to electrical heating elements or de-icing boots carried by the propeller blades. Each of the leads includes an elongated flexible braided copper tube for conducting electricity and which loosely surrounds a flexible multiple strand stainless steel cable, and an extruded flexible vinyl insulating tube loosely surrounds the braided tube. The leads provide for minimizing stresses and metal fatigue in the electrical conducting braided tube with changes in blade pitch and thereby provide for a substantially extended service life.
    Type: Grant
    Filed: December 7, 1989
    Date of Patent: June 4, 1991
    Assignee: Hartzell Propeller Inc.
    Inventors: David E. Ziegler, Arthur J. Bowser