Patents by Inventor David P. Harrell

David P. Harrell 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: 4639192
    Abstract: A propeller pitch controlling arrangement having a fuel economizer feature for use on marine vessels, has a mode selector valve operable to a normal mode and an economizer mode. In the economizer mode, a first pilot signal is transmitted to a path selector valve to establish a first flow path to a propeller pitch servomechanism. A second pilot signal is transmitted from a relay valve when the marine vessel speed drops below a predetermined value. The second pilot signal moves the path selector valve to a second position establishing a second flow path to the propeller pitch servomechanism. A first selected fluid pressure from a regulating valve arrangement mechanically linked to the engine fuel rack, is directed to the propeller pitch servomechanism when the first flow path is established. This first selected fluid pressure is proportional to the movement to the engine fuel rack.
    Type: Grant
    Filed: April 11, 1984
    Date of Patent: January 27, 1987
    Assignee: American Standard Inc.
    Inventor: David P. Harrell