Patents by Inventor James R Jefferson

James R Jefferson 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).

  • Control of a waterjet propelled vessel
    Patent number: 7743721
    Abstract: A method for controlling a watercraft includes acquiring a desired heading of the watercraft, acquiring an actual heading of the watercraft at time T0, calculating a heading error by comparing the desired heading with the actual heading and determining a rate of change of the heading error. A P gain, I gain and D gain for use in maintaining the heading of the watercraft is determined and used to calculate factors related to heading error, cumulative heading error and rate of change of heading error. These factors are summed to form a control value for deflecting a nozzle of the watercraft to maintain a heading of the watercraft. Further embodiments include methods for calculating and correcting a heading of the watercraft, as well as methods for controlling roll out and sideways motion of the watercraft.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: June 29, 2010
    Assignee: Rolls-Royce Naval Marine, Inc.
    Inventors: Andrew F. Barrett, James R. Jefferson
  • Control of a Waterjet Propelled Vessel
    Publication number: 20080027597
    Abstract: A method for controlling a watercraft includes acquiring a desired heading of the watercraft, acquiring an actual heading of the watercraft at time T0, calculating a heading error by comparing the desired heading with the actual heading and determining a rate of change of the heading error. A P gain, I gain and D gain for use in maintaining the heading of the watercraft is determined and used to calculate factors related to heading error, cumulative heading error and rate of change of heading error. These factors are summed to form a control value for deflecting a nozzle of the watercraft to maintain a heading of the watercraft. Further embodiments include methods for calculating and correcting a heading of the watercraft, as well as methods for controlling roll out and sideways motion of the watercraft.
    Type: Application
    Filed: December 1, 2004
    Publication date: January 31, 2008
    Inventors: Andrew F. Barrett, James R. Jefferson
  • Therapeutic cushion
    Patent number: D451197
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: November 27, 2001
    Inventor: James R Jefferson