Patents by Inventor Andrew Nicholas Hill

Andrew Nicholas Hill 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).

  • Linear free piston stirling machine
    Patent number: 7827789
    Abstract: A linear-free piston Stirling machine comprising a displacer and a power piston. A rod is attached at one end to the displacer, extends through the power piston and is mounted to the casing at its opposite end via a spring. A resilient stopper at the opposite end is arranged to contact the engine casing if the displacement of the displacer exceeds a predetermined limit.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: November 9, 2010
    Assignee: Microgen Energy Limited
    Inventors: Stephen Charles Welty, Andrew Nicholas Hill
  • Linear free piston Stirling machine
    Patent number: 7584612
    Abstract: A linear free piston Stirling machine having an overstroke prevention mechanism for the power piston. A resilient member is fixed to the casing which contacts the power piston 4 when its displacement exceeds a predetermined level.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: September 8, 2009
    Assignee: Microgen Energy Limited
    Inventor: Andrew Nicholas Hill
  • Linear free piston stirling machine
    Publication number: 20090094977
    Abstract: A linear free piston Stirling machine having a displacer piston mounted on first and second planar springs. The first spring has a stiffness which increases with increasing spring displacement. The second has a stiffness which is less variable with spring displacement to provide a combined stiffness which rapidly increases once the displacer piston displacement exceeds a fixed limit. Each of the springs has a plurality of spiral spring portions and a stress relieving hole beyond the outer edge of the spiral spring portions.
    Type: Application
    Filed: August 4, 2005
    Publication date: April 16, 2009
    Applicant: MICROGEN ENERGY LIMITED
    Inventor: Andrew Nicholas Hill
  • Linear Free Piston Stirling Machine
    Publication number: 20080256945
    Abstract: A linear-free piston Stirling machine comprising a displacer and a power piston. A rod is attached at one end to the displacer, extends through the power piston and is mounted to the casing at its opposite end via a spring. A resilient stopper at the opposite end is arranged to contact the engine casing if the displacement of the displacer exceeds a predetermined limit.
    Type: Application
    Filed: December 21, 2005
    Publication date: October 23, 2008
    Inventors: Stephen Charles Welty, Andrew Nicholas Hill