Patents by Inventor Da Hai He

Da Hai He 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).

  • Low resistivity materials with improved wear performance for electrical current transfer and methods for preparing same
    Patent number: 6679933
    Abstract: A copper graphite composite material suitable for use in applications such as brushes, switches and contact materials for rail systems and other industrial devices. The composite comprises a copper network matrix having a plurality of pores containing graphite. The composite may have an IACS value of at least 40% which may even be higher than 70% and a density value of at least 6.0 g/cm3. The method for preparation of the composite comprises mixing graphite and copper powder under non-oxidising conditions, compacting the mixture and sintering under non-oxidising conditions.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: January 20, 2004
    Assignees: Victorian Rail Track
    Inventors: Da Hai He, Rafael R. Manory, Norman J. Grady, Harry Sinkis, Clim Pacheco