Patents by Inventor John J. DuPlessis

John J. DuPlessis 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: 5047205
    Abstract: A method for producing a compacted fully dense permanent magnet by providing a particle charge of a permanent magnet alloy composition from which the article is to be made and placing the charge in a cylindrical container having a generally axially positioned core with the charge surrounding the core within the container. The container and charge are heated to an elevated temperature and extruded to compact the charge to a substantially fully dense permanent magnet article.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: September 10, 1991
    Assignee: Crucible Materials Corporation
    Inventors: Vijay K. Chandhok, Robert F. Krause, Bao-Min Ma, John J. DuPlessis
  • Patent number: 4971756
    Abstract: Producing a die for use in compacting permanent magnet alloy powder by placing a quantity of a magnetic or nonmagnetic alloy, which may be stainless steel, cobalt- or nickel-base, or a magnetic or nonmagnetic mixture of one of these alloys and carbide particles in a container, heating the particles to an elevated temperature and hot-isostatically compacting the particles at the elevated temperature to obtain a fully dense die blank and forming a die cavity in the die blank. Carbide particles may be mixed with the alloy particles. The die blank may have an exterior cladding of stainless steel.
    Type: Grant
    Filed: May 12, 1989
    Date of Patent: November 20, 1990
    Assignee: Crucible Materials Corporation
    Inventor: John J. DuPlessis