Patents by Inventor by Hiroshi Matushima, executor

by Hiroshi Matushima, executor 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).

  • Fc-Pt-Nb permanent magnet with an ultra-high coercive force and a large maximum energy product, and method for producing the same
    Patent number: 4863530
    Abstract: The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet are made by heating an alloy of the above main composition at 900.degree..about.1,400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.
    Type: Grant
    Filed: December 1, 1988
    Date of Patent: September 5, 1989
    Assignee: The Foundation: The Research Institute of Electric and Magnetic Alloys
    Inventors: Hakaru Masumoto, deceased, by Hiroshi Matushima, executor, Kiyoshi Watanabe
  • Fe-Pt-Nb permanent magnet with an ultra-high coercive force and a large maximum energy product
    Patent number: 4814027
    Abstract: The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma..sub.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet is made by heating an alloy of the above main composition at 900.degree..about.400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: March 21, 1989
    Assignee: The Foundation: The Research Institute of Electric and Magnetic Alloys
    Inventors: Hakaru Masumoto, deceased, Kiyoshi Watanabe, Hiroshi Matushima, executor