Patents by Inventor Takeo Tada

Takeo Tada 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).

  • Anisotropic polymeric magnet in the tubular form and process for producing the same
    Patent number: 4327346
    Abstract: In an anisotropic polymeric magnet in tubular form, the magnetization orientation is directed in one direction perpendicular to the axial line of the tubular magnet. In a bipolar anisotropic magnet in tubular form, the magnetic poles can be formed only at symmetrical portions of the magnet with respect to the axial line and an imaginary line connecting the magnetic poles with each other is parallel to said one direction.In order to symmetrically distribute the magnetism around a tubular bipolar anisotropic magnet, a weld line(s) formed by injection molding of a mixture of ferromagnetic material powder and polymeric material is located in the portion(s) of the magnet where the magnetic poles are not formed.
    Type: Grant
    Filed: February 14, 1980
    Date of Patent: April 27, 1982
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Takeo Tada, Katsuji Honda, Yoshifumi Hirata
  • Rubber or plastic magnet and magnetic powder for making the same
    Patent number: 4308155
    Abstract: A rubber or plastic magnet of high magnetic properties is produced by incorporating a magnetoplumbite type magnetic powder into a rubber or thermoplastic or thermosetting matrix at a high concentration with a high degree of orientation of the magnetic particles. Such high concentration and orientation can be obtained by using a magnetoplumbite type magnetic powder having a compressed density in the range between 3.30 g/cm.sup.3 and about 3.55 g/cm.sup.3 and an average particle size of about 1.00 and 1.50.mu., said particles being prepared by dry crushing process from coarse sintered particles and having predominantly single crystal structure.
    Type: Grant
    Filed: October 29, 1979
    Date of Patent: December 29, 1981
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Takeo Tada, Katsuji Honda, Masami Oguriyama
  • Process for producing flexible magnets
    Patent number: 4278556
    Abstract: Procedure for pulverizing ferrite particles for use in the production of flexible magnets utilizing alcohols containing up to 4 carbon atoms and having a boiling point up to 100.degree. C. as a pulverization promoter, annealing at an elevated temperature, and dispersing in a flexible, nonmagnetic matrix.
    Type: Grant
    Filed: May 17, 1979
    Date of Patent: July 14, 1981
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Takeo Tada
  • Magnet roller for electrostatic record developing device
    Patent number: 3988816
    Abstract: An improved roller, consisting in part of a cylindrical permanent magnet, for use in electrostatic record developing devices is disclosed. Of the plurality of magnetic poles formed on the cylindrical surface of the permanent magnet, two of the same polarity are positioned with an auxiliary magnetic pole of opposite polarity located therebetween. The magnetic field intensity of the auxiliary magnetic pole is from about 1/10 to 1/2 that of the other magnetic poles.
    Type: Grant
    Filed: October 23, 1975
    Date of Patent: November 2, 1976
    Assignee: TDK Electronics Company, Limited
    Inventor: Takeo Tada