Patents by Inventor Yozo Shirotori

Yozo Shirotori 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).

  • Bearing device
    Patent number: 4984909
    Abstract: An improved bearing device for use in a spindle motor for driving computer hard disks is disclosed. The device includes a shaft, bearings supporting the shaft, and a bearing holder for holding the bearings. The bearing holder is made of a magnetic material. The shaft, the bearings, and the bearing holder are made of materials having substantially the same thermal expansion coefficient.
    Type: Grant
    Filed: September 11, 1989
    Date of Patent: January 15, 1991
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventor: Yozo Shirotori
  • Bearing device
    Patent number: 4907897
    Abstract: An improved bearing device for use in a spindle motor for driving computer hard disks is disclosed. The device includes a shaft, bearings supporting the shaft, and a bearing holder for holding the bearings. The bearing holder is made of a magnetic material. The shaft, the bearings, and the bearing holder are made of materials having substantially the same thermal expansion coefficient.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: March 13, 1990
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventor: Yozo Shirotori
  • Disc drive motor
    Patent number: 4882643
    Abstract: A disc drive motor having a rotor magnet at the internal circumference surface of a hub supporting a disk at its external circumferential surface. The rotor magnet is opposed to an internal motor stator. The hub is formed by inserting a yoke made of magnetic material almost in the shape of cup during aluminum die casting. At least a part of the internal circumference surface of the yoke is exposed and the motor magnet is fixed to the exposed part at the internal circumference surface of the yoke.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: November 21, 1989
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventor: Yozo Shirotori
  • Brushless motor for driving magnetic disks
    Patent number: 4818907
    Abstract: A brushless motor for driving magnetic disks comprises: a housing having at least one through hole therein; a stator attached to the housing; a rotor having a driving magnet in opposing relationship with the stator; an element for detecting the magnetic pole of the driving magnet removably fitted into the at least one through hole; and means for sealing one open end on the side of the rotor, both when the detecting element is fitted into the through hole, and when the detecting element is removed from the through hole.
    Type: Grant
    Filed: December 3, 1987
    Date of Patent: April 4, 1989
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventor: Yozo Shirotori