Patents by Inventor Stephen Evanson

Stephen Evanson 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).

  • Apparatus for inspecting degradation/damage of a material using an AC magnet, a superconducting DC magnet and a SQUID sensor
    Patent number: 5331278
    Abstract: A non-destructive inspection apparatus includes a magnetic field applying device and a magnetic sensor. The magnetic field applying device is adapted to apply DC and AC magnetic fields to an object to be inspected. Degradation/damage of the object is detected by measuring a magnetic characteristic of the object in a state in which the DC and AC magnetic fields are applied. Also, a non-destructive inspection apparatus includes as a magnetic sensor a plurality of pickup coils and a SQUID(s) connected to the pickup coils and decides the form of a defect of an object to be inspected by producing a difference between outputs of the pickup coils or SQUIDs.
    Type: Grant
    Filed: September 11, 1991
    Date of Patent: July 19, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Stephen Evanson, Satoshi Kanno, Masahiro Otaka, Toshihiko Yoshimura, Kunio Hasegawa, Kazuo Takaku