Patents by Inventor Kenichi Hidejima

Kenichi Hidejima 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).

  • Eddy current defect-detecting system for determining an inner or outer defect and its depth in metal tubes
    Patent number: 4628260
    Abstract: An eddy current defect-detecting system for a metal tube comprises a detector including test coils movable axially through the metal tube for detecting as an impedance variation a variation in an eddy current produced due to a defect present in the metal tube, an oscillator for exciting the detector at a high frequency, a phase adjuster responsive to an oscillated output from the oscillator for adjusting the phase of the oscillated output to produce a first control signal, a phase shifter responsive to the first control signal from the phase adjuster for issuing a second control signal which is 90.degree.
    Type: Grant
    Filed: October 19, 1983
    Date of Patent: December 9, 1986
    Inventors: Sanshiro Kimoto, Hisao Kokubo, Yasunobu Yamabayashi, Kenichi Hidejima