Patents by Inventor Masaichi Koiwa

Masaichi Koiwa 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).

  • Method and apparatus for nondestructive testing of physical characteristics of a specimen using ultrasonic waves
    Patent number: 5533411
    Abstract: The sound velocity (V) in a cast specimen is measured with ultrasonic wave and the sound velocity ratio (V/Vm) between the sound velocity in said specimen and the sound velocity (Vm) in a specified metal corresponding to said specimen is attained; by converting this sound velocity ratio to a physical quantity to be determined (e.g., percent spheroidicity of graphite, state classification, tensile strength or percent elongation) in accordance with an empirical formula (530) or the like which relate to the sound velocity ratio, a physical characteristic value related to said specimen is computed. As a result, values of analysis on the state of castings structure and their characteristic values can be measured or computed with high probability in a nondestructive and convenient manner.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: July 9, 1996
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Masaichi Koiwa