Patents by Inventor Li XUE

Li XUE 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 monitoring spot welding process and method of the same
    Patent number: 6335504
    Abstract: The present invention discloses an apparatus and a method for monitoring the quality of a spot welding process. The measured electric current and voltage signals between electrodes of a spot welding system are converted into digital data first. Then the two digital data are processed to obtain their complex forms via Hillbert transform respectively to construct their imaginary part. Finally, the electrical impedance Zin is obtained from dividing the complex form of digital voltage by the complex form of digital current. The electrical impedance Zin can be applied to compare with historical data to diagnose the quality of spot-welding points.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: January 1, 2002
    Assignee: Essor International Inc.
    Inventors: Shih-Fu Ling, Li-Xue Wan