Patents by Inventor Yan-Yan Liu

Yan-Yan Liu 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).

  • Removable drain filter
    Patent number: 6143173
    Abstract: The present invention provides an economical and efficient means for removing grease and other contaminants from restaurant wastewater. There is a need for an easily removable drain filter. The present invention meets this need, as it is a low-cost, disposable, and efficient means for removing these contaminants.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: November 7, 2000
    Inventors: Dan Luo, Yan-Yan Liu