Patents by Inventor Hsu S. Chang

Hsu S. Chang 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).

  • Toilet sanitizing device
    Patent number: 5119517
    Abstract: A toilet sanitizing device is provided, wherein the toilet seat can be pre-heated before use and cleaned with liquid cleaner after use to avoid disease infection. The seat is raised by a servomotor into a position for cleaning responsive to signals from a pedal switch and an infrared detector.
    Type: Grant
    Filed: August 10, 1990
    Date of Patent: June 9, 1992
    Inventor: Hsu S. Chang