Patents by Inventor Chong Sun Yi

Chong Sun Yi 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).

  • Chalk board eraser
    Patent number: 4080683
    Abstract: A self-cleaning hand-held chalk board eraser is disclosed which includes a chalk trough for catching and collecting the loose chalk from a chalkboard, a roller, the outer surface of which is made of suitable chalk-erasing material, and a brush mounted in the eraser to remove the loose chalk from the roller material in such a way that the loose chalk becomes trapped in the chalk trough.
    Type: Grant
    Filed: November 22, 1976
    Date of Patent: March 28, 1978
    Inventor: Chong Sun Yi