Patents by Inventor Kun H. Chang

Kun H. 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).

  • Method of producing high-density PU foam material
    Patent number: 4666646
    Abstract: The present invention relates to a method of producing high-density PU foam material, which is characterized by its process of using comminuted waste foam material, as its primary raw material which is then dried and filtered before mixing with other chemical agents in proportion, such as Voranol 3800 polyo, Isocyanate and relatively small amount of Catalysts to make the individual particle and also those agents between particles to swell to proper size in mold. Then, the yet foamed material is compressed in a mechanical way and cooled down slowly in natural manner to produce high-density PU foam material.
    Type: Grant
    Filed: July 24, 1985
    Date of Patent: May 19, 1987
    Inventor: Kun H. Chang
  • Shoe pad
    Patent number: D302071
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: July 11, 1989
    Inventor: Kun H. Chang
  • Shoe pad
    Patent number: D306515
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: March 13, 1990
    Inventor: Kun H. Chang
  • Shoe pad
    Patent number: D306650
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: March 20, 1990
    Inventor: Kun H. Chang
  • Shoe pad
    Patent number: D306651
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: March 20, 1990
    Inventor: Kun H. Chang
  • Shoe pad
    Patent number: D313306
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: January 1, 1991
    Inventor: Kun H. Chang