Patents by Inventor Chunwen Han

Chunwen Han 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).

  • Ladder
    Patent number: D620132
    Type: Grant
    Filed: December 28, 2009
    Date of Patent: July 20, 2010
    Assignee: Guangzhou Hansheng Trade Development Co., Ltd.
    Inventor: Chunwen Han
  • Ladder hinge
    Patent number: D631562
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: January 25, 2011
    Assignee: Guangzhou Hansheng Trade Development Co., Ltd
    Inventor: Chunwen Han