Patents by Inventor Kai-Shun Mak

Kai-Shun Mak 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).

  • Child's magic drawing board
    Patent number: 5393231
    Abstract: A magic drawing board comprises a base, an opaque sheet mounted on the base, a flexible transparent sheet anchored along one edge thereof to the base, and a coupling mechanism comprising a coupling element on the base and a mating coupling element on the opposite edge of the transparent sheet for locating the transparent sheet in superposed position on the opaque sheet under uniform tension over the area of superposition, resulting in a higher quality image.
    Type: Grant
    Filed: June 1, 1992
    Date of Patent: February 28, 1995
    Assignee: Hop Lee Cheong Industrial Co. Ltd.
    Inventor: Kai-Shun Mak
  • Drawing board
    Patent number: D336751
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: June 22, 1993
    Assignee: Hop Lee Cheong Industrial Co.
    Inventor: Kai-Shun Mak
  • Drawing board
    Patent number: D345177
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: March 15, 1994
    Assignee: Hop Lee Cheong Industrial Co Ltd
    Inventor: Kai-Shun Mak
  • Drawing board
    Patent number: D356335
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: March 14, 1995
    Assignee: Hop Lee Cheong Industrial Company Ltd.
    Inventor: Kai-Shun Mak
  • Drawing board
    Patent number: D356336
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: March 14, 1995
    Assignee: Hop Lee Cheong Industrial Company Ltd.
    Inventor: Kai-Shun Mak