Patents by Inventor Yaw C. Wang

Yaw C. Wang 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).

  • Multipurpose ladder
    Patent number: 4699246
    Abstract: The present invention discloses a multipurpose ladder, and comprises four section-ladders; four pivot joint device provided between section-ladders, respectively, for connection but at least one pivot joint device being separable. Said pivot joint devices are available for bending or folding. So that, the multipurpose ladder can be change into a climbing ladder, horse ladder, frame ladder and right-angled ladder.
    Type: Grant
    Filed: October 2, 1986
    Date of Patent: October 13, 1987
    Inventor: Yaw C. Wang