Patents by Inventor Hsuen Chen Chang

Hsuen Chen 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).

  • Patent number: 6769330
    Abstract: A ratchet wrench includes a driving head having an inner peripheral gear, a wheel rotatably engaged in the driving head and having two openings formed in the outer peripheral portion. Two pawls are received in the openings of the wheel and each has a number of outer teeth for engaging with the inner peripheral gear of the driving head, and each has one end for being biased to engage into the end portions of the openings of the wheel by two springs, for greatly increasing the driving torque of the driving head to the wheel. The wheel has an engaging hole for receiving fasteners.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: August 3, 2004
    Inventor: Hsuen Chen Chang
  • Publication number: 20030136231
    Abstract: A ratchet wrench includes a driving head having an inner peripheral gear, a wheel rotatably engaged in the driving head and having two openings formed in the outer peripheral portion. Two pawls are received in the openings of the wheel and each has a number of outer teeth for engaging with the inner peripheral gear of the driving head, and each has one end for being biased to engage into the end portions of the openings of the wheel by two springs, for greatly increasing the driving torque of the driving head to the wheel. The wheel has an engaging hole for receiving fasteners.
    Type: Application
    Filed: September 27, 2002
    Publication date: July 24, 2003
    Inventor: Hsuen Chen Chang