Patents by Inventor Yung Chung Liao

Yung Chung Liao 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).

  • Ratchet driving tool
    Patent number: 6450067
    Abstract: A ratchet tool includes a housing having an internal gear, a shank rotatably secured in the housing and having two notches and two actuating surfaces for rotatably receiving two pawls, and a spring for biasing the pawls to engage with the internal gear. A control ferrule is rotatably engaged on the shank and includes two blocks for selectively disengaging the pawls from the internal gear. The actuating surfaces of the shank may be used for solidly engaging the pawls with the internal gear. The shank may be secured to various kinds of handles.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: September 17, 2002
    Inventor: Yung Chung Liao
  • Ratchet driving tool
    Patent number: 6349619
    Abstract: A ratchet tool includes a housing having an internal gear, a shank rotatably secured in the chamber of the housing and having two notches formed between a partition and two actuating surfaces for rotatably receiving two pawls, and a spring engaged between the pawls for biasing the pawls to engage with the internal gear. A control ferrule is rotatably engaged on the shank and includes two blocks for selectively disengaging the pawls from the internal gear. The actuating surfaces of the shank may be used for solidly engaging the pawls with the internal gear.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: February 26, 2002
    Inventor: Yung Chung Liao