Patents by Inventor Wen-Hwa Lu

Wen-Hwa Lu 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: 5666846
    Abstract: An apparatus and method for manufacturing seamless tubes from hollow billets that will not contain metal oxide, which may be introduced into the extruded metal tube from an oxide layer formed on the inner surface of the hollow billets, so as to improve the quality of the extruded product and extend the service life of the extrusion piercer rod. A de-oxide latch, which has a substantially circular disk shape and is dimensioned such that it is slightly larger than the inner diameter of the hollow billet, is placed in front of the piercer rod so as to remove the metal oxide layer formed on the inner surface of the hollow billet through an upsetting shearing force ahead of the normal stress generated by the forward movement of the extrusion stem. The extrusion apparatus also utilizes a screw and pierce doughnut combination to securely affix the piercer rod to the stem and to effectuate the extrusion of the hollow billet through an extrusion die to form seamless tubes.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: September 16, 1997
    Assignee: Industrial Technology Research Institute
    Inventors: Chin-Fu Chen, Wen-Hwa Lu, Shan-Chang Chueh
  • Patent number: 5533375
    Abstract: An apparatus and method for manufacturing seamless tubes from hollow billets that will not contain metal oxide, which may be introduced into the extruded metal tube from an oxide layer formed on the inner surface of the hollow billets, so as to improve the quality of the extruded product and extend the service life of the extrusion piercer rod. A de-oxide latch, which has a substantially circular disk shape and is dimensioned such that it is slightly larger than the inner diameter of the hollow billet, is placed in front of the piercer rod so as to remove the metal oxide layer formed on the inner surface of the hollow billet through an upsetting shearing force ahead of the normal stress generated by the forward movement of the extrusion stem. The extrusion apparatus also utilizes a screw and pierce doughnut combination to securely affix the piercer rod to the stem and to effectuate the extrusion of the hollow billet through an extrusion die to form seamless tubes.
    Type: Grant
    Filed: July 14, 1994
    Date of Patent: July 9, 1996
    Assignee: Industrial Technology Research Institute
    Inventors: Chin-Fu Chen, Wen-Hwa Lu, Shan-Chang Chueh