Patents Assigned to Chun Chen Screw Co., Ltd.
  • Screw with spiral triangular threads
    Patent number: 6468014
    Abstract: A screw includes a cylindrical shank having an upper portion formed with spiral circular threads and a lower portion formed with spiral triangular threads, each of the spiral triangular threads having three budges having three sharp edges and three pointed tips, the pointed tips of the spiral triangular threads being located at different positions, the cylindrical shank having a pointed end at a lower portion thereof, whereby the screw can be easily and rapidly turned into a piece of hard wood.
    Type: Grant
    Filed: January 17, 2001
    Date of Patent: October 22, 2002
    Assignee: Chun Chen Screw Co., Ltd.
    Inventor: Chun-Chin Chen
  • Screw with spiral triangular threads
    Patent number: 6254327
    Abstract: A screw comprising a shank having an upper portion formed with spiral circular threads and a lower portion formed with spiral triangular threads, each of said spiral triangular threads having three sharp edges and three pointed tips, said pointed tips of said spiral triangular threads being located at different positions, whereby the screw can be easily and rapidly turned into a piece of hard wood.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: July 3, 2001
    Assignee: Chun Chen Screw Co., Ltd.
    Inventor: Chun-Chin Chen