Patents Assigned to Yao Seibyo Kabushiki Kaisha
  • Patent number: 6000892
    Abstract: A wood screw is proposed for use with a material made mainly of plastic waste and wood chips. The wood screw includes a shank which has leading threads extending from the tip of the tapered portion to an intermediate point of the straight portion and have a first lead angle and a first thread angle. Trailing threads extend from the intermediate point toward a head and have a second lead angle and a second thread angle. The first lead angle is greater than the second lead angle, and the first thread angle is smaller than the second thread angle.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: December 14, 1999
    Assignee: Yao Seibyo Kabushiki Kaisha
    Inventor: Seiichiro Takasaki