Patents Assigned to Aisan kogyo Corporation
  • Patent number: 4944640
    Abstract: A burnishing drill having a drill body, the forward end of which is formed with a reduced-diameter portion having its external diameter smaller than the maximum external diameter of the drill body. The forward end of the drill body includes a pair of first cutting edges formed in the reduced-diameter to include with a first cutting angle, and a pair of second cutting edges formed to extend radially in a direction perpendicular to the first cutting edges at least from the inward position of a plane including the outermost peripheral walls of the first cutting edges to the position of another plane including the outermost peripheral wall of the drill body.Each of the first cutting edges extends radially outward from the center of the forward end of the dril body and includes axially in the rearward direction while each of the second cutting edges inclines extends radially outward from the drill body and inclines axially in the forward direction.
    Type: Grant
    Filed: September 7, 1989
    Date of Patent: July 31, 1990
    Assignees: Aisan kogyo Corporation, Fuji Seiko Corporation
    Inventors: Yasuhiro Suzuki, Tuguo Yoshikawa, Kazuhiro Shibata, Akio Fukui, Kiyotaka Shiga