Patents by Inventor Joo B. Kim

Joo B. Kim 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: 4209275
    Abstract: A twist drill for producing or enlarging holes in a metal workpiece includes a point with peripheral cutting shoulders and concave cutting lips leading inwardly from the shoulders to a central chisel point. The cutting shoulders are spaced slightly toward the shank end of the drill from the chisel point along the axis of the drill. The cutting lips are longitudinally convex so that points along the bases thereof will be spaced axially toward the drill shank from the cutting shoulders. The concave configuration along with the smooth curvature of the cutting lips facilitates quick removal of metal while causing minimal wear along the actual cutting surfaces. Chips are directed inwardly from the cutting shoulders and outwardly from the chisel point. The oppositely flowing chips converge within the drill flutes and are carried outward of the hole along the drill axis.
    Type: Grant
    Filed: October 30, 1978
    Date of Patent: June 24, 1980
    Inventor: Joo B. Kim