Patents Assigned to Geir Tandberg
  • Patent number: 5016718
    Abstract: A drill bit for drilling a hole in the ground, with cutting elements annularly cutting a core which, when it has reached a certain height, is continuously crushed by teeth on rolling cones. By combining these two processes, cutting and crushing, in this manner an improved drilling advancement is achieved as compared to separate use of the same processes. The cutting elements show relatively small variations as to radial positioning, which renders it possible to find a common approximately optimal rotational speed of said elements. The core is weak and may be drilled out relatively easily by the aid of crushing, as compared to drilling pure holes. This is due to the fact that the core geometry causes a more efficient growth of fractures for each tooth penetration, and that the core, due to annular cutting, is free from radial tensions from the surrounding rock formations.
    Type: Grant
    Filed: January 24, 1990
    Date of Patent: May 21, 1991
    Assignees: Geir Tandberg, Arild Rodland
    Inventor: Geir Tandberg