Patents Assigned to Hawera Probst Kommanditgesellschaft Harmetall-Werkzeugfabrik Ravensburg
  • Drilling tool, especially for hammer drills
    Patent number: 4002214
    Abstract: A boring tool, especially for drill hammers with a hollow drill core bit, which the inner thread of the hollow drill core bit connected directly to the borer shank and in which a corresponding outer thread provided on a holding mandrel form a part of the borer shank have a wire coil-thread insert inserted therebetween. The hollow drill core bit and the borer shank are provided with centering surfaces located between the windings of the wire coil thread insert and arranged in centering engagement with each other.
    Type: Grant
    Filed: April 23, 1975
    Date of Patent: January 11, 1977
    Assignee: Hawera Probst Kommanditgesellschaft Harmetall-Werkzeugfabrik Ravensburg
    Inventor: Dietrich Schaumann