3854840

Information

• Patent Grant
• 3854840

• References
• Source

• Patent Number

  3,854,840

• Date Filed

  Not available

• Date Issued

  Tuesday, December 17, 1974
  50 years ago

• CPC

  • B23B31/11 - Retention by threaded connection
  • B23B51/0473 - details about the connection between the driven shaft and the tubular cutting part
  • E21B10/02 - Core bits
  • E21B10/26 - Drill bits with leading portion, i.e. drill bits with a pilot cutter Drill bits for enlarging the borehole
  • E21B10/62 - characterised by parts
  • Y10T408/895 - Having axial, core-receiving central portion
  • Y10T408/8967 - and central lead-screw

• US Classifications

  • 408 - Cutting by use of rotating axially moving tool
  • 144 - Woodworking