3356167

Information

• Patent Grant
• 3356167

• References
• Source

• Patent Number

  3,356,167

• Date Filed

  Not available

• Date Issued

  Tuesday, December 5, 1967
  57 years ago

• CPC

  • E21B10/06 - Roller core bits
  • E21B4/16 - Plural down-hole drives
  • E21D9/1053 - for making a slit along the perimeter of the tunnel profile, the remaining core being removed subsequently

• US Classifications

  • 175 - Boring or penetrating the earth
  • 299 - Mining or in situ disintegration of hard material
  • 405 - Hydraulic and earth engineering