3840270

Information

• Patent Grant
• 3840270

• References
• Source

• Patent Number

  3,840,270

• Date Filed

  Not available

• Date Issued

  Tuesday, October 8, 1974
  50 years ago

• CPC

  • E21B10/04 - with core destroying means
  • E21B7/24 - Drilling using vibrating or oscillating means
  • E21D9/10 - Making by using boring or cutting machines
  • E21D9/1053 - for making a slit along the perimeter of the tunnel profile, the remaining core being removed subsequently

• US Classifications

  • 299 - Mining or in situ disintegration of hard material
  • 175 - Boring or penetrating the earth
  • 241 - Solid material comminution or disintegration