3865436

Information

• Patent Grant
• 3865436

• References
• Source

• Patent Number

  3,865,436

• Date Filed

  Not available

• Date Issued

  Tuesday, February 11, 1975
  50 years ago

• CPC

  • E21D9/1073 - applying thermal energy

• US Classifications

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