3644000

Information

• Patent Grant
• 3644000

• References
• Source

• Patent Number

  3,644,000

• Date Filed

  Not available

• Date Issued

  Tuesday, February 22, 1972
  52 years ago

• CPC

  • E21D9/1086 - Drives or transmissions specially adapted therefor

• US Classifications

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