3784257

Information

• Patent Grant
• 3784257

• References
• Source

• Patent Number

  3,784,257

• Date Filed

  Not available

• Date Issued

  Tuesday, January 8, 1974
  51 years ago

• CPC

  • E21D9/1093 - Devices for supporting, advancing or orientating the machine or the tool-carrier
  • E21D9/116 - by means of non-concentric rotary heads

• US Classifications

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