3475057

Information

• Patent Grant
• 3475057

• References
• Source

• Patent Number

  3,475,057

• Date Filed

  Not available

• Date Issued

  Tuesday, October 28, 1969
  55 years ago

• CPC

  • E21D9/116 - by means of non-concentric rotary heads

• US Classifications

  • 299 - Mining or in situ disintegration of hard material