3870369

Information

• Patent Grant
• 3870369

• References
• Source

• Patent Number

  3,870,369

• Date Filed

  Not available

• Date Issued

  Tuesday, March 11, 1975
  49 years ago

• CPC

  • E21D9/1026 - the tool-carrier being rotated about a transverse axis
  • E21D9/01 - Methods or apparatus for enlarging or restoring the cross-section of tunnels

• US Classifications

  • 299 - Mining or in situ disintegration of hard material