1917170

Information

• Patent Grant
• 1917170

• References
• Source

• Patent Number

  1,917,170

• Date Filed

  Not available

• Date Issued

  Tuesday, July 4, 1933
  91 years ago

• CPC

  • E21D9/0621 - Shield advancing devices
  • E21D11/07 - using brick- laying machines

• US Classifications

  • 405 - Hydraulic and earth engineering