3523426

Information

• Patent Grant
• 3523426

• References
• Source

• Patent Number

  3,523,426

• Date Filed

  Not available

• Date Issued

  Tuesday, August 11, 1970
  55 years ago

• CPC

  • E21D9/10 - Making by using boring or cutting machines
  • E21D9/04 - Driving tunnels or galleries through loose materials Apparatus therefor not otherwise provided for
  • E21D9/0873 - the shield being provided with devices for lining the tunnel

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 299 - Mining or in situ disintegration of hard material