3650116

Information

• Patent Grant
• 3650116

• References
• Source

• Patent Number

  3,650,116

• Date Filed

  Not available

• Date Issued

  Tuesday, March 21, 1972
  53 years ago

• CPC

  • E21D19/00 - Provisional protective covers for working space
  • E21D9/0879 - the shield being provided with devices for lining the tunnel

• US Classifications

  • 405 - Hydraulic and earth engineering