3902324

Information

• Patent Grant
• 3902324

• References
• Source

• Patent Number

  3,902,324

• Date Filed

  Not available

• Date Issued

  Tuesday, September 2, 1975
  49 years ago

• CPC

  • E21D23/0095 - Temporary supports at the driving front
  • E21D19/04 - for use in drifting galleries
  • E21D23/03 - having protective means

• US Classifications

  • 405 - Hydraulic and earth engineering