3299643

Information

• Patent Grant
• 3299643

• References
• Source

• Patent Number

  3,299,643

• Date Filed

  Not available

• Date Issued

  Tuesday, January 24, 1967
  57 years ago

• CPC

  • E21D9/04 - Driving tunnels or galleries through loose materials Apparatus therefor not otherwise provided for
  • E21D1/14 - Freezing apparatus
  • E21D9/001 - Improving soil or rock

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 062 - Refrigeration
  • 166 - Wells