3271962

Information

• Patent Grant
• 3271962

• References
• Source

• Patent Number

  3,271,962

• Date Filed

  Not available

• Date Issued

  Tuesday, September 13, 1966
  58 years ago

• CPC

  • E21D1/12 - by freezing
  • E21B43/281 - using heat

• US Classifications

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