2131180

Information

• Patent Grant
• 2131180

• References
• Source

• Patent Number

  2,131,180

• Date Filed

  Not available

• Date Issued

  Tuesday, September 27, 1938
  87 years ago

• CPC

  • E21C25/24 - with flat jibs only
  • E21C41/18 - for brown or hard coal

• US Classifications

  • 299 - Mining or in situ disintegration of hard material