1978367

Information

• Patent Grant
• 1978367

• References
• Source

• Patent Number

  1,978,367

• Date Filed

  Not available

• Date Issued

  Tuesday, October 23, 1934
  90 years ago

• CPC

  • E21C25/66 - Machines for making slits with additional arrangements for drilling

• US Classifications

  • 299 - Mining or in situ disintegration of hard material
  • 175 - Boring or penetrating the earth