1620985

Information

• Patent Grant
• 1620985

• References
• Source

• Patent Number

  1,620,985

• Date Filed

  Not available

• Date Issued

  Tuesday, March 15, 1927
  98 years ago

• CPC

  • E21B4/08 - impact being obtained by gravity only

• US Classifications

  • 175 - Boring or penetrating the earth