1981764

Information

• Patent Grant
• 1981764

• References
• Source

• Patent Number

  1,981,764

• Date Filed

  Not available

• Date Issued

  Tuesday, November 20, 1934
  90 years ago

• CPC

  • E21C3/18 - directly by a piston of an internal-combustion engine

• US Classifications

  • 123 - Internal-combustion engines
  • 173 - Tool driving or impacting