3631681

Information

• Patent Grant
• 3631681

• References
• Source

• Patent Number

  3,631,681

• Date Filed

  Not available

• Date Issued

  Tuesday, January 4, 1972
  53 years ago

• CPC

  • E21D23/0069 - without essential advancing shifting devices

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 248 - Supports