3439508

Information

• Patent Grant
• 3439508

• References
• Source

• Patent Number

  3,439,508

• Date Filed

  Not available

• Date Issued

  Tuesday, April 22, 1969
  55 years ago

• CPC

  • E21F15/02 - Supporting means
  • E21D23/0073 - with advancing shifting devices connected therewith
  • E21D23/16 - Hydraulic or pneumatic features

• US Classifications

  • 405 - Hydraulic and earth engineering
  • 299 - Mining or in situ disintegration of hard material