3225678

Information

• Patent Grant
• 3225678

• References
• Source

• Patent Number

  3,225,678

• Date Filed

  Not available

• Date Issued

  Tuesday, December 28, 1965
  58 years ago

• CPC

  • E21F1/006 - Ventilation at the working face of galleries or tunnels

• US Classifications

  • 454 - Ventilation
  • 299 - Mining or in situ disintegration of hard material