3715969

Information

• Patent Grant
• 3715969

• References
• Source

• Patent Number

  3,715,969

• Date Filed

  Not available

• Date Issued

  Tuesday, February 13, 1973
  51 years ago

• CPC

  • E21F1/14 - Air partitions Air locks
  • E21F1/04 - Air ducts

• US Classifications

  • 454 - Ventilation
  • 160 - Flexible or portable closure, partition, or panel
  • 299 - Mining or in situ disintegration of hard material