3747503

Information

• Patent Grant
• 3747503

• References
• Source

• Patent Number

  3,747,503

• Date Filed

  Not available

• Date Issued

  Tuesday, July 24, 1973
  51 years ago

• CPC

  • E21F1/14 - Air partitions Air locks
  • E21F1/10 - Air doors

• US Classifications

  • 454 - Ventilation
  • 405 - Hydraulic and earth engineering