2674820

Information

• Patent Grant
• 2674820

• References
• Source

• Patent Number

  2,674,820

• Date Filed

  Not available

• Date Issued

  Tuesday, April 13, 1954
  70 years ago

• CPC

  • G09F21/16 - Sky-writing

• US Classifications

  • 040 - Card, picture, or sign exhibiting
  • 340 - Communications: electrical
  • 361 - Electricity: electrical systems and devices