2721229

Information

• Patent Grant
• 2721229

• References
• Source

• Patent Number

  2,721,229

• Date Filed

  Not available

• Date Issued

  Tuesday, October 18, 1955
  69 years ago

• CPC

  • H04L17/14 - with optical sensing means

• US Classifications

  • 178 - Telegraphy
  • 370 - Multiplex communications