3444519

Information

• Patent Grant
• 3444519

• References
• Source

• Patent Number

  3,444,519

• Date Filed

  Not available

• Date Issued

  Tuesday, May 13, 1969
  55 years ago

• CPC

  • H04M15/18 - according to duration of the call , or the communication

• US Classifications

  • 379 - Telephonic communications
  • 340 - Communications: electrical