3919487

Information

• Patent Grant
• 3919487

• References
• Source

• Patent Number

  3,919,487

• Date Filed

  Not available

• Date Issued

  Tuesday, November 11, 1975
  49 years ago

• CPC

  • H04M3/12 - Marking faulty circuits "busy" Enabling equipment to disengage itself from faulty circuits; Using redundant circuits; Response of a circuit, apparatus or system to an error
  • H04Q5/02 - with direct connection for all subscribers

• US Classifications

  • 379 - Telephonic communications