3175045

Information

• Patent Grant
• 3175045

• References
• Source

• Patent Number

  3,175,045

• Date Filed

  Not available

• Date Issued

  Tuesday, March 23, 1965
  59 years ago

• CPC

  • H04M9/04 - involving a separate line for each pair of parties
  • H04M9/001 - Two-way communication systems between a limited number of parties
  • H04M19/04 - ringing-current generated at substation

• US Classifications

  • 379 - Telephonic communications