3506789

Information

• Patent Grant
• 3506789

• References
• Source

• Patent Number

  3,506,789

• Date Filed

  Not available

• Date Issued

  Tuesday, April 14, 1970
  54 years ago

• CPC

  • H04M19/06 - Current supply source at subordinate switching centre charged from main exchange

• US Classifications

  • 379 - Telephonic communications