2980898

Information

• Patent Grant
• 2980898

• References
• Source

• Patent Number

  2,980,898

• Date Filed

  Not available

• Date Issued

  Tuesday, April 18, 1961
  63 years ago

• CPC

  • G08B26/005 - with substations connected in series
  • H04Q1/26 - for signalling trouble in unoccupied sub-exchanges

• US Classifications

  • 340 - Communications: electrical
  • 379 - Telephonic communications