2291615

Information

• Patent Grant
• 2291615

• References
• Source

• Patent Number

  2,291,615

• Date Filed

  Not available

• Date Issued

  Tuesday, August 4, 1942
  82 years ago

• CPC

  • H04M19/02 - providing ringing current or supervisory tones
  • H01H50/72 - for mercury contact

• US Classifications

  • 379 - Telephonic communications