2808463

Information

• Patent Grant
• 2808463

• References
• Source

• Patent Number

  2,808,463

• Date Filed

  Not available

• Date Issued

  Tuesday, October 1, 1957
  67 years ago

• CPC

  • G10K11/025 - horns for impedance matching
  • G10K1/062 - electrically operated
  • G10K9/13 - using electromagnetic driving means
  • H04M1/02 - Constructional features of telephone sets
  • H04M19/04 - ringing-current generated at substation
  • H04Q5/08 - Signalling by continuous ac
  • H04R11/14 - Resonant transducers

• US Classifications

  • 340 - Communications: electrical
  • 181 - Acoustics
  • 379 - Telephonic communications