2709721

Information

• Patent Grant
• 2709721

• References
• Source

• Patent Number

  2,709,721

• Date Filed

  Not available

• Date Issued

  Tuesday, May 31, 1955
  69 years ago

• CPC

  • H04M15/10 - Metering calls from calling party
  • H01F19/02 - Audio-frequency transformers or mutual inductances
  • H04M1/02 - Constructional features of telephone sets
  • H04M7/08 - for phantom working
  • H04Q1/32 - using trains of dc pulses

• US Classifications

  • 379 - Telephonic communications
  • 333 - Wave transmission lines and networks