2220942

Information

• Patent Grant
• 2220942

• References
• Source

• Patent Number

  2,220,942

• Date Filed

  Not available

• Date Issued

  Tuesday, November 12, 1940
  84 years ago

• CPC

  • H04R13/02 - Telephone receivers
  • H04R11/00 - Transducers of moving-armature or moving-core type

• US Classifications

  • 381 - Electrical audio signal processing systems and devices
  • 181 - Acoustics