1446544

Information

• Patent Grant
• 1446544

• References
• Source

• Patent Number

  1,446,544

• Date Filed

  Not available

• Date Issued

  Tuesday, February 27, 1923
  102 years ago

• CPC

  • H04R21/023 - with more than one granular chamber

• US Classifications

  • 381 - Electrical audio signal processing systems and devices
  • 367 - Communications, electrical: acoustic wave systems and devices