1712920

Information

• Patent Grant
• 1712920

• References
• Source

• Patent Number

  1,712,920

• Date Filed

  Not available

• Date Issued

  Tuesday, May 14, 1929
  95 years ago

• CPC

  • H04R9/042 - by pressurised air

• US Classifications

  • 181 - Acoustics
  • 312 - Supports: cabinet structure
  • 381 - Electrical audio signal processing systems and devices