3489998

Information

• Patent Grant
• 3489998

• References
• Source

• Patent Number

  3,489,998

• Date Filed

  Not available

• Date Issued

  Tuesday, January 13, 1970
  55 years ago

• CPC

  • B60C23/0469 - Transmission by sound

• US Classifications

  • 340 - Communications: electrical
  • 116 - Signals and indicators