3729680

Information

• Patent Grant
• 3729680

• References
• Source

• Patent Number

  3,729,680

• Date Filed

  Not available

• Date Issued

  Tuesday, April 24, 1973
  51 years ago

• CPC

  • G08B3/1033 - with voice message alert
  • G08B3/1016 - using wireless transmission

• US Classifications

  • 340 - Communications: electrical