1659789

Information

• Patent Grant
• 1659789

• References
• Source

• Patent Number

  1,659,789

• Date Filed

  Not available

• Date Issued

  Tuesday, February 21, 1928
  97 years ago

• CPC

  • G08B5/28 - with hinged flap or arm

• US Classifications

  • 379 - Telephonic communications