1977860

Information

• Patent Grant
• 1977860

• References
• Source

• Patent Number

  1,977,860

• Date Filed

  Not available

• Date Issued

  Tuesday, October 23, 1934
  90 years ago

• CPC

  • G04C21/12 - by electro-acoustic means
  • H04M3/4876 - Time announcements

• US Classifications

  • 369 - Dynamic information storage or retrieval
  • 318 - Electricity: motive power systems
  • 368 - Horology: time measuring systems or devices
  • 968 - Horology