1639839

Information

• Patent Grant
• 1639839

• References
• Source

• Patent Number

  1,639,839

• Date Filed

  Not available

• Date Issued

  Tuesday, August 23, 1927
  97 years ago

• CPC

  • H04L15/30 - Writing recorders

• US Classifications

  • 178 - Telegraphy
  • 346 - Recorders