1809821

Information

• Patent Grant
• 1809821

• References
• Source

• Patent Number

  1,809,821

• Date Filed

  Not available

• Date Issued

  Tuesday, June 16, 1931
  93 years ago

• CPC

  • H04L15/30 - Writing recorders

• US Classifications

  • 178 - Telegraphy
  • 346 - Recorders