1920237

Information

• Patent Grant
• 1920237

• References
• Source

• Patent Number

  1,920,237

• Date Filed

  Not available

• Date Issued

  Tuesday, August 1, 1933
  92 years ago

• CPC

  • H04L15/32 - Perforating recorders

• US Classifications

  • 346 - Recorders
  • 340 - Communications: electrical