1758194

Information

• Patent Grant
• 1758194

• References
• Source

• Patent Number

  1,758,194

• Date Filed

  Not available

• Date Issued

  Tuesday, May 13, 1930
  95 years ago

• CPC

  • H04L25/46 - using tuning forks or vibrating reeds

• US Classifications

  • 178 - Telegraphy
  • 246 - Railway switches and signals