1770805

Information

• Patent Grant
• 1770805

• References
• Source

• Patent Number

  1,770,805

• Date Filed

  Not available

• Date Issued

  Tuesday, July 15, 1930
  94 years ago

• CPC

  • B61L3/20 - employing different frequences or coded pulse groups

• US Classifications

  • 246 - Railway switches and signals