1817692

Information

• Patent Grant
• 1817692

• References
• Source

• Patent Number

  1,817,692

• Date Filed

  Not available

• Date Issued

  Tuesday, August 4, 1931
  93 years ago

• CPC

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

• US Classifications

  • 191 - Electricity: transmission to vehicles
  • 246 - Railway switches and signals