1475709

Information

• Patent Grant
• 1475709

• References
• Source

• Patent Number

  1,475,709

• Date Filed

  Not available

• Date Issued

  Tuesday, November 27, 1923
  101 years ago

• CPC

  • B61L5/1827 - using light sources of different colours and a common optical system

• US Classifications

  • 246 - Railway switches and signals
  • 340 - Communications: electrical