928021

Information

• Patent Grant
• 928021

• References
• Source

• Patent Number

  928,021

• Date Filed

  Not available

• Date Issued

  Tuesday, July 13, 1909
  115 years ago

• CPC

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

• US Classifications

  • 246 - Railway switches and signals