1789251

Information

• Patent Grant
• 1789251

• References
• Source

• Patent Number

  1,789,251

• Date Filed

  Not available

• Date Issued

  Tuesday, January 13, 1931
  93 years ago

• CPC

  • B61L3/065 - controlling optically

• US Classifications

  • 246 - Railway switches and signals
  • 250 - Radiant energy