3721821

Information

• Patent Grant
• 3721821

• References
• Source

• Patent Number

  3,721,821

• Date Filed

  Not available

• Date Issued

  Tuesday, March 20, 1973
  51 years ago

• CPC

  • G01P13/045 - with speed indication
  • B61L1/10 - actuated by electromagnetic radiation actuated by particle radiation
  • G01P3/66 - using electric or magnetic means

• US Classifications

  • 246 - Railway switches and signals
  • 324 - Electricity: measuring and testing
  • 340 - Communications: electrical