1952369

Information

• Patent Grant
• 1952369

• References
• Source

• Patent Number

  1,952,369

• Date Filed

  Not available

• Date Issued

  Tuesday, March 27, 1934
  90 years ago

• CPC

  • H04Q9/06 - Calling by using amplitude or polarity of dc

• US Classifications

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