1557221

Information

• Patent Grant
• 1557221

• References
• Source

• Patent Number

  1,557,221

• Date Filed

  Not available

• Date Issued

  Tuesday, October 13, 1925
  99 years ago

• CPC

  • H02P25/12 - with shiftable brushes

• US Classifications

  • 318 - Electricity: motive power systems