2500507

Information

• Patent Grant
• 2500507

• References
• Source

• Patent Number

  2,500,507

• Date Filed

  Not available

• Date Issued

  Tuesday, March 14, 1950
  74 years ago

• CPC

  • G09B13/02 - Dummy practice keyboard apparatus

• US Classifications

  • 434 - Education and demonstration
  • 340 - Communications: electrical