1789228

Information

• Patent Grant
• 1789228

• References
• Source

• Patent Number

  1,789,228

• Date Filed

  Not available

• Date Issued

  Tuesday, January 13, 1931
  94 years ago

• CPC

  • G01J3/526 - for choosing a combination of different colours
  • G01J3/461 - with colour spinners

• US Classifications

  • 434 - Education and demonstration