1668844

Information

• Patent Grant
• 1668844

• References
• Source

• Patent Number

  1,668,844

• Date Filed

  Not available

• Date Issued

  Tuesday, May 8, 1928
  96 years ago

• CPC

  • G09B19/18 - Book-keeping or economics
  • G09B1/28 - the elements being slidable

• US Classifications

  • 434 - Education and demonstration