3851394

Information

• Patent Grant
• 3851394

• References
• Source

• Patent Number

  3,851,394

• Date Filed

  Not available

• Date Issued

  Tuesday, December 3, 1974
  50 years ago

• CPC

  • B43L13/149 - including grids

• US Classifications

  • 033 - Geometrical instruments
  • 434 - Education and demonstration