1977140

Information

• Patent Grant
• 1977140

• References
• Source

• Patent Number

  1,977,140

• Date Filed

  Not available

• Date Issued

  Tuesday, October 16, 1934
  90 years ago

• CPC

  • B44B3/001 - by copying
  • B44B2700/021 - by copying

• US Classifications

  • 033 - Geometrical instruments