1456137

Information

• Patent Grant
• 1456137

• References
• Source

• Patent Number

  1,456,137

• Date Filed

  Not available

• Date Issued

  Tuesday, May 22, 1923
  101 years ago

• CPC

  • G03B9/60 - by varying speed of movement of obturating members

• US Classifications

  • 396 - Photography