1522180

Information

• Patent Grant
• 1522180

• References
• Source

• Patent Number

  1,522,180

• Date Filed

  Not available

• Date Issued

  Tuesday, January 6, 1925
  101 years ago

• CPC

  • H04M1/32 - Locking setting devices during transmission to prevent interference by user

• US Classifications

  • 379 - Telephonic communications