3634631

Information

• Patent Grant
• 3634631

• References
• Source

• Patent Number

  3,634,631

• Date Filed

  Not available

• Date Issued

  Tuesday, January 11, 1972
  53 years ago

• CPC

  • H04M1/278 - using punched cards or tapes

• US Classifications

  • 379 - Telephonic communications