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US 1,408,446 A · Inventors: BULLITT DIXON THOMAS

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted March 7, 1922. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by March 7, 1939.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJanuary 15, 1920
GrantedMarch 7, 1922
Term endedMarch 7, 1939
Application number—
Classification (CPC)H04L5/14 +1 more
Length4 pages

Timeline

Timeline From USPTO dates

1921192319251927192919311933193519371939Application filedJan 15, 1920Patent grantedMarch 7, 1922Term endedMarch 7, 1939

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