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Testing system

US 1,445,258 A · Inventors: WILLIAMS JR SAMUEL B et al.

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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 February 13, 1923. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by February 13, 1940.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledFebruary 5, 1919
GrantedFebruary 13, 1923
Term endedFebruary 13, 1940
Application number—
Classification (CPC)H04Q3/00
Length12 pages

Timeline

Timeline From USPTO dates

1920192319261929193219351938Application filedFeb 5, 1919Patent grantedFeb 13, 1923Term endedFeb 13, 1940

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