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Air cleaner

US 1,407,968 A · Inventors: WICKERSHAM ELMER E

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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 28, 1922. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by February 28, 1939.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJune 1, 1918
GrantedFebruary 28, 1922
Term endedFebruary 28, 1939
Application number—
Classification (CPC)F02M35/022 +1 more
Length5 pages

Timeline

Timeline From USPTO dates

1919192219251928193119341937Application filedJune 1, 1918Patent grantedFeb 28, 1922Term endedFeb 28, 1939

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