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Furnace-cleaner

US 1,388,560 A · Inventors: DE GRAFF JAN

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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 August 23, 1921. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by August 23, 1938.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledOctober 18, 1919
GrantedAugust 23, 1921
Term endedAugust 23, 1938
Application number—
Classification (CPC)F23J3/02 +1 more
Length3 pages

Timeline

Timeline From USPTO dates

1920192219241926192819301932193419361938Application filedOct 18, 1919Patent grantedAug 23, 1921Term endedAug 23, 1938

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