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Process of making waterproof paper

US 1,723,355 A · Inventors: LESTER KIRSCHBRAUN

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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 6, 1929. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by August 6, 1946.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledSeptember 10, 1919
GrantedAugust 6, 1929
Term endedAugust 6, 1946
Application number—
Classification (CPC)D21H17/68 +2 more
Length2 pages

Timeline

Timeline From USPTO dates

192019231926192919321935193819411944Application filedSep 10, 1919Patent grantedAug 6, 1929Term endedAug 6, 1946

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