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Method of pulping hardwood by a neutral sulfite process

US 3,003,909 A · Inventors: OLSON KERMIT 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.

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Why it's free to use

  • Granted October 10, 1961. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by October 10, 1978.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJanuary 30, 1957
GrantedOctober 10, 1961
Term endedOctober 10, 1978
Application number—
Classification (CPC)D21C3/06
Length4 pages

Timeline

Timeline From USPTO dates

1958196119641967197019731976Application filedJan 30, 1957Patent grantedOct 10, 1961Term endedOct 10, 1978

Sources & verification

Official USPTO records

Full published documentText and every drawing sheet as a PDF.USPTOFile historyStatus, office actions, notices, fee records and petitions.USPTO Patent CenterPatent Public Search recordSearchable full text and bibliographic data.USPTO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comJustia PatentsFull text, claims and classification.patents.justia.comFreePatentsOnlineFull text and PDF.freepatentsonline.comEspacenetForeign family and legal status.European Patent Office

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