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US 1,998,441 A · Inventors: CAMPBELL ARCHIBALD A

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The published document from the USPTO: abstract, claims, description and drawings. Open it full size

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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 April 23, 1935. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by April 23, 1952.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledFebruary 27, 1933
GrantedApril 23, 1935
Term endedApril 23, 1952
Application number—
Classification (CPC)F01B7/20
Length6 pages

Timeline

Timeline From USPTO dates

1934193619381940194219441946194819501952Application filedFeb 27, 1933Patent grantedApril 23, 1935Term endedApril 23, 1952

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

Everything on this page comes from the USPTO record linked above.