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Fuel-fired heat pump system

US 3,400,554 A · Inventors: DENNIS DAVID D et al.

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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 September 10, 1968. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by September 10, 1985.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMarch 17, 1967
GrantedSeptember 10, 1968
Term endedSeptember 10, 1985
Application number—
Classification (CPC)F25B29/00 +2 more
Length7 pages

Timeline

Timeline From USPTO dates

196819701972197419761978198019821984Application filedMarch 17, 1967Patent grantedSep 10, 1968Term endedSep 10, 1985

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.