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Switch arrangement for changing transformer voltage ratio

US 3,440,586 A · Inventors: JOHNSTON RICHMOND P et al.

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2 drawing sheets

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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 22, 1969. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by April 22, 1986.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMarch 21, 1967
GrantedApril 22, 1969
Term endedApril 22, 1986
Application number—
Classification (CPC)H01H9/0005 +1 more
Length6 pages

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

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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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