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Telephone system utilizing register controlled final selector switches

US 2,454,809 A · Inventors: JACOB KRUITHOF 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 November 30, 1948. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by November 30, 1965.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJanuary 16, 1943
GrantedNovember 30, 1948
Term endedNovember 30, 1965
Application number—
Classification (CPC)H04Q1/18
Length14 pages

Timeline

Timeline From USPTO dates

19441947195019531956195919621965Application filedJan 16, 1943Patent grantedNov 30, 1948Term endedNov 30, 1965

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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