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Machine-switching telephone system

US 1,504,267 A · Inventors: LIPA POLINKOWSKY

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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 August 12, 1924. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by August 12, 1941.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledOctober 18, 1918
GrantedAugust 12, 1924
Term endedAugust 12, 1941
Application number—
Classification (CPC)H04M5/08
Length5 pages

Timeline

Timeline From USPTO dates

19191922192519281931193419371940Application filedOct 18, 1918Patent grantedAug 12, 1924Term endedAug 12, 1941

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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