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Impedance inverter

US 2,197,348 A · Inventors: ROBERTS WALTER VAN B

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Overview

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 16, 1940. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by April 16, 1957.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMay 17, 1938
GrantedApril 16, 1940
Term endedApril 16, 1957
Application number—
Classification (CPC)H03H11/40 +1 more
Length4 pages

Timeline

Timeline From USPTO dates

1939194119431945194719491951195319551957Application filedMay 17, 1938Patent grantedApril 16, 1940Term endedApril 16, 1957

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.