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Expired European patentEurope

Screw rotor tooth profile

EP 0194444 B1 · Applicant: HITACHI, LTD.

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed February 6, 1986 and granted May 2, 1990. A European patent lasts at most 20 years from filing, so its term ended February 6, 2006.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by August 6, 2011.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledFebruary 6, 1986
PublishedSeptember 17, 1986
GrantedMay 2, 1990
Term endedFebruary 6, 2006
Application numberEP 86101538
Classification (CPC)F01C1/084

Timeline

Timeline From EPO dates

1987198919911993199519971999200120032005Application filedFeb 6, 1986PublishedSep 17, 1986Patent grantedMay 2, 1990Term endedFeb 6, 2006

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.