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Expired European patentEurope

Air classifier

EP 0023320 B1 · Applicant: ONODA CEMENT COMPANY, 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 July 17, 1980 and granted March 7, 1984. A European patent lasts at most 20 years from filing, so its term ended July 17, 2000.
  • 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 January 17, 2006.
  • 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.
FiledJuly 17, 1980
PublishedFebruary 4, 1981
GrantedMarch 7, 1984
Term endedJuly 17, 2000
Application numberEP 80104199
Classification (CPC)B07B7/08 +2 more

Timeline

Timeline From EPO dates

1981198319851987198919911993199519971999Application filedJuly 17, 1980PublishedFeb 4, 1981Patent grantedMarch 7, 1984Term endedJuly 17, 2000

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.