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Expired European patentEurope

Method to reduce the flight noise for aircraft provided with propellers moved by piston engines

EP 0313944 B1 · Applicant: Deutsche Forschungsanstalt für Luft- und Raumfahrt e.V.

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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 October 15, 1988 and granted October 16, 1991. A European patent lasts at most 20 years from filing, so its term ended October 15, 2008.
  • 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 April 15, 2014.
  • 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.
FiledOctober 15, 1988
PublishedMay 3, 1989
GrantedOctober 16, 1991
Term endedOctober 15, 2008
Application numberEP 88117178
Classification (CPC)B64D33/06 +1 more

Timeline

Timeline From EPO dates

1989199119931995199719992001200320052007Application filedOct 15, 1988PublishedMay 3, 1989Patent grantedOct 16, 1991Term endedOct 15, 2008

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

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