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Expired European patentEurope

Switching stage for controlling a tetrode

EP 0038440 B1 · Applicant: SIEMENS AKTIENGESELLSCHAFT

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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 March 30, 1981 and granted June 13, 1984. A European patent lasts at most 20 years from filing, so its term ended March 30, 2001.
  • 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 September 30, 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.
FiledMarch 30, 1981
PublishedOctober 28, 1981
GrantedJune 13, 1984
Term endedMarch 30, 2001
Application numberEP 81102397
Classification (CPC)H03F3/24

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedMarch 30, 1981PublishedOct 28, 1981Patent grantedJune 13, 1984Term endedMarch 30, 2001

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.