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RoebelstabPatent. Auszug aus RoebelPatentschrift vom Mrz SpannungsWechsel ABB Ludwig Roebel First uploader was Flodur at org de This image is in the public domain due to its age Ludwig Roebel died br original text historisches Dokument PDold Original upload log de Wdwd CommonsHelper page de RoebelstabPatent Flodur