Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Friedrich GraepelfiledCriticalFriedrich Graepel
Priority to BE573636ApriorityCriticalpatent/BE573636A/fr
Publication of BE573636ApublicationCriticalpatent/BE573636A/fr