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.)
Publication date
Publication of BE521374ApublicationCriticalpatent/BE521374A/fr
Priority claimed from DEJ6120Aexternal-prioritypatent/DE1137686B1/de
Priority claimed from DEJ6121Aexternal-prioritypatent/DE1063088B1/de
Priority claimed from DE1952J0002104external-prioritypatent/DE1678695U/de
Priority claimed from DEJ6342Aexternal-prioritypatent/DE1156710B1/de