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 of NL258436ApublicationCriticalpatent/NL258436A/xx
Priority claimed from FR811580Aexternal-prioritypatent/FR1250532A/fr
Priority claimed from FR819430Aexternal-prioritypatent/FR77228E/fr
Priority claimed from FR842168Aexternal-prioritypatent/FR78601E/fr