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 British Railways BoardfiledCriticalBritish Railways Board
Priority to ZA708414ApriorityCriticalpatent/ZA708414B/en
Publication of ZA708414BpublicationCriticalpatent/ZA708414B/en