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 Hydril CofiledCriticalHydril Co
Priority claimed from EP84900664Aexternal-prioritypatent/EP0131618B1/de
Application grantedgrantedCritical
Publication of ATE35844T1publicationCriticalpatent/ATE35844T1/de