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Priority claimed from US708416Aexternal-prioritypatent/US2903823A/en
Priority claimed from FR796831Aexternal-prioritypatent/FR1226881A/en
Application filed by Einar WestfordfiledCriticalEinar Westford
Application grantedgrantedCritical
Publication of BE580285QpublicationCriticalpatent/BE580285Q/en