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Priority claimed from US06/310,046external-prioritypatent/US4993632A/en
Priority claimed from US06/323,274external-prioritypatent/US4467967A/en
Application filed by Hedlund MfgfiledCriticalHedlund Mfg
Priority claimed from EP19820109170external-prioritypatent/EP0077000B1/de
Application grantedgrantedCritical
Publication of ATE33913T1publicationCriticalpatent/ATE33913T1/de