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Priority claimed from US07/215,743external-prioritypatent/US4898287A/en
Priority claimed from US07/290,635external-prioritypatent/US4905850A/en
Priority claimed from US07/353,395external-prioritypatent/US4993564A/en
Application filed by John A BlattfiledCriticalJohn A Blatt
Priority claimed from EP89908933Aexternal-prioritypatent/EP0423237B1/de
Application grantedgrantedCritical
Publication of ATE105622T1publicationCriticalpatent/ATE105622T1/de