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Priority claimed from US06/485,738external-prioritypatent/US4492027A/en
Priority claimed from US06/534,760external-prioritypatent/US4516323A/en
Application filed by Bettcher IndustriesfiledCriticalBettcher Industries
Application grantedgrantedCritical
Publication of ATE39077T1publicationCriticalpatent/ATE39077T1/de