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
Priority claimed from US07/199,971external-prioritypatent/US4839930A/en
Priority claimed from US07/261,943external-prioritypatent/US4926510A/en
Priority claimed from US07/316,047external-prioritypatent/US4908888A/en
Application filed by Watkins Mfg CorpfiledCriticalWatkins Mfg Corp
Priority claimed from EP19890305181external-prioritypatent/EP0343912B1/de
Application grantedgrantedCritical
Publication of ATE100307T1publicationCriticalpatent/ATE100307T1/de