Legal status (The legal status 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 status listed.)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oglebay Norton Co
Original Assignee
Oglebay Norton Co
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
Application filed by Oglebay Norton CofiledCriticalOglebay Norton Co
Priority to FR67427ApriorityCriticalpatent/FR1488467A/fr
Application grantedgrantedCritical
Publication of FR1488467ApublicationCriticalpatent/FR1488467A/fr