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.)
Expired
Application number
CA876612A
Inventor
Walter M. Charman, Jr.
George J. Middaugh, Jr.
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
Publication date
Application grantedgrantedCritical
Publication of CA876612ApublicationCriticalpatent/CA876612A/en