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
CA692255A
Inventor
M. Frank Joseph
E. Boyer Neil
A. Crookston James
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.)
AP Green Fire Brick Co
Original Assignee
AP Green Fire Brick Co
Publication date
Application grantedgrantedCritical
Publication of CA692255ApublicationCriticalpatent/CA692255A/en