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
CA734329A
Inventor
Van De Walle Therese
Fourcade Robert
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.)
Houilleres du Bassin du Nord et du Pas de Calais
Original Assignee
Houilleres du Bassin du Nord et du Pas de Calais
Publication date
Application grantedgrantedCritical
Publication of CA734329ApublicationCriticalpatent/CA734329A/en