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
CA911182A
Inventor
S. Muller Donald
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.)
Boart Drilling and Contracting Ltd
Original Assignee
Boart Drilling and Contracting Ltd
Publication date
Application grantedgrantedCritical
Publication of CA911182ApublicationCriticalpatent/CA911182A/en