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
CA916449A
Inventor
R. Estabrook Mark
F. W. Treder Wilfred
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.)
Barnes Drill Co
Original Assignee
Barnes Drill Co
Publication date
Application grantedgrantedCritical
Publication of CA916449ApublicationCriticalpatent/CA916449A/en