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
CA816473A
Inventor
O. Young Joe
Antonio Guevara, Jr.
E. Layne Max
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.)
LAYNE AND BOWLER
Original Assignee
LAYNE AND BOWLER
Publication date
Application grantedgrantedCritical
Publication of CA816473ApublicationCriticalpatent/CA816473A/en