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
CA640174A
Inventor
Van't Spijker Peter
Sweep Eduard
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.)
Shell USA Inc
Original Assignee
Eduard Sweep
Peter Van't Spijker
Shell Oil Co
Publication date
Application grantedgrantedCritical
Publication of CA640174ApublicationCriticalpatent/CA640174A/en