Granted Patent
Utility
US 4,679,987 · App. 06/864,269
Self-priming liquid ring pump methods and apparatus
Inventor:
Ole B. Olsen
Patented Case
View Patent ↗
Granted: Jul 14, 1987
Filed: May 19, 1986
Inventor
Ole B. Olsen
Assignee (at issue)
The Nash Engineering Company
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.