Granted Patent
Utility
US 4,732,290 · App. 06/860,599
Load isolating gas well
Inventor:
Walter R. Hallen
Patented Case
View Patent ↗
Granted: Mar 22, 1988
Filed: May 7, 1986
Inventor
Walter R. Hallen
Assignee (at issue)
REXNORD GMBH
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.