Granted Patent
Utility
US 5,164,145 · App. 07/595,039
Rotary furnace oil seal employing endothermic gas purge
Inventor:
John W. Smith
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: Oct 10, 1990
Inventor
John W. Smith
Assignee (at issue)
Thermo Process Systems Inc.
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.