Granted Patent
Utility
US 4,346,997 · App. 06/157,841
Positive pressure maintenance for sample presentation
Inventor:
Robert F. Willis
Patented Case
View Patent ↗
Granted: Aug 31, 1982
Filed: Jun 9, 1980
Inventor
Robert F. Willis
Assignee (at issue)
Burlington Industries LLC
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.