Granted Patent
Utility
US 4,638,539 · App. 06/767,400
Aspirating/ventilating apparatus and method
Inventor:
Darrel Palmer
Patented Case
View Patent ↗
Granted: Jan 27, 1987
Filed: Aug 20, 1985
Inventor
Darrel Palmer
Assignee (at issue)
Ballard Medical Products
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.