Granted Patent
Utility
US 4,807,845 · App. 07/103,058
Tube valve
Inventor:
Larry W. Darnell
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Sep 30, 1987
Inventor
Larry W. Darnell
Assignee (at issue)
Kardiothor, 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.