Granted Patent
Utility
US 4,963,135 · App. 07/363,749
Floatation chamber for use in a chest drainage device
Inventor:
Michael J. Kerwin
Patented Case
View Patent ↗
Granted: Oct 16, 1990
Filed: Jun 9, 1989
Inventor
Michael J. Kerwin
Assignee (at issue)
Sherwood Medical Company
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.