Granted Patent
Utility
US 4,642,097 · App. 06/715,928
Left ventrical vacuum control and pressure relief valve
Inventor:
George G. Siposs
Patented Case
View Patent ↗
Granted: Feb 10, 1987
Filed: Mar 25, 1985
Inventor
George G. Siposs
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.