Granted Patent
Utility
US 5,988,231 · App. 08/658,804
Valve stem for transferring fluid between sealed containers
Inventor:
Robert R. Blake
Patented Case
View Patent ↗
Granted: Nov 23, 1999
Filed: Jun 7, 1996
Inventor
Robert R. Blake
Assignee (at issue)
Precision Valve Corporation
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.