Granted Patent
Utility
US 4,809,949 · App. 07/148,680
Plug valve
Inventor:
Kenneth E. Rakieski
Patented Case
View Patent ↗
Granted: Mar 7, 1989
Filed: Jan 26, 1988
Inventor
Kenneth E. Rakieski
Assignee (at issue)
Dresser Industries, 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.