Granted Patent
Utility
US 4,834,340 · App. 07/233,488
Quarter-turn plug valve having adjustable bonnet and tapered raised valve seats
Inventor:
Harry W. Girdley
Patented Case
View Patent ↗
Granted: May 30, 1989
Filed: Aug 17, 1988
Inventor
Harry W. Girdley
Assignee (at issue)
Henry Vogt Machine Co.
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.