Granted Patent
Utility
US 5,009,393 · App. 07/537,367
Linear flow turn down valve
Inventor:
Dale Massey
Patented Case
View Patent ↗
Granted: Apr 23, 1991
Filed: Jun 13, 1990
Inventor
Dale Massey
Assignee (at issue)
Harper-Wyman 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.