Granted Patent
Utility
US 4,570,901 · App. 06/687,293
Positioning assembly for use with rotatable valves
Inventor:
Edward G. Holtgraver
Patented Case
View Patent ↗
Granted: Feb 18, 1986
Filed: Dec 28, 1984
Inventor
Edward G. Holtgraver
Assignee (at issue)
Keystone International
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.