Granted Patent
Utility
US 4,249,574 · App. 05/884,913
Orifice trim and backpressure plate for high pressure valves
Inventors:
Ira H. Schnall, Walter W. Mott
Patented Case
View Patent ↗
Granted: Feb 10, 1981
Filed: Mar 9, 1978
Inventors
Ira H. Schnall
Walter W. Mott
Assignee (at issue)
Copes-Vulcan, 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.