Granted Patent
Utility
US 4,168,721 · App. 05/807,265
Pressure control valve
Inventor:
Otto Mueller
Patented Case
View Patent ↗
Granted: Sep 25, 1979
Filed: Jun 16, 1977
Inventor
Otto Mueller
Assignee (at issue)
Massey Ferguson Group Limited
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.