Granted Patent
Utility
US 4,227,380 · App. 06/092,901
Single casing, multiple duty valve
Inventors:
F. Michael Laucks, Rudolph Stegmann
Patented Case
View Patent ↗
Granted: Oct 14, 1980
Filed: Nov 9, 1979
Inventors
F. Michael Laucks
Rudolph Stegmann
Assignee (at issue)
Frick 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.