Granted Patent
Utility
US 4,257,444 · App. 06/027,846
Insert check valve or the like
Inventors:
Francis H. Ogle, Jr., Ernest R. Koppl
Patented Case
View Patent ↗
Granted: Mar 24, 1981
Filed: Apr 6, 1979
Inventors
Francis H. Ogle, Jr.
Ernest R. Koppl
Assignee (at issue)
Transamerica DeLaval 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.