Granted Patent
Utility
US 4,432,416 · App. 06/351,547
Well flow control apparatus
Inventors:
William R. Welch, Ernest P. Fisher, Jr., John H. Yonker
Patented Case
View Patent ↗
Granted: Feb 21, 1984
Filed: Feb 23, 1982
Inventors
William R. Welch
Ernest P. Fisher, Jr.
John H. Yonker
Assignee (at issue)
Otis Engineering Corporation
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.