Granted Patent
Utility
US 4,646,828 · App. 06/793,842
Apparatus for enhanced oil recovery
Inventors:
Carl M. Schwab, Jr., Clark E. Robison, James B. Renfroe, Jr.
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Nov 1, 1985
Inventors
Carl M. Schwab, Jr.
Clark E. Robison
James B. Renfroe, Jr.
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.