Granted Patent
Utility
US 4,754,807 · App. 07/023,219
Sand screen for production oil wells
Inventor:
Udo Lange
Patented Case
View Patent ↗
Granted: Jul 5, 1988
Filed: Mar 9, 1987
Inventor
Udo Lange
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.