Granted Patent
Utility
US 4,921,538 · App. 07/207,637
Method for recycle and use of contaminated soil and sludge
Inventors:
Fred A. Lafser, Jr., Robert J. Schreiber
Patented Case
View Patent ↗
Granted: May 1, 1990
Filed: Jun 16, 1988
Inventors
Fred A. Lafser, Jr.
Robert J. Schreiber
Assignee (at issue)
Industrial Waste Management, 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.