Granted Patent
Utility
US 4,881,475 · App. 07/172,373
Method for cleaning up contaminated soil
Inventor:
Laurens C. De Leur
Patented Case
View Patent ↗
Granted: Nov 21, 1989
Filed: Mar 24, 1988
Inventor
Laurens C. De Leur
Assignee (at issue)
B.V. Aannemingsbedriof N.B.M.
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.