Granted Patent
Utility
US 4,245,570 · App. 06/033,434
Sewage sludge disposal apparatus and method of disposal
Inventor:
Robert M. Williams
Patented Case
View Patent ↗
Granted: Jan 20, 1981
Filed: Apr 26, 1979
Inventor
Robert M. Williams
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.