Granted Patent
Utility
US 5,011,596 · App. 07/586,331
Method of depressing readily floatable silicate materials
Inventor:
Douglas R. Shaw
Patented Case
View Patent ↗
Granted: Apr 30, 1991
Filed: Sep 19, 1990
Inventor
Douglas R. Shaw
Assignee (at issue)
Weyerhaeuser NR Company
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.