Granted Patent
Utility
US 5,201,839 · App. 07/762,055
Countercurrent drum mixer with second heat source
Inventor:
George W. Swisher, Jr.
Patented Case
View Patent ↗
Granted: Apr 13, 1993
Filed: Sep 19, 1991
Inventor
George W. Swisher, Jr.
Assignee (at issue)
CMI LIMITED CO.
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.