Granted Patent
Utility
US 5,470,146 · App. 07/815,591
Countercurrent drum mixer asphalt plant
Inventor:
Michael R. Hawkins
Patented Case
View Patent ↗
Granted: Nov 28, 1995
Filed: Dec 27, 1991
Inventor
Michael R. Hawkins
Assignee (at issue)
Standard Havens, 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.