Granted Patent
Utility
US 4,993,839 · App. 07/325,783
Method and apparatus for producing asphaltic mix
Inventor:
J. Donald Brock
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Mar 20, 1989
Inventor
J. Donald Brock
Assignee (at issue)
Astec Industries, 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.