Granted Patent
Utility
US 4,858,347 · App. 07/185,983
Continuous excavating apparatus and methods
Inventors:
R. A. Hanson, Jerry Morton
Patented Case
View Patent ↗
Granted: Aug 22, 1989
Filed: Apr 25, 1988
Inventors
R. A. Hanson
Jerry Morton
Assignee (at issue)
R. A. Hanson Company, 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.