Granted Patent
Utility
US 4,770,253 · App. 07/017,394
Grader blade with tiered inserts on leading edge
Inventors:
Robert P. Hallissy, Edmund Isakov, John F. Kita, Earle W. Stephenson
Patented Case
View Patent ↗
Granted: Sep 13, 1988
Filed: Feb 20, 1987
Inventors
Robert P. Hallissy
Edmund Isakov
John F. Kita
Earle W. Stephenson
Assignee (at issue)
KENNAMETAL 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.