Granted Patent
Utility
US 4,716,976 · App. 06/924,528
Rotary percussion drill bit
Inventor:
Edmund Isakov
Patented Case
View Patent ↗
Granted: Jan 5, 1988
Filed: Oct 28, 1986
Inventor
Edmund Isakov
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.