Granted Patent
Utility
US 4,190,128 · App. 05/971,844
Roof drill bit with hexagonal body portion
Inventor:
Kenneth C. Emmerich
Patented Case
View Patent ↗
Granted: Feb 26, 1980
Filed: Dec 21, 1978
Inventor
Kenneth C. Emmerich
Assignee (at issue)
Fansteel 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.