Granted Patent
Utility
US 3,938,231 · App. 05/557,397
Center cutting end mill
Inventor:
David Alan Hopkins
Patented Case
View Patent ↗
Granted: Feb 17, 1976
Filed: Mar 11, 1975
Inventor
David Alan Hopkins
Assignee (at issue)
The Valeron Corporation
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.