Granted Patent
Utility
US 4,707,950 · App. 06/936,385
Ring grinding tool
Inventor:
Katsuhiro Kawasaki
Patented Case
View Patent ↗
Granted: Nov 24, 1987
Filed: Dec 1, 1986
Inventor
Katsuhiro Kawasaki
Assignee (at issue)
Tohoyogyo Co., Ltd.
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.