Granted Patent
Utility
US 5,131,639 · App. 07/633,988
Backing plate retainer
Inventor:
Hideo Nonaka
Patented Case
View Patent ↗
Granted: Jul 21, 1992
Filed: Dec 26, 1990
Inventor
Hideo Nonaka
Assignee (at issue)
Yoshida Kogyo K.K.
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.