Granted Patent
Utility
US 5,129,784 · App. 07/745,909
Ceramic rotor and metal shaft assembly
Inventors:
Takaya Yoshikawa, Noboru Ishida
Patented Case
View Patent ↗
Granted: Jul 14, 1992
Filed: Aug 15, 1991
Inventors
Takaya Yoshikawa
Noboru Ishida
Assignee (at issue)
NGK SPARK PLUG 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.