Granted Patent
Utility
US 4,840,854 · App. 07/097,343
Reinforced plate-like sintered bodies
Inventors:
Takao Kojima, Tetsusyo Yamada
Patented Case
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Granted: Jun 20, 1989
Filed: Sep 11, 1987
Inventors
Takao Kojima
Tetsusyo Yamada
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.