Granted Patent
Utility
US 4,814,664 · App. 07/156,260
Igniter with wear indicator
Inventor:
Tom L. Rothenbuhler
Patented Case
View Patent ↗
Granted: Mar 21, 1989
Filed: Feb 16, 1988
Inventor
Tom L. Rothenbuhler
Assignee (at issue)
Champion Spark Plug Company
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.