Granted Patent
Utility
US 4,879,009 · App. 07/240,777
Method of preparing an asbestos diaphragm
Inventor:
Jerry N. Kinney
Patented Case
View Patent ↗
Granted: Nov 7, 1989
Filed: Sep 2, 1988
Inventor
Jerry N. Kinney
Assignee (at issue)
PPG Industries, Inc.
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.