Granted Patent
Utility
US 4,891,107 · App. 06/777,483
Porous diaphragm for electrochemical cell
Inventors:
Dennis F. Dong, Arthur L. Clifford
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Sep 19, 1985
Inventors
Dennis F. Dong
Arthur L. Clifford
Assignee (at issue)
H-D Tech 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.