Granted Patent
Utility
US 4,489,025 · App. 05/969,587
Preparation of dimensionally stable asbestos diaphragms
Inventors:
Robert W. Fenn, III, Emory J. Pless, Richard L. Harris, Kevin J. O'Leary
Patented Case
View Patent ↗
Granted: Dec 18, 1984
Filed: Dec 14, 1978
Inventors
Robert W. Fenn, III
Emory J. Pless
Richard L. Harris
Kevin J. O'Leary
Assignee (at issue)
Diamond Shamrock Chemicals 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.