Granted Patent
Utility
US 4,919,797 · App. 07/308,338
Screening apparatus for paper making stock
Inventors:
David E. Chupka, Irenee J. Phillippe
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Feb 9, 1989
Inventors
David E. Chupka
Irenee J. Phillippe
Assignee (at issue)
Black Clawson Company, 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.