Granted Patent
Utility
US 4,973,441 · App. 07/385,622
Method of manufacturing a compressibility gradient in paper
Inventor:
Samuel F. Keller
Patented Case
View Patent ↗
Granted: Nov 27, 1990
Filed: Jul 26, 1989
Inventor
Samuel F. Keller
Assignee (at issue)
Beloit Corporation
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.