Granted Patent
Utility
US 5,643,677 · App. 08/306,529
Aminoplast/polyurethane wear layer for PVC support surface
Inventors:
Joseph P. Feifer, Mary B. Grubb, Claude R.. Rupp, William T. Sigman
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Sep 15, 1994
Inventors
Joseph P. Feifer
Mary B. Grubb
Claude R.. Rupp
William T. Sigman
Assignee (at issue)
ARMSTRONG WORLD 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.