Granted Patent
Utility
US 4,693,772 · App. 06/945,144
Hot applied, expandable sealer
Inventor:
William A. Douglas
Patented Case
View Patent ↗
Granted: Sep 15, 1987
Filed: Dec 22, 1986
Inventor
William A. Douglas
Assignee (at issue)
United Technologies Automotive
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.