Granted Patent
Utility
US 5,720,486 · App. 08/739,740
Self-formed labyrinth seal
Inventors:
William J. Hutchings, Stephen L. Markle, David Engel, Joel S. Berg
Patented Case
View Patent ↗
Granted: Feb 24, 1998
Filed: Nov 7, 1996
Inventors
William J. Hutchings
Stephen L. Markle
David Engel
Joel S. Berg
Assignee (at issue)
Federal Signal 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.