Granted Patent
Utility
US 4,407,021 · App. 06/249,114
Suspension system for headgear
Inventors:
Douglas R. Kralik, Hal D. Mitchell
Patented Case
View Patent ↗
Granted: Oct 4, 1983
Filed: Mar 30, 1981
Inventors
Douglas R. Kralik
Hal D. Mitchell
Assignee (at issue)
Figgie Inernational 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.