Granted Patent
Utility
US 6,317,895 · App. 09/353,504
Safety helmet assembly
Inventors:
Richard A. Erth, Layton A. Wise
Patented Case
View Patent ↗
Granted: Nov 20, 2001
Filed: Jul 14, 1999
Inventors
Richard A. Erth
Layton A. Wise
Assignee (at issue)
Mine Safety Appliances Company, LLC
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.