Granted Patent
Utility
US 4,554,639 · App. 06/482,594
Audio dosimeter
Inventors:
William Brent Baker, Harry Edwards Betsill
Patented Case
View Patent ↗
Granted: Nov 19, 1985
Filed: Apr 6, 1983
Inventors
William Brent Baker
Harry Edwards Betsill
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.