Granted Patent
Utility
US 5,829,431 · App. 08/806,063
Microphone attenuation device for use in oxygen breathing masks
Inventors:
Gary R. Hannah, Randy G. Stratman
Patented Case
View Patent ↗
Granted: Nov 3, 1998
Filed: Feb 25, 1997
Inventors
Gary R. Hannah
Randy G. Stratman
Assignee (at issue)
Puritan-Bennett 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.