Granted Patent
Utility
US 4,375,016 · App. 06/144,340
Vented ear tip for hearing aid and adapter coupler therefore
Inventor:
Mas Harada
Patented Case
View Patent ↗
Granted: Feb 22, 1983
Filed: Apr 28, 1980
Inventor
Mas Harada
Assignee (at issue)
Qualitone Hearing Aids 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.