Granted Patent
Utility
US 4,335,920 · App. 06/169,869
Headrest for a dental chair
Inventor:
Emil Hirth
Patented Case
View Patent ↗
Granted: Jun 22, 1982
Filed: Jul 17, 1980
Inventor
Emil Hirth
Assignee (at issue)
Sybron 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.