Granted Patent
Utility
US 4,223,552 · App. 06/022,622
Apparatus and method for sensing a substance on a liquid surface
Inventor:
Sanders Goldstein
Patented Case
View Patent ↗
Granted: Sep 23, 1980
Filed: Mar 21, 1979
Inventor
Sanders Goldstein
Assignee (at issue)
Emhart Industries, 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.