Granted Patent
Utility
US 4,761,848 · App. 07/074,574
Suction-operated automatic swimming pool cleaner
Inventor:
Helmut Hofmann
Patented Case
View Patent ↗
Granted: Aug 9, 1988
Filed: Jul 17, 1987
Inventor
Helmut Hofmann
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.