Granted Patent
Utility
US 4,928,326 · App. 07/177,070
Vacuum sewer arrangement
Inventors:
Henry Olin, Gunnar Lindroos, Sven Oldfelt
Patented Case
View Patent ↗
Granted: May 29, 1990
Filed: Apr 4, 1988
Inventors
Henry Olin
Gunnar Lindroos
Sven Oldfelt
Assignee (at issue)
Oy Wartsila Ab
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.