Granted Patent
Utility
US 5,000,658 · App. 07/372,526
Apparatus for pumping high consistency fiber suspension
Inventor:
Toivo Niskanen
Patented Case
View Patent ↗
Granted: Mar 19, 1991
Filed: Jun 22, 1989
Inventor
Toivo Niskanen
Assignee (at issue)
A. Ahlstrom 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.