Granted Patent
Utility
US 5,996,520 · App. 09/031,141
Icebreaking method and icebreaker
Inventors:
Matti Arpiainen, Magnus Backstrom, Torsten Heideman, Tom Mattson, Erkki Ranki
Patented Case
View Patent ↗
Granted: Dec 7, 1999
Filed: Feb 26, 1998
Inventors
Matti Arpiainen
Magnus Backstrom
Torsten Heideman
Tom Mattson
Erkki Ranki
Assignee (at issue)
Kvaerner Masa-Yards Oy
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.