Granted Patent
Utility
US 6,453,990 · App. 09/794,014
Layered heat exchanger
Inventors:
Naohisa Higashiyama, Nobuyuki Okuda, Hisashi Ide, Yoshinori Nakata
Patented Case
View Patent ↗
Granted: Sep 24, 2002
Filed: Feb 28, 2001
Inventors
Naohisa Higashiyama
Nobuyuki Okuda
Hisashi Ide
Yoshinori Nakata
Assignee (at issue)
Showa Denko K.K.
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.