Granted Patent
Utility
US 5,553,377 · App. 08/283,504
Method of making refrigerant tubes for heat exchangers
Inventors:
Hirosaburo Hirano, Yuji Yamamoto, Shinji Ito
Patented Case
View Patent ↗
Granted: Sep 10, 1996
Filed: Aug 1, 1994
Inventors
Hirosaburo Hirano
Yuji Yamamoto
Shinji Ito
Assignee (at issue)
Showa Aluminum Corp.
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.