Granted Patent
Utility
US 4,296,308 · App. 06/072,843
Apparatus for welding impeller
Inventors:
Syuhei Nakahama, Etsu Yamashita
Patented Case
View Patent ↗
Granted: Oct 20, 1981
Filed: Sep 6, 1979
Inventors
Syuhei Nakahama
Etsu Yamashita
Assignee (at issue)
CARRIER 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.