Granted Patent
Utility
US 5,215,429 · App. 07/819,022
Regenerative turbine having predetermined clearance relationship between channel ring and impeller
Inventor:
Hongwei Sun
Patented Case
View Patent ↗
Granted: Jun 1, 1993
Filed: Jan 10, 1992
Inventor
Hongwei Sun
Assignee (at issue)
Federal Signal 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.