Granted Patent
Utility
US 4,375,937 · App. 06/229,295
Roto-dynamic pump with a backflow recirculator
Inventor:
Paul V. Cooper
Patented Case
View Patent ↗
Granted: Mar 8, 1983
Filed: Jan 28, 1981
Inventor
Paul V. Cooper
Assignee (at issue)
Ingersoll-Rand Company
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.