Granted Patent
Utility
US 4,824,322 · App. 06/638,493
Peripheral toroidal blowers
Inventor:
Andrew H. Middleton
Patented Case
View Patent ↗
Granted: Apr 25, 1989
Filed: Aug 7, 1984
Inventor
Andrew H. Middleton
Assignee (at issue)
British Gas
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.