Granted Patent
Utility
US 5,925,293 · App. 08/895,483
Mixer sparging apparatus
Inventor:
Richard Howk
Patented Case
View Patent ↗
Granted: Jul 20, 1999
Filed: Jul 16, 1997
Inventor
Richard Howk
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.