Granted Patent
Utility
US 5,375,654 · App. 08/153,180
Turbulating heat exchange tube and system
Inventors:
Jerry M. Hougland, Lloyd F. Hay
Patented Case
View Patent ↗
Granted: Dec 27, 1994
Filed: Nov 16, 1993
Inventors
Jerry M. Hougland
Lloyd F. Hay
Assignee (at issue)
FR Mfg. 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.