Granted Patent
Utility
US 4,501,302 · App. 06/541,709
Air gap pipe
Inventor:
Jon W. Harwood
Patented Case
View Patent ↗
Granted: Feb 26, 1985
Filed: Oct 14, 1983
Inventor
Jon W. Harwood
Assignee (at issue)
APX Group, Inc.
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.