Granted Patent
Utility
US 5,168,721 · App. 07/676,740
Refrigerant recovery device
Inventors:
John P. Hancock, Ralph A. McClelland
Patented Case
View Patent ↗
Granted: Dec 8, 1992
Filed: Mar 28, 1991
Inventors
John P. Hancock
Ralph A. McClelland
Assignee (at issue)
K-Whit Tools, 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.