Granted Patent
Utility
US 4,503,887 · App. 06/340,616
Pilot-operated dual flow rate valve
Inventors:
Terence L. Johnson, Lance Guthreau
Patented Case
View Patent ↗
Granted: Mar 12, 1985
Filed: Jan 19, 1982
Inventors
Terence L. Johnson
Lance Guthreau
Assignee (at issue)
Automatic Switch Company
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.