Granted Patent
Utility
US 5,042,697 · App. 07/411,530
Pressure regulators
Inventor:
William E. Warren
Patented Case
View Patent ↗
Granted: Aug 27, 1991
Filed: Oct 2, 1989
Inventor
William E. Warren
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT 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.