Granted Patent
Utility
US 4,383,546 · App. 06/211,878
High temperature, high pressure valve
Inventor:
Thomas Charles Walters
Patented Case
View Patent ↗
Granted: May 17, 1983
Filed: Dec 1, 1980
Inventor
Thomas Charles Walters
Assignee (at issue)
Ecolaire Incorporated
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.