Granted Patent
Utility
US 4,457,490 · App. 06/344,501
High temperature valve and seat therefor
Inventor:
William B. Scobie
Patented Case
View Patent ↗
Granted: Jul 3, 1984
Filed: Feb 1, 1982
Inventor
William B. Scobie
Assignee (at issue)
Keystone International
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.