Granted Patent
Utility
US 5,083,582 · App. 07/660,389
Valve with removable insert
Inventor:
John E. Lawson
Patented Case
View Patent ↗
Granted: Jan 28, 1992
Filed: Feb 25, 1991
Inventor
John E. Lawson
Assignee (at issue)
Cooper Industries Holdings
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.