Granted Patent
Utility
US 5,435,520 · App. 08/302,579
Backseat assembly for an expanding gate valve
Inventor:
Larry A. Vyvial
Patented Case
View Patent ↗
Granted: Jul 25, 1995
Filed: Sep 7, 1994
Inventor
Larry A. Vyvial
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.