Granted Patent
Utility
US 5,341,835 · App. 07/989,619
Lubrication system for valve seat of a gate valve
Inventor:
William W. Lanning
Patented Case
View Patent ↗
Granted: Aug 30, 1994
Filed: Dec 14, 1992
Inventor
William W. Lanning
Assignee (at issue)
Foster Valve 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.