Granted Patent
Utility
US 4,543,981 · App. 06/427,350
Sliding gate valves
Inventors:
Kenneth W. Bates, Norman H. Watts
Patented Case
View Patent ↗
Granted: Oct 1, 1985
Filed: Sep 29, 1982
Inventors
Kenneth W. Bates
Norman H. Watts
Assignee (at issue)
USS Engineers and Consultants, Inc.
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.