Granted Patent
Utility
US 4,389,037 · App. 06/159,017
Double disc gate vale with replaceable spacer ring
Inventor:
Ronald J. Anders
Patented Case
View Patent ↗
Granted: Jun 21, 1983
Filed: Jun 13, 1980
Inventor
Ronald J. Anders
Assignee (at issue)
Rockwell International 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.