Granted Patent
Utility
US 4,917,355 · App. 07/355,282
Stop valve
Inventors:
Richard C. G. Dark, William L. Wright
Patented Case
View Patent ↗
Granted: Apr 17, 1990
Filed: May 22, 1989
Inventors
Richard C. G. Dark
William L. Wright
Assignee (at issue)
Robert Manufacturing Company
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.