Granted Patent
Utility
US 5,406,970 · App. 08/083,135
Chemical injection system
Inventors:
Stephen E. Marshall, Mark Zeck
Patented Case
View Patent ↗
Granted: Apr 18, 1995
Filed: Jun 25, 1993
Inventors
Stephen E. Marshall
Mark Zeck
Assignee (at issue)
Y-Z Industries 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.