Granted Patent
Utility
US 4,562,854 · App. 06/655,480
Piston actuated chemical injection valve
Inventors:
Ronald E. Pringle, Arthur J. Morris, John Johnson
Patented Case
View Patent ↗
Granted: Jan 7, 1986
Filed: Sep 27, 1984
Inventors
Ronald E. Pringle
Arthur J. Morris
John Johnson
Assignee (at issue)
Camco 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.