Granted Patent
Utility
US 4,569,394 · App. 06/584,584
Method and apparatus for increasing the concentration of proppant in well stimulation techniques
Inventors:
Ronald E. Sweatman, Earl R. Freeman, John Gottschling
Patented Case
View Patent ↗
Granted: Feb 11, 1986
Filed: Feb 29, 1984
Inventors
Ronald E. Sweatman
Earl R. Freeman
John Gottschling
Assignee (at issue)
Hughes Tool Company LLC
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.